diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 5f8ab5daf..a705d90b1 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,1008 +1,1010 @@
 # Copyright (c) 2017 The Bitcoin developers
 
 project(bitcoind)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 # Default visibility is hidden on all targets.
 set(CMAKE_C_VISIBILITY_PRESET hidden)
 set(CMAKE_CXX_VISIBILITY_PRESET hidden)
 
 option(BUILD_BITCOIN_WALLET "Activate the wallet functionality" ON)
 option(BUILD_BITCOIN_ZMQ "Activate the ZeroMQ functionalities" ON)
 option(BUILD_BITCOIN_CLI "Build bitcoin-cli" ON)
 option(BUILD_BITCOIN_TX "Build bitcoin-tx" ON)
 option(BUILD_BITCOIN_QT "Build bitcoin-qt" ON)
 option(BUILD_BITCOIN_SEEDER "Build bitcoin-seeder" ON)
 option(BUILD_LIBBITCOINCONSENSUS "Build the bitcoinconsenus shared library" ON)
 option(BUILD_BITCOIN_CHAINSTATE "Build bitcoin-chainstate" OFF)
 option(ENABLE_BIP70 "Enable BIP70 (payment protocol) support in GUI" ON)
 option(ENABLE_HARDENING "Harden the executables" ON)
 option(ENABLE_REDUCE_EXPORTS "Reduce the amount of exported symbols" OFF)
 option(ENABLE_STATIC_LIBSTDCXX "Statically link libstdc++" OFF)
 option(ENABLE_GLIBC_BACK_COMPAT "Enable Glibc compatibility features" OFF)
 option(ENABLE_QRCODE "Enable QR code display" ON)
 option(ENABLE_UPNP "Enable UPnP support" ON)
 option(START_WITH_UPNP "Make UPnP the default to map ports" OFF)
 option(ENABLE_NATPMP "Enable NAT-PMP support" ON)
 option(START_WITH_NATPMP "Make NAT-PMP the default to map ports" OFF)
 option(ENABLE_CLANG_TIDY "Enable clang-tidy checks for Bitcoin ABC" OFF)
 option(ENABLE_PROFILING "Select the profiling tool to use" OFF)
 option(ENABLE_TRACING "Enable eBPF user static defined tracepoints" OFF)
 
 # Linker option
 if(CMAKE_CROSSCOMPILING)
 	set(DEFAULT_LINKER "")
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
 	set(DEFAULT_LINKER lld)
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
 	set(DEFAULT_LINKER gold)
 else()
 	set(DEFAULT_LINKER "")
 endif()
 set(USE_LINKER "${DEFAULT_LINKER}" CACHE STRING "Linker to be used (default: ${DEFAULT_LINKER}). Set to empty string to use the system's default.")
 
 set(OS_WITH_JEMALLOC_AS_SYSTEM_DEFAULT
 	"Android"
 	"FreeBSD"
 	"NetBSD"
 )
 if(NOT CMAKE_SYSTEM_NAME IN_LIST OS_WITH_JEMALLOC_AS_SYSTEM_DEFAULT)
 	set(USE_JEMALLOC_DEFAULT ON)
 endif()
 
 # FIXME: Building against jemalloc causes the software to segfault on OSX.
 # See https://github.com/Bitcoin-ABC/bitcoin-abc/issues/401
 if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin" AND NOT CMAKE_CROSSCOMPILING)
 	set(USE_JEMALLOC_DEFAULT OFF)
 endif()
 
 option(USE_JEMALLOC "Use jemalloc as an allocation library" ${USE_JEMALLOC_DEFAULT})
 
 if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
 	set(DEFAULT_ENABLE_DBUS_NOTIFICATIONS ON)
 endif()
 option(ENABLE_DBUS_NOTIFICATIONS "Enable DBus desktop notifications. Linux only." ${DEFAULT_ENABLE_DBUS_NOTIFICATIONS})
 
 # If ccache is available, then use it.
 find_program(CCACHE ccache)
 if(CCACHE)
 	message(STATUS "Using ccache: ${CCACHE}")
 	set(CMAKE_C_COMPILER_LAUNCHER ${CCACHE})
 	set(CMAKE_CXX_COMPILER_LAUNCHER ${CCACHE})
 endif(CCACHE)
 
 # Disable what we do not need for the native build.
 include(NativeExecutable)
 native_add_cmake_flags(
 	"-DBUILD_BITCOIN_WALLET=OFF"
 	"-DBUILD_BITCOIN_CHRONIK=OFF"
 	"-DBUILD_BITCOIN_QT=OFF"
 	"-DBUILD_BITCOIN_ZMQ=OFF"
 	"-DENABLE_QRCODE=OFF"
 	"-DENABLE_NATPMP=OFF"
 	"-DENABLE_UPNP=OFF"
 	"-DUSE_JEMALLOC=OFF"
 	"-DENABLE_CLANG_TIDY=OFF"
 	"-DENABLE_BIP70=OFF"
 	"-DUSE_LINKER="
 )
 
 if(ENABLE_CLANG_TIDY)
 	include(ClangTidy)
 endif()
 
 if(ENABLE_SANITIZERS)
 	include(Sanitizers)
 	enable_sanitizers(${ENABLE_SANITIZERS})
 endif()
 
 include(AddCompilerFlags)
 
 if(USE_LINKER)
 	set(LINKER_FLAG "-fuse-ld=${USE_LINKER}")
 	custom_check_linker_flag(IS_LINKER_SUPPORTED ${LINKER_FLAG})
 	if(NOT IS_LINKER_SUPPORTED)
 		message(FATAL_ERROR "The ${USE_LINKER} linker is not supported, make sure ${USE_LINKER} is properly installed or use -DUSE_LINKER= to use the system's linker")
 	endif()
 
 	add_linker_flags(${LINKER_FLAG})
 
 	# Remember the selected linker, it will be used for the subsequent
 	# custom_check_linker_flag calls
 	set(GLOBAL_LINKER_FLAGS ${LINKER_FLAG} CACHE INTERNAL "Additional linker flags for flag support checking")
 endif()
 
 # Prefer -g3, defaults to -g if unavailable
 foreach(LANGUAGE C CXX)
 	set(COMPILER_DEBUG_LEVEL -g)
 	check_compiler_flags(G3_IS_SUPPORTED ${LANGUAGE} -g3)
 	if(${G3_IS_SUPPORTED})
 		set(COMPILER_DEBUG_LEVEL -g3)
 	endif()
 	add_compile_options_to_configuration_for_language(Debug ${LANGUAGE} ${COMPILER_DEBUG_LEVEL})
 endforeach()
 
 # Define some debugging symbols when the Debug build type is selected.
 add_compile_definitions_to_configuration(Debug DEBUG DEBUG_LOCKORDER ABORT_ON_FAILED_ASSUME)
 
 # Add -ftrapv when building in Debug
 add_compile_options_to_configuration(Debug -ftrapv)
 
 # All versions of gcc that we commonly use for building are subject to bug
 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90348. To work around that, set
 # -fstack-reuse=none for all gcc builds. (Only gcc understands this flag)
 if(CMAKE_CXX_COMPILER_ID MATCHES "GNU")
 	add_compiler_flags(-fstack-reuse=none)
 endif()
 
 if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 	# Ensure that WINDRES_PREPROC is enabled when using windres.
 	list(APPEND CMAKE_RC_FLAGS "-DWINDRES_PREPROC")
 
 	# Build all static so there is no dll file to distribute.
 	add_linker_flags(-static)
 
 	add_compile_definitions(
 		# Windows 7
 		_WIN32_WINNT=0x0601
 		# Internet Explorer 5.01 (!)
 		_WIN32_IE=0x0501
 		# Define WIN32_LEAN_AND_MEAN to exclude APIs such as Cryptography, DDE,
 		# RPC, Shell, and Windows Sockets.
 		WIN32_LEAN_AND_MEAN
 	)
 
 	# We require Windows 7 (NT 6.1) or later
 	add_linker_flags(-Wl,--major-subsystem-version,6 -Wl,--minor-subsystem-version,1)
 endif()
 
 if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
 	add_compile_definitions(MAC_OSX OBJC_OLD_DISPATCH_PROTOTYPES=0)
 	add_linker_flags(-Wl,-dead_strip_dylibs)
 endif()
 
 if(ENABLE_REDUCE_EXPORTS)
 	# Default visibility is set by CMAKE_<LANG>_VISIBILITY_PRESET, but this
 	# doesn't tell if the visibility set is effective.
 	# Check if the flag -fvisibility=hidden is supported, as using the hidden
 	# visibility is a requirement to reduce exports.
 	check_compiler_flags(HAS_CXX_FVISIBILITY CXX -fvisibility=hidden)
 	if(NOT HAS_CXX_FVISIBILITY)
 		message(FATAL_ERROR "Cannot set default symbol visibility. Use -DENABLE_REDUCE_EXPORTS=OFF.")
 	endif()
 
 	# Also hide symbols from static libraries
 	add_linker_flags(-Wl,--exclude-libs,libstdc++)
 endif()
 
 # Enable statically linking libstdc++
 if(ENABLE_STATIC_LIBSTDCXX)
 	add_linker_flags(-static-libstdc++)
 endif()
 
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 if(ENABLE_HARDENING)
 	# Enable stack protection
 	add_cxx_compiler_flags(-fstack-protector-all -Wstack-protector)
 
 	# Enable control-flow enforcement
 	add_cxx_compiler_flags(-fcf-protection=full)
 
 	if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 		# stack-clash-protection does not work properly when building for Windows.
 		# See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90458
 		add_cxx_compiler_flags(-fstack-clash-protection)
 	endif()
 	add_linker_flags(-Wl,-z,noexecstack)
 
 	# Enable some buffer overflow checking, except in -O0 builds which
 	# do not support them
 	add_compiler_flags(-U_FORTIFY_SOURCE)
 	add_compile_options($<$<NOT:$<CONFIG:Debug>>:-D_FORTIFY_SOURCE=2>)
 
 	# Enable ASLR (these flags are primarily targeting MinGw)
 	add_linker_flags(-Wl,--enable-reloc-section -Wl,--dynamicbase -Wl,--nxcompat -Wl,--high-entropy-va)
 
 	# Make the relocated sections read-only
 	add_linker_flags(-Wl,-z,relro -Wl,-z,now)
 
 	# Avoids mixing code pages with data to improve cache performance as well
 	# as security
 	add_linker_flags(-Wl,-z,separate-code)
 
 	# CMake provides the POSITION_INDEPENDENT_CODE property to set PIC/PIE.
 	cmake_policy(SET CMP0083 NEW)
 	include(CheckPIESupported)
 	check_pie_supported()
 
 	if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 		# MinGw provides its own libssp for stack smashing protection
 		link_libraries(ssp)
 	endif()
 endif()
 
 if(ENABLE_PROFILING MATCHES "gprof")
 	message(STATUS "Enable profiling with gprof")
 
 	# -pg is incompatible with -pie. Since hardening and profiling together
 	# doesn't make sense, we simply make them mutually exclusive here.
 	# Additionally, hardened toolchains may force -pie by default, in which
 	# case it needs to be turned off with -no-pie.
 	if(ENABLE_HARDENING)
 		message(FATAL_ERROR "Profiling with gprof requires disabling hardening with -DENABLE_HARDENING=OFF.")
 	endif()
 	add_linker_flags(-no-pie)
 
 	add_compiler_flags(-pg)
 	add_linker_flags(-pg)
 endif()
 
 # Enable warning
 add_c_compiler_flags(-Wnested-externs -Wstrict-prototypes)
 add_compiler_flags(
 	-Wall
 	-Wextra
 	-Wformat
 	-Wgnu
 	-Wvla
 	-Wcast-align
 	-Wunused-parameter
 	-Wmissing-braces
 	-Wthread-safety
 	-Wrange-loop-analysis
 	-Wredundant-decls
 	-Wunreachable-code-loop-increment
 	-Wsign-compare
 	-Wconditional-uninitialized
 	-Wduplicated-branches
 	-Wduplicated-cond
 	-Wlogical-op
 	-Wdocumentation
 )
 add_compiler_flag_group(-Wformat -Wformat-security)
 add_cxx_compiler_flags(
 	-Wredundant-move
 	-Woverloaded-virtual
 )
 
 if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
 	# GCC has no flag variant which is granular enough to avoid raising the clang
 	# -Wshadow-uncaptured-local equivalent. This is causing a lot of warnings
 	# on serialize.h which cannot be disabled locally, so drop the flag.
 	add_compiler_flags(
 		-Wshadow
 		-Wshadow-field
 	)
 endif()
 
 option(EXTRA_WARNINGS "Enable extra warnings" OFF)
 if(EXTRA_WARNINGS)
 	add_cxx_compiler_flags(-Wsuggest-override)
 else()
 	add_compiler_flags(
 		-Wno-unused-parameter
 		-Wno-implicit-fallthrough
 		-Wno-psabi
 	)
 endif()
 
 # libtool style configure
 add_subdirectory(config)
 
 # Enable LFS (Large File Support) on targets that don't have it natively.
 # This should be defined before the libraries are included as leveldb need the
 # definition to be set.
 if(NOT HAVE_LARGE_FILE_SUPPORT)
 	add_compile_definitions(_FILE_OFFSET_BITS=64)
 	add_linker_flags(-Wl,--large-address-aware)
 endif()
 
 if(ENABLE_GLIBC_BACK_COMPAT)
 	# Wrap some glibc functions with ours
 	add_linker_flags(-Wl,--wrap=exp)
 	add_linker_flags(-Wl,--wrap=log)
 	add_linker_flags(-Wl,--wrap=log2)
 	add_linker_flags(-Wl,--wrap=pow)
 
 	if(NOT HAVE_LARGE_FILE_SUPPORT)
 		add_linker_flags(-Wl,--wrap=fcntl -Wl,--wrap=fcntl64)
 	endif()
 endif()
 
 if(USE_JEMALLOC)
 	# Most of the sanitizers require their instrumented allocation functions to
 	# be fully functional. This is obviously the case for all the memory related
 	# sanitizers (asan, lsan, msan) but not only.
 	if(ENABLE_SANITIZERS)
 		message(WARNING "Jemalloc is incompatible with the sanitizers and has been disabled.")
 	else()
 		find_package(Jemalloc 3.6.0 REQUIRED)
 		link_libraries(Jemalloc::jemalloc)
 	endif()
 endif()
 
 # These flags are needed for using std::filesystem with GCC < 9.1 & Clang < 9.0
 # Since these are optional libraries they need to be placed accordingly on the
 # command line.
 add_linker_flags(-lstdc++fs -lc++fs)
 custom_check_linker_flag(LINKER_HAS_STDCXXFS "-lstdc++fs")
 if(LINKER_HAS_STDCXXFS)
     link_libraries(stdc++fs)
 endif()
 custom_check_linker_flag(LINKER_HAS_CXXFS "-lc++fs")
 if(LINKER_HAS_CXXFS)
     link_libraries(c++fs)
 endif()
 
 
 # Make sure that all the global compiler and linker flags are set BEFORE
 # including the libraries so they apply as needed.
 
 
 # libraries
 add_subdirectory(crypto)
 add_subdirectory(leveldb)
 add_subdirectory(secp256k1)
 add_subdirectory(univalue)
 
 # Find the git root, and returns the full path to the .git/logs/HEAD file if
 # it exists.
 function(find_git_head_logs_file RESULT)
 	find_package(Git)
 	if(GIT_FOUND)
 		execute_process(
 			COMMAND "${GIT_EXECUTABLE}" "rev-parse" "--show-toplevel"
 			WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
 			OUTPUT_VARIABLE GIT_ROOT
 			RESULT_VARIABLE GIT_RESULT
 			OUTPUT_STRIP_TRAILING_WHITESPACE
 			ERROR_QUIET
 		)
 
 		if(GIT_RESULT EQUAL 0)
 			set(GIT_LOGS_DIR "${GIT_ROOT}/.git/logs")
 			set(GIT_HEAD_LOGS_FILE "${GIT_LOGS_DIR}/HEAD")
 			# If the .git/logs/HEAD does not exist, create it
 			if(NOT EXISTS "${GIT_HEAD_LOGS_FILE}")
 				file(MAKE_DIRECTORY "${GIT_LOGS_DIR}")
 				file(TOUCH "${GIT_HEAD_LOGS_FILE}")
 			endif()
 			set(${RESULT} "${GIT_HEAD_LOGS_FILE}" PARENT_SCOPE)
 		endif()
 	endif()
 endfunction()
 
 find_git_head_logs_file(GIT_HEAD_LOGS_FILE)
 
 set(OBJ_DIR "${CMAKE_CURRENT_BINARY_DIR}/obj")
 file(MAKE_DIRECTORY "${OBJ_DIR}")
 set(BUILD_HEADER "${OBJ_DIR}/build.h")
 set(BUILD_HEADER_TMP "${BUILD_HEADER}.tmp")
 
 add_custom_command(
 	DEPENDS
 		"${GIT_HEAD_LOGS_FILE}"
 		"${CMAKE_SOURCE_DIR}/share/genbuild.sh"
 	OUTPUT
 		"${BUILD_HEADER}"
 	COMMAND
 		"${CMAKE_SOURCE_DIR}/share/genbuild.sh"
 		"${BUILD_HEADER_TMP}"
 		"${CMAKE_SOURCE_DIR}"
 	COMMAND
 		${CMAKE_COMMAND} -E copy_if_different "${BUILD_HEADER_TMP}" "${BUILD_HEADER}"
 	COMMAND
 		${CMAKE_COMMAND} -E remove "${BUILD_HEADER_TMP}"
 )
 
 # Because the Bitcoin ABc source code is disorganised, we
 # end up with a bunch of libraries without any apparent
 # cohesive structure. This is inherited from Bitcoin Core
 # and reflecting this.
 # TODO: Improve the structure once cmake is rocking.
 
 # Various completely unrelated features shared by all executables.
 add_library(util
 	chainparamsbase.cpp
 	clientversion.cpp
 	compat/glibcxx_sanity.cpp
 	compat/strnlen.cpp
 	currencyunit.cpp
 	fs.cpp
 	interfaces/handler.cpp
 	logging.cpp
 	random.cpp
 	randomenv.cpp
 	rcu.cpp
 	rpc/request.cpp
 	support/cleanse.cpp
 	support/lockedpool.cpp
 	sync.cpp
 	threadinterrupt.cpp
 	uint256.cpp
 	util/asmap.cpp
 	util/bip32.cpp
 	util/bytevectorhash.cpp
 	util/check.cpp
 	util/hasher.cpp
 	util/error.cpp
 	util/getuniquepath.cpp
 	util/message.cpp
 	util/moneystr.cpp
 	util/readwritefile.cpp
 	util/settings.cpp
 	util/string.cpp
 	util/sock.cpp
 	util/spanparsing.cpp
 	util/strencodings.cpp
 	util/string.cpp
 	util/system.cpp
 	util/thread.cpp
 	util/threadnames.cpp
 	util/time.cpp
 	util/tokenpipe.cpp
 	util/url.cpp
 
 	# obj/build.h
 	"${BUILD_HEADER}"
 )
 
 target_compile_definitions(util PUBLIC HAVE_CONFIG_H HAVE_BUILD_INFO)
 target_include_directories(util
 	PUBLIC
 		.
 		# To access the config/ and obj/ directories
 		${CMAKE_CURRENT_BINARY_DIR}
 )
 
 if(ENABLE_GLIBC_BACK_COMPAT)
 	target_sources(util PRIVATE compat/glibc_compat.cpp)
 endif()
 
 # Work around jemalloc printing harmless warnings to stderr with qemu.
 # We match the emulator against qemu but not ^qemu so we are compatible with the
 # use of absolute paths.
 if(CMAKE_CROSSCOMPILING AND USE_JEMALLOC AND CMAKE_CROSSCOMPILING_EMULATOR MATCHES "qemu-.+")
 	message(WARNING "Overriding Jemalloc malloc_message() function for use with QEMU.")
 	target_sources(util PRIVATE jemalloc_message.cpp)
 endif()
 
 set(Boost_USE_STATIC_LIBS ON)
 
 macro(link_windows_dependencies TARGET)
 	find_package(SHLWAPI REQUIRED)
 	target_link_libraries(${TARGET} SHLWAPI::shlwapi)
 
 	find_library(WS2_32_LIBRARY NAMES ws2_32)
 	target_link_libraries(${TARGET} ${WS2_32_LIBRARY})
 endmacro()
 
 # Target specific configs
 if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 	set(Boost_USE_STATIC_RUNTIME ON)
 	set(Boost_THREADAPI win32)
 
 	link_windows_dependencies(util)
 endif()
 
 target_link_libraries(util univalue crypto)
 
 macro(link_event TARGET)
 	non_native_target_link_libraries(${TARGET} Event 2.0.22 ${ARGN})
 endmacro()
 
 link_event(util event)
 
 macro(link_boost_headers_only TARGET)
 	non_native_target_link_headers_only(${TARGET} Boost 1.64 ${ARGN})
 endmacro()
 
 link_boost_headers_only(util headers)
 
 set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
 target_link_libraries(util Threads::Threads)
 
 function(add_network_sources NETWORK_SOURCES)
 	set(NETWORK_DIR abc)
 
 	list(TRANSFORM
 		ARGN
 		PREPEND "networks/${NETWORK_DIR}/"
 		OUTPUT_VARIABLE NETWORK_SOURCES
 	)
 	set(NETWORK_SOURCES ${NETWORK_SOURCES} PARENT_SCOPE)
 endfunction()
 
 add_network_sources(NETWORK_SOURCES
 	checkpoints.cpp
 	chainparamsconstants.cpp
 )
 
 # More completely unrelated features shared by all executables.
 # Because nothing says this is different from util than "common"
 add_library(common
 	base58.cpp
 	bloom.cpp
 	cashaddr.cpp
 	cashaddrenc.cpp
 	chainparams.cpp
 	config.cpp
 	consensus/merkle.cpp
 	coins.cpp
 	compressor.cpp
 	eventloop.cpp
 	feerate.cpp
 	core_read.cpp
 	core_write.cpp
 	key.cpp
 	key_io.cpp
 	merkleblock.cpp
 	net_permissions.cpp
 	netaddress.cpp
 	netbase.cpp
 	outputtype.cpp
 	policy/policy.cpp
 	primitives/block.cpp
 	protocol.cpp
 	psbt.cpp
 	rpc/rawtransaction_util.cpp
 	rpc/util.cpp
 	scheduler.cpp
 	warnings.cpp
 
 	${NETWORK_SOURCES}
 )
 
 target_link_libraries(common bitcoinconsensus util secp256k1 script)
 
 # script library
 add_library(script
 	script/bitfield.cpp
 	script/descriptor.cpp
 	script/interpreter.cpp
 	script/script.cpp
 	script/script_error.cpp
 	script/sigencoding.cpp
 	script/sign.cpp
 	script/signingprovider.cpp
 	script/standard.cpp
 )
 
 target_link_libraries(script common)
 
 # libbitcoinconsensus
 add_library(bitcoinconsensus
 	arith_uint256.cpp
 	hash.cpp
 	primitives/transaction.cpp
 	pubkey.cpp
 	uint256.cpp
 	util/strencodings.cpp
 	consensus/amount.cpp
 	consensus/tx_check.cpp
 )
 
 target_link_libraries(bitcoinconsensus script)
 
 include(InstallationHelper)
 if(BUILD_LIBBITCOINCONSENSUS)
 	target_compile_definitions(bitcoinconsensus
 		PUBLIC
 			BUILD_BITCOIN_INTERNAL
 			HAVE_CONSENSUS_LIB
 	)
 
 	install_shared_library(bitcoinconsensus
 		script/bitcoinconsensus.cpp
 		PUBLIC_HEADER script/bitcoinconsensus.h
 	)
 endif()
 
 # Bitcoin server facilities
 add_library(server
 	addrdb.cpp
 	addrman.cpp
 	avalanche/avalanche.cpp
 	avalanche/compactproofs.cpp
 	avalanche/delegation.cpp
 	avalanche/delegationbuilder.cpp
 	avalanche/peermanager.cpp
 	avalanche/processor.cpp
 	avalanche/proof.cpp
 	avalanche/proofid.cpp
 	avalanche/proofbuilder.cpp
 	avalanche/proofpool.cpp
 	avalanche/voterecord.cpp
 	banman.cpp
 	blockencodings.cpp
 	blockfileinfo.cpp
 	blockfilter.cpp
 	blockindex.cpp
 	chain.cpp
 	checkpoints.cpp
 	config.cpp
 	consensus/activation.cpp
 	consensus/tx_verify.cpp
 	dbwrapper.cpp
 	deploymentstatus.cpp
 	dnsseeds.cpp
 	flatfile.cpp
 	headerssync.cpp
 	httprpc.cpp
 	httpserver.cpp
 	i2p.cpp
 	index/base.cpp
 	index/blockfilterindex.cpp
 	index/coinstatsindex.cpp
 	index/txindex.cpp
 	init.cpp
 	init/common.cpp
 	invrequest.cpp
+	kernel/cs_main.cpp
 	kernel/disconnected_transactions.cpp
 	kernel/mempool_persist.cpp
 	mapport.cpp
 	mempool_args.cpp
 	minerfund.cpp
 	net.cpp
 	net_processing.cpp
 	node/blockstorage.cpp
 	node/caches.cpp
 	node/chainstate.cpp
 	node/coin.cpp
 	node/coinstats.cpp
 	node/context.cpp
 	node/interfaces.cpp
 	node/mempool_persist_args.cpp
 	node/miner.cpp
 	node/psbt.cpp
 	node/transaction.cpp
 	node/ui_interface.cpp
 	node/utxo_snapshot.cpp
 	node/validation_cache_args.cpp
 	noui.cpp
 	policy/block/minerfund.cpp
 	policy/block/preconsensus.cpp
 	policy/block/stakingrewards.cpp
 	policy/fees.cpp
 	policy/packages.cpp
 	policy/settings.cpp
 	pow/aserti32d.cpp
 	pow/daa.cpp
 	pow/eda.cpp
 	pow/grasberg.cpp
 	pow/pow.cpp
 	rest.cpp
 	rpc/abc.cpp
 	rpc/avalanche.cpp
 	rpc/blockchain.cpp
 	rpc/command.cpp
 	rpc/mempool.cpp
 	rpc/mining.cpp
 	rpc/misc.cpp
 	rpc/net.cpp
 	rpc/rawtransaction.cpp
 	rpc/server.cpp
 	rpc/server_util.cpp
 	rpc/txoutproof.cpp
 	script/scriptcache.cpp
 	script/sigcache.cpp
 	shutdown.cpp
 	timedata.cpp
 	torcontrol.cpp
 	txdb.cpp
 	txmempool.cpp
 	txorphanage.cpp
 	validation.cpp
 	validationinterface.cpp
 	versionbits.cpp
 )
 
 target_include_directories(server PRIVATE leveldb/helpers/memenv)
 
 target_link_libraries(server
 	bitcoinconsensus
 	leveldb
 	memenv
 )
 
 link_event(server event)
 if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 	link_event(server pthreads)
 endif()
 
 if(ENABLE_UPNP)
 	find_package(MiniUPnPc 1.9 REQUIRED)
 	target_link_libraries(server MiniUPnPc::miniupnpc)
 
 	if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 		# TODO: check if we are really using a static library. Assume this is
 		# the one from the depends for now since the native windows build is not
 		# supported.
 		target_compile_definitions(server
 			PUBLIC -DSTATICLIB
 			PUBLIC -DMINIUPNP_STATICLIB
 		)
 	endif()
 endif()
 
 if(ENABLE_NATPMP)
 	find_package(NATPMP REQUIRED)
 	target_link_libraries(server NATPMP::natpmp)
 
 	if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 		target_compile_definitions(server
 			PUBLIC -DSTATICLIB
 			PUBLIC -DNATPMP_STATICLIB
 		)
 	endif()
 endif()
 
 # Test suites.
 add_subdirectory(test)
 add_subdirectory(avalanche/test)
 add_subdirectory(pow/test)
 
 # Benchmark suite.
 add_subdirectory(bench)
 
 include(BinaryTest)
 include(WindowsVersionInfo)
 
 # Wallet
 if(BUILD_BITCOIN_WALLET)
 	add_subdirectory(wallet)
 	target_link_libraries(server wallet)
 
 	# bitcoin-wallet
 	add_executable(bitcoin-wallet bitcoin-wallet.cpp)
 	generate_windows_version_info(bitcoin-wallet
 		DESCRIPTION "CLI tool for ${PACKAGE_NAME} wallets"
 	)
 
 	target_link_libraries(bitcoin-wallet wallet-tool common util)
 
 	add_to_symbols_check(bitcoin-wallet)
 	add_to_security_check(bitcoin-wallet)
 
 	install_target(bitcoin-wallet)
 	install_manpages(bitcoin-wallet)
 else()
 	target_sources(server PRIVATE dummywallet.cpp)
 endif()
 
 # ZeroMQ
 if(BUILD_BITCOIN_ZMQ)
 	add_subdirectory(zmq)
 	target_link_libraries(server zmq)
 
 	# FIXME: This is needed because of an unwanted dependency:
 	# zmqpublishnotifier.cpp -> blockstorage.h -> txdb.h -> dbwrapper.h -> leveldb/db.h
 	target_link_libraries(zmq leveldb)
 endif()
 
 # RPC client support
 add_library(rpcclient
 	compat/stdin.cpp
 	rpc/client.cpp
 )
 
 target_link_libraries(rpcclient univalue util)
 
 # bitcoin-seeder
 if(BUILD_BITCOIN_SEEDER)
 	add_subdirectory(seeder)
 endif()
 
 # bitcoin-cli
 if(BUILD_BITCOIN_CLI)
 	add_executable(bitcoin-cli bitcoin-cli.cpp)
 	generate_windows_version_info(bitcoin-cli
 		DESCRIPTION "JSON-RPC client for ${PACKAGE_NAME}"
 	)
 
 	target_link_libraries(bitcoin-cli common rpcclient)
 	link_event(bitcoin-cli event)
 
 	add_to_symbols_check(bitcoin-cli)
 	add_to_security_check(bitcoin-cli)
 
 	install_target(bitcoin-cli)
 	install_manpages(bitcoin-cli)
 endif()
 
 # bitcoin-tx
 if(BUILD_BITCOIN_TX)
 	add_executable(bitcoin-tx bitcoin-tx.cpp)
 	generate_windows_version_info(bitcoin-tx
 		DESCRIPTION "CLI Bitcoin transaction editor utility"
 	)
 
 	target_link_libraries(bitcoin-tx bitcoinconsensus)
 
 	add_to_symbols_check(bitcoin-tx)
 	add_to_security_check(bitcoin-tx)
 
 	install_target(bitcoin-tx)
 	install_manpages(bitcoin-tx)
 endif()
 
 # bitcoin-chainstate
 if(BUILD_BITCOIN_CHAINSTATE)
 	# TODO: libbitcoinkernel is a work in progress consensus engine library, as more
 	#       and more modules are decoupled from the consensus engine, this list will
 	#       shrink to only those which are absolutely necessary. For example, things
 	#       like index/*.cpp will be removed.
 	add_library(bitcoinkernel
 		kernel/bitcoinkernel.cpp
+		kernel/cs_main.cpp
 		kernel/disconnected_transactions.cpp
 		kernel/mempool_persist.cpp
 		arith_uint256.cpp
 		blockfileinfo.cpp
 		blockfilter.cpp
 		blockindex.cpp
 		bloom.cpp
 		chain.cpp
 		chainparamsbase.cpp
 		chainparams.cpp
 		checkpoints.cpp
 		clientversion.cpp
 		coins.cpp
 		compat/glibcxx_sanity.cpp
 		compressor.cpp
 		config.cpp
 		consensus/activation.cpp
 		consensus/amount.cpp
 		consensus/merkle.cpp
 		consensus/tx_check.cpp
 		consensus/tx_verify.cpp
 		core_read.cpp
 		dbwrapper.cpp
 		deploymentstatus.cpp
 		eventloop.cpp
 		feerate.cpp
 		flatfile.cpp
 		fs.cpp
 		hash.cpp
 		index/base.cpp
 		index/blockfilterindex.cpp
 		index/coinstatsindex.cpp
 		init/common.cpp
 		key.cpp
 		logging.cpp
 		networks/abc/chainparamsconstants.cpp
 		networks/abc/checkpoints.cpp
 		node/blockstorage.cpp
 		node/chainstate.cpp
 		node/coinstats.cpp
 		node/ui_interface.cpp
 		node/utxo_snapshot.cpp
 		policy/fees.cpp
 		policy/packages.cpp
 		policy/policy.cpp
 		policy/settings.cpp
 		pow/aserti32d.cpp
 		pow/daa.cpp
 		pow/eda.cpp
 		pow/pow.cpp
 		primitives/block.cpp
 		primitives/transaction.cpp
 		pubkey.cpp
 		random.cpp
 		randomenv.cpp
 		rcu.cpp
 		scheduler.cpp
 		script/bitfield.cpp
 		script/interpreter.cpp
 		script/script.cpp
 		script/scriptcache.cpp
 		script/script_error.cpp
 		script/sigcache.cpp
 		script/sigencoding.cpp
 		script/standard.cpp
 		shutdown.cpp
 		support/cleanse.cpp
 		support/lockedpool.cpp
 		sync.cpp
 		threadinterrupt.cpp
 		txdb.cpp
 		txmempool.cpp
 		uint256.cpp
 		util/bytevectorhash.cpp
 		util/check.cpp
 		util/getuniquepath.cpp
 		util/hasher.cpp
 		util/moneystr.cpp
 		util/settings.cpp
 		util/strencodings.cpp
 		util/string.cpp
 		util/system.cpp
 		util/thread.cpp
 		util/threadnames.cpp
 		util/time.cpp
 		util/tokenpipe.cpp
 		validation.cpp
 		validationinterface.cpp
 		versionbits.cpp
 		warnings.cpp
 
 		# Bitcoin ABC specific dependencies that will not go away with Core backports
 		addrdb.cpp   # via banman.cpp
 		addrman.cpp  # via net.cpp
 		banman.cpp   # via net.cpp
 		base58.cpp   # via key_io.cpp
 		avalanche/avalanche.cpp
 		avalanche/delegation.cpp
 		avalanche/delegationbuilder.cpp
 		avalanche/peermanager.cpp
 		avalanche/processor.cpp
 		avalanche/proof.cpp
 		avalanche/proofid.cpp
 		avalanche/proofpool.cpp
 		avalanche/voterecord.cpp
 		cashaddr.cpp         # via cashaddrenc.cpp
 		cashaddrenc.cpp      # via key_io.cpp
 		dnsseeds.cpp         # via net.cpp (GetRandomizedDNSSeeds)
 		i2p.cpp              # via net.cppTx
 		key_io.cpp           # avalanche/processor.cpp uses DecodeSecret
 		minerfund.cpp        # via policy/block/minerfund.cpp
 		net.cpp              # avalanche uses CConnman
 		netaddress.cpp       # via net.cpp
 		netbase.cpp          # via net.cpp
 		net_permissions.cpp  # via net.cpp
 		policy/block/minerfund.cpp
 		policy/block/preconsensus.cpp
 		policy/block/stakingrewards.cpp
 		protocol.cpp            # avalanche/processor.cpp uses NetMsgType
 		timedata.cpp            # via net.cpp
 		util/asmap.cpp          # via netaddress.cpp
 		util/error.cpp          # via net_permissions.cpp (ResolveErrMsg)
 		util/readwritefile.cpp  # via i2p.cpp
 		util/sock.cpp           # via net.cpp
 	)
 
 	target_include_directories(bitcoinkernel
 		PUBLIC
 			.
 			leveldb/helpers/memenv
 			# To access the config/ and obj/ directories
 			${CMAKE_CURRENT_BINARY_DIR}
 	)
 	target_link_libraries(bitcoinkernel crypto univalue secp256k1 leveldb memenv)
 	link_boost_headers_only(bitcoinkernel headers)
 
 	if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 		link_windows_dependencies(bitcoinkernel)
 	endif()
 
 	add_executable(bitcoin-chainstate bitcoin-chainstate.cpp)
 
 	target_link_libraries(bitcoin-chainstate bitcoinkernel)
 
 	generate_windows_version_info(bitcoin-chainstate
 		DESCRIPTION "CLI Datadir information utility (experimental)"
 	)
 
 	add_to_symbols_check(bitcoin-chainstate)
 	add_to_security_check(bitcoin-chainstate)
 endif()
 
 # bitcoind
 add_executable(bitcoind bitcoind.cpp)
 target_link_libraries(bitcoind server)
 generate_windows_version_info(bitcoind
 	DESCRIPTION "Bitcoin node with a JSON-RPC server"
 )
 add_to_symbols_check(bitcoind)
 add_to_security_check(bitcoind)
 
 install_target(bitcoind)
 install_manpages(bitcoind)
 
 # Bitcoin-qt
 if(BUILD_BITCOIN_QT)
 	add_subdirectory(qt)
 endif()
diff --git a/src/bench/rpc_mempool.cpp b/src/bench/rpc_mempool.cpp
index bd73ac183..fd1b185ca 100644
--- a/src/bench/rpc_mempool.cpp
+++ b/src/bench/rpc_mempool.cpp
@@ -1,49 +1,50 @@
 // Copyright (c) 2011-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <bench/bench.h>
 #include <chainparamsbase.h>
 #include <consensus/amount.h>
+#include <kernel/cs_main.h>
 #include <kernel/mempool_entry.h>
 #include <rpc/mempool.h>
 #include <test/util/setup_common.h>
 #include <txmempool.h>
 
 #include <univalue.h>
 
 static void AddTx(const CTransactionRef &tx, const Amount &fee,
                   CTxMemPool &pool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs) {
     LockPoints lp;
     pool.addUnchecked(CTxMemPoolEntryRef::make(tx, fee, /*time=*/0,
                                                /*height=*/1,
                                                /*_sigChecks=*/1, lp));
 }
 
 static void RpcMempool(benchmark::Bench &bench) {
     const TestingSetup test_setup{
         CBaseChainParams::MAIN,
         /* extra_args */
         {
             "-nodebuglogfile",
             "-nodebug",
         },
     };
     CTxMemPool &pool = *Assert(test_setup.m_node.mempool);
     LOCK2(cs_main, pool.cs);
 
     for (int i = 0; i < 1000; ++i) {
         CMutableTransaction tx = CMutableTransaction();
         tx.vin.resize(1);
         tx.vin[0].scriptSig = CScript() << OP_1;
         tx.vout.resize(1);
         tx.vout[0].scriptPubKey = CScript() << OP_1 << OP_EQUAL;
         tx.vout[0].nValue = i * COIN;
         const CTransactionRef tx_r{MakeTransactionRef(tx)};
         AddTx(tx_r, /* fee */ i * COIN, pool);
     }
 
     bench.run([&] { (void)MempoolToJSON(pool, /*verbose*/ true); });
 }
 
 BENCHMARK(RpcMempool);
diff --git a/src/blockindex.h b/src/blockindex.h
index 835ac1b7f..4250150ae 100644
--- a/src/blockindex.h
+++ b/src/blockindex.h
@@ -1,259 +1,258 @@
 // Copyright (c) 2009-2020 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_BLOCKINDEX_H
 #define BITCOIN_BLOCKINDEX_H
 
 #include <arith_uint256.h>
 #include <blockstatus.h>
 #include <flatfile.h>
+#include <kernel/cs_main.h>
 #include <primitives/block.h>
 #include <sync.h>
 #include <tinyformat.h>
 #include <uint256.h>
 #include <util/time.h>
 
 struct BlockHash;
 
-extern RecursiveMutex cs_main;
-
 /**
  * The block chain is a tree shaped structure starting with the genesis block at
  * the root, with each block potentially having multiple candidates to be the
  * next block. A blockindex may have multiple pprev pointing to it, but at most
  * one of them can be part of the currently active branch.
  */
 class CBlockIndex {
 public:
     //! pointer to the hash of the block, if any. Memory is owned by this
     //! CBlockIndex
     const BlockHash *phashBlock{nullptr};
 
     //! pointer to the index of the predecessor of this block
     CBlockIndex *pprev{nullptr};
 
     //! pointer to the index of some further predecessor of this block
     CBlockIndex *pskip{nullptr};
 
     //! height of the entry in the chain. The genesis block has height 0
     int nHeight{0};
 
     //! Which # file this block is stored in (blk?????.dat)
     int nFile GUARDED_BY(::cs_main){0};
 
     //! Byte offset within blk?????.dat where this block's data is stored
     unsigned int nDataPos GUARDED_BY(::cs_main){0};
 
     //! Byte offset within rev?????.dat where this block's undo data is stored
     unsigned int nUndoPos GUARDED_BY(::cs_main){0};
 
     //! (memory only) Total amount of work (expected number of hashes) in the
     //! chain up to and including this block
     arith_uint256 nChainWork{};
 
     //! Number of transactions in this block.
     //! Note: in a potential headers-first mode, this number cannot be relied
     //! upon
     //! Note: this value is faked during UTXO snapshot load to ensure that
     //! LoadBlockIndex() will load index entries for blocks that we lack data
     //! for.
     //! @sa ActivateSnapshot
     unsigned int nTx{0};
 
     //! Size of this block.
     //! Note: in a potential headers-first mode, this number cannot be relied
     //! upon
     unsigned int nSize{0};
 
     //! (memory only) Number of transactions in the chain up to and including
     //! this block.
     //! This value will be non-zero only if and only if transactions for this
     //! block and all its parents are available. Change to 64-bit type when
     //! necessary; won't happen before 2030
     //!
     //! Note: this value is faked during use of a UTXO snapshot because we don't
     //! have the underlying block data available during snapshot load.
     //! @sa AssumeutxoData
     //! @sa ActivateSnapshot
     unsigned int nChainTx{0};
 
 private:
     //! (memory only) Size of all blocks in the chain up to and including this
     //! block. This value will be non-zero only if and only if transactions for
     //! this block and all its parents are available.
     uint64_t nChainSize{0};
 
 public:
     //! Verification status of this block. See enum BlockStatus
     BlockStatus nStatus GUARDED_BY(::cs_main){};
 
     //! block header
     int32_t nVersion{0};
     uint256 hashMerkleRoot{};
     uint32_t nTime{0};
     uint32_t nBits{0};
     uint32_t nNonce{0};
 
     //! (memory only) Sequential id assigned to distinguish order in which
     //! blocks are received.
     int32_t nSequenceId{0};
 
     //! (memory only) block header metadata
     uint64_t nTimeReceived{0};
 
     //! (memory only) Maximum nTime in the chain up to and including this block.
     unsigned int nTimeMax{0};
 
     explicit CBlockIndex() = default;
 
     explicit CBlockIndex(const CBlockHeader &block)
         : nVersion{block.nVersion}, hashMerkleRoot{block.hashMerkleRoot},
           nTime{block.nTime}, nBits{block.nBits}, nNonce{block.nNonce},
           nTimeReceived{0} {}
 
     FlatFilePos GetBlockPos() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         AssertLockHeld(::cs_main);
         FlatFilePos ret;
         if (nStatus.hasData()) {
             ret.nFile = nFile;
             ret.nPos = nDataPos;
         }
         return ret;
     }
 
     FlatFilePos GetUndoPos() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         AssertLockHeld(::cs_main);
         FlatFilePos ret;
         if (nStatus.hasUndo()) {
             ret.nFile = nFile;
             ret.nPos = nUndoPos;
         }
         return ret;
     }
 
     CBlockHeader GetBlockHeader() const {
         CBlockHeader block;
         block.nVersion = nVersion;
         if (pprev) {
             block.hashPrevBlock = pprev->GetBlockHash();
         }
         block.hashMerkleRoot = hashMerkleRoot;
         block.nTime = nTime;
         block.nBits = nBits;
         block.nNonce = nNonce;
         return block;
     }
 
     BlockHash GetBlockHash() const { return *phashBlock; }
 
     /**
      * Get the number of transaction in the chain so far.
      */
     int64_t GetChainTxCount() const { return nChainTx; }
 
     /**
      * Get the size of all the blocks in the chain so far.
      */
     uint64_t GetChainSize() const { return nChainSize; }
 
     /**
      * Update chain tx stats.
      */
     bool UpdateChainStats();
 
     /**
      * Check whether this block's and all previous blocks' transactions have
      * been downloaded (and stored to disk) at some point.
      *
      * Does not imply the transactions are consensus-valid (ConnectTip might
      * fail) Does not imply the transactions are still stored on disk.
      * (IsBlockPruned might return true)
      */
     bool HaveTxsDownloaded() const { return GetChainTxCount() != 0; }
 
     NodeSeconds Time() const {
         return NodeSeconds{std::chrono::seconds{nTime}};
     }
 
     int64_t GetBlockTime() const { return int64_t(nTime); }
 
     int64_t GetBlockTimeMax() const { return int64_t(nTimeMax); }
 
     int64_t GetHeaderReceivedTime() const { return nTimeReceived; }
 
     int64_t GetReceivedTimeDiff() const {
         return GetHeaderReceivedTime() - GetBlockTime();
     }
 
     static constexpr int nMedianTimeSpan = 11;
 
     int64_t GetMedianTimePast() const {
         int64_t pmedian[nMedianTimeSpan];
         int64_t *pbegin = &pmedian[nMedianTimeSpan];
         int64_t *pend = &pmedian[nMedianTimeSpan];
 
         const CBlockIndex *pindex = this;
         for (int i = 0; i < nMedianTimeSpan && pindex;
              i++, pindex = pindex->pprev) {
             *(--pbegin) = pindex->GetBlockTime();
         }
 
         std::sort(pbegin, pend);
         return pbegin[(pend - pbegin) / 2];
     }
 
     std::string ToString() const {
         return strprintf(
             "CBlockIndex(pprev=%p, nHeight=%d, merkle=%s, hashBlock=%s)", pprev,
             nHeight, hashMerkleRoot.ToString(), GetBlockHash().ToString());
     }
 
     //! Check whether this block index entry is valid up to the passed validity
     //! level.
     bool IsValid(enum BlockValidity nUpTo = BlockValidity::TRANSACTIONS) const
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         AssertLockHeld(::cs_main);
         return nStatus.isValid(nUpTo);
     }
 
     //! @returns true if the block is assumed-valid; this means it is queued
     //! to be validated by a background chainstate.
     bool IsAssumedValid() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         AssertLockHeld(::cs_main);
         return nStatus.isAssumedValid();
     }
 
     //! Raise the validity level of this block index entry.
     //! Returns true if the validity was changed.
     bool RaiseValidity(enum BlockValidity nUpTo)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         AssertLockHeld(::cs_main);
         // Only validity flags allowed.
         if (nStatus.isInvalid()) {
             return false;
         }
 
         if (nStatus.getValidity() >= nUpTo) {
             return false;
         }
 
         // If this block had been marked assumed-valid and we're raising
         // its validity to a certain point, there is no longer an assumption.
         if (IsAssumedValid() && nUpTo >= BlockValidity::SCRIPTS) {
             nStatus = nStatus.withClearedAssumedValidFlags();
         }
 
         nStatus = nStatus.withValidity(nUpTo);
         return true;
     }
 
     //! Build the skiplist pointer for this entry.
     void BuildSkip();
 
     //! Efficiently find an ancestor of this block.
     CBlockIndex *GetAncestor(int height);
     const CBlockIndex *GetAncestor(int height) const;
 };
 
 #endif // BITCOIN_BLOCKINDEX_H
diff --git a/src/chain.h b/src/chain.h
index 09a571a68..cdc2dc21e 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -1,219 +1,218 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_CHAIN_H
 #define BITCOIN_CHAIN_H
 
 #include <arith_uint256.h>
 #include <blockindex.h>
 #include <blockstatus.h>
 #include <blockvalidity.h>
 #include <consensus/params.h>
 #include <crypto/common.h> // for ReadLE64
 #include <flatfile.h>
+#include <kernel/cs_main.h>
 #include <primitives/block.h>
 #include <sync.h>
 #include <tinyformat.h>
 #include <uint256.h>
 
 #include <unordered_map>
 #include <vector>
 
 /**
  * Maximum amount of time that a block timestamp is allowed to exceed the
  * current network-adjusted time before the block will be accepted.
  */
 static constexpr int64_t MAX_FUTURE_BLOCK_TIME = 2 * 60 * 60;
 
 /**
  * Timestamp window used as a grace period by code that compares external
  * timestamps (such as timestamps passed to RPCs, or wallet key creation times)
  * to block timestamps. This should be set at least as high as
  * MAX_FUTURE_BLOCK_TIME.
  */
 static constexpr int64_t TIMESTAMP_WINDOW = MAX_FUTURE_BLOCK_TIME;
 
 /**
  * Maximum gap between node time and block time used
  * for the "Catching up..." mode in GUI.
  *
  * Ref: https://github.com/bitcoin/bitcoin/pull/1026
  */
 static constexpr int64_t MAX_BLOCK_TIME_GAP = 90 * 60;
 
-extern RecursiveMutex cs_main;
-
 arith_uint256 GetBlockProof(const CBlockIndex &block);
 
 /**
  * Return the time it would take to redo the work difference between from and
  * to, assuming the current hashrate corresponds to the difficulty at tip, in
  * seconds.
  */
 int64_t GetBlockProofEquivalentTime(const CBlockIndex &to,
                                     const CBlockIndex &from,
                                     const CBlockIndex &tip,
                                     const Consensus::Params &);
 /**
  * Find the forking point between two chain tips.
  */
 const CBlockIndex *LastCommonAncestor(const CBlockIndex *pa,
                                       const CBlockIndex *pb);
 
 /**
  * Check if two block index are on the same fork.
  */
 bool AreOnTheSameFork(const CBlockIndex *pa, const CBlockIndex *pb);
 
 /** Used to marshal pointers into hashes for db storage. */
 class CDiskBlockIndex : public CBlockIndex {
 public:
     static constexpr int TRACK_SIZE_VERSION = 220800;
 
     BlockHash hashPrev;
 
     CDiskBlockIndex() : hashPrev() {}
 
     explicit CDiskBlockIndex(const CBlockIndex *pindex) : CBlockIndex(*pindex) {
         hashPrev = (pprev ? pprev->GetBlockHash() : BlockHash());
     }
 
     SERIALIZE_METHODS(CDiskBlockIndex, obj) {
         LOCK(::cs_main);
         int _nVersion = s.GetVersion();
         if (!(s.GetType() & SER_GETHASH)) {
             READWRITE(VARINT_MODE(_nVersion, VarIntMode::NONNEGATIVE_SIGNED));
         }
 
         READWRITE(VARINT_MODE(obj.nHeight, VarIntMode::NONNEGATIVE_SIGNED));
         READWRITE(obj.nStatus);
         READWRITE(VARINT(obj.nTx));
 
         // The size of the blocks are tracked starting at version 0.22.8
         if (obj.nStatus.hasData() && _nVersion >= TRACK_SIZE_VERSION) {
             READWRITE(VARINT(obj.nSize));
         }
 
         if (obj.nStatus.hasData() || obj.nStatus.hasUndo()) {
             READWRITE(VARINT_MODE(obj.nFile, VarIntMode::NONNEGATIVE_SIGNED));
         }
         if (obj.nStatus.hasData()) {
             READWRITE(VARINT(obj.nDataPos));
         }
         if (obj.nStatus.hasUndo()) {
             READWRITE(VARINT(obj.nUndoPos));
         }
 
         // block header
         READWRITE(obj.nVersion);
         READWRITE(obj.hashPrev);
         READWRITE(obj.hashMerkleRoot);
         READWRITE(obj.nTime);
         READWRITE(obj.nBits);
         READWRITE(obj.nNonce);
     }
 
     BlockHash GetBlockHash() const {
         CBlockHeader block;
         block.nVersion = nVersion;
         block.hashPrevBlock = hashPrev;
         block.hashMerkleRoot = hashMerkleRoot;
         block.nTime = nTime;
         block.nBits = nBits;
         block.nNonce = nNonce;
         return block.GetHash();
     }
 
     std::string ToString() const {
         std::string str = "CDiskBlockIndex(";
         str += CBlockIndex::ToString();
         str += strprintf("\n                hashBlock=%s, hashPrev=%s)",
                          GetBlockHash().ToString(), hashPrev.ToString());
         return str;
     }
 };
 
 /**
  * An in-memory indexed chain of blocks.
  */
 class CChain {
 private:
     std::vector<CBlockIndex *> vChain;
 
 public:
     /**
      * Returns the index entry for the genesis block of this chain, or nullptr
      * if none.
      */
     CBlockIndex *Genesis() const {
         return vChain.size() > 0 ? vChain[0] : nullptr;
     }
 
     /**
      * Returns the index entry for the tip of this chain, or nullptr if none.
      */
     CBlockIndex *Tip() const {
         return vChain.size() > 0 ? vChain[vChain.size() - 1] : nullptr;
     }
 
     /**
      * Returns the index entry at a particular height in this chain, or nullptr
      * if no such height exists.
      */
     CBlockIndex *operator[](int nHeight) const {
         if (nHeight < 0 || nHeight >= (int)vChain.size()) {
             return nullptr;
         }
         return vChain[nHeight];
     }
 
     /** Efficiently check whether a block is present in this chain. */
     bool Contains(const CBlockIndex *pindex) const {
         return (*this)[pindex->nHeight] == pindex;
     }
 
     /**
      * Find the successor of a block in this chain, or nullptr if the given
      * index is not found or is the tip.
      */
     CBlockIndex *Next(const CBlockIndex *pindex) const {
         if (!Contains(pindex)) {
             return nullptr;
         }
 
         return (*this)[pindex->nHeight + 1];
     }
 
     /**
      * Return the maximal height in the chain. Is equal to chain.Tip() ?
      * chain.Tip()->nHeight : -1.
      */
     int Height() const { return int(vChain.size()) - 1; }
 
     /** Set/initialize a chain with a given tip. */
     void SetTip(CBlockIndex *pindex);
 
     /** Return a CBlockLocator that refers to the tip of this chain */
     CBlockLocator GetLocator() const;
 
     /**
      * Find the last common block between this chain and a block index entry.
      */
     const CBlockIndex *FindFork(const CBlockIndex *pindex) const;
 
     /**
      * Find the earliest block with timestamp equal or greater than the given
      * time and height equal or greater than the given height.
      */
     CBlockIndex *FindEarliestAtLeast(int64_t nTime, int height) const;
 };
 
 /** Get a locator for a block index entry. */
 CBlockLocator GetLocator(const CBlockIndex *index);
 
 /** Construct a list of hash entries to put in a locator.  */
 std::vector<BlockHash> LocatorEntries(const CBlockIndex *index);
 
 #endif // BITCOIN_CHAIN_H
diff --git a/src/kernel/cs_main.cpp b/src/kernel/cs_main.cpp
new file mode 100644
index 000000000..c3a08c969
--- /dev/null
+++ b/src/kernel/cs_main.cpp
@@ -0,0 +1,7 @@
+// Copyright (c) 2023 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <sync.h>
+
+RecursiveMutex cs_main;
diff --git a/src/kernel/cs_main.h b/src/kernel/cs_main.h
new file mode 100644
index 000000000..8d03903b8
--- /dev/null
+++ b/src/kernel/cs_main.h
@@ -0,0 +1,22 @@
+// Copyright (c) 2023 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_KERNEL_CS_MAIN_H
+#define BITCOIN_KERNEL_CS_MAIN_H
+
+#include <sync.h>
+
+/**
+ * Mutex to guard access to validation specific variables, such as reading
+ * or changing the chainstate.
+ *
+ * This may also need to be locked when updating the transaction pool, e.g. on
+ * AcceptToMemoryPool. See CTxMemPool::cs comment for details.
+ *
+ * The transaction pool has a separate lock to allow reading from it and the
+ * chainstate at the same time.
+ */
+extern RecursiveMutex cs_main;
+
+#endif // BITCOIN_KERNEL_CS_MAIN_H
diff --git a/src/net.h b/src/net.h
index f219450ec..ac60c7ca8 100644
--- a/src/net.h
+++ b/src/net.h
@@ -1,1412 +1,1412 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2019 The Bitcoin Core developers
 // Copyright (c) 2017-2019 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_NET_H
 #define BITCOIN_NET_H
 
 #include <avalanche/proofid.h>
 #include <avalanche/proofradixtreeadapter.h>
 #include <bloom.h>
 #include <chainparams.h>
 #include <compat.h>
 #include <consensus/amount.h>
 #include <crypto/siphash.h>
 #include <hash.h>
 #include <i2p.h>
+#include <kernel/cs_main.h>
 #include <logging.h>
 #include <net_permissions.h>
 #include <netaddress.h>
 #include <nodeid.h>
 #include <protocol.h>
 #include <pubkey.h>
 #include <radix.h>
 #include <random.h>
 #include <span.h>
 #include <streams.h>
 #include <sync.h>
 #include <threadinterrupt.h>
 #include <uint256.h>
 #include <util/check.h>
 #include <util/time.h>
-#include <validation.h> // For cs_main
 
 #include <atomic>
 #include <condition_variable>
 #include <cstdint>
 #include <deque>
 #include <functional>
 #include <list>
 #include <map>
 #include <memory>
 #include <thread>
 #include <vector>
 
 class AddrMan;
 class BanMan;
 class Config;
 class CNode;
 class CScheduler;
 struct bilingual_str;
 
 /** Default for -whitelistrelay. */
 static const bool DEFAULT_WHITELISTRELAY = true;
 /** Default for -whitelistforcerelay. */
 static const bool DEFAULT_WHITELISTFORCERELAY = false;
 
 /**
  * Time after which to disconnect, after waiting for a ping response (or
  * inactivity).
  */
 static constexpr std::chrono::minutes TIMEOUT_INTERVAL{20};
 /** Run the feeler connection loop once every 2 minutes. **/
 static constexpr auto FEELER_INTERVAL = 2min;
 /** Run the extra block-relay-only connection loop once every 5 minutes. **/
 static constexpr auto EXTRA_BLOCK_RELAY_ONLY_PEER_INTERVAL = 5min;
 /** Maximum length of the user agent string in `version` message */
 static const unsigned int MAX_SUBVERSION_LENGTH = 256;
 /**
  * Maximum number of automatic outgoing nodes over which we'll relay everything
  * (blocks, tx, addrs, etc)
  */
 static const int MAX_OUTBOUND_FULL_RELAY_CONNECTIONS = 16;
 /** Maximum number of addnode outgoing nodes */
 static const int MAX_ADDNODE_CONNECTIONS = 8;
 /** Maximum number of block-relay-only outgoing connections */
 static const int MAX_BLOCK_RELAY_ONLY_CONNECTIONS = 2;
 /**
  * Maximum number of avalanche enabled outgoing connections by default.
  * Can be overridden with the -maxavalancheoutbound option.
  */
 static const int DEFAULT_MAX_AVALANCHE_OUTBOUND_CONNECTIONS = 300;
 /** Maximum number of feeler connections */
 static const int MAX_FEELER_CONNECTIONS = 1;
 /** -listen default */
 static const bool DEFAULT_LISTEN = true;
 /**
  * The maximum number of peer connections to maintain.
  * This quantity might not be reachable on some systems, especially on platforms
  * that do not provide a working poll() interface.
  */
 static const unsigned int DEFAULT_MAX_PEER_CONNECTIONS = 4096;
 /** The default for -maxuploadtarget. 0 = Unlimited */
 static constexpr uint64_t DEFAULT_MAX_UPLOAD_TARGET = 0;
 /** Default for blocks only*/
 static const bool DEFAULT_BLOCKSONLY = false;
 /** -peertimeout default */
 static const int64_t DEFAULT_PEER_CONNECT_TIMEOUT = 60;
 /** Number of file descriptors required for message capture **/
 static const int NUM_FDS_MESSAGE_CAPTURE = 1;
 
 static const bool DEFAULT_FORCEDNSSEED = false;
 static const bool DEFAULT_DNSSEED = true;
 static const bool DEFAULT_FIXEDSEEDS = true;
 static const size_t DEFAULT_MAXRECEIVEBUFFER = 5 * 1000;
 static const size_t DEFAULT_MAXSENDBUFFER = 1 * 1000;
 
 struct AddedNodeInfo {
     std::string strAddedNode;
     CService resolvedAddress;
     bool fConnected;
     bool fInbound;
 };
 
 struct CNodeStats;
 class CClientUIInterface;
 
 struct CSerializedNetMsg {
     CSerializedNetMsg() = default;
     CSerializedNetMsg(CSerializedNetMsg &&) = default;
     CSerializedNetMsg &operator=(CSerializedNetMsg &&) = default;
     // No copying, only moves.
     CSerializedNetMsg(const CSerializedNetMsg &msg) = delete;
     CSerializedNetMsg &operator=(const CSerializedNetMsg &) = delete;
 
     CSerializedNetMsg Copy() const {
         CSerializedNetMsg copy;
         copy.data = data;
         copy.m_type = m_type;
         return copy;
     }
 
     std::vector<uint8_t> data;
     std::string m_type;
 };
 
 const std::vector<std::string> CONNECTION_TYPE_DOC{
     "outbound-full-relay (default automatic connections)",
     "block-relay-only (does not relay transactions or addresses)",
     "inbound (initiated by the peer)",
     "manual (added via addnode RPC or -addnode/-connect configuration options)",
     "addr-fetch (short-lived automatic connection for soliciting addresses)",
     "feeler (short-lived automatic connection for testing addresses)"};
 
 /**
  * Different types of connections to a peer. This enum encapsulates the
  * information we have available at the time of opening or accepting the
  * connection. Aside from INBOUND, all types are initiated by us.
  */
 enum class ConnectionType {
     /**
      * Inbound connections are those initiated by a peer. This is the only
      * property we know at the time of connection, until P2P messages are
      * exchanged.
      */
     INBOUND,
 
     /**
      * These are the default connections that we use to connect with the
      * network. There is no restriction on what is relayed- by default we relay
      * blocks, addresses & transactions. We automatically attempt to open
      * MAX_OUTBOUND_FULL_RELAY_CONNECTIONS using addresses from our AddrMan.
      */
     OUTBOUND_FULL_RELAY,
 
     /**
      * We open manual connections to addresses that users explicitly inputted
      * via the addnode RPC, or the -connect command line argument. Even if a
      * manual connection is misbehaving, we do not automatically disconnect or
      * add it to our discouragement filter.
      */
     MANUAL,
 
     /**
      * Feeler connections are short-lived connections made to check that a node
      * is alive. They can be useful for:
      * - test-before-evict: if one of the peers is considered for eviction from
      *   our AddrMan because another peer is mapped to the same slot in the
      *   tried table, evict only if this longer-known peer is offline.
      * - move node addresses from New to Tried table, so that we have more
      *   connectable addresses in our AddrMan.
      * Note that in the literature ("Eclipse Attacks on Bitcoin’s Peer-to-Peer
      * Network") only the latter feature is referred to as "feeler connections",
      * although in our codebase feeler connections encompass test-before-evict
      * as well.
      * We make these connections approximately every FEELER_INTERVAL:
      * first we resolve previously found collisions if they exist
      * (test-before-evict), otherwise connect to a node from the new table.
      */
     FEELER,
 
     /**
      * We use block-relay-only connections to help prevent against partition
      * attacks. By not relaying transactions or addresses, these connections
      * are harder to detect by a third party, thus helping obfuscate the
      * network topology. We automatically attempt to open
      * MAX_BLOCK_RELAY_ONLY_ANCHORS using addresses from our anchors.dat. Then
      * addresses from our AddrMan if MAX_BLOCK_RELAY_ONLY_CONNECTIONS
      * isn't reached yet.
      */
     BLOCK_RELAY,
 
     /**
      * AddrFetch connections are short lived connections used to solicit
      * addresses from peers. These are initiated to addresses submitted via the
      * -seednode command line argument, or under certain conditions when the
      * AddrMan is empty.
      */
     ADDR_FETCH,
 
     /**
      * Special case of connection to a full relay outbound with avalanche
      * service enabled.
      */
     AVALANCHE_OUTBOUND,
 };
 
 /** Convert ConnectionType enum to a string value */
 std::string ConnectionTypeAsString(ConnectionType conn_type);
 
 /**
  * Look up IP addresses from all interfaces on the machine and add them to the
  * list of local addresses to self-advertise.
  * The loopback interface is skipped and only the first address from each
  * interface is used.
  */
 void Discover();
 
 uint16_t GetListenPort();
 
 enum {
     // unknown
     LOCAL_NONE,
     // address a local interface listens on
     LOCAL_IF,
     // address explicit bound to
     LOCAL_BIND,
     // address reported by UPnP or NAT-PMP
     LOCAL_MAPPED,
     // address explicitly specified (-externalip=)
     LOCAL_MANUAL,
 
     LOCAL_MAX
 };
 
 bool IsPeerAddrLocalGood(CNode *pnode);
 /** Returns a local address that we should advertise to this peer. */
 std::optional<CService> GetLocalAddrForPeer(CNode &node);
 
 /**
  * Mark a network as reachable or unreachable (no automatic connects to it)
  * @note Networks are reachable by default
  */
 void SetReachable(enum Network net, bool reachable);
 /** @returns true if the network is reachable, false otherwise */
 bool IsReachable(enum Network net);
 /** @returns true if the address is in a reachable network, false otherwise */
 bool IsReachable(const CNetAddr &addr);
 
 bool AddLocal(const CService &addr, int nScore = LOCAL_NONE);
 bool AddLocal(const CNetAddr &addr, int nScore = LOCAL_NONE);
 void RemoveLocal(const CService &addr);
 bool SeenLocal(const CService &addr);
 bool IsLocal(const CService &addr);
 bool GetLocal(CService &addr, const CNetAddr *paddrPeer = nullptr);
 CService GetLocalAddress(const CNetAddr &addrPeer);
 
 extern bool fDiscover;
 extern bool fListen;
 
 struct LocalServiceInfo {
     int nScore;
     uint16_t nPort;
 };
 
 extern GlobalMutex g_maplocalhost_mutex;
 extern std::map<CNetAddr, LocalServiceInfo>
     mapLocalHost GUARDED_BY(g_maplocalhost_mutex);
 
 extern const std::string NET_MESSAGE_COMMAND_OTHER;
 // Command, total bytes
 typedef std::map<std::string, uint64_t> mapMsgCmdSize;
 
 /**
  * POD that contains various stats about a node.
  * Usually constructed from CConman::GetNodeStats. Stats are filled from the
  * node using CNode::copyStats.
  */
 struct CNodeStats {
     NodeId nodeid;
     std::chrono::seconds m_last_send;
     std::chrono::seconds m_last_recv;
     std::chrono::seconds m_last_tx_time;
     std::chrono::seconds m_last_proof_time;
     std::chrono::seconds m_last_block_time;
     std::chrono::seconds m_connected;
     int64_t nTimeOffset;
     std::string m_addr_name;
     int nVersion;
     std::string cleanSubVer;
     bool fInbound;
     bool m_bip152_highbandwidth_to;
     bool m_bip152_highbandwidth_from;
     int m_starting_height;
     uint64_t nSendBytes;
     mapMsgCmdSize mapSendBytesPerMsgCmd;
     uint64_t nRecvBytes;
     mapMsgCmdSize mapRecvBytesPerMsgCmd;
     NetPermissionFlags m_permissionFlags;
     std::chrono::microseconds m_last_ping_time;
     std::chrono::microseconds m_min_ping_time;
     // Our address, as reported by the peer
     std::string addrLocal;
     // Address of this peer
     CAddress addr;
     // Bind address of our side of the connection
     CAddress addrBind;
     // Network the peer connected through
     Network m_network;
     uint32_t m_mapped_as;
     ConnectionType m_conn_type;
     std::optional<double> m_availabilityScore;
 };
 
 /**
  * Transport protocol agnostic message container.
  * Ideally it should only contain receive time, payload,
  * type and size.
  */
 class CNetMessage {
 public:
     //! received message data
     CDataStream m_recv;
     //! time of message receipt
     std::chrono::microseconds m_time{0};
     bool m_valid_netmagic = false;
     bool m_valid_header = false;
     bool m_valid_checksum = false;
     //! size of the payload
     uint32_t m_message_size{0};
     //! used wire size of the message (including header/checksum)
     uint32_t m_raw_message_size{0};
     std::string m_type;
 
     CNetMessage(CDataStream &&recv_in) : m_recv(std::move(recv_in)) {}
 
     void SetVersion(int nVersionIn) { m_recv.SetVersion(nVersionIn); }
 };
 
 /**
  * The TransportDeserializer takes care of holding and deserializing the
  * network receive buffer. It can deserialize the network buffer into a
  * transport protocol agnostic CNetMessage (command & payload)
  */
 class TransportDeserializer {
 public:
     // returns true if the current deserialization is complete
     virtual bool Complete() const = 0;
     // set the serialization context version
     virtual void SetVersion(int version) = 0;
     /** read and deserialize data, advances msg_bytes data pointer */
     virtual int Read(const Config &config, Span<const uint8_t> &msg_bytes) = 0;
     // decomposes a message from the context
     virtual CNetMessage GetMessage(const Config &config,
                                    std::chrono::microseconds time) = 0;
     virtual ~TransportDeserializer() {}
 };
 
 class V1TransportDeserializer final : public TransportDeserializer {
 private:
     mutable CHash256 hasher;
     mutable uint256 data_hash;
 
     // Parsing header (false) or data (true)
     bool in_data;
     // Partially received header.
     CDataStream hdrbuf;
     // Complete header.
     CMessageHeader hdr;
     // Received message data.
     CDataStream vRecv;
     uint32_t nHdrPos;
     uint32_t nDataPos;
 
     const uint256 &GetMessageHash() const;
     int readHeader(const Config &config, Span<const uint8_t> msg_bytes);
     int readData(Span<const uint8_t> msg_bytes);
 
     void Reset() {
         vRecv.clear();
         hdrbuf.clear();
         hdrbuf.resize(24);
         in_data = false;
         nHdrPos = 0;
         nDataPos = 0;
         data_hash.SetNull();
         hasher.Reset();
     }
 
 public:
     V1TransportDeserializer(
         const CMessageHeader::MessageMagic &pchMessageStartIn, int nTypeIn,
         int nVersionIn)
         : hdrbuf(nTypeIn, nVersionIn), hdr(pchMessageStartIn),
           vRecv(nTypeIn, nVersionIn) {
         Reset();
     }
 
     bool Complete() const override {
         if (!in_data) {
             return false;
         }
 
         return (hdr.nMessageSize == nDataPos);
     }
 
     void SetVersion(int nVersionIn) override {
         hdrbuf.SetVersion(nVersionIn);
         vRecv.SetVersion(nVersionIn);
     }
     int Read(const Config &config, Span<const uint8_t> &msg_bytes) override {
         int ret = in_data ? readData(msg_bytes) : readHeader(config, msg_bytes);
         if (ret < 0) {
             Reset();
         } else {
             msg_bytes = msg_bytes.subspan(ret);
         }
         return ret;
     }
 
     CNetMessage GetMessage(const Config &config,
                            std::chrono::microseconds time) override;
 };
 
 /**
  * The TransportSerializer prepares messages for the network transport
  */
 class TransportSerializer {
 public:
     // prepare message for transport (header construction, error-correction
     // computation, payload encryption, etc.)
     virtual void prepareForTransport(const Config &config,
                                      CSerializedNetMsg &msg,
                                      std::vector<uint8_t> &header) = 0;
     virtual ~TransportSerializer() {}
 };
 
 class V1TransportSerializer : public TransportSerializer {
 public:
     void prepareForTransport(const Config &config, CSerializedNetMsg &msg,
                              std::vector<uint8_t> &header) override;
 };
 
 /** Information about a peer */
 class CNode {
     friend class CConnman;
     friend struct ConnmanTestMsg;
 
 public:
     std::unique_ptr<TransportDeserializer> m_deserializer;
     std::unique_ptr<TransportSerializer> m_serializer;
 
     // socket
     SOCKET hSocket GUARDED_BY(cs_hSocket);
     /** Total size of all vSendMsg entries. */
     size_t nSendSize GUARDED_BY(cs_vSend){0};
     /** Offset inside the first vSendMsg already sent */
     size_t nSendOffset GUARDED_BY(cs_vSend){0};
     uint64_t nSendBytes GUARDED_BY(cs_vSend){0};
     std::deque<std::vector<uint8_t>> vSendMsg GUARDED_BY(cs_vSend);
     Mutex cs_vSend;
     Mutex cs_hSocket;
     Mutex cs_vRecv;
 
     RecursiveMutex cs_vProcessMsg;
     std::list<CNetMessage> vProcessMsg GUARDED_BY(cs_vProcessMsg);
     size_t nProcessQueueSize{0};
 
     uint64_t nRecvBytes GUARDED_BY(cs_vRecv){0};
 
     std::atomic<std::chrono::seconds> m_last_send{0s};
     std::atomic<std::chrono::seconds> m_last_recv{0s};
     //! Unix epoch time at peer connection
     const std::chrono::seconds m_connected;
     std::atomic<int64_t> nTimeOffset{0};
     // Address of this peer
     const CAddress addr;
     // Bind address of our side of the connection
     const CAddress addrBind;
     const std::string m_addr_name;
     //! Whether this peer is an inbound onion, i.e. connected via our Tor onion
     //! service.
     const bool m_inbound_onion;
     std::atomic<int> nVersion{0};
     // The nonce provided by the remote host.
     uint64_t nRemoteHostNonce{0};
     // The extra entropy provided by the remote host.
     uint64_t nRemoteExtraEntropy{0};
     /**
      * cleanSubVer is a sanitized string of the user agent byte array we read
      * from the wire. This cleaned string can safely be logged or displayed.
      */
     Mutex m_subver_mutex;
     std::string cleanSubVer GUARDED_BY(m_subver_mutex){};
     // This peer is preferred for eviction.
     bool m_prefer_evict{false};
     bool HasPermission(NetPermissionFlags permission) const {
         return NetPermissions::HasFlag(m_permissionFlags, permission);
     }
     std::atomic_bool fSuccessfullyConnected{false};
     // Setting fDisconnect to true will cause the node to be disconnected the
     // next time DisconnectNodes() runs
     std::atomic_bool fDisconnect{false};
     CSemaphoreGrant grantOutbound;
     std::atomic<int> nRefCount{0};
 
     const uint64_t nKeyedNetGroup;
     std::atomic_bool fPauseRecv{false};
     std::atomic_bool fPauseSend{false};
 
     bool IsOutboundOrBlockRelayConn() const {
         switch (m_conn_type) {
             case ConnectionType::OUTBOUND_FULL_RELAY:
             case ConnectionType::BLOCK_RELAY:
             case ConnectionType::AVALANCHE_OUTBOUND:
                 return true;
             case ConnectionType::INBOUND:
             case ConnectionType::MANUAL:
             case ConnectionType::ADDR_FETCH:
             case ConnectionType::FEELER:
                 return false;
         } // no default case, so the compiler can warn about missing cases
 
         assert(false);
     }
 
     bool IsFullOutboundConn() const {
         return m_conn_type == ConnectionType::OUTBOUND_FULL_RELAY ||
                m_conn_type == ConnectionType::AVALANCHE_OUTBOUND;
     }
 
     bool IsManualConn() const { return m_conn_type == ConnectionType::MANUAL; }
 
     bool IsBlockOnlyConn() const {
         return m_conn_type == ConnectionType::BLOCK_RELAY;
     }
 
     bool IsFeelerConn() const { return m_conn_type == ConnectionType::FEELER; }
 
     bool IsAddrFetchConn() const {
         return m_conn_type == ConnectionType::ADDR_FETCH;
     }
 
     bool IsInboundConn() const {
         return m_conn_type == ConnectionType::INBOUND;
     }
 
     bool IsAvalancheOutboundConnection() const {
         return m_conn_type == ConnectionType::AVALANCHE_OUTBOUND;
     }
 
     bool ExpectServicesFromConn() const {
         switch (m_conn_type) {
             case ConnectionType::INBOUND:
             case ConnectionType::MANUAL:
             case ConnectionType::FEELER:
                 return false;
             case ConnectionType::OUTBOUND_FULL_RELAY:
             case ConnectionType::BLOCK_RELAY:
             case ConnectionType::ADDR_FETCH:
             case ConnectionType::AVALANCHE_OUTBOUND:
                 return true;
         } // no default case, so the compiler can warn about missing cases
 
         assert(false);
     }
 
     /**
      * Get network the peer connected through.
      *
      * Returns Network::NET_ONION for *inbound* onion connections,
      * and CNetAddr::GetNetClass() otherwise. The latter cannot be used directly
      * because it doesn't detect the former, and it's not the responsibility of
      * the CNetAddr class to know the actual network a peer is connected
      * through.
      *
      * @return network the peer connected through.
      */
     Network ConnectedThroughNetwork() const;
 
     // We selected peer as (compact blocks) high-bandwidth peer (BIP152)
     std::atomic<bool> m_bip152_highbandwidth_to{false};
     // Peer selected us as (compact blocks) high-bandwidth peer (BIP152)
     std::atomic<bool> m_bip152_highbandwidth_from{false};
 
     /**
      * Whether this peer provides all services that we want.
      * Used for eviction decisions
      */
     std::atomic_bool m_has_all_wanted_services{false};
 
     /**
      * Whether we should relay transactions to this peer (their version
      * message did not include fRelay=false and this is not a block-relay-only
      * connection). This only changes from false to true. It will never change
      * back to false. Used only in inbound eviction logic.
      */
     std::atomic_bool m_relays_txs{false};
 
     /**
      * Whether this peer has loaded a bloom filter. Used only in inbound
      * eviction logic.
      */
     std::atomic_bool m_bloom_filter_loaded{false};
 
     // True if we know this peer is using Avalanche (at least polling)
     std::atomic<bool> m_avalanche_enabled{false};
 
     mutable Mutex cs_avalanche_pubkey;
     // Pubkey used to verify signatures on Avalanche messages from this peer
     std::optional<CPubKey> m_avalanche_pubkey GUARDED_BY(cs_avalanche_pubkey);
 
     /** The node was polled for count invs */
     void invsPolled(uint32_t count);
 
     /** The node voted for count invs */
     void invsVoted(uint32_t count);
 
     /**
      * The availability score is calculated using an exponentially weighted
      * average.
      * This has several interesting properties:
      *  - The most recent polls/responses have more weight than the previous
      * ones. A node that recently stopped answering will see its ratio
      * decrease quickly.
      *  - This is a low-pass filter, so it causes delay. This means that a
      * node needs to have a track record for the ratio to be high. A node
      * that has been little requested will have a lower ratio than a node
      * that failed to answer a few polls but answered a lot of them.
      *  - It is cheap to compute.
      *
      * This is expected to be called at a fixed interval of
      * AVALANCHE_STATISTICS_REFRESH_PERIOD.
      */
     void updateAvailabilityScore(double decayFactor);
     double getAvailabilityScore() const;
 
     // Store the next time we will consider a getavaaddr message from this peer
     std::chrono::seconds m_nextGetAvaAddr{0};
 
     // The last time the node sent us a faulty message
     std::atomic<std::chrono::seconds> m_avalanche_last_message_fault{0s};
     // How much faulty messages did this node accumulate
     std::atomic<int> m_avalanche_message_fault_counter{0};
 
     SteadyMilliseconds m_last_poll{};
 
     /**
      * UNIX epoch time of the last block received from this peer that we had
      * not yet seen (e.g. not already received from another peer), that passed
      * preliminary validity checks and was saved to disk, even if we don't
      * connect the block or it eventually fails connection. Used as an inbound
      * peer eviction criterium in CConnman::AttemptToEvictConnection.
      */
     std::atomic<std::chrono::seconds> m_last_block_time{0s};
 
     /**
      * UNIX epoch time of the last transaction received from this peer that we
      * had not yet seen (e.g. not already received from another peer) and that
      * was accepted into our mempool. Used as an inbound peer eviction criterium
      * in CConnman::AttemptToEvictConnection.
      */
     std::atomic<std::chrono::seconds> m_last_tx_time{0s};
 
     /**
      * UNIX epoch time of the last proof received from this peer that we
      * had not yet seen (e.g. not already received from another peer) and that
      * was accepted into our proof pool. Used as an inbound peer eviction
      * criterium in CConnman::AttemptToEvictConnection.
      */
     std::atomic<std::chrono::seconds> m_last_proof_time{0s};
 
     /** Last measured round-trip time. Used only for RPC/GUI stats/debugging.*/
     std::atomic<std::chrono::microseconds> m_last_ping_time{0us};
 
     /**
      * Lowest measured round-trip time. Used as an inbound peer eviction
      * criterium in CConnman::AttemptToEvictConnection.
      */
     std::atomic<std::chrono::microseconds> m_min_ping_time{
         std::chrono::microseconds::max()};
 
     CNode(NodeId id, SOCKET hSocketIn, const CAddress &addrIn,
           uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn,
           uint64_t nLocalExtraEntropyIn, const CAddress &addrBindIn,
           const std::string &addrNameIn, ConnectionType conn_type_in,
           bool inbound_onion);
     ~CNode();
     CNode(const CNode &) = delete;
     CNode &operator=(const CNode &) = delete;
 
     /**
      * A ping-pong round trip has completed successfully. Update latest and
      * minimum ping times.
      */
     void PongReceived(std::chrono::microseconds ping_time) {
         m_last_ping_time = ping_time;
         m_min_ping_time = std::min(m_min_ping_time.load(), ping_time);
     }
 
     NodeId GetId() const { return id; }
 
     uint64_t GetLocalNonce() const { return nLocalHostNonce; }
     uint64_t GetLocalExtraEntropy() const { return nLocalExtraEntropy; }
 
     int GetRefCount() const {
         assert(nRefCount >= 0);
         return nRefCount;
     }
 
     /**
      * Receive bytes from the buffer and deserialize them into messages.
      *
      * @param[in]   msg_bytes   The raw data
      * @param[out]  complete    Set True if at least one message has been
      *                          deserialized and is ready to be processed
      * @return  True if the peer should stay connected,
      *          False if the peer should be disconnected from.
      */
     bool ReceiveMsgBytes(const Config &config, Span<const uint8_t> msg_bytes,
                          bool &complete) EXCLUSIVE_LOCKS_REQUIRED(!cs_vRecv);
 
     void SetCommonVersion(int greatest_common_version) {
         Assume(m_greatest_common_version == INIT_PROTO_VERSION);
         m_greatest_common_version = greatest_common_version;
     }
     int GetCommonVersion() const { return m_greatest_common_version; }
 
     CService GetAddrLocal() const EXCLUSIVE_LOCKS_REQUIRED(!m_addr_local_mutex);
     //! May not be called more than once
     void SetAddrLocal(const CService &addrLocalIn)
         EXCLUSIVE_LOCKS_REQUIRED(!m_addr_local_mutex);
 
     CNode *AddRef() {
         nRefCount++;
         return this;
     }
 
     void Release() { nRefCount--; }
 
     void CloseSocketDisconnect() EXCLUSIVE_LOCKS_REQUIRED(!cs_hSocket);
 
     void copyStats(CNodeStats &stats)
         EXCLUSIVE_LOCKS_REQUIRED(!m_subver_mutex, !m_addr_local_mutex,
                                  !cs_vSend, !cs_vRecv);
 
     std::string ConnectionTypeAsString() const {
         return ::ConnectionTypeAsString(m_conn_type);
     }
 
 private:
     const NodeId id;
     const uint64_t nLocalHostNonce;
     const uint64_t nLocalExtraEntropy;
     const ConnectionType m_conn_type;
     std::atomic<int> m_greatest_common_version{INIT_PROTO_VERSION};
 
     NetPermissionFlags m_permissionFlags{NetPermissionFlags::None};
     // Used only by SocketHandler thread
     std::list<CNetMessage> vRecvMsg;
 
     // Our address, as reported by the peer
     mutable Mutex m_addr_local_mutex;
     CService addrLocal GUARDED_BY(m_addr_local_mutex);
 
     /**
      * The inventories polled and voted counters since last score
      * computation, stored as a pair of uint32_t with the poll counter
      * being the 32 lowest bits and the vote counter the 32 highest bits.
      */
     std::atomic<uint64_t> invCounters{0};
 
     /** The last computed score */
     std::atomic<double> availabilityScore{0.};
 
     mapMsgCmdSize mapSendBytesPerMsgCmd GUARDED_BY(cs_vSend);
     mapMsgCmdSize mapRecvBytesPerMsgCmd GUARDED_BY(cs_vRecv);
 };
 
 /**
  * Interface for message handling
  */
 class NetEventsInterface {
 public:
     /**
      * Mutex for anything that is only accessed via the msg processing thread
      */
     static Mutex g_msgproc_mutex;
 
     /** Initialize a peer (setup state, queue any initial messages) */
     virtual void InitializeNode(const Config &config, CNode &node,
                                 ServiceFlags our_services) = 0;
 
     /** Handle removal of a peer (clear state) */
     virtual void FinalizeNode(const Config &config, const CNode &node) = 0;
 
     /**
      * Process protocol messages received from a given node
      *
      * @param[in]   config          The applicable configuration object.
      * @param[in]   pnode           The node which we have received messages
      * from.
      * @param[in]   interrupt       Interrupt condition for processing threads
      * @return                      True if there is more work to be done
      */
     virtual bool ProcessMessages(const Config &config, CNode *pnode,
                                  std::atomic<bool> &interrupt)
         EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex) = 0;
 
     /**
      * Send queued protocol messages to a given node.
      *
      * @param[in]   config          The applicable configuration object.
      * @param[in]   pnode           The node which we are sending messages to.
      * @return                      True if there is more work to be done
      */
     virtual bool SendMessages(const Config &config, CNode *pnode)
         EXCLUSIVE_LOCKS_REQUIRED(g_msgproc_mutex) = 0;
 
 protected:
     /**
      * Protected destructor so that instances can only be deleted by derived
      * classes. If that restriction is no longer desired, this should be made
      * public and virtual.
      */
     ~NetEventsInterface() = default;
 };
 
 namespace {
 struct CConnmanTest;
 }
 
 class NetEventsInterface;
 class CConnman {
 public:
     enum NumConnections {
         CONNECTIONS_NONE = 0,
         CONNECTIONS_IN = (1U << 0),
         CONNECTIONS_OUT = (1U << 1),
         CONNECTIONS_ALL = (CONNECTIONS_IN | CONNECTIONS_OUT),
     };
 
     struct Options {
         ServiceFlags nLocalServices = NODE_NONE;
         int nMaxConnections = 0;
         int m_max_outbound_full_relay = 0;
         int m_max_outbound_block_relay = 0;
         int m_max_avalanche_outbound = 0;
         int nMaxAddnode = 0;
         int nMaxFeeler = 0;
         CClientUIInterface *uiInterface = nullptr;
         std::vector<NetEventsInterface *> m_msgproc;
         BanMan *m_banman = nullptr;
         unsigned int nSendBufferMaxSize = 0;
         unsigned int nReceiveFloodSize = 0;
         uint64_t nMaxOutboundLimit = 0;
         int64_t m_peer_connect_timeout = DEFAULT_PEER_CONNECT_TIMEOUT;
         std::vector<std::string> vSeedNodes;
         std::vector<NetWhitelistPermissions> vWhitelistedRange;
         std::vector<NetWhitebindPermissions> vWhiteBinds;
         std::vector<CService> vBinds;
         std::vector<CService> onion_binds;
         /// True if the user did not specify -bind= or -whitebind= and thus
         /// we should bind on `0.0.0.0` (IPv4) and `::` (IPv6).
         bool bind_on_any;
         bool m_use_addrman_outgoing = true;
         std::vector<std::string> m_specified_outgoing;
         std::vector<std::string> m_added_nodes;
         bool m_i2p_accept_incoming = true;
     };
 
     void Init(const Options &connOptions)
         EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex) {
         nLocalServices = connOptions.nLocalServices;
         nMaxConnections = connOptions.nMaxConnections;
         m_use_addrman_outgoing = connOptions.m_use_addrman_outgoing;
         nMaxAddnode = connOptions.nMaxAddnode;
         nMaxFeeler = connOptions.nMaxFeeler;
         {
             // Lock cs_main to prevent a potential race with the peer validation
             // logic thread.
             LOCK(::cs_main);
             m_max_outbound_full_relay =
                 std::min(connOptions.m_max_outbound_full_relay,
                          connOptions.nMaxConnections);
             m_max_avalanche_outbound = connOptions.m_max_avalanche_outbound;
             m_max_outbound_block_relay = connOptions.m_max_outbound_block_relay;
             m_max_outbound = m_max_outbound_full_relay +
                              m_max_outbound_block_relay + nMaxFeeler +
                              m_max_avalanche_outbound;
         }
         m_client_interface = connOptions.uiInterface;
         m_banman = connOptions.m_banman;
         m_msgproc = connOptions.m_msgproc;
         nSendBufferMaxSize = connOptions.nSendBufferMaxSize;
         nReceiveFloodSize = connOptions.nReceiveFloodSize;
         m_peer_connect_timeout =
             std::chrono::seconds{connOptions.m_peer_connect_timeout};
         {
             LOCK(cs_totalBytesSent);
             nMaxOutboundLimit = connOptions.nMaxOutboundLimit;
         }
         vWhitelistedRange = connOptions.vWhitelistedRange;
         {
             LOCK(m_added_nodes_mutex);
             m_added_nodes = connOptions.m_added_nodes;
         }
         m_onion_binds = connOptions.onion_binds;
     }
 
     CConnman(const Config &configIn, uint64_t seed0, uint64_t seed1,
              AddrMan &addrmanIn, bool network_active = true);
     ~CConnman();
 
     bool Start(CScheduler &scheduler, const Options &options)
         EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex, !m_addr_fetches_mutex,
                                  !mutexMsgProc);
 
     void StopThreads();
     void StopNodes();
     void Stop() {
         StopThreads();
         StopNodes();
     };
 
     void Interrupt() EXCLUSIVE_LOCKS_REQUIRED(!mutexMsgProc);
     bool GetNetworkActive() const { return fNetworkActive; };
     bool GetUseAddrmanOutgoing() const { return m_use_addrman_outgoing; };
     void SetNetworkActive(bool active);
     void OpenNetworkConnection(const CAddress &addrConnect, bool fCountFailure,
                                CSemaphoreGrant *grantOutbound,
                                const char *strDest, ConnectionType conn_type);
     bool CheckIncomingNonce(uint64_t nonce);
 
     bool ForNode(NodeId id, std::function<bool(CNode *pnode)> func);
 
     void PushMessage(CNode *pnode, CSerializedNetMsg &&msg);
 
     using NodeFn = std::function<void(CNode *)>;
     void ForEachNode(const NodeFn &func) {
         LOCK(m_nodes_mutex);
         for (auto &&node : m_nodes) {
             if (NodeFullyConnected(node)) {
                 func(node);
             }
         }
     };
 
     void ForEachNode(const NodeFn &func) const {
         LOCK(m_nodes_mutex);
         for (auto &&node : m_nodes) {
             if (NodeFullyConnected(node)) {
                 func(node);
             }
         }
     };
 
     // Addrman functions
     /**
      * Return all or many randomly selected addresses, optionally by network.
      *
      * @param[in] max_addresses  Maximum number of addresses to return
      *                           (0 = all).
      * @param[in] max_pct        Maximum percentage of addresses to return
      *                           (0 = all).
      * @param[in] network        Select only addresses of this network
      *                           (nullopt = all).
      */
     std::vector<CAddress> GetAddresses(size_t max_addresses, size_t max_pct,
                                        std::optional<Network> network) const;
     /**
      * Cache is used to minimize topology leaks, so it should
      * be used for all non-trusted calls, for example, p2p.
      * A non-malicious call (from RPC or a peer with addr permission) should
      * call the function without a parameter to avoid using the cache.
      */
     std::vector<CAddress> GetAddresses(CNode &requestor, size_t max_addresses,
                                        size_t max_pct);
 
     // This allows temporarily exceeding m_max_outbound_full_relay, with the
     // goal of finding a peer that is better than all our current peers.
     void SetTryNewOutboundPeer(bool flag);
     bool GetTryNewOutboundPeer() const;
 
     void StartExtraBlockRelayPeers() {
         LogPrint(BCLog::NET, "net: enabling extra block-relay-only peers\n");
         m_start_extra_block_relay_peers = true;
     }
 
     // Return the number of outbound peers we have in excess of our target (eg,
     // if we previously called SetTryNewOutboundPeer(true), and have since set
     // to false, we may have extra peers that we wish to disconnect). This may
     // return a value less than (num_outbound_connections - num_outbound_slots)
     // in cases where some outbound connections are not yet fully connected, or
     // not yet fully disconnected.
     int GetExtraFullOutboundCount() const;
     // Count the number of block-relay-only peers we have over our limit.
     int GetExtraBlockRelayCount() const;
 
     bool AddNode(const std::string &node)
         EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex);
     bool RemoveAddedNode(const std::string &node)
         EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex);
     std::vector<AddedNodeInfo> GetAddedNodeInfo() const
         EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex);
 
     /**
      * Attempts to open a connection. Currently only used from tests.
      *
      * @param[in]   address     Address of node to try connecting to
      * @param[in]   conn_type   ConnectionType::OUTBOUND,
      *                          ConnectionType::BLOCK_RELAY,
      *                          ConnectionType::ADDR_FETCH, or
      *                          ConnectionType::FEELER
      * @return      bool        Returns false if there are no available
      *                          slots for this connection:
      *                          - conn_type not a supported ConnectionType
      *                          - Max total outbound connection capacity filled
      *                          - Max connection capacity for type is filled
      */
     bool AddConnection(const std::string &address, ConnectionType conn_type);
 
     size_t GetNodeCount(NumConnections num) const;
     void GetNodeStats(std::vector<CNodeStats> &vstats) const;
     bool DisconnectNode(const std::string &node);
     bool DisconnectNode(const CSubNet &subnet);
     bool DisconnectNode(const CNetAddr &addr);
     bool DisconnectNode(NodeId id);
 
     //! Used to convey which local services we are offering peers during node
     //! connection.
     //!
     //! The data returned by this is used in CNode construction,
     //! which is used to advertise which services we are offering
     //! that peer during `net_processing.cpp:PushNodeVersion()`.
     ServiceFlags GetLocalServices() const;
 
     uint64_t GetMaxOutboundTarget() const;
     std::chrono::seconds GetMaxOutboundTimeframe() const;
 
     //! check if the outbound target is reached. If param
     //! historicalBlockServingLimit is set true, the function will response true
     //! if the limit for serving historical blocks has been reached.
     bool OutboundTargetReached(bool historicalBlockServingLimit) const;
 
     //! response the bytes left in the current max outbound cycle in case of no
     //! limit, it will always response 0
     uint64_t GetOutboundTargetBytesLeft() const;
 
     //! returns the time in second left in the current max outbound cycle in
     //! case of no limit, it will always return 0
     std::chrono::seconds GetMaxOutboundTimeLeftInCycle() const;
 
     uint64_t GetTotalBytesRecv() const;
     uint64_t GetTotalBytesSent() const;
 
     /** Get a unique deterministic randomizer. */
     CSipHasher GetDeterministicRandomizer(uint64_t id) const;
 
     unsigned int GetReceiveFloodSize() const;
 
     void WakeMessageHandler() EXCLUSIVE_LOCKS_REQUIRED(!mutexMsgProc);
 
     /**
      * Return true if we should disconnect the peer for failing an inactivity
      * check.
      */
     bool ShouldRunInactivityChecks(const CNode &node,
                                    std::chrono::seconds now) const;
 
 private:
     struct ListenSocket {
     public:
         SOCKET socket;
         inline void AddSocketPermissionFlags(NetPermissionFlags &flags) const {
             NetPermissions::AddFlag(flags, m_permissions);
         }
         ListenSocket(SOCKET socket_, NetPermissionFlags permissions_)
             : socket(socket_), m_permissions(permissions_) {}
 
     private:
         NetPermissionFlags m_permissions;
     };
 
     bool BindListenPort(const CService &bindAddr, bilingual_str &strError,
                         NetPermissionFlags permissions);
     bool Bind(const CService &addr, unsigned int flags,
               NetPermissionFlags permissions);
     bool InitBinds(const Options &options);
 
     void ThreadOpenAddedConnections()
         EXCLUSIVE_LOCKS_REQUIRED(!m_added_nodes_mutex);
     void AddAddrFetch(const std::string &strDest)
         EXCLUSIVE_LOCKS_REQUIRED(!m_addr_fetches_mutex);
     void ProcessAddrFetch() EXCLUSIVE_LOCKS_REQUIRED(!m_addr_fetches_mutex);
     void
     ThreadOpenConnections(std::vector<std::string> connect,
                           std::function<void(const CAddress &, ConnectionType)>
                               mockOpenConnection)
         EXCLUSIVE_LOCKS_REQUIRED(!m_addr_fetches_mutex, !m_added_nodes_mutex,
                                  !m_nodes_mutex);
     void ThreadMessageHandler() EXCLUSIVE_LOCKS_REQUIRED(!mutexMsgProc);
     void ThreadI2PAcceptIncoming();
     void AcceptConnection(const ListenSocket &hListenSocket);
 
     /**
      * Create a `CNode` object from a socket that has just been accepted and add
      * the node to the `m_nodes` member.
      * @param[in] hSocket Connected socket to communicate with the peer.
      * @param[in] permissionFlags The peer's permissions.
      * @param[in] addr_bind The address and port at our side of the connection.
      * @param[in] addr The address and port at the peer's side of the connection
      */
     void CreateNodeFromAcceptedSocket(SOCKET hSocket,
                                       NetPermissionFlags permissionFlags,
                                       const CAddress &addr_bind,
                                       const CAddress &addr);
 
     void DisconnectNodes();
     void NotifyNumConnectionsChanged();
     /** Return true if the peer is inactive and should be disconnected. */
     bool InactivityCheck(const CNode &node) const;
     bool GenerateSelectSet(std::set<SOCKET> &recv_set,
                            std::set<SOCKET> &send_set,
                            std::set<SOCKET> &error_set);
     void SocketEvents(std::set<SOCKET> &recv_set, std::set<SOCKET> &send_set,
                       std::set<SOCKET> &error_set);
     void SocketHandler() EXCLUSIVE_LOCKS_REQUIRED(!mutexMsgProc);
     void ThreadSocketHandler() EXCLUSIVE_LOCKS_REQUIRED(!mutexMsgProc);
     void ThreadDNSAddressSeed()
         EXCLUSIVE_LOCKS_REQUIRED(!m_addr_fetches_mutex, !m_nodes_mutex);
 
     uint64_t CalculateKeyedNetGroup(const CAddress &ad) const;
 
     CNode *FindNode(const CNetAddr &ip);
     CNode *FindNode(const CSubNet &subNet);
     CNode *FindNode(const std::string &addrName);
     CNode *FindNode(const CService &addr);
 
     /**
      * Determine whether we're already connected to a given address, in order to
      * avoid initiating duplicate connections.
      */
     bool AlreadyConnectedToAddress(const CAddress &addr);
 
     bool AttemptToEvictConnection();
     CNode *ConnectNode(CAddress addrConnect, const char *pszDest,
                        bool fCountFailure, ConnectionType conn_type);
     void AddWhitelistPermissionFlags(NetPermissionFlags &flags,
                                      const CNetAddr &addr) const;
 
     void DeleteNode(CNode *pnode);
 
     NodeId GetNewNodeId();
 
     size_t SocketSendData(CNode &node) const
         EXCLUSIVE_LOCKS_REQUIRED(node.cs_vSend);
     void DumpAddresses();
 
     // Network stats
     void RecordBytesRecv(uint64_t bytes);
     void RecordBytesSent(uint64_t bytes);
 
     /**
      * Return vector of current BLOCK_RELAY peers.
      */
     std::vector<CAddress> GetCurrentBlockRelayOnlyConns() const;
 
     // Whether the node should be passed out in ForEach* callbacks
     static bool NodeFullyConnected(const CNode *pnode);
 
     const Config *config;
 
     // Network usage totals
     mutable RecursiveMutex cs_totalBytesSent;
     std::atomic<uint64_t> nTotalBytesRecv{0};
     uint64_t nTotalBytesSent GUARDED_BY(cs_totalBytesSent){0};
 
     // outbound limit & stats
     uint64_t nMaxOutboundTotalBytesSentInCycle GUARDED_BY(cs_totalBytesSent){0};
     std::chrono::seconds
         nMaxOutboundCycleStartTime GUARDED_BY(cs_totalBytesSent){0};
     uint64_t nMaxOutboundLimit GUARDED_BY(cs_totalBytesSent);
 
     // P2P timeout in seconds
     std::chrono::seconds m_peer_connect_timeout;
 
     // Whitelisted ranges. Any node connecting from these is automatically
     // whitelisted (as well as those connecting to whitelisted binds).
     std::vector<NetWhitelistPermissions> vWhitelistedRange;
 
     unsigned int nSendBufferMaxSize{0};
     unsigned int nReceiveFloodSize{0};
 
     std::vector<ListenSocket> vhListenSocket;
     std::atomic<bool> fNetworkActive{true};
     bool fAddressesInitialized{false};
     AddrMan &addrman;
     std::deque<std::string> m_addr_fetches GUARDED_BY(m_addr_fetches_mutex);
     Mutex m_addr_fetches_mutex;
     std::vector<std::string> m_added_nodes GUARDED_BY(m_added_nodes_mutex);
     mutable Mutex m_added_nodes_mutex;
     std::vector<CNode *> m_nodes GUARDED_BY(m_nodes_mutex);
     std::list<CNode *> m_nodes_disconnected;
     mutable RecursiveMutex m_nodes_mutex;
     std::atomic<NodeId> nLastNodeId{0};
     unsigned int nPrevNodeCount{0};
 
     /**
      * Cache responses to addr requests to minimize privacy leak.
      * Attack example: scraping addrs in real-time may allow an attacker
      * to infer new connections of the victim by detecting new records
      * with fresh timestamps (per self-announcement).
      */
     struct CachedAddrResponse {
         std::vector<CAddress> m_addrs_response_cache;
         std::chrono::microseconds m_cache_entry_expiration{0};
     };
 
     /**
      * Addr responses stored in different caches
      * per (network, local socket) prevent cross-network node identification.
      * If a node for example is multi-homed under Tor and IPv6,
      * a single cache (or no cache at all) would let an attacker
      * to easily detect that it is the same node by comparing responses.
      * Indexing by local socket prevents leakage when a node has multiple
      * listening addresses on the same network.
      *
      * The used memory equals to 1000 CAddress records (or around 40 bytes) per
      * distinct Network (up to 5) we have/had an inbound peer from,
      * resulting in at most ~196 KB. Every separate local socket may
      * add up to ~196 KB extra.
      */
     std::map<uint64_t, CachedAddrResponse> m_addr_response_caches;
 
     /**
      * Services this node offers.
      *
      * This data is replicated in each Peer instance we create.
      *
      * This data is not marked const, but after being set it should not
      * change.
      *
      * \sa Peer::m_our_services
      */
     ServiceFlags nLocalServices;
 
     std::unique_ptr<CSemaphore> semOutbound;
     std::unique_ptr<CSemaphore> semAddnode;
     int nMaxConnections;
 
     // How many full-relay (tx, block, addr) outbound peers we want
     int m_max_outbound_full_relay;
 
     // How many block-relay only outbound peers we want
     // We do not relay tx or addr messages with these peers
     int m_max_outbound_block_relay;
 
     // How many avalanche enabled outbound peers we want
     int m_max_avalanche_outbound;
 
     int nMaxAddnode;
     int nMaxFeeler;
     int m_max_outbound;
     bool m_use_addrman_outgoing;
     CClientUIInterface *m_client_interface;
     // FIXME m_msgproc is a terrible name
     std::vector<NetEventsInterface *> m_msgproc;
     /**
      * Pointer to this node's banman. May be nullptr - check existence before
      * dereferencing.
      */
     BanMan *m_banman;
 
     /**
      * Addresses that were saved during the previous clean shutdown. We'll
      * attempt to make block-relay-only connections to them.
      */
     std::vector<CAddress> m_anchors;
 
     /** SipHasher seeds for deterministic randomness */
     const uint64_t nSeed0, nSeed1;
 
     /** flag for waking the message processor. */
     bool fMsgProcWake GUARDED_BY(mutexMsgProc);
 
     std::condition_variable condMsgProc;
     Mutex mutexMsgProc;
     std::atomic<bool> flagInterruptMsgProc{false};
 
     /**
      * This is signaled when network activity should cease.
      * A pointer to it is saved in `m_i2p_sam_session`, so make sure that
      * the lifetime of `interruptNet` is not shorter than
      * the lifetime of `m_i2p_sam_session`.
      */
     CThreadInterrupt interruptNet;
 
     /**
      * I2P SAM session.
      * Used to accept incoming and make outgoing I2P connections.
      */
     std::unique_ptr<i2p::sam::Session> m_i2p_sam_session;
 
     std::thread threadDNSAddressSeed;
     std::thread threadSocketHandler;
     std::thread threadOpenAddedConnections;
     std::thread threadOpenConnections;
     std::thread threadMessageHandler;
     std::thread threadI2PAcceptIncoming;
 
     /**
      * flag for deciding to connect to an extra outbound peer, in excess of
      * m_max_outbound_full_relay. This takes the place of a feeler connection.
      */
     std::atomic_bool m_try_another_outbound_peer;
 
     /**
      * flag for initiating extra block-relay-only peer connections.
      * this should only be enabled after initial chain sync has occurred,
      * as these connections are intended to be short-lived and low-bandwidth.
      */
     std::atomic_bool m_start_extra_block_relay_peers{false};
 
     /**
      * A vector of -bind=<address>:<port>=onion arguments each of which is
      * an address and port that are designated for incoming Tor connections.
      */
     std::vector<CService> m_onion_binds;
 
     friend struct ::CConnmanTest;
     friend struct ConnmanTestMsg;
 };
 
 std::string getSubVersionEB(uint64_t MaxBlockSize);
 std::string userAgent(const Config &config);
 
 /** Dump binary message to file, with timestamp */
 void CaptureMessageToFile(const CAddress &addr, const std::string &msg_type,
                           Span<const uint8_t> data, bool is_incoming);
 
 /**
  * Defaults to `CaptureMessageToFile()`, but can be overridden by unit tests.
  */
 extern std::function<void(const CAddress &addr, const std::string &msg_type,
                           Span<const uint8_t> data, bool is_incoming)>
     CaptureMessage;
 
 struct NodeEvictionCandidate {
     NodeId id;
     std::chrono::seconds m_connected;
     std::chrono::microseconds m_min_ping_time;
     std::chrono::seconds m_last_block_time;
     std::chrono::seconds m_last_proof_time;
     std::chrono::seconds m_last_tx_time;
     bool fRelevantServices;
     bool m_relay_txs;
     bool fBloomFilter;
     uint64_t nKeyedNetGroup;
     bool prefer_evict;
     bool m_is_local;
     Network m_network;
     double availabilityScore;
 };
 
 /**
  * Select an inbound peer to evict after filtering out (protecting) peers having
  * distinct, difficult-to-forge characteristics. The protection logic picks out
  * fixed numbers of desirable peers per various criteria, followed by (mostly)
  * ratios of desirable or disadvantaged peers. If any eviction candidates
  * remain, the selection logic chooses a peer to evict.
  */
 [[nodiscard]] std::optional<NodeId>
 SelectNodeToEvict(std::vector<NodeEvictionCandidate> &&vEvictionCandidates);
 
 /**
  * Protect desirable or disadvantaged inbound peers from eviction by ratio.
  *
  * This function protects half of the peers which have been connected the
  * longest, to replicate the non-eviction implicit behavior and preclude attacks
  * that start later.
  *
  * Half of these protected spots (1/4 of the total) are reserved for the
  * following categories of peers, sorted by longest uptime, even if they're not
  * longest uptime overall:
  *
  * - onion peers connected via our tor control service
  *
  * - localhost peers, as manually configured hidden services not using
  *   `-bind=addr[:port]=onion` will not be detected as inbound onion connections
  *
  * - I2P peers
  *
  * This helps protect these privacy network peers, which tend to be otherwise
  * disadvantaged under our eviction criteria for their higher min ping times
  * relative to IPv4/IPv6 peers, and favorise the diversity of peer connections.
  */
 void ProtectEvictionCandidatesByRatio(
     std::vector<NodeEvictionCandidate> &vEvictionCandidates);
 
 #endif // BITCOIN_NET_H
diff --git a/src/node/blockstorage.h b/src/node/blockstorage.h
index e0fb1b922..4fdd7eb4c 100644
--- a/src/node/blockstorage.h
+++ b/src/node/blockstorage.h
@@ -1,247 +1,246 @@
 // Copyright (c) 2011-2021 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_NODE_BLOCKSTORAGE_H
 #define BITCOIN_NODE_BLOCKSTORAGE_H
 
 #include <cstdint>
 #include <vector>
 
 #include <chain.h>
 #include <fs.h>
+#include <kernel/cs_main.h>
 #include <protocol.h> // For CMessageHeader::MessageStartChars
 #include <sync.h>
 #include <txdb.h>
 
-extern RecursiveMutex cs_main;
-
 class ArgsManager;
 class BlockValidationState;
 class CBlock;
 class CBlockFileInfo;
 class CBlockHeader;
 class CBlockUndo;
 class CChain;
 class CChainParams;
 class CTxUndo;
 class Chainstate;
 class ChainstateManager;
 struct CCheckpointData;
 class Config;
 struct FlatFilePos;
 namespace Consensus {
 struct Params;
 }
 
 namespace node {
 static constexpr bool DEFAULT_STOPAFTERBLOCKIMPORT{false};
 
 /** The pre-allocation chunk size for blk?????.dat files (since 0.8) */
 static constexpr unsigned int BLOCKFILE_CHUNK_SIZE = 0x1000000; // 16 MiB
 /** The pre-allocation chunk size for rev?????.dat files (since 0.8) */
 static const unsigned int UNDOFILE_CHUNK_SIZE = 0x100000; // 1 MiB
 /** The maximum size of a blk?????.dat file (since 0.8) */
 static const unsigned int MAX_BLOCKFILE_SIZE = 0x8000000; // 128 MiB
 
 /** Size of header written by WriteBlockToDisk before a serialized CBlock */
 static constexpr size_t BLOCK_SERIALIZATION_HEADER_SIZE =
     CMessageHeader::MESSAGE_START_SIZE + sizeof(unsigned int);
 
 extern std::atomic_bool fImporting;
 extern std::atomic_bool fReindex;
 extern bool fPruneMode;
 extern uint64_t nPruneTarget;
 
 // Because validation code takes pointers to the map's CBlockIndex objects, if
 // we ever switch to another associative container, we need to either use a
 // container that has stable addressing (true of all std associative
 // containers), or make the key a `std::unique_ptr<CBlockIndex>`
 using BlockMap = std::unordered_map<BlockHash, CBlockIndex, BlockHasher>;
 
 /**
  * Maintains a tree of blocks (stored in `m_block_index`) which is consulted
  * to determine where the most-work tip is.
  *
  * This data is used mostly in `Chainstate` - information about, e.g.,
  * candidate tips is not maintained here.
  */
 class BlockManager {
     friend Chainstate;
     friend ChainstateManager;
 
 private:
     /**
      * Load the blocktree off disk and into memory. Populate certain metadata
      * per index entry (nStatus, nChainWork, nTimeMax, etc.) as well as
      * peripheral collections like m_dirty_blockindex.
      */
     bool LoadBlockIndex(const Consensus::Params &consensus_params)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     void FlushBlockFile(bool fFinalize = false, bool finalize_undo = false);
     void FlushUndoFile(int block_file, bool finalize = false);
     bool FindBlockPos(FlatFilePos &pos, unsigned int nAddSize,
                       unsigned int nHeight, CChain &active_chain,
                       uint64_t nTime, bool fKnown);
     bool FindUndoPos(BlockValidationState &state, int nFile, FlatFilePos &pos,
                      unsigned int nAddSize);
 
     /**
      * Calculate the block/rev files to delete based on height specified
      * by user with RPC command pruneblockchain
      */
     void FindFilesToPruneManual(std::set<int> &setFilesToPrune,
                                 int nManualPruneHeight, int chain_tip_height);
 
     /**
      * Prune block and undo files (blk???.dat and undo???.dat) so that the disk
      * space used is less than a user-defined target. The user sets the target
      * (in MB) on the command line or in config file.  This will be run on
      * startup and whenever new space is allocated in a block or undo file,
      * staying below the target. Changing back to unpruned requires a reindex
      * (which in this case means the blockchain must be re-downloaded.)
      *
      * Pruning functions are called from FlushStateToDisk when the
      * m_check_for_pruning flag has been set. Block and undo files are deleted
      * in lock-step (when blk00003.dat is deleted, so is rev00003.dat.) Pruning
      * cannot take place until the longest chain is at least a certain length
      * (CChainParams::nPruneAfterHeight). Pruning will never delete a block
      * within a defined distance (currently 288) from the active chain's tip.
      * The block index is updated by unsetting HAVE_DATA and HAVE_UNDO for any
      * blocks that were stored in the deleted files. A db flag records the fact
      * that at least some block files have been pruned.
      *
      * @param[out]   setFilesToPrune   The set of file indices that can be
      *                                 unlinked will be returned
      */
     void FindFilesToPrune(std::set<int> &setFilesToPrune,
                           uint64_t nPruneAfterHeight, int chain_tip_height,
                           int prune_height, bool is_ibd);
 
     RecursiveMutex cs_LastBlockFile;
     std::vector<CBlockFileInfo> m_blockfile_info;
     int m_last_blockfile = 0;
     /**
      * Global flag to indicate we should check to see if there are
      * block/undo files that should be deleted.  Set on startup
      * or if we allocate more file space when we're in prune mode
      */
     bool m_check_for_pruning = false;
 
     /** Dirty block index entries. */
     std::set<CBlockIndex *> m_dirty_blockindex;
 
     /** Dirty block file entries. */
     std::set<int> m_dirty_fileinfo;
 
 public:
     BlockMap m_block_index GUARDED_BY(cs_main);
 
     std::vector<CBlockIndex *> GetAllBlockIndices()
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     /**
      * All pairs A->B, where A (or one of its ancestors) misses transactions,
      * but B has transactions. Pruned nodes may have entries where B is missing
      * data.
      */
     std::multimap<CBlockIndex *, CBlockIndex *> m_blocks_unlinked;
 
     std::unique_ptr<CBlockTreeDB> m_block_tree_db GUARDED_BY(::cs_main);
 
     bool WriteBlockIndexDB() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
     bool LoadBlockIndexDB(const Consensus::Params &consensus_params)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     CBlockIndex *AddToBlockIndex(const CBlockHeader &block,
                                  CBlockIndex *&best_header)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     /** Create a new block index entry for a given block hash */
     CBlockIndex *InsertBlockIndex(const BlockHash &hash)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     //! Mark one block file as pruned (modify associated database entries)
     void PruneOneBlockFile(const int fileNumber)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     CBlockIndex *LookupBlockIndex(const BlockHash &hash)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     const CBlockIndex *LookupBlockIndex(const BlockHash &hash) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** Get block file info entry for one block file */
     CBlockFileInfo *GetBlockFileInfo(size_t n);
 
     bool WriteUndoDataForBlock(const CBlockUndo &blockundo,
                                BlockValidationState &state, CBlockIndex *pindex,
                                const CChainParams &chainparams)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     /**
      * Store block on disk. If dbp is not nullptr, then it provides the known
      * position of the block within a block file on disk.
      */
     FlatFilePos SaveBlockToDisk(const CBlock &block, int nHeight,
                                 CChain &active_chain,
                                 const CChainParams &chainparams,
                                 const FlatFilePos *dbp);
 
     /** Whether running in -prune mode. */
     [[nodiscard]] bool IsPruneMode() const { return fPruneMode; }
 
     /** Attempt to stay below this number of bytes of block files. */
     [[nodiscard]] uint64_t GetPruneTarget() const { return nPruneTarget; }
 
     [[nodiscard]] bool LoadingBlocks() const { return fImporting || fReindex; }
 
     /**
      * Calculate the amount of disk space the block & undo files currently use
      */
     uint64_t CalculateCurrentUsage();
 
     //! Returns last CBlockIndex* that is a checkpoint
     const CBlockIndex *GetLastCheckpoint(const CCheckpointData &data)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** True if any block files have ever been pruned. */
     bool m_have_pruned = false;
 
     //! Check whether the block associated with this index entry is pruned or
     //! not.
     bool IsBlockPruned(const CBlockIndex *pblockindex)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 };
 
 //! Find the first block that is not pruned
 const CBlockIndex *GetFirstStoredBlock(const CBlockIndex *start_block)
     EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
 void CleanupBlockRevFiles();
 
 /** Open a block file (blk?????.dat) */
 FILE *OpenBlockFile(const FlatFilePos &pos, bool fReadOnly = false);
 /** Translation to a filesystem path. */
 fs::path GetBlockPosFilename(const FlatFilePos &pos);
 
 /**
  *  Actually unlink the specified files
  */
 void UnlinkPrunedFiles(const std::set<int> &setFilesToPrune);
 
 /** Functions for disk access for blocks */
 bool ReadBlockFromDisk(CBlock &block, const FlatFilePos &pos,
                        const Consensus::Params &consensusParams);
 bool ReadBlockFromDisk(CBlock &block, const CBlockIndex *pindex,
                        const Consensus::Params &consensusParams);
 bool UndoReadFromDisk(CBlockUndo &blockundo, const CBlockIndex *pindex);
 
 /** Functions for disk access for txs */
 bool ReadTxFromDisk(CMutableTransaction &tx, const FlatFilePos &pos);
 bool ReadTxUndoFromDisk(CTxUndo &tx, const FlatFilePos &pos);
 
 void ThreadImport(const Config &config, ChainstateManager &chainman,
                   std::vector<fs::path> vImportFiles, const ArgsManager &args,
                   const fs::path &mempool_path);
 } // namespace node
 
 #endif // BITCOIN_NODE_BLOCKSTORAGE_H
diff --git a/src/node/utxo_snapshot.h b/src/node/utxo_snapshot.h
index 68fc40126..aca97d11a 100644
--- a/src/node/utxo_snapshot.h
+++ b/src/node/utxo_snapshot.h
@@ -1,70 +1,68 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_NODE_UTXO_SNAPSHOT_H
 #define BITCOIN_NODE_UTXO_SNAPSHOT_H
 
 #include <fs.h>
 #include <primitives/blockhash.h>
 #include <serialize.h>
 #include <validation.h>
 
 #include <optional>
 
 struct BlockHash;
 
-extern RecursiveMutex cs_main;
-
 namespace node {
 //! Metadata describing a serialized version of a UTXO set from which an
 //! assumeutxo Chainstate can be constructed.
 class SnapshotMetadata {
 public:
     //! The hash of the block that reflects the tip of the chain for the
     //! UTXO set contained in this snapshot.
     BlockHash m_base_blockhash;
 
     //! The number of coins in the UTXO set contained in this snapshot. Used
     //! during snapshot load to estimate progress of UTXO set reconstruction.
     uint64_t m_coins_count = 0;
 
     SnapshotMetadata() {}
     SnapshotMetadata(const BlockHash &base_blockhash, uint64_t coins_count,
                      uint64_t nchaintx)
         : m_base_blockhash(base_blockhash), m_coins_count(coins_count) {}
 
     SERIALIZE_METHODS(SnapshotMetadata, obj) {
         READWRITE(obj.m_base_blockhash, obj.m_coins_count);
     }
 };
 
 //! The file in the snapshot chainstate dir which stores the base blockhash.
 //! This is needed to reconstruct snapshot chainstates on init.
 //!
 //! Because we only allow loading a single snapshot at a time, there will only
 //! be one chainstate directory with this filename present within it.
 const fs::path SNAPSHOT_BLOCKHASH_FILENAME{"base_blockhash"};
 
 //! Write out the blockhash of the snapshot base block that was used to
 //! construct this chainstate. This value is read in during subsequent
 //! initializations and used to reconstruct snapshot-based chainstates.
 bool WriteSnapshotBaseBlockhash(Chainstate &snapshot_chainstate)
     EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
 //! Read the blockhash of the snapshot base block that was used to construct the
 //! chainstate.
 std::optional<BlockHash> ReadSnapshotBaseBlockhash(const fs::path &chaindir)
     EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
 //! Suffix appended to the chainstate (leveldb) dir when created based upon
 //! a snapshot.
 constexpr std::string_view SNAPSHOT_CHAINSTATE_SUFFIX = "_snapshot";
 
 //! Return a path to the snapshot-based chainstate dir, if one exists.
 std::optional<fs::path> FindSnapshotChainstateDir();
 
 } // namespace node
 
 #endif // BITCOIN_NODE_UTXO_SNAPSHOT_H
diff --git a/src/rpc/blockchain.h b/src/rpc/blockchain.h
index 6865cea46..b888e56f7 100644
--- a/src/rpc/blockchain.h
+++ b/src/rpc/blockchain.h
@@ -1,58 +1,56 @@
 // Copyright (c) 2017-2019 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_RPC_BLOCKCHAIN_H
 #define BITCOIN_RPC_BLOCKCHAIN_H
 
 #include <fs.h>
 #include <streams.h>
 #include <sync.h>
 #include <validation.h>
 
 #include <univalue.h>
 
 #include <any>
 
 class CBlock;
 class CBlockIndex;
 class Chainstate;
 class RPCHelpMan;
 namespace node {
 struct NodeContext;
 } // namespace node
 
-extern RecursiveMutex cs_main;
-
 RPCHelpMan getblockchaininfo();
 
 /**
  * Get the required difficulty of the next block w/r/t the given block index.
  *
  * @return A floating point number that is a multiple of the main net minimum
  * difficulty (4295032833 hashes).
  */
 double GetDifficulty(const CBlockIndex *blockindex);
 
 /** Callback for when block tip changed. */
 void RPCNotifyBlockChange(const CBlockIndex *pindex);
 
 /** Block description to JSON */
 UniValue blockToJSON(node::BlockManager &blockman, const CBlock &block,
                      const CBlockIndex *tip, const CBlockIndex *blockindex,
                      bool txDetails = false) LOCKS_EXCLUDED(cs_main);
 
 /** Block header to JSON */
 UniValue blockheaderToJSON(const CBlockIndex *tip,
                            const CBlockIndex *blockindex)
     LOCKS_EXCLUDED(cs_main);
 
 /**
  * Helper to create UTXO snapshots given a chainstate and a file handle.
  * @return a UniValue map containing metadata about the snapshot.
  */
 UniValue CreateUTXOSnapshot(node::NodeContext &node, Chainstate &chainstate,
                             AutoFile &afile, const fs::path &path,
                             const fs::path &tmppath);
 
 #endif // BITCOIN_RPC_BLOCKCHAIN_H
diff --git a/src/script/scriptcache.h b/src/script/scriptcache.h
index b41f7317e..ec83f69ad 100644
--- a/src/script/scriptcache.h
+++ b/src/script/scriptcache.h
@@ -1,66 +1,63 @@
 // Copyright (c) 2017 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_SCRIPT_SCRIPTCACHE_H
 #define BITCOIN_SCRIPT_SCRIPTCACHE_H
 
 #include <array>
 #include <cstdint>
 
+#include <kernel/cs_main.h>
 #include <sync.h>
 
-// Actually declared in validation.cpp; can't include because of circular
-// dependency.
-extern RecursiveMutex cs_main;
-
 class CTransaction;
 
 /**
  * The script cache is a map using a key/value element, that caches the
  * success of executing a specific transaction's input scripts under a
  * specific set of flags, along with any associated information learned
  * during execution.
  *
  * The key is slightly shorter than a power-of-two size to make room for
  * the value.
  */
 class ScriptCacheKey {
     std::array<uint8_t, 28> data;
 
 public:
     ScriptCacheKey() = default;
     ScriptCacheKey(const ScriptCacheKey &rhs) = default;
     ScriptCacheKey(const CTransaction &tx, uint32_t flags);
 
     ScriptCacheKey &operator=(const ScriptCacheKey &rhs) = default;
 
     bool operator==(const ScriptCacheKey &rhs) const {
         return rhs.data == data;
     }
 
     friend class ScriptCacheHasher;
 };
 
 // DoS prevention: limit cache size to 32MiB (over 1000000 entries on 64-bit
 // systems). Due to how we count cache size, actual memory usage is slightly
 // more (~32.25 MiB)
 static constexpr size_t DEFAULT_MAX_SCRIPT_CACHE_BYTES{32 << 20};
 
 /** Initializes the script-execution cache */
 [[nodiscard]] bool InitScriptExecutionCache(size_t max_size_bytes);
 
 /**
  * Check if a given key is in the cache, and if so, return its values.
  * (if not found, nSigChecks may or may not be set to an arbitrary value)
  */
 bool IsKeyInScriptCache(ScriptCacheKey key, bool erase, int &nSigChecksOut)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 /**
  * Add an entry in the cache.
  */
 void AddKeyInScriptCache(ScriptCacheKey key, int nSigChecks)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 #endif // BITCOIN_SCRIPT_SCRIPTCACHE_H
diff --git a/src/test/mempool_tests.cpp b/src/test/mempool_tests.cpp
index 41fd56539..e39bfeaf3 100644
--- a/src/test/mempool_tests.cpp
+++ b/src/test/mempool_tests.cpp
@@ -1,584 +1,584 @@
 // Copyright (c) 2011-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <txmempool.h>
 
 #include <kernel/disconnected_transactions.h>
 #include <kernel/mempool_entry.h>
 #include <policy/settings.h>
 #include <reverse_iterator.h>
 #include <util/system.h>
 #include <util/time.h>
 
 #include <test/util/setup_common.h>
 
 #include <boost/test/unit_test.hpp>
 
 #include <algorithm>
 #include <vector>
 
 BOOST_FIXTURE_TEST_SUITE(mempool_tests, TestingSetup)
 
 static constexpr auto REMOVAL_REASON_DUMMY = MemPoolRemovalReason::REPLACED;
 
 BOOST_AUTO_TEST_CASE(MempoolRemoveTest) {
     // Test CTxMemPool::remove functionality
 
     TestMemPoolEntryHelper entry;
     // Parent transaction with three children, and three grand-children:
     CMutableTransaction txParent;
     txParent.vin.resize(1);
     txParent.vin[0].scriptSig = CScript() << OP_11;
     txParent.vout.resize(3);
     for (int i = 0; i < 3; i++) {
         txParent.vout[i].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
         txParent.vout[i].nValue = 33000 * SATOSHI;
     }
     CMutableTransaction txChild[3];
     for (int i = 0; i < 3; i++) {
         txChild[i].vin.resize(1);
         txChild[i].vin[0].scriptSig = CScript() << OP_11;
         txChild[i].vin[0].prevout = COutPoint(txParent.GetId(), i);
         txChild[i].vout.resize(1);
         txChild[i].vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
         txChild[i].vout[0].nValue = 11000 * SATOSHI;
     }
     CMutableTransaction txGrandChild[3];
     for (int i = 0; i < 3; i++) {
         txGrandChild[i].vin.resize(1);
         txGrandChild[i].vin[0].scriptSig = CScript() << OP_11;
         txGrandChild[i].vin[0].prevout = COutPoint(txChild[i].GetId(), 0);
         txGrandChild[i].vout.resize(1);
         txGrandChild[i].vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
         txGrandChild[i].vout[0].nValue = 11000 * SATOSHI;
     }
 
     CTxMemPool &testPool = *Assert(m_node.mempool);
-    LOCK2(cs_main, testPool.cs);
+    LOCK2(::cs_main, testPool.cs);
 
     // Nothing in pool, remove should do nothing:
     unsigned int poolSize = testPool.size();
     testPool.removeRecursive(CTransaction(txParent), REMOVAL_REASON_DUMMY);
     BOOST_CHECK_EQUAL(testPool.size(), poolSize);
 
     // Just the parent:
     testPool.addUnchecked(entry.FromTx(txParent));
     poolSize = testPool.size();
     testPool.removeRecursive(CTransaction(txParent), REMOVAL_REASON_DUMMY);
     BOOST_CHECK_EQUAL(testPool.size(), poolSize - 1);
 
     // Parent, children, grandchildren:
     testPool.addUnchecked(entry.FromTx(txParent));
     for (int i = 0; i < 3; i++) {
         testPool.addUnchecked(entry.FromTx(txChild[i]));
         testPool.addUnchecked(entry.FromTx(txGrandChild[i]));
     }
     // Remove Child[0], GrandChild[0] should be removed:
     poolSize = testPool.size();
     testPool.removeRecursive(CTransaction(txChild[0]), REMOVAL_REASON_DUMMY);
     BOOST_CHECK_EQUAL(testPool.size(), poolSize - 2);
     // ... make sure grandchild and child are gone:
     poolSize = testPool.size();
     testPool.removeRecursive(CTransaction(txGrandChild[0]),
                              REMOVAL_REASON_DUMMY);
     BOOST_CHECK_EQUAL(testPool.size(), poolSize);
     poolSize = testPool.size();
     testPool.removeRecursive(CTransaction(txChild[0]), REMOVAL_REASON_DUMMY);
     BOOST_CHECK_EQUAL(testPool.size(), poolSize);
     // Remove parent, all children/grandchildren should go:
     poolSize = testPool.size();
     testPool.removeRecursive(CTransaction(txParent), REMOVAL_REASON_DUMMY);
     BOOST_CHECK_EQUAL(testPool.size(), poolSize - 5);
     BOOST_CHECK_EQUAL(testPool.size(), 0UL);
 
     // Add children and grandchildren, but NOT the parent (simulate the parent
     // being in a block)
     for (int i = 0; i < 3; i++) {
         testPool.addUnchecked(entry.FromTx(txChild[i]));
         testPool.addUnchecked(entry.FromTx(txGrandChild[i]));
     }
 
     // Now remove the parent, as might happen if a block-re-org occurs but the
     // parent cannot be put into the mempool (maybe because it is non-standard):
     poolSize = testPool.size();
     testPool.removeRecursive(CTransaction(txParent), REMOVAL_REASON_DUMMY);
     BOOST_CHECK_EQUAL(testPool.size(), poolSize - 6);
     BOOST_CHECK_EQUAL(testPool.size(), 0UL);
 }
 
 BOOST_AUTO_TEST_CASE(MempoolClearTest) {
     // Test CTxMemPool::clear functionality
 
     TestMemPoolEntryHelper entry;
     // Create a transaction
     CMutableTransaction txParent;
     txParent.vin.resize(1);
     txParent.vin[0].scriptSig = CScript() << OP_11;
     txParent.vout.resize(3);
     for (int i = 0; i < 3; i++) {
         txParent.vout[i].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
         txParent.vout[i].nValue = 33000 * SATOSHI;
     }
 
     CTxMemPool &testPool = *Assert(m_node.mempool);
     LOCK2(cs_main, testPool.cs);
 
     // Nothing in pool, clear should do nothing:
     testPool.clear();
     BOOST_CHECK_EQUAL(testPool.size(), 0UL);
 
     // Add the transaction
     testPool.addUnchecked(entry.FromTx(txParent));
     BOOST_CHECK_EQUAL(testPool.size(), 1UL);
     BOOST_CHECK_EQUAL(testPool.mapTx.size(), 1UL);
     BOOST_CHECK_EQUAL(testPool.mapNextTx.size(), 1UL);
 
     // CTxMemPool's members should be empty after a clear
     testPool.clear();
     BOOST_CHECK_EQUAL(testPool.size(), 0UL);
     BOOST_CHECK_EQUAL(testPool.mapTx.size(), 0UL);
     BOOST_CHECK_EQUAL(testPool.mapNextTx.size(), 0UL);
 }
 
 template <typename name>
 static void CheckSort(CTxMemPool &pool, std::vector<std::string> &sortedOrder,
                       const std::string &testcase)
     EXCLUSIVE_LOCKS_REQUIRED(pool.cs) {
     BOOST_CHECK_EQUAL(pool.size(), sortedOrder.size());
     typename CTxMemPool::indexed_transaction_set::index<name>::type::iterator
         it = pool.mapTx.get<name>().begin();
     int count = 0;
     for (; it != pool.mapTx.get<name>().end(); ++it, ++count) {
         BOOST_CHECK_MESSAGE((*it)->GetTx().GetId().ToString() ==
                                 sortedOrder[count],
                             (*it)->GetTx().GetId().ToString()
                                 << " != " << sortedOrder[count] << " in test "
                                 << testcase << ":" << count);
     }
 }
 
 BOOST_AUTO_TEST_CASE(MempoolIndexingTest) {
     CTxMemPool &pool = *Assert(m_node.mempool);
     LOCK2(cs_main, pool.cs);
     TestMemPoolEntryHelper entry;
 
     /**
      * Remove the default nonzero sigChecks, since the below tests are
      * focussing on fee-based ordering and involve some artificially very tiny
      * 21-byte transactions without any inputs.
      */
     entry.SigChecks(0);
 
     /* 3rd highest fee */
     CMutableTransaction tx1 = CMutableTransaction();
     tx1.vout.resize(1);
     tx1.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
     tx1.vout[0].nValue = 10 * COIN;
 
     /* highest fee */
     CMutableTransaction tx2 = CMutableTransaction();
     tx2.vout.resize(1);
     tx2.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
     tx2.vout[0].nValue = 2 * COIN;
     pool.addUnchecked(entry.Fee(20000 * SATOSHI).FromTx(tx2));
 
     /* lowest fee */
     CMutableTransaction tx3 = CMutableTransaction();
     tx3.vout.resize(1);
     tx3.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
     tx3.vout[0].nValue = 5 * COIN;
     pool.addUnchecked(entry.Fee(Amount::zero()).FromTx(tx3));
 
     /* 2nd highest fee */
     CMutableTransaction tx4 = CMutableTransaction();
     tx4.vout.resize(1);
     tx4.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
     tx4.vout[0].nValue = 6 * COIN;
     pool.addUnchecked(entry.Fee(15000 * SATOSHI).FromTx(tx4));
 
     /* equal fee rate to tx1, but arrived later to the mempool */
     CMutableTransaction tx5 = CMutableTransaction();
     tx5.vout.resize(1);
     tx5.vout[0].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
     tx5.vout[0].nValue = 11 * COIN;
     pool.addUnchecked(entry.Fee(10000 * SATOSHI).Time(100).FromTx(tx1));
     pool.addUnchecked(entry.Fee(10000 * SATOSHI).Time(200).FromTx(tx5));
     BOOST_CHECK_EQUAL(pool.size(), 5UL);
 
     std::vector<std::string> sortedOrder;
     sortedOrder.resize(5);
     sortedOrder[0] = tx2.GetId().ToString(); // 20000
     sortedOrder[1] = tx4.GetId().ToString(); // 15000
     sortedOrder[3] = tx5.GetId().ToString(); // 10000
     sortedOrder[2] = tx1.GetId().ToString(); // 10000
     sortedOrder[4] = tx3.GetId().ToString(); // 0
     CheckSort<modified_feerate>(pool, sortedOrder, "MempoolIndexingTest1");
 }
 
 BOOST_AUTO_TEST_CASE(MempoolSizeLimitTest) {
     CTxMemPool &pool = *Assert(m_node.mempool);
     LOCK2(cs_main, pool.cs);
     TestMemPoolEntryHelper entry;
     Amount feeIncrement = MEMPOOL_FULL_FEE_INCREMENT.GetFeePerK();
 
     CMutableTransaction tx1 = CMutableTransaction();
     tx1.vin.resize(1);
     tx1.vin[0].scriptSig = CScript() << OP_1;
     tx1.vout.resize(1);
     tx1.vout[0].scriptPubKey = CScript() << OP_1 << OP_EQUAL;
     tx1.vout[0].nValue = 10 * COIN;
     pool.addUnchecked(entry.Fee(20000 * SATOSHI).FromTx(tx1));
 
     CMutableTransaction tx2 = CMutableTransaction();
     tx2.vin.resize(1);
     tx2.vin[0].scriptSig = CScript() << OP_2;
     tx2.vout.resize(1);
     tx2.vout[0].scriptPubKey = CScript() << OP_2 << OP_EQUAL;
     tx2.vout[0].nValue = 10 * COIN;
     pool.addUnchecked(entry.Fee(4000 * SATOSHI).FromTx(tx2));
 
     // should do nothing
     pool.TrimToSize(pool.DynamicMemoryUsage());
     BOOST_CHECK(pool.exists(tx1.GetId()));
     BOOST_CHECK(pool.exists(tx2.GetId()));
 
     // should remove the lower-feerate transaction
     pool.TrimToSize(pool.DynamicMemoryUsage() * 3 / 4);
     BOOST_CHECK(pool.exists(tx1.GetId()));
     BOOST_CHECK(!pool.exists(tx2.GetId()));
 
     pool.addUnchecked(entry.FromTx(tx2));
     CMutableTransaction tx3 = CMutableTransaction();
     tx3.vin.resize(1);
     tx3.vin[0].prevout = COutPoint(tx2.GetId(), 0);
     tx3.vin[0].scriptSig = CScript() << OP_2;
     tx3.vout.resize(1);
     tx3.vout[0].scriptPubKey = CScript() << OP_3 << OP_EQUAL;
     tx3.vout[0].nValue = 10 * COIN;
     pool.addUnchecked(entry.Fee(16000 * SATOSHI).FromTx(tx3));
 
     // tx2 should be removed, tx3 is a child of tx2, so it should be removed
     // even though it has highest fee.
     pool.TrimToSize(pool.DynamicMemoryUsage() * 3 / 4);
     BOOST_CHECK(pool.exists(tx1.GetId()));
     BOOST_CHECK(!pool.exists(tx2.GetId()));
     BOOST_CHECK(!pool.exists(tx3.GetId()));
 
     // mempool is limited to tx1's size in memory usage, so nothing fits
     std::vector<COutPoint> vNoSpendsRemaining;
     pool.TrimToSize(CTransaction(tx1).GetTotalSize(), &vNoSpendsRemaining);
     BOOST_CHECK(!pool.exists(tx1.GetId()));
     BOOST_CHECK(!pool.exists(tx2.GetId()));
     BOOST_CHECK(!pool.exists(tx3.GetId()));
     // This vector should only contain 'root' (not unconfirmed) outpoints
     // Though both tx2 and tx3 were removed, tx3's input came from tx2.
     BOOST_CHECK_EQUAL(vNoSpendsRemaining.size(), 1);
     BOOST_CHECK(vNoSpendsRemaining == std::vector<COutPoint>{COutPoint()});
 
     // maxFeeRateRemoved was set by the transaction with the highest fee,
     // that was not removed because it was a child of another tx.
     CFeeRate maxFeeRateRemoved(20000 * SATOSHI,
                                CTransaction(tx1).GetTotalSize());
     BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(),
                       maxFeeRateRemoved.GetFeePerK() + feeIncrement);
 
     CMutableTransaction tx4 = CMutableTransaction();
     tx4.vin.resize(2);
     tx4.vin[0].prevout = COutPoint();
     tx4.vin[0].scriptSig = CScript() << OP_4;
     tx4.vin[1].prevout = COutPoint();
     tx4.vin[1].scriptSig = CScript() << OP_4;
     tx4.vout.resize(2);
     tx4.vout[0].scriptPubKey = CScript() << OP_4 << OP_EQUAL;
     tx4.vout[0].nValue = 10 * COIN;
     tx4.vout[1].scriptPubKey = CScript() << OP_4 << OP_EQUAL;
     tx4.vout[1].nValue = 10 * COIN;
 
     CMutableTransaction tx5 = CMutableTransaction();
     tx5.vin.resize(2);
     tx5.vin[0].prevout = COutPoint(tx4.GetId(), 0);
     tx5.vin[0].scriptSig = CScript() << OP_4;
     tx5.vin[1].prevout = COutPoint();
     tx5.vin[1].scriptSig = CScript() << OP_5;
     tx5.vout.resize(2);
     tx5.vout[0].scriptPubKey = CScript() << OP_5 << OP_EQUAL;
     tx5.vout[0].nValue = 10 * COIN;
     tx5.vout[1].scriptPubKey = CScript() << OP_5 << OP_EQUAL;
     tx5.vout[1].nValue = 10 * COIN;
 
     CMutableTransaction tx6 = CMutableTransaction();
     tx6.vin.resize(2);
     tx6.vin[0].prevout = COutPoint(tx4.GetId(), 1);
     tx6.vin[0].scriptSig = CScript() << OP_4;
     tx6.vin[1].prevout = COutPoint();
     tx6.vin[1].scriptSig = CScript() << OP_6;
     tx6.vout.resize(2);
     tx6.vout[0].scriptPubKey = CScript() << OP_6 << OP_EQUAL;
     tx6.vout[0].nValue = 10 * COIN;
     tx6.vout[1].scriptPubKey = CScript() << OP_6 << OP_EQUAL;
     tx6.vout[1].nValue = 10 * COIN;
 
     CMutableTransaction tx7 = CMutableTransaction();
     tx7.vin.resize(2);
     tx7.vin[0].prevout = COutPoint(tx5.GetId(), 0);
     tx7.vin[0].scriptSig = CScript() << OP_5;
     tx7.vin[1].prevout = COutPoint(tx6.GetId(), 0);
     tx7.vin[1].scriptSig = CScript() << OP_6;
     tx7.vout.resize(2);
     tx7.vout[0].scriptPubKey = CScript() << OP_7 << OP_EQUAL;
     tx7.vout[0].nValue = 10 * COIN;
     tx7.vout[1].scriptPubKey = CScript() << OP_7 << OP_EQUAL;
     tx7.vout[1].nValue = 10 * COIN;
 
     pool.addUnchecked(entry.Fee(7000 * SATOSHI).FromTx(tx4));
     pool.addUnchecked(entry.Fee(1000 * SATOSHI).FromTx(tx5));
     pool.addUnchecked(entry.Fee(1100 * SATOSHI).FromTx(tx6));
     pool.addUnchecked(entry.Fee(9000 * SATOSHI).FromTx(tx7));
 
     // we only require this to remove, at max, 2 txn, because it's not clear
     // what we're really optimizing for aside from that
     pool.TrimToSize(pool.DynamicMemoryUsage() - 1);
     BOOST_CHECK(pool.exists(tx4.GetId()));
     BOOST_CHECK(pool.exists(tx6.GetId()));
     BOOST_CHECK(!pool.exists(tx7.GetId()));
 
     if (!pool.exists(tx5.GetId())) {
         pool.addUnchecked(entry.Fee(1000 * SATOSHI).FromTx(tx5));
     }
     pool.addUnchecked(entry.Fee(9000 * SATOSHI).FromTx(tx7));
 
     // should maximize mempool size by only removing 5/7
     pool.TrimToSize(pool.DynamicMemoryUsage() / 2);
     BOOST_CHECK(pool.exists(tx4.GetId()));
     BOOST_CHECK(!pool.exists(tx5.GetId()));
     BOOST_CHECK(pool.exists(tx6.GetId()));
     BOOST_CHECK(!pool.exists(tx7.GetId()));
 
     pool.addUnchecked(entry.Fee(1000 * SATOSHI).FromTx(tx5));
     pool.addUnchecked(entry.Fee(9000 * SATOSHI).FromTx(tx7));
 
     std::vector<CTransactionRef> vtx;
     SetMockTime(42);
     SetMockTime(42 + CTxMemPool::ROLLING_FEE_HALFLIFE);
     BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(),
                       maxFeeRateRemoved.GetFeePerK() + feeIncrement);
     // ... we should keep the same min fee until we get a block
     DisconnectedBlockTransactions disconnectedBlockTxs;
     disconnectedBlockTxs.removeForBlock(vtx, pool);
     SetMockTime(42 + 2 * CTxMemPool::ROLLING_FEE_HALFLIFE);
     BOOST_CHECK_EQUAL(pool.GetMinFee(1).GetFeePerK(),
                       (maxFeeRateRemoved.GetFeePerK() + feeIncrement) / 2);
     // ... then feerate should drop 1/2 each halflife
 
     SetMockTime(42 + 2 * CTxMemPool::ROLLING_FEE_HALFLIFE +
                 CTxMemPool::ROLLING_FEE_HALFLIFE / 2);
 
     BOOST_CHECK_EQUAL(
         pool.GetMinFee(pool.DynamicMemoryUsage() * 5 / 2).GetFeePerK(),
         (maxFeeRateRemoved.GetFeePerK() + feeIncrement) / 4);
     // ... with a 1/2 halflife when mempool is < 1/2 its target size
 
     SetMockTime(42 + 2 * CTxMemPool::ROLLING_FEE_HALFLIFE +
                 CTxMemPool::ROLLING_FEE_HALFLIFE / 2 +
                 CTxMemPool::ROLLING_FEE_HALFLIFE / 4);
     BOOST_CHECK_EQUAL(
         pool.GetMinFee(pool.DynamicMemoryUsage() * 9 / 2).GetFeePerK(),
         (maxFeeRateRemoved.GetFeePerK() + feeIncrement) / 8 + SATOSHI);
     // ... with a 1/4 halflife when mempool is < 1/4 its target size
 }
 
 // expectedSize can be smaller than correctlyOrderedIds.size(), since we
 // might be testing intermediary states. Just avoiding some slice operations,
 void CheckDisconnectPoolOrder(DisconnectedBlockTransactions &disconnectPool,
                               std::vector<TxId> correctlyOrderedIds,
                               unsigned int expectedSize) {
     int i = 0;
     BOOST_CHECK_EQUAL(disconnectPool.GetQueuedTx().size(), expectedSize);
     // Txns in queuedTx's insertion_order index are sorted from children to
     // parent txn
     for (const CTransactionRef &tx :
          reverse_iterate(disconnectPool.GetQueuedTx().get<insertion_order>())) {
         BOOST_CHECK(tx->GetId() == correctlyOrderedIds[i]);
         i++;
     }
 }
 
 typedef std::vector<CMutableTransaction *> vecptx;
 
 BOOST_AUTO_TEST_CASE(TestImportMempool) {
     CMutableTransaction chainedTxn[5];
     std::vector<TxId> correctlyOrderedIds;
     COutPoint lastOutpoint;
 
     // Construct a chain of 5 transactions
     for (int i = 0; i < 5; i++) {
         chainedTxn[i].vin.emplace_back(lastOutpoint);
         chainedTxn[i].vout.emplace_back(10 * SATOSHI, CScript() << OP_TRUE);
         correctlyOrderedIds.push_back(chainedTxn[i].GetId());
         lastOutpoint = COutPoint(correctlyOrderedIds[i], 0);
     }
 
     // The first 3 txns simulate once confirmed transactions that have been
     // disconnected. We test 3 different orders: in order, one case of mixed
     // order and inverted order.
     vecptx disconnectedTxnsInOrder = {&chainedTxn[0], &chainedTxn[1],
                                       &chainedTxn[2]};
     vecptx disconnectedTxnsMixedOrder = {&chainedTxn[1], &chainedTxn[2],
                                          &chainedTxn[0]};
     vecptx disconnectedTxnsInvertedOrder = {&chainedTxn[2], &chainedTxn[1],
                                             &chainedTxn[0]};
 
     // The last 2 txns simulate a chain of unconfirmed transactions in the
     // mempool. We test 2 different orders: in and out of order.
     vecptx unconfTxnsInOrder = {&chainedTxn[3], &chainedTxn[4]};
     vecptx unconfTxnsOutOfOrder = {&chainedTxn[4], &chainedTxn[3]};
 
     // Now we test all combinations of the previously defined orders for
     // disconnected and unconfirmed txns. The expected outcome is to have these
     // transactions in the correct order in queuedTx, as defined in
     // correctlyOrderedIds.
     for (auto &disconnectedTxns :
          {disconnectedTxnsInOrder, disconnectedTxnsMixedOrder,
           disconnectedTxnsInvertedOrder}) {
         for (auto &unconfTxns : {unconfTxnsInOrder, unconfTxnsOutOfOrder}) {
             CTxMemPool &testPool = *Assert(m_node.mempool);
             // addForBlock inserts disconnectTxns in disconnectPool. They
             // simulate transactions that were once confirmed in a block
             std::vector<CTransactionRef> vtx;
             for (auto tx : disconnectedTxns) {
                 vtx.push_back(MakeTransactionRef(*tx));
             }
             DisconnectedBlockTransactions disconnectPool;
             LOCK2(cs_main, testPool.cs);
             {
                 disconnectPool.addForBlock(vtx, testPool);
                 CheckDisconnectPoolOrder(disconnectPool, correctlyOrderedIds,
                                          disconnectedTxns.size());
 
                 // If the mempool is empty, importMempool doesn't change
                 // disconnectPool
                 disconnectPool.importMempool(testPool);
                 CheckDisconnectPoolOrder(disconnectPool, correctlyOrderedIds,
                                          disconnectedTxns.size());
 
                 // Add all unconfirmed transactions in testPool
                 for (auto tx : unconfTxns) {
                     TestMemPoolEntryHelper entry;
                     testPool.addUnchecked(entry.FromTx(*tx));
                 }
 
                 // Now we test importMempool with a non empty mempool
                 disconnectPool.importMempool(testPool);
             }
             CheckDisconnectPoolOrder(disconnectPool, correctlyOrderedIds,
                                      disconnectedTxns.size() +
                                          unconfTxns.size());
             // We must clear disconnectPool to not trigger the assert in its
             // destructor
             disconnectPool.clear();
         }
     }
 }
 
 inline CTransactionRef
 make_tx(std::vector<Amount> &&output_values,
         std::vector<CTransactionRef> &&inputs = std::vector<CTransactionRef>(),
         std::vector<uint32_t> &&input_indices = std::vector<uint32_t>()) {
     CMutableTransaction tx = CMutableTransaction();
     tx.vin.resize(inputs.size());
     tx.vout.resize(output_values.size());
     for (size_t i = 0; i < inputs.size(); ++i) {
         tx.vin[i].prevout =
             COutPoint(inputs[i]->GetId(),
                       input_indices.size() > i ? input_indices[i] : 0);
     }
     for (size_t i = 0; i < output_values.size(); ++i) {
         tx.vout[i].scriptPubKey = CScript() << OP_11 << OP_EQUAL;
         tx.vout[i].nValue = output_values[i];
     }
     return MakeTransactionRef(tx);
 }
 
 BOOST_AUTO_TEST_CASE(GetModifiedFeeRateTest) {
     CMutableTransaction tx = CMutableTransaction();
     tx.vin.resize(1);
 
     // Make tx exactly 1000 bytes.
     const size_t dummyDataSize =
         1000 -
         (GetSerializeSize(tx, PROTOCOL_VERSION) + 5 /* OP_PUSHDATA2 and ?? */);
 
     tx.vin[0].scriptSig << std::vector<uint8_t>(dummyDataSize);
     assert(GetSerializeSize(tx, PROTOCOL_VERSION) == 1000);
 
     TestMemPoolEntryHelper entry;
 
     auto entryNormal = entry.Fee(1000 * SATOSHI).FromTx(tx);
     BOOST_CHECK_EQUAL(1000 * SATOSHI,
                       entryNormal->GetModifiedFeeRate().GetFee(1000));
 
     // Add modified fee
     CTxMemPoolEntryRef entryFeeModified = entry.Fee(1000 * SATOSHI).FromTx(tx);
     entryFeeModified->UpdateFeeDelta(1000 * SATOSHI);
     BOOST_CHECK_EQUAL(2000 * SATOSHI,
                       entryFeeModified->GetModifiedFeeRate().GetFee(1000));
 
     // Excessive sigop count "modifies" size
     CTxMemPoolEntryRef entrySizeModified =
         entry.Fee(1000 * SATOSHI)
             .SigChecks(2000 / DEFAULT_BYTES_PER_SIGCHECK)
             .FromTx(tx);
     BOOST_CHECK_EQUAL(500 * SATOSHI,
                       entrySizeModified->GetModifiedFeeRate().GetFee(1000));
 }
 
 BOOST_AUTO_TEST_CASE(CompareTxMemPoolEntryByModifiedFeeRateTest) {
     CTransactionRef a = make_tx(/* output_values */ {1 * COIN});
     CTransactionRef b = make_tx(/* output_values */ {2 * COIN});
 
     // For this test, we want b to have lower txid.
     if (a->GetId() < b->GetId()) {
         std::swap(a, b);
     }
     BOOST_CHECK_GT(a->GetId(), b->GetId());
 
     TestMemPoolEntryHelper entry;
     CompareTxMemPoolEntryByModifiedFeeRate compare;
 
     auto checkOrdering = [&compare](const auto &a, const auto &b) {
         BOOST_CHECK(compare(a, b));
         BOOST_CHECK(!compare(b, a));
     };
 
     // If the fees and entryId are the same, lower TxId should sort before
     checkOrdering(entry.Fee(100 * SATOSHI).FromTx(b),
                   entry.Fee(100 * SATOSHI).FromTx(a));
     // Earlier entryId, same fee, should sort before
     checkOrdering(entry.Fee(100 * SATOSHI).EntryId(1).FromTx(a),
                   entry.Fee(100 * SATOSHI).EntryId(2).FromTx(b));
     // Higher fee, earlier entryId should sort before
     checkOrdering(entry.Fee(101 * SATOSHI).EntryId(1).FromTx(a),
                   entry.Fee(100 * SATOSHI).EntryId(2).FromTx(b));
     // Higher fee, same entryId should sort before
     checkOrdering(entry.Fee(101 * SATOSHI).FromTx(a),
                   entry.Fee(100 * SATOSHI).FromTx(b));
 
     // Same with fee delta.
     {
         CTxMemPoolEntryRef entryA = entry.Fee(100 * SATOSHI).FromTx(a);
         CTxMemPoolEntryRef entryB = entry.Fee(200 * SATOSHI).FromTx(b);
         // .. A and B have same modified fee, ordering is by lowest txid
         entryA->UpdateFeeDelta(100 * SATOSHI);
         checkOrdering(entryB, entryA);
     }
     // .. A is first entering the mempool
     CTxMemPoolEntryRef entryA = entry.Fee(100 * SATOSHI).EntryId(1).FromTx(a);
     CTxMemPoolEntryRef entryB = entry.Fee(100 * SATOSHI).EntryId(2).FromTx(b);
     checkOrdering(entryA, entryB);
     // .. B has higher modified fee.
     entryB->UpdateFeeDelta(1 * SATOSHI);
     checkOrdering(entryB, entryA);
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/txvalidationcache_tests.cpp b/src/test/txvalidationcache_tests.cpp
index fedbbd16d..4dae01e59 100644
--- a/src/test/txvalidationcache_tests.cpp
+++ b/src/test/txvalidationcache_tests.cpp
@@ -1,687 +1,687 @@
 // Copyright (c) 2011-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <chain.h>
 #include <config.h>
 #include <consensus/validation.h>
 #include <kernel/validation_cache_sizes.h>
 #include <key.h>
 #include <policy/policy.h>
 #include <script/scriptcache.h>
 #include <script/sighashtype.h>
 #include <script/sign.h>
 #include <script/signingprovider.h>
 #include <txmempool.h>
 #include <validation.h>
 
 #include <test/lcg.h>
 #include <test/sigutil.h>
 #include <test/util/setup_common.h>
 
 #include <boost/test/unit_test.hpp>
 
 BOOST_AUTO_TEST_SUITE(txvalidationcache_tests)
 
 BOOST_FIXTURE_TEST_CASE(tx_mempool_block_doublespend, TestChain100Setup) {
     // Make sure skipping validation of transactions that were validated going
     // into the memory pool does not allow double-spends in blocks to pass
     // validation when they should not.
     CScript scriptPubKey = CScript() << ToByteVector(coinbaseKey.GetPubKey())
                                      << OP_CHECKSIG;
 
     const auto ToMemPool = [this](const CMutableTransaction &tx) {
         LOCK(cs_main);
 
         const MempoolAcceptResult result =
             m_node.chainman->ProcessTransaction(MakeTransactionRef(tx));
         return result.m_result_type == MempoolAcceptResult::ResultType::VALID;
     };
 
     // Create a double-spend of mature coinbase txn:
     std::vector<CMutableTransaction> spends;
     spends.resize(2);
     for (int i = 0; i < 2; i++) {
         spends[i].nVersion = 1;
         spends[i].vin.resize(1);
         spends[i].vin[0].prevout = COutPoint(m_coinbase_txns[0]->GetId(), 0);
         spends[i].vout.resize(1);
         spends[i].vout[0].nValue = 11 * CENT;
         spends[i].vout[0].scriptPubKey = scriptPubKey;
 
         // Sign:
         std::vector<uint8_t> vchSig;
         uint256 hash = SignatureHash(scriptPubKey, CTransaction(spends[i]), 0,
                                      SigHashType().withForkId(),
                                      m_coinbase_txns[0]->vout[0].nValue);
         BOOST_CHECK(coinbaseKey.SignECDSA(hash, vchSig));
         vchSig.push_back(uint8_t(SIGHASH_ALL | SIGHASH_FORKID));
         spends[i].vin[0].scriptSig << vchSig;
     }
 
     CBlock block;
 
     // Test 1: block with both of those transactions should be rejected.
     block = CreateAndProcessBlock(spends, scriptPubKey);
     {
         LOCK(cs_main);
         BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() !=
                     block.GetHash());
     }
 
     // Test 2: ... and should be rejected if spend1 is in the memory pool
     BOOST_CHECK(ToMemPool(spends[0]));
     block = CreateAndProcessBlock(spends, scriptPubKey);
     {
         LOCK(cs_main);
         BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() !=
                     block.GetHash());
     }
     m_node.mempool->clear();
 
     // Test 3: ... and should be rejected if spend2 is in the memory pool
     BOOST_CHECK(ToMemPool(spends[1]));
     block = CreateAndProcessBlock(spends, scriptPubKey);
     {
         LOCK(cs_main);
         BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() !=
                     block.GetHash());
     }
     m_node.mempool->clear();
 
     // Final sanity test: first spend in mempool, second in block, that's OK:
     std::vector<CMutableTransaction> oneSpend;
     oneSpend.push_back(spends[0]);
     BOOST_CHECK(ToMemPool(spends[1]));
     block = CreateAndProcessBlock(oneSpend, scriptPubKey);
     {
         LOCK(cs_main);
         BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() ==
                     block.GetHash());
     }
     // spends[1] should have been removed from the mempool when the block with
     // spends[0] is accepted:
     BOOST_CHECK_EQUAL(m_node.mempool->size(), 0U);
 }
 
 static inline bool
 CheckInputScripts(const CTransaction &tx, TxValidationState &state,
                   const CCoinsViewCache &view, const uint32_t flags,
                   bool sigCacheStore, bool scriptCacheStore,
                   const PrecomputedTransactionData &txdata, int &nSigChecksOut,
                   std::vector<CScriptCheck> *pvChecks,
                   CheckInputsLimiter *pBlockLimitSigChecks = nullptr)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     // nSigChecksTxLimiter need to outlive this function call, because test
     // cases are using pvChecks, so the verification is done asynchronously.
     static TxSigCheckLimiter nSigChecksTxLimiter;
     nSigChecksTxLimiter = TxSigCheckLimiter();
     return CheckInputScripts(
         tx, state, view, flags, sigCacheStore, scriptCacheStore, txdata,
         nSigChecksOut, nSigChecksTxLimiter, pBlockLimitSigChecks, pvChecks);
 }
 
 // Run CheckInputScripts (using CoinsTip()) on the given transaction, for all
 // script flags. Test that CheckInputScripts passes for all flags that don't
 // overlap with the failing_flags argument, but otherwise fails.
 // CHECKLOCKTIMEVERIFY and CHECKSEQUENCEVERIFY (and future NOP codes that may
 // get reassigned) have an interaction with DISCOURAGE_UPGRADABLE_NOPS: if the
 // script flags used contain DISCOURAGE_UPGRADABLE_NOPS but don't contain
 // CHECKLOCKTIMEVERIFY (or CHECKSEQUENCEVERIFY), but the script does contain
 // OP_CHECKLOCKTIMEVERIFY (or OP_CHECKSEQUENCEVERIFY), then script execution
 // should fail.
 // Capture this interaction with the upgraded_nop argument: set it when
 // evaluating any script flag that is implemented as an upgraded NOP code.
 static void ValidateCheckInputsForAllFlags(
     const CTransaction &tx, uint32_t failing_flags, uint32_t required_flags,
     bool add_to_cache, CCoinsViewCache &active_coins_tip,
-    int expected_sigchecks) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
+    int expected_sigchecks) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
     PrecomputedTransactionData txdata(tx);
 
     MMIXLinearCongruentialGenerator lcg;
     for (int i = 0; i < 4096; i++) {
         uint32_t test_flags = lcg.next() | required_flags;
         TxValidationState state;
 
         // Filter out incompatible flag choices
         if ((test_flags & SCRIPT_VERIFY_CLEANSTACK)) {
             // CLEANSTACK requires P2SH, see VerifyScript() in
             // script/interpreter.cpp
             test_flags |= SCRIPT_VERIFY_P2SH;
         }
 
         int nSigChecksDirect = 0xf00d;
         bool ret =
             CheckInputScripts(tx, state, &active_coins_tip, test_flags, true,
                               add_to_cache, txdata, nSigChecksDirect);
 
         // CheckInputScripts should succeed iff test_flags doesn't intersect
         // with failing_flags
         bool expected_return_value = !(test_flags & failing_flags);
         BOOST_CHECK_EQUAL(ret, expected_return_value);
 
         if (ret) {
             BOOST_CHECK(nSigChecksDirect == expected_sigchecks);
         }
 
         // Test the caching
         if (ret && add_to_cache) {
             // Check that we get a cache hit if the tx was valid
             std::vector<CScriptCheck> scriptchecks;
             int nSigChecksCached = 0xbeef;
             BOOST_CHECK(CheckInputScripts(
                 tx, state, &active_coins_tip, test_flags, true, add_to_cache,
                 txdata, nSigChecksCached, &scriptchecks));
             BOOST_CHECK(nSigChecksCached == nSigChecksDirect);
             BOOST_CHECK(scriptchecks.empty());
         } else {
             // Check that we get script executions to check, if the transaction
             // was invalid, or we didn't add to cache.
             std::vector<CScriptCheck> scriptchecks;
             int nSigChecksUncached = 0xbabe;
             BOOST_CHECK(CheckInputScripts(
                 tx, state, &active_coins_tip, test_flags, true, add_to_cache,
                 txdata, nSigChecksUncached, &scriptchecks));
             BOOST_CHECK(!ret || nSigChecksUncached == 0);
             BOOST_CHECK_EQUAL(scriptchecks.size(), tx.vin.size());
         }
     }
 }
 
 BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup) {
     // Test that passing CheckInputScripts with one set of script flags doesn't
     // imply that we would pass again with a different set of flags.
     CScript p2pk_scriptPubKey =
         CScript() << ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;
     CScript p2sh_scriptPubKey =
         GetScriptForDestination(ScriptHash(p2pk_scriptPubKey));
     CScript p2pkh_scriptPubKey =
         GetScriptForDestination(PKHash(coinbaseKey.GetPubKey()));
 
     FillableSigningProvider keystore;
     BOOST_CHECK(keystore.AddKey(coinbaseKey));
     BOOST_CHECK(keystore.AddCScript(p2pk_scriptPubKey));
 
     CMutableTransaction funding_tx;
     // Needed when spending the output of this transaction
     CScript noppyScriptPubKey;
     // Create a transaction output that can fail DISCOURAGE_UPGRADABLE_NOPS
     // checks when spent. This is for testing consensus vs non-standard rules in
     // `checkinputs_test`.
     {
         funding_tx.nVersion = 1;
         funding_tx.vin.resize(1);
         funding_tx.vin[0].prevout = COutPoint(m_coinbase_txns[0]->GetId(), 0);
         funding_tx.vout.resize(1);
         funding_tx.vout[0].nValue = 50 * COIN;
 
         noppyScriptPubKey << OP_IF << OP_NOP10 << OP_ENDIF << OP_1;
         funding_tx.vout[0].scriptPubKey = noppyScriptPubKey;
         std::vector<uint8_t> fundingVchSig;
         uint256 fundingSigHash = SignatureHash(
             p2pk_scriptPubKey, CTransaction(funding_tx), 0,
             SigHashType().withForkId(), m_coinbase_txns[0]->vout[0].nValue);
         BOOST_CHECK(coinbaseKey.SignECDSA(fundingSigHash, fundingVchSig));
         fundingVchSig.push_back(uint8_t(SIGHASH_ALL | SIGHASH_FORKID));
         funding_tx.vin[0].scriptSig << fundingVchSig;
     }
 
     // Spend the funding transaction by mining it into a block
     {
         CBlock block = CreateAndProcessBlock({funding_tx}, p2pk_scriptPubKey);
         LOCK(cs_main);
         BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() ==
                     block.GetHash());
         BOOST_CHECK(
             m_node.chainman->ActiveChainstate().CoinsTip().GetBestBlock() ==
             block.GetHash());
     }
 
     // flags to test: SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY,
     // SCRIPT_VERIFY_CHECKSEQUENCE_VERIFY,
     // SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS, uncompressed pubkey thing
 
     // Create 2 outputs that match the three scripts above, spending the first
     // coinbase tx.
     CMutableTransaction spend_tx;
     spend_tx.nVersion = 1;
     spend_tx.vin.resize(1);
     spend_tx.vin[0].prevout = COutPoint(funding_tx.GetId(), 0);
     spend_tx.vout.resize(4);
     spend_tx.vout[0].nValue = 11 * CENT;
     spend_tx.vout[0].scriptPubKey = p2sh_scriptPubKey;
     spend_tx.vout[1].nValue = 11 * CENT;
     spend_tx.vout[1].scriptPubKey =
         CScript() << OP_CHECKLOCKTIMEVERIFY << OP_DROP
                   << ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;
     spend_tx.vout[2].nValue = 11 * CENT;
     spend_tx.vout[2].scriptPubKey =
         CScript() << OP_CHECKSEQUENCEVERIFY << OP_DROP
                   << ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;
     spend_tx.vout[3].nValue = 11 * CENT;
     spend_tx.vout[3].scriptPubKey = p2sh_scriptPubKey;
 
     // "Sign" the main transaction that we spend from.
     {
         // This will cause OP_NOP10 to execute.
         spend_tx.vin[0].scriptSig << OP_1;
     }
 
     // Test that invalidity under a set of flags doesn't preclude validity under
     // other (eg consensus) flags.
     // spend_tx is invalid according to DISCOURAGE_UPGRADABLE_NOPS
     {
         const CTransaction tx(spend_tx);
 
         LOCK(cs_main);
 
         TxValidationState state;
         PrecomputedTransactionData ptd_spend_tx(tx);
         int nSigChecksDummy;
 
         BOOST_CHECK(!CheckInputScripts(
             tx, state, &m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS, true, true, ptd_spend_tx,
             nSigChecksDummy, nullptr));
 
         // If we call again asking for scriptchecks (as happens in
         // ConnectBlock), we should add a script check object for this -- we're
         // not caching invalidity (if that changes, delete this test case).
         std::vector<CScriptCheck> scriptchecks;
         BOOST_CHECK(CheckInputScripts(
             tx, state, &m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS, true, true, ptd_spend_tx,
             nSigChecksDummy, &scriptchecks));
         BOOST_CHECK_EQUAL(scriptchecks.size(), 1U);
 
         // Test that CheckInputScripts returns true iff cleanstack-enforcing
         // flags are not present. Don't add these checks to the cache, so that
         // we can test later that block validation works fine in the absence of
         // cached successes.
         ValidateCheckInputsForAllFlags(
             tx, SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS, 0, false,
             m_node.chainman->ActiveChainstate().CoinsTip(), 0);
     }
 
     // And if we produce a block with this tx, it should be valid, even though
     // there's no cache entry.
     CBlock block;
 
     block = CreateAndProcessBlock({spend_tx}, p2pk_scriptPubKey);
     LOCK(cs_main);
     BOOST_CHECK(m_node.chainman->ActiveTip()->GetBlockHash() ==
                 block.GetHash());
     BOOST_CHECK(m_node.chainman->ActiveChainstate().CoinsTip().GetBestBlock() ==
                 block.GetHash());
 
     // Test P2SH: construct a transaction that is valid without P2SH, and then
     // test validity with P2SH.
     {
         CMutableTransaction invalid_under_p2sh_tx;
         invalid_under_p2sh_tx.nVersion = 1;
         invalid_under_p2sh_tx.vin.resize(1);
         invalid_under_p2sh_tx.vin[0].prevout = COutPoint(spend_tx.GetId(), 0);
         invalid_under_p2sh_tx.vout.resize(1);
         invalid_under_p2sh_tx.vout[0].nValue = 11 * CENT;
         invalid_under_p2sh_tx.vout[0].scriptPubKey = p2pk_scriptPubKey;
         std::vector<uint8_t> vchSig2(p2pk_scriptPubKey.begin(),
                                      p2pk_scriptPubKey.end());
         invalid_under_p2sh_tx.vin[0].scriptSig << vchSig2;
 
         ValidateCheckInputsForAllFlags(
             CTransaction(invalid_under_p2sh_tx), SCRIPT_VERIFY_P2SH, 0, true,
             m_node.chainman->ActiveChainstate().CoinsTip(), 0);
     }
 
     // Test CHECKLOCKTIMEVERIFY
     {
         CMutableTransaction invalid_with_cltv_tx;
         invalid_with_cltv_tx.nVersion = 1;
         invalid_with_cltv_tx.nLockTime = 100;
         invalid_with_cltv_tx.vin.resize(1);
         invalid_with_cltv_tx.vin[0].prevout = COutPoint(spend_tx.GetId(), 1);
         invalid_with_cltv_tx.vin[0].nSequence = 0;
         invalid_with_cltv_tx.vout.resize(1);
         invalid_with_cltv_tx.vout[0].nValue = 11 * CENT;
         invalid_with_cltv_tx.vout[0].scriptPubKey = p2pk_scriptPubKey;
 
         // Sign
         std::vector<uint8_t> vchSig;
         uint256 hash = SignatureHash(
             spend_tx.vout[1].scriptPubKey, CTransaction(invalid_with_cltv_tx),
             0, SigHashType().withForkId(), spend_tx.vout[1].nValue);
         BOOST_CHECK(coinbaseKey.SignECDSA(hash, vchSig));
         vchSig.push_back(uint8_t(SIGHASH_ALL | SIGHASH_FORKID));
         invalid_with_cltv_tx.vin[0].scriptSig = CScript() << vchSig << 101;
 
         ValidateCheckInputsForAllFlags(
             CTransaction(invalid_with_cltv_tx),
             SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY | SCRIPT_ENABLE_REPLAY_PROTECTION,
             SCRIPT_ENABLE_SIGHASH_FORKID, true,
             m_node.chainman->ActiveChainstate().CoinsTip(), 1);
 
         // Make it valid, and check again
         invalid_with_cltv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
         TxValidationState state;
 
         CTransaction transaction(invalid_with_cltv_tx);
         PrecomputedTransactionData txdata(transaction);
 
         int nSigChecksRet;
         BOOST_CHECK(CheckInputScripts(
             transaction, state, m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS, true, true, txdata, nSigChecksRet,
             nullptr));
         BOOST_CHECK(nSigChecksRet == 1);
     }
 
     // TEST CHECKSEQUENCEVERIFY
     {
         CMutableTransaction invalid_with_csv_tx;
         invalid_with_csv_tx.nVersion = 2;
         invalid_with_csv_tx.vin.resize(1);
         invalid_with_csv_tx.vin[0].prevout = COutPoint(spend_tx.GetId(), 2);
         invalid_with_csv_tx.vin[0].nSequence = 100;
         invalid_with_csv_tx.vout.resize(1);
         invalid_with_csv_tx.vout[0].nValue = 11 * CENT;
         invalid_with_csv_tx.vout[0].scriptPubKey = p2pk_scriptPubKey;
 
         // Sign
         std::vector<uint8_t> vchSig;
         uint256 hash = SignatureHash(
             spend_tx.vout[2].scriptPubKey, CTransaction(invalid_with_csv_tx), 0,
             SigHashType().withForkId(), spend_tx.vout[2].nValue);
         BOOST_CHECK(coinbaseKey.SignECDSA(hash, vchSig));
         vchSig.push_back(uint8_t(SIGHASH_ALL | SIGHASH_FORKID));
         invalid_with_csv_tx.vin[0].scriptSig = CScript() << vchSig << 101;
 
         ValidateCheckInputsForAllFlags(
             CTransaction(invalid_with_csv_tx),
             SCRIPT_VERIFY_CHECKSEQUENCEVERIFY | SCRIPT_ENABLE_REPLAY_PROTECTION,
             SCRIPT_ENABLE_SIGHASH_FORKID, true,
             m_node.chainman->ActiveChainstate().CoinsTip(), 1);
 
         // Make it valid, and check again
         invalid_with_csv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
         TxValidationState state;
 
         CTransaction transaction(invalid_with_csv_tx);
         PrecomputedTransactionData txdata(transaction);
 
         int nSigChecksRet;
         BOOST_CHECK(CheckInputScripts(
             transaction, state, &m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS, true, true, txdata, nSigChecksRet,
             nullptr));
         BOOST_CHECK(nSigChecksRet == 1);
     }
 
     // TODO: add tests for remaining script flags
 
     {
         // Test a transaction with multiple inputs.
         CMutableTransaction tx;
 
         tx.nVersion = 1;
         tx.vin.resize(2);
         tx.vin[0].prevout = COutPoint(spend_tx.GetId(), 0);
         tx.vin[1].prevout = COutPoint(spend_tx.GetId(), 3);
         tx.vout.resize(1);
         tx.vout[0].nValue = 22 * CENT;
         tx.vout[0].scriptPubKey = p2pk_scriptPubKey;
 
         // Sign
         {
             SignatureData sigdata;
             BOOST_CHECK(ProduceSignature(
                 keystore,
                 MutableTransactionSignatureCreator(&tx, 0, 11 * CENT,
                                                    SigHashType().withForkId()),
                 spend_tx.vout[0].scriptPubKey, sigdata));
             UpdateInput(tx.vin[0], sigdata);
         }
         {
             SignatureData sigdata;
             BOOST_CHECK(ProduceSignature(
                 keystore,
                 MutableTransactionSignatureCreator(&tx, 1, 11 * CENT,
                                                    SigHashType().withForkId()),
                 spend_tx.vout[3].scriptPubKey, sigdata));
             UpdateInput(tx.vin[1], sigdata);
         }
 
         // This should be valid under all script flags that support our sighash
         // convention.
         ValidateCheckInputsForAllFlags(
             CTransaction(tx), SCRIPT_ENABLE_REPLAY_PROTECTION,
             SCRIPT_ENABLE_SIGHASH_FORKID | SCRIPT_VERIFY_P2SH, true,
             m_node.chainman->ActiveChainstate().CoinsTip(), 2);
 
         {
             // Try checking this valid transaction with sigchecks limiter
             // supplied. Each input consumes 1 sigcheck.
 
             TxValidationState state;
             CTransaction transaction(tx);
             PrecomputedTransactionData txdata(transaction);
             const uint32_t flags =
                 STANDARD_SCRIPT_VERIFY_FLAGS | SCRIPT_ENFORCE_SIGCHECKS;
             int nSigChecksDummy;
 
             /**
              * Parallel validation initially works (no cached value), but
              * evaluation of the script checks produces a failure.
              */
             std::vector<CScriptCheck> scriptchecks1;
             CheckInputsLimiter sigchecklimiter1(1);
             BOOST_CHECK(CheckInputScripts(
                 transaction, state,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, &scriptchecks1,
                 &sigchecklimiter1));
             // the first check passes but it did consume the limit.
             BOOST_CHECK(scriptchecks1[1]());
             BOOST_CHECK(sigchecklimiter1.check());
             // the second check (the first input) fails due to the limiter.
             BOOST_CHECK(!scriptchecks1[0]());
             BOOST_CHECK_EQUAL(scriptchecks1[0].GetScriptError(),
                               ScriptError::SIGCHECKS_LIMIT_EXCEEDED);
             BOOST_CHECK(!sigchecklimiter1.check());
 
             // Serial validation fails with the limiter.
             CheckInputsLimiter sigchecklimiter2(1);
             TxValidationState state2;
             BOOST_CHECK(!CheckInputScripts(
                 transaction, state2,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, nullptr, &sigchecklimiter2));
             BOOST_CHECK(!sigchecklimiter2.check());
             BOOST_CHECK_EQUAL(state2.GetRejectReason(),
                               "non-mandatory-script-verify-flag (Validation "
                               "resources exceeded (SigChecks))");
 
             /**
              * A slightly more permissive limiter (just enough) passes, and
              * allows caching the result.
              */
             std::vector<CScriptCheck> scriptchecks3;
             CheckInputsLimiter sigchecklimiter3(2);
             // first in parallel
             BOOST_CHECK(CheckInputScripts(
                 transaction, state,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, &scriptchecks3,
                 &sigchecklimiter3));
             BOOST_CHECK(scriptchecks3[1]());
             BOOST_CHECK(scriptchecks3[0]());
             BOOST_CHECK(sigchecklimiter3.check());
             // then in serial, caching the result.
             CheckInputsLimiter sigchecklimiter4(2);
             BOOST_CHECK(CheckInputScripts(
                 transaction, state,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, nullptr, &sigchecklimiter4));
             BOOST_CHECK(sigchecklimiter4.check());
             // now in parallel again, grabbing the cached result.
             std::vector<CScriptCheck> scriptchecks5;
             CheckInputsLimiter sigchecklimiter5(2);
             BOOST_CHECK(CheckInputScripts(
                 transaction, state,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, &scriptchecks5,
                 &sigchecklimiter5));
             BOOST_CHECK(scriptchecks5.empty());
             BOOST_CHECK(sigchecklimiter5.check());
 
             /**
              * Going back to the lower limit, we now fail immediately due to the
              * caching.
              */
             CheckInputsLimiter sigchecklimiter6(1);
             TxValidationState state6;
             BOOST_CHECK(!CheckInputScripts(
                 transaction, state6,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, nullptr, &sigchecklimiter6));
             BOOST_CHECK_EQUAL(state6.GetRejectReason(), "too-many-sigchecks");
             BOOST_CHECK_EQUAL(state6.GetResult(),
                               TxValidationResult::TX_CONSENSUS);
             BOOST_CHECK(!sigchecklimiter6.check());
             // even in parallel validation, immediate fail from the cache.
             std::vector<CScriptCheck> scriptchecks7;
             CheckInputsLimiter sigchecklimiter7(1);
             TxValidationState state7;
             BOOST_CHECK(!CheckInputScripts(
                 transaction, state7,
                 &m_node.chainman->ActiveChainstate().CoinsTip(), flags, true,
                 true, txdata, nSigChecksDummy, &scriptchecks7,
                 &sigchecklimiter7));
             BOOST_CHECK_EQUAL(state7.GetRejectReason(), "too-many-sigchecks");
             BOOST_CHECK_EQUAL(state6.GetResult(),
                               TxValidationResult::TX_CONSENSUS);
             BOOST_CHECK(!sigchecklimiter7.check());
             BOOST_CHECK(scriptchecks7.empty());
         }
 
         // Check that if the second input is invalid, but the first input is
         // valid, the transaction is not cached.
         // Invalidate vin[1]
         tx.vin[1].scriptSig = CScript();
 
         TxValidationState state;
         CTransaction transaction(tx);
         PrecomputedTransactionData txdata(transaction);
 
         // This transaction is now invalid because the second signature is
         // missing.
         int nSigChecksDummy;
         BOOST_CHECK(!CheckInputScripts(
             transaction, state, &m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS, true, true, txdata, nSigChecksDummy,
             nullptr));
 
         // Make sure this transaction was not cached (ie becausethe first input
         // was valid)
         std::vector<CScriptCheck> scriptchecks;
         BOOST_CHECK(CheckInputScripts(
             transaction, state, &m_node.chainman->ActiveChainstate().CoinsTip(),
             STANDARD_SCRIPT_VERIFY_FLAGS | SCRIPT_ENFORCE_SIGCHECKS, true, true,
             txdata, nSigChecksDummy, &scriptchecks));
         // Should get 2 script checks back -- caching is on a whole-transaction
         // basis.
         BOOST_CHECK_EQUAL(scriptchecks.size(), 2U);
 
         // Execute the first check, and check its result
         BOOST_CHECK(scriptchecks[0]());
         BOOST_CHECK_EQUAL(scriptchecks[0].GetScriptError(), ScriptError::OK);
         BOOST_CHECK_EQUAL(
             scriptchecks[0].GetScriptExecutionMetrics().nSigChecks, 1);
         // The second check does fail
         BOOST_CHECK(!scriptchecks[1]());
         BOOST_CHECK_EQUAL(scriptchecks[1].GetScriptError(),
                           ScriptError::INVALID_STACK_OPERATION);
     }
 }
 
 BOOST_AUTO_TEST_CASE(scriptcache_values) {
     LOCK(cs_main);
     // Test insertion and querying of keys&values from the script cache.
 
     // Define a couple of macros (handier than functions since errors will print
     // out the correct line number)
 #define CHECK_CACHE_HAS(key, expected_sigchecks)                               \
     {                                                                          \
         int nSigChecksRet(0x12345678 ^ (expected_sigchecks));                  \
         BOOST_CHECK(IsKeyInScriptCache(key, false, nSigChecksRet));            \
         BOOST_CHECK(nSigChecksRet == (expected_sigchecks));                    \
     }
 #define CHECK_CACHE_MISSING(key)                                               \
     {                                                                          \
         int dummy;                                                             \
         BOOST_CHECK(!IsKeyInScriptCache(key, false, dummy));                   \
     }
 
     // construct four distinct keys from very slightly different data
     CMutableTransaction tx1;
     tx1.nVersion = 1;
     CMutableTransaction tx2;
     tx2.nVersion = 2;
     uint32_t flagsA = 0x7fffffff;
     uint32_t flagsB = 0xffffffff;
     ScriptCacheKey key1A(CTransaction(tx1), flagsA);
     ScriptCacheKey key1B(CTransaction(tx1), flagsB);
     ScriptCacheKey key2A(CTransaction(tx2), flagsA);
     ScriptCacheKey key2B(CTransaction(tx2), flagsB);
 
     BOOST_CHECK(key1A == key1A);
     BOOST_CHECK(!(key1A == key1B));
     BOOST_CHECK(!(key1A == key2A));
     BOOST_CHECK(!(key1A == key2B));
     BOOST_CHECK(key1B == key1B);
     BOOST_CHECK(!(key1B == key2A));
     BOOST_CHECK(!(key1B == key2B));
     BOOST_CHECK(key2A == key2A);
     BOOST_CHECK(!(key2A == key2B));
     BOOST_CHECK(key2B == key2B);
 
     // Key is not yet inserted.
     CHECK_CACHE_MISSING(key1A);
     // Add the key and check it worked
     AddKeyInScriptCache(key1A, 42);
     CHECK_CACHE_HAS(key1A, 42);
 
     CHECK_CACHE_MISSING(key1B);
     CHECK_CACHE_MISSING(key2A);
     CHECK_CACHE_MISSING(key2B);
 
     // 0 may be stored
     AddKeyInScriptCache(key1B, 0);
 
     // Calculate the most possible transaction sigchecks that can occur in a
     // standard transaction, and make sure the cache can hold it.
     //
     // To be pessimistic, use consensus (MAX_TX_SIZE) instead of policy
     // (MAX_STANDARD_TX_SIZE) since that particular policy limit is bypassed on
     // testnet.
     //
     // Assume that a standardness rule limiting density to ~33 bytes/sigcheck is
     // in place.
     const int max_standard_sigchecks = 1 + (MAX_TX_SIZE / 33);
     AddKeyInScriptCache(key2A, max_standard_sigchecks);
 
     // Read out values again.
     CHECK_CACHE_HAS(key1A, 42);
     CHECK_CACHE_HAS(key1B, 0);
     CHECK_CACHE_HAS(key2A, max_standard_sigchecks);
     CHECK_CACHE_MISSING(key2B);
 
     // Try overwriting an existing entry with different value (should never
     // happen in practice but see what happens).
     AddKeyInScriptCache(key1A, 99);
     // This succeeds without error, but (currently) no replacement is done.
     // It would also be acceptable to overwrite, but if we ever come to a
     // situation where this matters then neither alternative is better.
     CHECK_CACHE_HAS(key1A, 42);
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/validation_chainstatemanager_tests.cpp b/src/test/validation_chainstatemanager_tests.cpp
index 463874246..1893d8545 100644
--- a/src/test/validation_chainstatemanager_tests.cpp
+++ b/src/test/validation_chainstatemanager_tests.cpp
@@ -1,736 +1,736 @@
 // Copyright (c) 2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 //
 #include <chainparams.h>
 #include <config.h>
 #include <consensus/validation.h>
 #include <kernel/disconnected_transactions.h>
 #include <node/utxo_snapshot.h>
 #include <random.h>
 #include <rpc/blockchain.h>
 #include <sync.h>
 #include <test/util/chainstate.h>
 #include <test/util/setup_common.h>
 #include <timedata.h>
 #include <validation.h>
 #include <validationinterface.h>
 
 #include <tinyformat.h>
 
 #include <vector>
 
 #include <boost/test/unit_test.hpp>
 
 using node::SnapshotMetadata;
 
 BOOST_FIXTURE_TEST_SUITE(validation_chainstatemanager_tests, ChainTestingSetup)
 
 //! Basic tests for ChainstateManager.
 //!
 //! First create a legacy (IBD) chainstate, then create a snapshot chainstate.
 BOOST_AUTO_TEST_CASE(chainstatemanager) {
     ChainstateManager &manager = *m_node.chainman;
     CTxMemPool &mempool = *m_node.mempool;
 
     std::vector<Chainstate *> chainstates;
 
     BOOST_CHECK(!manager.SnapshotBlockhash().has_value());
 
     // Create a legacy (IBD) chainstate.
     //
     Chainstate &c1 =
         WITH_LOCK(::cs_main, return manager.InitializeChainstate(&mempool));
     chainstates.push_back(&c1);
     c1.InitCoinsDB(
         /* cache_size_bytes */ 1 << 23, /* in_memory */ true,
         /* should_wipe */ false);
     WITH_LOCK(::cs_main, c1.InitCoinsCache(1 << 23));
 
     BOOST_CHECK(!manager.IsSnapshotActive());
     BOOST_CHECK(WITH_LOCK(::cs_main, return !manager.IsSnapshotValidated()));
     auto all = manager.GetAll();
     BOOST_CHECK_EQUAL_COLLECTIONS(all.begin(), all.end(), chainstates.begin(),
                                   chainstates.end());
 
     auto &active_chain =
         WITH_LOCK(manager.GetMutex(), return manager.ActiveChain());
     BOOST_CHECK_EQUAL(&active_chain, &c1.m_chain);
 
     BOOST_CHECK_EQUAL(
         WITH_LOCK(manager.GetMutex(), return manager.ActiveHeight()), -1);
 
     auto active_tip = WITH_LOCK(manager.GetMutex(), return manager.ActiveTip());
     auto exp_tip = c1.m_chain.Tip();
     BOOST_CHECK_EQUAL(active_tip, exp_tip);
 
     BOOST_CHECK(!manager.SnapshotBlockhash().has_value());
 
     // Create a snapshot-based chainstate.
     //
     const BlockHash snapshot_blockhash{GetRandHash()};
     Chainstate &c2 = WITH_LOCK(
         ::cs_main,
         return manager.ActivateExistingSnapshot(&mempool, snapshot_blockhash));
     chainstates.push_back(&c2);
 
     BOOST_CHECK_EQUAL(manager.SnapshotBlockhash().value(), snapshot_blockhash);
 
     c2.InitCoinsDB(
         /* cache_size_bytes */ 1 << 23, /* in_memory */ true,
         /* should_wipe */ false);
     WITH_LOCK(::cs_main, c2.InitCoinsCache(1 << 23));
     // Unlike c1, which doesn't have any blocks. Gets us different tip, height.
     c2.LoadGenesisBlock();
     BlockValidationState _;
     BOOST_CHECK(c2.ActivateBestChain(GetConfig(), _, nullptr));
 
     BOOST_CHECK(manager.IsSnapshotActive());
     BOOST_CHECK(WITH_LOCK(::cs_main, return !manager.IsSnapshotValidated()));
     BOOST_CHECK_EQUAL(&c2, &manager.ActiveChainstate());
     BOOST_CHECK(&c1 != &manager.ActiveChainstate());
     auto all2 = manager.GetAll();
     BOOST_CHECK_EQUAL_COLLECTIONS(all2.begin(), all2.end(), chainstates.begin(),
                                   chainstates.end());
 
     auto &active_chain2 =
         WITH_LOCK(manager.GetMutex(), return manager.ActiveChain());
     BOOST_CHECK_EQUAL(&active_chain2, &c2.m_chain);
 
     BOOST_CHECK_EQUAL(
         WITH_LOCK(manager.GetMutex(), return manager.ActiveHeight()), 0);
 
     auto active_tip2 =
         WITH_LOCK(manager.GetMutex(), return manager.ActiveTip());
     auto exp_tip2 = c2.m_chain.Tip();
     BOOST_CHECK_EQUAL(active_tip2, exp_tip2);
 
     // Ensure that these pointers actually correspond to different
     // CCoinsViewCache instances.
     BOOST_CHECK(exp_tip != exp_tip2);
 
     // Let scheduler events finish running to avoid accessing memory that is
     // going to be unloaded
     SyncWithValidationInterfaceQueue();
 }
 
 //! Test rebalancing the caches associated with each chainstate.
 BOOST_AUTO_TEST_CASE(chainstatemanager_rebalance_caches) {
     ChainstateManager &manager = *m_node.chainman;
     CTxMemPool &mempool = *m_node.mempool;
 
     size_t max_cache = 10000;
     manager.m_total_coinsdb_cache = max_cache;
     manager.m_total_coinstip_cache = max_cache;
 
     std::vector<Chainstate *> chainstates;
 
     // Create a legacy (IBD) chainstate.
     //
     Chainstate &c1 =
-        WITH_LOCK(cs_main, return manager.InitializeChainstate(&mempool));
+        WITH_LOCK(::cs_main, return manager.InitializeChainstate(&mempool));
     chainstates.push_back(&c1);
     c1.InitCoinsDB(
         /* cache_size_bytes */ 1 << 23, /* in_memory */ true,
         /* should_wipe */ false);
 
     {
         LOCK(::cs_main);
         c1.InitCoinsCache(1 << 23);
         BOOST_REQUIRE(c1.LoadGenesisBlock());
         c1.CoinsTip().SetBestBlock(BlockHash{InsecureRand256()});
         manager.MaybeRebalanceCaches();
     }
 
     BOOST_CHECK_EQUAL(c1.m_coinstip_cache_size_bytes, max_cache);
     BOOST_CHECK_EQUAL(c1.m_coinsdb_cache_size_bytes, max_cache);
 
     // Create a snapshot-based chainstate.
     //
     Chainstate &c2 =
         WITH_LOCK(cs_main, return manager.ActivateExistingSnapshot(
                                &mempool, BlockHash{GetRandHash()}));
     chainstates.push_back(&c2);
     c2.InitCoinsDB(
         /* cache_size_bytes */ 1 << 23, /* in_memory */ true,
         /* should_wipe */ false);
 
     {
         LOCK(::cs_main);
         c2.InitCoinsCache(1 << 23);
         BOOST_REQUIRE(c2.LoadGenesisBlock());
         c2.CoinsTip().SetBestBlock(BlockHash{InsecureRand256()});
         manager.MaybeRebalanceCaches();
     }
 
     // Since both chainstates are considered to be in initial block download,
     // the snapshot chainstate should take priority.
     BOOST_CHECK_CLOSE(c1.m_coinstip_cache_size_bytes, max_cache * 0.05, 1);
     BOOST_CHECK_CLOSE(c1.m_coinsdb_cache_size_bytes, max_cache * 0.05, 1);
     BOOST_CHECK_CLOSE(c2.m_coinstip_cache_size_bytes, max_cache * 0.95, 1);
     BOOST_CHECK_CLOSE(c2.m_coinsdb_cache_size_bytes, max_cache * 0.95, 1);
 }
 
 struct SnapshotTestSetup : TestChain100Setup {
     // Run with coinsdb on the filesystem to support, e.g., moving invalidated
     // chainstate dirs to "*_invalid".
     //
     // Note that this means the tests run considerably slower than in-memory DB
     // tests, but we can't otherwise test this functionality since it relies on
     // destructive filesystem operations.
     SnapshotTestSetup()
         : TestChain100Setup{
               {},
               {},
               /*coins_db_in_memory=*/false,
               /*block_tree_db_in_memory=*/false,
           } {}
 
     std::tuple<Chainstate *, Chainstate *> SetupSnapshot() {
         ChainstateManager &chainman = *Assert(m_node.chainman);
 
         BOOST_CHECK(!chainman.IsSnapshotActive());
 
         {
             LOCK(::cs_main);
             BOOST_CHECK(!chainman.IsSnapshotValidated());
             BOOST_CHECK(!node::FindSnapshotChainstateDir());
         }
 
         size_t initial_size;
         size_t initial_total_coins{100};
 
         // Make some initial assertions about the contents of the chainstate.
         {
             LOCK(::cs_main);
             CCoinsViewCache &ibd_coinscache =
                 chainman.ActiveChainstate().CoinsTip();
             initial_size = ibd_coinscache.GetCacheSize();
             size_t total_coins{0};
 
             for (CTransactionRef &txn : m_coinbase_txns) {
                 COutPoint op{txn->GetId(), 0};
                 BOOST_CHECK(ibd_coinscache.HaveCoin(op));
                 total_coins++;
             }
 
             BOOST_CHECK_EQUAL(total_coins, initial_total_coins);
             BOOST_CHECK_EQUAL(initial_size, initial_total_coins);
         }
 
         Chainstate &validation_chainstate = chainman.ActiveChainstate();
 
         // Snapshot should refuse to load at this height.
         BOOST_REQUIRE(!CreateAndActivateUTXOSnapshot(this));
         BOOST_CHECK(!chainman.ActiveChainstate().m_from_snapshot_blockhash);
         BOOST_CHECK(!chainman.SnapshotBlockhash());
 
         // Mine 10 more blocks, putting at us height 110 where a valid
         // assumeutxo value can be found.
         constexpr int snapshot_height = 110;
         mineBlocks(10);
         initial_size += 10;
         initial_total_coins += 10;
 
         // Should not load malleated snapshots
         BOOST_REQUIRE(!CreateAndActivateUTXOSnapshot(
             this, [](AutoFile &auto_infile, SnapshotMetadata &metadata) {
                 // A UTXO is missing but count is correct
                 metadata.m_coins_count -= 1;
 
                 COutPoint outpoint;
                 Coin coin;
 
                 auto_infile >> outpoint;
                 auto_infile >> coin;
             }));
 
         BOOST_CHECK(!node::FindSnapshotChainstateDir());
 
         BOOST_REQUIRE(!CreateAndActivateUTXOSnapshot(
             this, [](AutoFile &auto_infile, SnapshotMetadata &metadata) {
                 // Coins count is larger than coins in file
                 metadata.m_coins_count += 1;
             }));
         BOOST_REQUIRE(!CreateAndActivateUTXOSnapshot(
             this, [](AutoFile &auto_infile, SnapshotMetadata &metadata) {
                 // Coins count is smaller than coins in file
                 metadata.m_coins_count -= 1;
             }));
         BOOST_REQUIRE(!CreateAndActivateUTXOSnapshot(
             this, [](AutoFile &auto_infile, SnapshotMetadata &metadata) {
                 // Wrong hash
                 metadata.m_base_blockhash = BlockHash{uint256::ZERO};
             }));
         BOOST_REQUIRE(!CreateAndActivateUTXOSnapshot(
             this, [](AutoFile &auto_infile, SnapshotMetadata &metadata) {
                 // Wrong hash
                 metadata.m_base_blockhash = BlockHash{uint256::ONE};
             }));
 
         BOOST_REQUIRE(CreateAndActivateUTXOSnapshot(this));
         BOOST_CHECK(fs::exists(*node::FindSnapshotChainstateDir()));
 
         // Ensure our active chain is the snapshot chainstate.
         BOOST_CHECK(
             !chainman.ActiveChainstate().m_from_snapshot_blockhash->IsNull());
         BOOST_CHECK_EQUAL(
             *chainman.ActiveChainstate().m_from_snapshot_blockhash,
             *chainman.SnapshotBlockhash());
 
         Chainstate &snapshot_chainstate = chainman.ActiveChainstate();
 
         {
             LOCK(::cs_main);
 
             fs::path found = *node::FindSnapshotChainstateDir();
 
             // Note: WriteSnapshotBaseBlockhash() is implicitly tested above.
             BOOST_CHECK_EQUAL(*node::ReadSnapshotBaseBlockhash(found),
                               *chainman.SnapshotBlockhash());
 
             // Ensure that the genesis block was not marked assumed-valid.
             BOOST_CHECK(!chainman.ActiveChain().Genesis()->IsAssumedValid());
         }
 
         const AssumeutxoData &au_data = *ExpectedAssumeutxo(
             snapshot_height, ::GetConfig().GetChainParams());
         const CBlockIndex *tip =
             WITH_LOCK(chainman.GetMutex(), return chainman.ActiveTip());
 
         BOOST_CHECK_EQUAL(tip->nChainTx, au_data.nChainTx);
 
         // To be checked against later when we try loading a subsequent
         // snapshot.
         BlockHash loaded_snapshot_blockhash{*chainman.SnapshotBlockhash()};
 
         // Make some assertions about the both chainstates. These checks ensure
         // the legacy chainstate hasn't changed and that the newly created
         // chainstate reflects the expected content.
         {
             LOCK(::cs_main);
             int chains_tested{0};
 
             for (Chainstate *chainstate : chainman.GetAll()) {
                 BOOST_TEST_MESSAGE("Checking coins in "
                                    << chainstate->ToString());
                 CCoinsViewCache &coinscache = chainstate->CoinsTip();
 
                 // Both caches will be empty initially.
                 BOOST_CHECK_EQUAL((unsigned int)0, coinscache.GetCacheSize());
 
                 size_t total_coins{0};
 
                 for (CTransactionRef &txn : m_coinbase_txns) {
                     COutPoint op{txn->GetId(), 0};
                     BOOST_CHECK(coinscache.HaveCoin(op));
                     total_coins++;
                 }
 
                 BOOST_CHECK_EQUAL(initial_size, coinscache.GetCacheSize());
                 BOOST_CHECK_EQUAL(total_coins, initial_total_coins);
                 chains_tested++;
             }
 
             BOOST_CHECK_EQUAL(chains_tested, 2);
         }
 
         // Mine some new blocks on top of the activated snapshot chainstate.
         constexpr size_t new_coins{100};
         mineBlocks(new_coins); // Defined in TestChain100Setup.
 
         {
             LOCK(::cs_main);
             size_t coins_in_active{0};
             size_t coins_in_background{0};
             size_t coins_missing_from_background{0};
 
             for (Chainstate *chainstate : chainman.GetAll()) {
                 BOOST_TEST_MESSAGE("Checking coins in "
                                    << chainstate->ToString());
                 CCoinsViewCache &coinscache = chainstate->CoinsTip();
                 bool is_background = chainstate != &chainman.ActiveChainstate();
 
                 for (CTransactionRef &txn : m_coinbase_txns) {
                     COutPoint op{txn->GetId(), 0};
                     if (coinscache.HaveCoin(op)) {
                         (is_background ? coins_in_background
                                        : coins_in_active)++;
                     } else if (is_background) {
                         coins_missing_from_background++;
                     }
                 }
             }
 
             BOOST_CHECK_EQUAL(coins_in_active, initial_total_coins + new_coins);
             BOOST_CHECK_EQUAL(coins_in_background, initial_total_coins);
             BOOST_CHECK_EQUAL(coins_missing_from_background, new_coins);
         }
 
         // Snapshot should refuse to load after one has already loaded.
         BOOST_REQUIRE(!CreateAndActivateUTXOSnapshot(this));
 
         // Snapshot blockhash should be unchanged.
         BOOST_CHECK_EQUAL(
             *chainman.ActiveChainstate().m_from_snapshot_blockhash,
             loaded_snapshot_blockhash);
         return std::make_tuple(&validation_chainstate, &snapshot_chainstate);
     }
 
     //! Simulate a restart of the node by flushing all state to disk, clearing
     //! the existing ChainstateManager, and unloading the block index.
     //!
     //! @returns a reference to the "restarted" ChainstateManager
     ChainstateManager &SimulateNodeRestart() {
         ChainstateManager &chainman = *Assert(m_node.chainman);
 
         BOOST_TEST_MESSAGE("Simulating node restart");
         {
             for (Chainstate *cs : chainman.GetAll()) {
                 LOCK(::cs_main);
                 cs->ForceFlushStateToDisk();
             }
             // Process all callbacks referring to the old manager before wiping
             // it.
             SyncWithValidationInterfaceQueue();
             LOCK(::cs_main);
             chainman.ResetChainstates();
             BOOST_CHECK_EQUAL(chainman.GetAll().size(), 0);
             const ChainstateManager::Options chainman_opts{
                 .config = ::GetConfig(),
                 .adjusted_time_callback = GetAdjustedTime,
             };
             // For robustness, ensure the old manager is destroyed before
             // creating a new one.
             m_node.chainman.reset();
             m_node.chainman.reset(new ChainstateManager(chainman_opts));
         }
         return *Assert(m_node.chainman);
     }
 };
 
 //! Test basic snapshot activation.
 BOOST_FIXTURE_TEST_CASE(chainstatemanager_activate_snapshot,
                         SnapshotTestSetup) {
     this->SetupSnapshot();
 }
 
 //! Test LoadBlockIndex behavior when multiple chainstates are in use.
 //!
 //! - First, verfiy that setBlockIndexCandidates is as expected when using a
 //!   single, fully-validating chainstate.
 //!
 //! - Then mark a region of the chain BLOCK_ASSUMED_VALID and introduce a second
 //!   chainstate that will tolerate assumed-valid blocks. Run LoadBlockIndex()
 //!   and ensure that the first chainstate only contains fully validated blocks
 //!   and the other chainstate contains all blocks, even those assumed-valid.
 //!
 BOOST_FIXTURE_TEST_CASE(chainstatemanager_loadblockindex, TestChain100Setup) {
     ChainstateManager &chainman = *Assert(m_node.chainman);
     CBlockIndex *assumed_tip{
         WITH_LOCK(chainman.GetMutex(), return chainman.ActiveTip())};
 
     auto reload_all_block_indexes = [&]() {
         for (Chainstate *cs : chainman.GetAll()) {
             LOCK(::cs_main);
             cs->UnloadBlockIndex();
             BOOST_CHECK(cs->setBlockIndexCandidates.empty());
         }
 
         WITH_LOCK(::cs_main, chainman.LoadBlockIndex());
     };
 
     // Ensure that without any assumed-valid BlockIndex entries, all entries are
     // considered tip candidates.
     reload_all_block_indexes();
     Chainstate &cs1 = chainman.ActiveChainstate();
     BOOST_CHECK_EQUAL(cs1.setBlockIndexCandidates.size(),
                       cs1.m_chain.Height() + 1);
 
     // Mark some region of the chain assumed-valid.
     int num_indexes{0};
     int num_assumed_valid{0};
     const int expected_assumed_valid{20};
     const int last_assumed_valid_idx{40};
     const int assumed_valid_start_idx =
         last_assumed_valid_idx - expected_assumed_valid;
 
     CBlockIndex *validated_tip{nullptr};
     for (int i = 0; i <= cs1.m_chain.Height(); ++i) {
         LOCK(::cs_main);
         auto index = cs1.m_chain[i];
 
         if (i < last_assumed_valid_idx && i >= assumed_valid_start_idx) {
             index->nStatus = BlockStatus()
                                  .withValidity(BlockValidity::TREE)
                                  .withAssumedValid();
         }
 
         ++num_indexes;
         if (index->IsAssumedValid()) {
             ++num_assumed_valid;
         }
 
         // Note the last fully-validated block as the expected validated tip.
         if (i == (assumed_valid_start_idx - 1)) {
             validated_tip = index;
             BOOST_CHECK(!index->IsAssumedValid());
         }
     }
 
     BOOST_CHECK_EQUAL(expected_assumed_valid, num_assumed_valid);
 
     Chainstate &cs2 =
         *WITH_LOCK(::cs_main, return &chainman.ActivateExistingSnapshot(
                                   &*m_node.mempool, BlockHash{GetRandHash()}));
 
     reload_all_block_indexes();
 
     // The fully validated chain only has candidates up to the start of the
     // assumed-valid blocks.
     BOOST_CHECK_EQUAL(cs1.setBlockIndexCandidates.count(validated_tip), 1);
     BOOST_CHECK_EQUAL(cs1.setBlockIndexCandidates.count(assumed_tip), 0);
     BOOST_CHECK_EQUAL(cs1.setBlockIndexCandidates.size(),
                       assumed_valid_start_idx);
 
     // The assumed-valid tolerant chain has all blocks as candidates.
     BOOST_CHECK_EQUAL(cs2.setBlockIndexCandidates.count(validated_tip), 1);
     BOOST_CHECK_EQUAL(cs2.setBlockIndexCandidates.count(assumed_tip), 1);
     BOOST_CHECK_EQUAL(cs2.setBlockIndexCandidates.size(), num_indexes);
 }
 
 //! Ensure that snapshot chainstates initialize properly when found on disk.
 BOOST_FIXTURE_TEST_CASE(chainstatemanager_snapshot_init, SnapshotTestSetup) {
     ChainstateManager &chainman = *Assert(m_node.chainman);
     Chainstate &bg_chainstate = chainman.ActiveChainstate();
 
     this->SetupSnapshot();
 
     fs::path snapshot_chainstate_dir = *node::FindSnapshotChainstateDir();
     BOOST_CHECK(fs::exists(snapshot_chainstate_dir));
     BOOST_CHECK_EQUAL(snapshot_chainstate_dir,
                       gArgs.GetDataDirNet() / "chainstate_snapshot");
 
     BOOST_CHECK(chainman.IsSnapshotActive());
     const BlockHash snapshot_tip_hash = WITH_LOCK(
         chainman.GetMutex(), return chainman.ActiveTip()->GetBlockHash());
 
     auto all_chainstates = chainman.GetAll();
     BOOST_CHECK_EQUAL(all_chainstates.size(), 2);
 
     // "Rewind" the background chainstate so that its tip is not at the
     // base block of the snapshot - this is so after simulating a node restart,
     // it will initialize instead of attempting to complete validation.
     //
     // Note that this is not a realistic use of DisconnectTip().
     DisconnectedBlockTransactions unused_pool;
     BlockValidationState unused_state;
     {
         LOCK2(::cs_main, bg_chainstate.MempoolMutex());
         BOOST_CHECK(bg_chainstate.DisconnectTip(unused_state, &unused_pool));
         // to avoid queuedTx assertion errors on teardown
         unused_pool.clear();
     }
     BOOST_CHECK_EQUAL(bg_chainstate.m_chain.Height(), 109);
 
     // Test that simulating a shutdown (resetting ChainstateManager) and then
     // performing chainstate reinitializing successfully cleans up the
     // background-validation chainstate data, and we end up with a single
     // chainstate that is at tip.
     ChainstateManager &chainman_restarted = this->SimulateNodeRestart();
 
     BOOST_TEST_MESSAGE("Performing Load/Verify/Activate of chainstate");
 
     // This call reinitializes the chainstates.
     this->LoadVerifyActivateChainstate(::GetConfig());
 
     {
         LOCK(chainman_restarted.GetMutex());
         BOOST_CHECK_EQUAL(chainman_restarted.GetAll().size(), 2);
         BOOST_CHECK(chainman_restarted.IsSnapshotActive());
         BOOST_CHECK(!chainman_restarted.IsSnapshotValidated());
 
         BOOST_CHECK_EQUAL(chainman_restarted.ActiveTip()->GetBlockHash(),
                           snapshot_tip_hash);
         BOOST_CHECK_EQUAL(chainman_restarted.ActiveHeight(), 210);
     }
 
     BOOST_TEST_MESSAGE("Ensure we can mine blocks on top of the initialized "
                        "snapshot chainstate");
     mineBlocks(10);
     {
         LOCK(chainman_restarted.GetMutex());
         BOOST_CHECK_EQUAL(chainman_restarted.ActiveHeight(), 220);
 
         // Background chainstate should be unaware of new blocks on the snapshot
         // chainstate.
         for (const Chainstate *cs : chainman_restarted.GetAll()) {
             if (cs != &chainman_restarted.ActiveChainstate()) {
                 BOOST_CHECK_EQUAL(cs->m_chain.Height(), 109);
             }
         }
     }
 }
 
 BOOST_FIXTURE_TEST_CASE(chainstatemanager_snapshot_completion,
                         SnapshotTestSetup) {
     this->SetupSnapshot();
 
     ChainstateManager &chainman = *Assert(m_node.chainman);
     Chainstate &active_cs = chainman.ActiveChainstate();
     auto tip_cache_before_complete = active_cs.m_coinstip_cache_size_bytes;
     auto db_cache_before_complete = active_cs.m_coinsdb_cache_size_bytes;
 
     SnapshotCompletionResult res;
     auto mock_shutdown = [](bilingual_str msg) {};
 
     fs::path snapshot_chainstate_dir = *node::FindSnapshotChainstateDir();
     BOOST_CHECK(fs::exists(snapshot_chainstate_dir));
     BOOST_CHECK_EQUAL(snapshot_chainstate_dir,
                       gArgs.GetDataDirNet() / "chainstate_snapshot");
 
     BOOST_CHECK(chainman.IsSnapshotActive());
     const BlockHash snapshot_tip_hash = WITH_LOCK(
         chainman.GetMutex(), return chainman.ActiveTip()->GetBlockHash());
 
     res = WITH_LOCK(::cs_main, return chainman.MaybeCompleteSnapshotValidation(
                                    mock_shutdown));
     BOOST_CHECK_EQUAL(res, SnapshotCompletionResult::SUCCESS);
 
     WITH_LOCK(::cs_main, BOOST_CHECK(chainman.IsSnapshotValidated()));
     BOOST_CHECK(chainman.IsSnapshotActive());
 
     // Cache should have been rebalanced and reallocated to the "only" remaining
     // chainstate.
     BOOST_CHECK(active_cs.m_coinstip_cache_size_bytes >
                 tip_cache_before_complete);
     BOOST_CHECK(active_cs.m_coinsdb_cache_size_bytes >
                 db_cache_before_complete);
 
     auto all_chainstates = chainman.GetAll();
     BOOST_CHECK_EQUAL(all_chainstates.size(), 1);
     BOOST_CHECK_EQUAL(all_chainstates[0], &active_cs);
 
     // Trying completion again should return false.
     res = WITH_LOCK(::cs_main, return chainman.MaybeCompleteSnapshotValidation(
                                    mock_shutdown));
     BOOST_CHECK_EQUAL(res, SnapshotCompletionResult::SKIPPED);
 
     // The invalid snapshot path should not have been used.
     fs::path snapshot_invalid_dir =
         gArgs.GetDataDirNet() / "chainstate_snapshot_INVALID";
     BOOST_CHECK(!fs::exists(snapshot_invalid_dir));
     // chainstate_snapshot should still exist.
     BOOST_CHECK(fs::exists(snapshot_chainstate_dir));
 
     // Test that simulating a shutdown (reseting ChainstateManager) and then
     // performing chainstate reinitializing successfully cleans up the
     // background-validation chainstate data, and we end up with a single
     // chainstate that is at tip.
     ChainstateManager &chainman_restarted = this->SimulateNodeRestart();
 
     BOOST_TEST_MESSAGE("Performing Load/Verify/Activate of chainstate");
 
     // This call reinitializes the chainstates, and should clean up the now
     // unnecessary background-validation leveldb contents.
     this->LoadVerifyActivateChainstate(::GetConfig());
 
     BOOST_CHECK(!fs::exists(snapshot_invalid_dir));
     // chainstate_snapshot should now *not* exist.
     BOOST_CHECK(!fs::exists(snapshot_chainstate_dir));
 
     const Chainstate &active_cs2 = chainman_restarted.ActiveChainstate();
 
     {
         LOCK(chainman_restarted.GetMutex());
         BOOST_CHECK_EQUAL(chainman_restarted.GetAll().size(), 1);
         BOOST_CHECK(!chainman_restarted.IsSnapshotActive());
         BOOST_CHECK(!chainman_restarted.IsSnapshotValidated());
         BOOST_CHECK(active_cs2.m_coinstip_cache_size_bytes >
                     tip_cache_before_complete);
         BOOST_CHECK(active_cs2.m_coinsdb_cache_size_bytes >
                     db_cache_before_complete);
 
         BOOST_CHECK_EQUAL(chainman_restarted.ActiveTip()->GetBlockHash(),
                           snapshot_tip_hash);
         BOOST_CHECK_EQUAL(chainman_restarted.ActiveHeight(), 210);
     }
 
     BOOST_TEST_MESSAGE(
         "Ensure we can mine blocks on top of the \"new\" IBD chainstate");
     mineBlocks(10);
     {
         LOCK(chainman_restarted.GetMutex());
         BOOST_CHECK_EQUAL(chainman_restarted.ActiveHeight(), 220);
     }
 }
 
 BOOST_FIXTURE_TEST_CASE(chainstatemanager_snapshot_completion_hash_mismatch,
                         SnapshotTestSetup) {
     auto chainstates = this->SetupSnapshot();
     Chainstate &validation_chainstate = *std::get<0>(chainstates);
     ChainstateManager &chainman = *Assert(m_node.chainman);
     SnapshotCompletionResult res;
     auto mock_shutdown = [](bilingual_str msg) {};
 
     // Test tampering with the IBD UTXO set with an extra coin to ensure it
     // causes snapshot completion to fail.
     CCoinsViewCache &ibd_coins =
         WITH_LOCK(::cs_main, return validation_chainstate.CoinsTip());
     CScript script;
     script.assign(InsecureRandBits(6), 0);
     Coin badcoin{CTxOut{int64_t(InsecureRand32()) * SATOSHI, script},
                  /*nHeightIn=*/1, /*IsCoinbase=*/false};
     TxId txid{InsecureRand256()};
     ibd_coins.AddCoin(COutPoint(txid, 0), std::move(badcoin), false);
 
     fs::path snapshot_chainstate_dir =
         gArgs.GetDataDirNet() / "chainstate_snapshot";
     BOOST_CHECK(fs::exists(snapshot_chainstate_dir));
 
     res = WITH_LOCK(::cs_main, return chainman.MaybeCompleteSnapshotValidation(
                                    mock_shutdown));
     BOOST_CHECK_EQUAL(res, SnapshotCompletionResult::HASH_MISMATCH);
 
     auto all_chainstates = chainman.GetAll();
     BOOST_CHECK_EQUAL(all_chainstates.size(), 1);
     BOOST_CHECK_EQUAL(all_chainstates[0], &validation_chainstate);
     BOOST_CHECK_EQUAL(&chainman.ActiveChainstate(), &validation_chainstate);
 
     fs::path snapshot_invalid_dir =
         gArgs.GetDataDirNet() / "chainstate_snapshot_INVALID";
     BOOST_CHECK(fs::exists(snapshot_invalid_dir));
 
     // Test that simulating a shutdown (reseting ChainstateManager) and then
     // performing chainstate reinitializing successfully loads only the
     // fully-validated chainstate data, and we end up with a single chainstate
     // that is at tip.
     ChainstateManager &chainman_restarted = this->SimulateNodeRestart();
 
     BOOST_TEST_MESSAGE("Performing Load/Verify/Activate of chainstate");
 
     // This call reinitializes the chainstates, and should clean up the now
     // unnecessary background-validation leveldb contents.
     this->LoadVerifyActivateChainstate(::GetConfig());
 
     BOOST_CHECK(fs::exists(snapshot_invalid_dir));
     BOOST_CHECK(!fs::exists(snapshot_chainstate_dir));
 
     {
         LOCK(::cs_main);
         BOOST_CHECK_EQUAL(chainman_restarted.GetAll().size(), 1);
         BOOST_CHECK(!chainman_restarted.IsSnapshotActive());
         BOOST_CHECK(!chainman_restarted.IsSnapshotValidated());
         BOOST_CHECK_EQUAL(chainman_restarted.ActiveHeight(), 210);
     }
 
     BOOST_TEST_MESSAGE(
         "Ensure we can mine blocks on top of the \"new\" IBD chainstate");
     mineBlocks(10);
     {
         LOCK(::cs_main);
         BOOST_CHECK_EQUAL(chainman_restarted.ActiveHeight(), 220);
     }
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/txdb.h b/src/txdb.h
index 2b98a987b..e6273ccc5 100644
--- a/src/txdb.h
+++ b/src/txdb.h
@@ -1,143 +1,140 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_TXDB_H
 #define BITCOIN_TXDB_H
 
 #include <blockfileinfo.h>
 #include <coins.h>
 #include <dbwrapper.h>
 #include <flatfile.h>
 #include <fs.h>
+#include <kernel/cs_main.h>
 #include <util/result.h>
 
 #include <cstddef>
 #include <cstdint>
 #include <functional>
 #include <memory>
 #include <optional>
 #include <string>
 #include <utility>
 #include <vector>
 
 struct BlockHash;
 class CBlockFileInfo;
 class CBlockIndex;
 class COutPoint;
 
 namespace Consensus {
 struct Params;
 };
 
 //! min. -dbcache (MiB)
 static constexpr int64_t MIN_DB_CACHE_MB = 4;
 //! max. -dbcache (MiB)
 static constexpr int64_t MAX_DB_CACHE_MB = sizeof(void *) > 4 ? 16384 : 1024;
 //! -dbcache default (MiB)
 static constexpr int64_t DEFAULT_DB_CACHE_MB = 1024;
 //! -dbbatchsize default (bytes)
 static constexpr int64_t DEFAULT_DB_BATCH_SIZE = 16 << 20;
 //! Max memory allocated to block tree DB specific cache, if no -txindex (MiB)
 static constexpr int64_t MAX_BLOCK_DB_CACHE_MB = 2;
 //! Max memory allocated to block tree DB specific cache, if -txindex (MiB)
 // Unlike for the UTXO database, for the txindex scenario the leveldb cache make
 // a meaningful difference:
 // https://github.com/bitcoin/bitcoin/pull/8273#issuecomment-229601991
 static constexpr int64_t MAX_TX_INDEX_CACHE_MB = 1024;
 //! Max memory allocated to all block filter index caches combined in MiB.
 static constexpr int64_t MAX_FILTER_INDEX_CACHE_MB = 1024;
 //! Max memory allocated to coin DB specific cache (MiB)
 static constexpr int64_t MAX_COINS_DB_CACHE_MB = 8;
 
-// Actually declared in validation.cpp; can't include because of circular
-// dependency.
-extern RecursiveMutex cs_main;
-
 /** CCoinsView backed by the coin database (chainstate/) */
 class CCoinsViewDB final : public CCoinsView {
 protected:
     std::unique_ptr<CDBWrapper> m_db;
     fs::path m_ldb_path;
     bool m_is_memory;
 
 public:
     /**
      * @param[in] ldb_path    Location in the filesystem where leveldb data will
      * be stored.
      */
     explicit CCoinsViewDB(fs::path ldb_path, size_t nCacheSize, bool fMemory,
                           bool fWipe);
 
     bool GetCoin(const COutPoint &outpoint, Coin &coin) const override;
     bool HaveCoin(const COutPoint &outpoint) const override;
     BlockHash GetBestBlock() const override;
     std::vector<BlockHash> GetHeadBlocks() const override;
     bool BatchWrite(CCoinsMap &mapCoins, const BlockHash &hashBlock) override;
     CCoinsViewCursor *Cursor() const override;
 
     //! Attempt to update from an older database format.
     //! Returns whether an error occurred.
     bool Upgrade();
     size_t EstimateSize() const override;
 
     //! Dynamically alter the underlying leveldb cache size.
     void ResizeCache(size_t new_cache_size) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     //! @returns filesystem path to on-disk storage or std::nullopt if in
     //! memory.
     std::optional<fs::path> StoragePath() { return m_db->StoragePath(); }
 };
 
 /** Specialization of CCoinsViewCursor to iterate over a CCoinsViewDB */
 class CCoinsViewDBCursor : public CCoinsViewCursor {
 public:
     ~CCoinsViewDBCursor() {}
 
     bool GetKey(COutPoint &key) const override;
     bool GetValue(Coin &coin) const override;
     unsigned int GetValueSize() const override;
 
     bool Valid() const override;
     void Next() override;
 
 private:
     CCoinsViewDBCursor(CDBIterator *pcursorIn, const BlockHash &hashBlockIn)
         : CCoinsViewCursor(hashBlockIn), pcursor(pcursorIn) {}
     std::unique_ptr<CDBIterator> pcursor;
     std::pair<char, COutPoint> keyTmp;
 
     friend class CCoinsViewDB;
 };
 
 /** Access to the block database (blocks/index/) */
 class CBlockTreeDB : public CDBWrapper {
 public:
     explicit CBlockTreeDB(size_t nCacheSize, bool fMemory = false,
                           bool fWipe = false);
 
     bool WriteBatchSync(
         const std::vector<std::pair<int, const CBlockFileInfo *>> &fileInfo,
         int nLastFile, const std::vector<const CBlockIndex *> &blockinfo);
     bool ReadBlockFileInfo(int nFile, CBlockFileInfo &info);
     bool ReadLastBlockFile(int &nFile);
     bool WriteReindexing(bool fReindexing);
     bool IsReindexing() const;
     bool WriteFlag(const std::string &name, bool fValue);
     bool ReadFlag(const std::string &name, bool &fValue);
     bool LoadBlockIndexGuts(
         const Consensus::Params &params,
         std::function<CBlockIndex *(const BlockHash &)> insertBlockIndex)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
     ;
 
     //! Attempt to update from an older database format.
     //! Returns whether an error occurred.
     bool Upgrade();
 };
 
 [[nodiscard]] util::Result<void>
 CheckLegacyTxindex(CBlockTreeDB &block_tree_db);
 
 #endif // BITCOIN_TXDB_H
diff --git a/src/txmempool.h b/src/txmempool.h
index 622b01c9f..7888949ad 100644
--- a/src/txmempool.h
+++ b/src/txmempool.h
@@ -1,612 +1,611 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_TXMEMPOOL_H
 #define BITCOIN_TXMEMPOOL_H
 
 #include <coins.h>
 #include <consensus/amount.h>
 #include <core_memusage.h>
 #include <indirectmap.h>
+#include <kernel/cs_main.h>
 #include <kernel/mempool_entry.h>
 #include <kernel/mempool_options.h>
 #include <policy/packages.h>
 #include <primitives/transaction.h>
 #include <radix.h>
 #include <sync.h>
 #include <uint256radixkey.h>
 #include <util/hasher.h>
 
 #include <boost/multi_index/hashed_index.hpp>
 #include <boost/multi_index/ordered_index.hpp>
 #include <boost/multi_index/sequenced_index.hpp>
 #include <boost/multi_index_container.hpp>
 
 #include <atomic>
 #include <map>
 #include <optional>
 #include <set>
 #include <string>
 #include <unordered_map>
 #include <utility>
 #include <vector>
 
 class CChain;
 class Chainstate;
 class Config;
 
-extern RecursiveMutex cs_main;
-
 /**
  * Fake height value used in Coins to signify they are only in the memory
  * pool(since 0.8)
  */
 static const uint32_t MEMPOOL_HEIGHT = 0x7FFFFFFF;
 
 // extracts a transaction id from CTxMemPoolEntry or CTransactionRef
 struct mempoolentry_txid {
     typedef TxId result_type;
 
     result_type operator()(const CTxMemPoolEntryRef &entry) const {
         return entry->GetTx().GetId();
     }
 
     result_type operator()(const CTransactionRef &tx) const {
         return tx->GetId();
     }
 };
 
 /**
  * Radix tree adapter for storing a CTxMemPoolEntry as a tree element.
  */
 struct MemPoolEntryRadixTreeAdapter {
     Uint256RadixKey getId(const CTxMemPoolEntry &entry) const {
         return entry.GetSharedTx()->GetId();
     }
 };
 
 // used by the entry_time index
 struct CompareTxMemPoolEntryByEntryTime {
     bool operator()(const CTxMemPoolEntryRef &a,
                     const CTxMemPoolEntryRef &b) const {
         return a->GetTime() < b->GetTime();
     }
 };
 
 // used by the entry_id index
 struct CompareTxMemPoolEntryByEntryId {
     bool operator()(const CTxMemPoolEntryRef &a,
                     const CTxMemPoolEntryRef &b) const {
         return a->GetEntryId() < b->GetEntryId();
     }
 };
 
 /**
  * \class CompareTxMemPoolEntryByModifiedFeeRate
  *
  *  Sort by feerate of entry (modfee/vsize) in descending order.
  *  This is used by the block assembler (mining).
  */
 struct CompareTxMemPoolEntryByModifiedFeeRate {
     // Used in tests
     bool operator()(const CTxMemPoolEntry &a, const CTxMemPoolEntry &b) const {
         const CFeeRate frA = a.GetModifiedFeeRate();
         const CFeeRate frB = b.GetModifiedFeeRate();
 
         // Sort by modified fee rate first
         if (frA != frB) {
             return frA > frB;
         }
 
         // Ties are broken by whichever is topologically earlier
         // (this helps mining code avoid some backtracking).
         if (a.GetEntryId() != b.GetEntryId()) {
             return a.GetEntryId() < b.GetEntryId();
         }
 
         // If nothing else, sort by txid (this should never happen as entryID is
         // expected to be unique).
         return a.GetSharedTx()->GetId() < b.GetSharedTx()->GetId();
     }
 
     bool operator()(const CTxMemPoolEntryRef &a,
                     const CTxMemPoolEntryRef &b) const {
         return operator()(*a, *b);
     }
 };
 
 // Multi_index tag names
 struct entry_time {};
 struct modified_feerate {};
 struct entry_id {};
 
 /**
  * Information about a mempool transaction.
  */
 struct TxMempoolInfo {
     /** The transaction itself */
     CTransactionRef tx;
 
     /** Time the transaction entered the mempool. */
     std::chrono::seconds m_time;
 
     /** Fee of the transaction. */
     Amount fee;
 
     /** Virtual size of the transaction. */
     size_t vsize;
 
     /** The fee delta. */
     Amount nFeeDelta;
 };
 
 /**
  * Reason why a transaction was removed from the mempool, this is passed to the
  * notification signal.
  */
 enum class MemPoolRemovalReason {
     //! Expired from mempool
     EXPIRY,
     //! Removed in size limiting
     SIZELIMIT,
     //! Removed for reorganization
     REORG,
     //! Removed for block
     BLOCK,
     //! Removed for conflict with in-block transaction
     CONFLICT,
     //! Removed for replacement
     REPLACED,
     //! Removed by avalanche vote
     AVALANCHE,
 };
 
 /**
  * CTxMemPool stores valid-according-to-the-current-best-chain transactions that
  * may be included in the next block.
  *
  * Transactions are added when they are seen on the network (or created by the
  * local node), but not all transactions seen are added to the pool. For
  * example, the following new transactions will not be added to the mempool:
  * - a transaction which doesn't meet the minimum fee requirements.
  * - a new transaction that double-spends an input of a transaction already in
  * the pool.
  * - a non-standard transaction.
  *
  * CTxMemPool::mapTx, and CTxMemPoolEntry bookkeeping:
  *
  * mapTx is a boost::multi_index that sorts the mempool on 3 criteria:
  * - transaction hash
  * - time in mempool
  * - entry id (this is a topological index)
  *
  * Note: the term "descendant" refers to in-mempool transactions that depend on
  * this one, while "ancestor" refers to in-mempool transactions that a given
  * transaction depends on.
  *
  * When a new transaction is added to the mempool, it has no in-mempool children
  * (because any such children would be an orphan). So in addUnchecked(), we:
  * - update a new entry's setMemPoolParents to include all in-mempool parents
  * - update the new entry's direct parents to include the new tx as a child
  *
  * When a transaction is removed from the mempool, we must:
  * - update all in-mempool parents to not track the tx in setMemPoolChildren
  * - update all in-mempool children to not include it as a parent
  *
  * These happen in UpdateForRemoveFromMempool(). (Note that when removing a
  * transaction along with its descendants, we must calculate that set of
  * transactions to be removed before doing the removal, or else the mempool can
  * be in an inconsistent state where it's impossible to walk the ancestors of a
  * transaction.)
  *
  * In the event of a reorg, the invariant that all newly-added tx's have no
  * in-mempool children must be maintained.  On top of this, we use a topological
  * index (GetEntryId).  As such, we always dump mempool tx's into a disconnect
  * pool on reorg, and simply add them one by one, along with tx's from
  * disconnected blocks, when the reorg is complete.
  */
 class CTxMemPool {
 private:
     //! Value n means that 1 times in n we check.
     const int m_check_ratio;
     //! Used by getblocktemplate to trigger CreateNewBlock() invocation
     std::atomic<uint32_t> nTransactionsUpdated{0};
 
     //! sum of all mempool tx's sizes.
     uint64_t totalTxSize GUARDED_BY(cs);
     //! sum of all mempool tx's fees (NOT modified fee)
     Amount m_total_fee GUARDED_BY(cs);
     //! sum of dynamic memory usage of all the map elements (NOT the maps
     //! themselves)
     uint64_t cachedInnerUsage GUARDED_BY(cs);
 
     mutable int64_t lastRollingFeeUpdate GUARDED_BY(cs);
     mutable bool blockSinceLastRollingFeeBump GUARDED_BY(cs);
     //! minimum fee to get into the pool, decreases exponentially
     mutable double rollingMinimumFeeRate GUARDED_BY(cs);
 
     // In-memory counter for external mempool tracking purposes.
     // This number is incremented once every time a transaction
     // is added or removed from the mempool for any reason.
     mutable uint64_t m_sequence_number GUARDED_BY(cs){1};
 
     void trackPackageRemoved(const CFeeRate &rate) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     bool m_load_tried GUARDED_BY(cs){false};
 
     //! Used by addUnchecked to generate ever-increasing
     //! CTxMemPoolEntry::entryId's
     uint64_t nextEntryId GUARDED_BY(cs) = 1;
 
 public:
     // public only for testing
     static const int ROLLING_FEE_HALFLIFE = 60 * 60 * 12;
 
     typedef boost::multi_index_container<
         CTxMemPoolEntryRef,
         boost::multi_index::indexed_by<
             // indexed by txid
             boost::multi_index::hashed_unique<mempoolentry_txid,
                                               SaltedTxIdHasher>,
             // sorted by fee rate
             boost::multi_index::ordered_non_unique<
                 boost::multi_index::tag<modified_feerate>,
                 boost::multi_index::identity<CTxMemPoolEntryRef>,
                 CompareTxMemPoolEntryByModifiedFeeRate>,
             // sorted by entry time
             boost::multi_index::ordered_non_unique<
                 boost::multi_index::tag<entry_time>,
                 boost::multi_index::identity<CTxMemPoolEntryRef>,
                 CompareTxMemPoolEntryByEntryTime>,
             // sorted topologically (insertion order)
             boost::multi_index::ordered_unique<
                 boost::multi_index::tag<entry_id>,
                 boost::multi_index::identity<CTxMemPoolEntryRef>,
                 CompareTxMemPoolEntryByEntryId>>>
         indexed_transaction_set;
 
     /**
      * This mutex needs to be locked when accessing `mapTx` or other members
      * that are guarded by it.
      *
      * @par Consistency guarantees
      *
      * By design, it is guaranteed that:
      *
      * 1. Locking both `cs_main` and `mempool.cs` will give a view of mempool
      *    that is consistent with current chain tip (`ActiveChain()` and
      *    `CoinsTip()`) and is fully populated. Fully populated means that if
      *    the current active chain is missing transactions that were present in
      *    a previously active chain, all the missing transactions will have been
      *    re-added to the mempool and should be present if they meet size and
      *    consistency constraints.
      *
      * 2. Locking `mempool.cs` without `cs_main` will give a view of a mempool
      *    consistent with some chain that was active since `cs_main` was last
      *    locked, and that is fully populated as described above. It is ok for
      *    code that only needs to query or remove transactions from the mempool
      *    to lock just `mempool.cs` without `cs_main`.
      *
      * To provide these guarantees, it is necessary to lock both `cs_main` and
      * `mempool.cs` whenever adding transactions to the mempool and whenever
      * changing the chain tip. It's necessary to keep both mutexes locked until
      * the mempool is consistent with the new chain tip and fully populated.
      */
     mutable RecursiveMutex cs;
     indexed_transaction_set mapTx GUARDED_BY(cs);
 
     using txiter = indexed_transaction_set::nth_index<0>::type::const_iterator;
     typedef std::set<txiter, CompareIteratorById> setEntries;
     typedef std::set<txiter, CompareIteratorByRevEntryId> setRevTopoEntries;
 
     RadixTree<CTxMemPoolEntry, MemPoolEntryRadixTreeAdapter> finalizedTxs;
 
 private:
     void UpdateParent(txiter entry, txiter parent, bool add)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
     void UpdateChild(txiter entry, txiter child, bool add)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * Track locally submitted transactions to periodically retry initial
      * broadcast
      */
     std::set<TxId> m_unbroadcast_txids GUARDED_BY(cs);
 
     /**
      * Helper function to calculate all in-mempool ancestors of staged_ancestors
      * param@[in]   staged_ancestors    Should contain entries in the mempool.
      * param@[out]  setAncestors        Will be populated with all mempool
      *                                  ancestors.
      */
     bool CalculateAncestors(setEntries &setAncestors,
                             CTxMemPoolEntry::Parents &staged_ancestors) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
 public:
     indirectmap<COutPoint, const CTransaction *> mapNextTx GUARDED_BY(cs);
     std::map<TxId, Amount> mapDeltas GUARDED_BY(cs);
 
     using Options = kernel::MemPoolOptions;
 
     const int64_t m_max_size_bytes;
     const std::chrono::seconds m_expiry;
     const CFeeRate m_min_relay_feerate;
     const CFeeRate m_dust_relay_feerate;
     const bool m_permit_bare_multisig;
     const std::optional<unsigned> m_max_datacarrier_bytes;
     const bool m_require_standard;
 
     /**
      * Create a new CTxMemPool.
      * Sanity checks will be off by default for performance, because otherwise
      * accepting transactions becomes O(N^2) where N is the number of
      * transactions in the pool.
      */
     CTxMemPool(const Options &opts);
     ~CTxMemPool();
 
     /**
      * If sanity-checking is turned on, check makes sure the pool is consistent
      * (does not contain two transactions that spend the same inputs, all inputs
      * are in the mapNextTx array). If sanity-checking is turned off, check does
      * nothing.
      */
     void check(const CCoinsViewCache &active_coins_tip,
                int64_t spendheight) const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     // addUnchecked must update state for all parents of a given transaction,
     // updating child links as necessary.
     void addUnchecked(CTxMemPoolEntryRef entry)
         EXCLUSIVE_LOCKS_REQUIRED(cs, cs_main);
 
     void removeRecursive(const CTransaction &tx, MemPoolRemovalReason reason)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
     void removeConflicts(const CTransaction &tx) EXCLUSIVE_LOCKS_REQUIRED(cs);
     void updateFeeForBlock() EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     void clear();
     // lock free
     void _clear() EXCLUSIVE_LOCKS_REQUIRED(cs);
     bool CompareTopologically(const TxId &txida, const TxId &txidb) const;
     void getAllTxIds(std::vector<TxId> &vtxid) const;
     bool isSpent(const COutPoint &outpoint) const;
     unsigned int GetTransactionsUpdated() const;
     void AddTransactionsUpdated(unsigned int n);
     /**
      * Check that none of this transactions inputs are in the mempool, and thus
      * the tx is not dependent on other mempool transactions to be included in a
      * block.
      */
     bool HasNoInputsOf(const CTransaction &tx) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /** Affect CreateNewBlock prioritisation of transactions */
     void PrioritiseTransaction(const TxId &txid, const Amount nFeeDelta);
     void ApplyDelta(const TxId &txid, Amount &nFeeDelta) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
     void ClearPrioritisation(const TxId &txid) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /** Get the transaction in the pool that spends the same prevout */
     const CTransaction *GetConflictTx(const COutPoint &prevout) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /** Returns an iterator to the given txid, if found */
     std::optional<txiter> GetIter(const TxId &txid) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * Translate a set of txids into a set of pool iterators to avoid repeated
      * lookups.
      */
     setEntries GetIterSet(const std::set<TxId> &txids) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * Remove a set of transactions from the mempool. If a transaction is in
      * this set, then all in-mempool descendants must also be in the set, unless
      * this transaction is being removed for being in a block.
      */
     void RemoveStaged(const setEntries &stage, MemPoolRemovalReason reason)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * Try to calculate all in-mempool ancestors of entry.
      *  (these are all calculated including the tx itself)
      * fSearchForParents = whether to search a tx's vin for in-mempool parents,
      * or look up parents from m_parents. Must be true for entries not in the
      * mempool
      */
     bool CalculateMemPoolAncestors(const CTxMemPoolEntryRef &entry,
                                    setEntries &setAncestors,
                                    bool fSearchForParents = true) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * Populate setDescendants with all in-mempool descendants of hash.
      * Assumes that setDescendants includes all in-mempool descendants of
      * anything already in it.
      */
     void CalculateDescendants(txiter it, setEntries &setDescendants) const
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * The minimum fee to get into the mempool, which may itself not be enough
      * for larger-sized transactions.
      */
     CFeeRate GetMinFee() const { return GetMinFee(m_max_size_bytes); }
     CFeeRate GetMinFee(size_t sizelimit) const;
 
     /**
      * Remove transactions from the mempool until its dynamic size is <=
      * sizelimit. pvNoSpendsRemaining, if set, will be populated with the list
      * of outpoints which are not in mempool which no longer have any spends in
      * this mempool.
      */
     void TrimToSize(size_t sizelimit,
                     std::vector<COutPoint> *pvNoSpendsRemaining = nullptr)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * Expire all transaction (and their dependencies) in the mempool older than
      * time. Return the number of removed transactions.
      */
     int Expire(std::chrono::seconds time) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * Reduce the size of the mempool by expiring and then trimming the mempool.
      */
     void LimitSize(CCoinsViewCache &coins_cache)
         EXCLUSIVE_LOCKS_REQUIRED(cs, ::cs_main);
 
     /**
      * @returns true if we've made an attempt to load the mempool regardless of
      *          whether the attempt was successful or not
      */
     bool GetLoadTried() const;
 
     /**
      * Set whether or not we've made an attempt to load the mempool (regardless
      * of whether the attempt was successful or not)
      */
     void SetLoadTried(bool load_tried);
 
     unsigned long size() const {
         LOCK(cs);
         return mapTx.size();
     }
 
     uint64_t GetTotalTxSize() const EXCLUSIVE_LOCKS_REQUIRED(cs) {
         AssertLockHeld(cs);
         return totalTxSize;
     }
 
     Amount GetTotalFee() const EXCLUSIVE_LOCKS_REQUIRED(cs) {
         AssertLockHeld(cs);
         return m_total_fee;
     }
 
     bool exists(const TxId &txid) const {
         LOCK(cs);
         return mapTx.count(txid) != 0;
     }
 
     bool setAvalancheFinalized(const CTxMemPoolEntryRef &tx)
         EXCLUSIVE_LOCKS_REQUIRED(cs) {
         return finalizedTxs.insert(tx);
     }
 
     bool isAvalancheFinalized(const TxId &txid) const {
         LOCK(cs);
         return finalizedTxs.get(txid) != nullptr;
     }
 
     CTransactionRef get(const TxId &txid) const;
     TxMempoolInfo info(const TxId &txid) const;
     std::vector<TxMempoolInfo> infoAll() const;
 
     CFeeRate estimateFee() const;
 
     size_t DynamicMemoryUsage() const;
 
     /** Adds a transaction to the unbroadcast set */
     void AddUnbroadcastTx(const TxId &txid) {
         LOCK(cs);
         // Sanity check the transaction is in the mempool & insert into
         // unbroadcast set.
         if (exists(txid)) {
             m_unbroadcast_txids.insert(txid);
         }
     }
 
     /** Removes a transaction from the unbroadcast set */
     void RemoveUnbroadcastTx(const TxId &txid, const bool unchecked = false);
 
     /** Returns transactions in unbroadcast set */
     std::set<TxId> GetUnbroadcastTxs() const {
         LOCK(cs);
         return m_unbroadcast_txids;
     }
 
     /** Returns whether a txid is in the unbroadcast set */
     bool IsUnbroadcastTx(const TxId &txid) const EXCLUSIVE_LOCKS_REQUIRED(cs) {
         AssertLockHeld(cs);
         return (m_unbroadcast_txids.count(txid) != 0);
     }
 
     /** Guards this internal counter for external reporting */
     uint64_t GetAndIncrementSequence() const EXCLUSIVE_LOCKS_REQUIRED(cs) {
         return m_sequence_number++;
     }
 
     uint64_t GetSequence() const EXCLUSIVE_LOCKS_REQUIRED(cs) {
         return m_sequence_number;
     }
 
 private:
     /** Set ancestor state for an entry */
     void UpdateEntryForAncestors(txiter it, const setEntries *setAncestors)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
     /**
      * Update parents of `it` to add/remove it as a child transaction.
      */
     void UpdateParentsOf(bool add, txiter it) EXCLUSIVE_LOCKS_REQUIRED(cs);
     /**
      * For each transaction being removed, update ancestors and any direct
      * children.
      */
     void UpdateForRemoveFromMempool(const setEntries &entriesToRemove)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
     /** Sever link between specified transaction and direct children. */
     void UpdateChildrenForRemoval(txiter entry) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /**
      * Before calling removeUnchecked for a given transaction,
      * UpdateForRemoveFromMempool must be called on the entire (dependent) set
      * of transactions being removed at the same time. We use each
      * CTxMemPoolEntry's setMemPoolParents in order to walk ancestors of a given
      * transaction that is removed, so we can't remove intermediate transactions
      * in a chain before we've updated all the state for the removal.
      */
     void removeUnchecked(txiter entry, MemPoolRemovalReason reason)
         EXCLUSIVE_LOCKS_REQUIRED(cs);
 };
 
 /**
  * CCoinsView that brings transactions from a mempool into view.
  * It does not check for spendings by memory pool transactions.
  * Instead, it provides access to all Coins which are either unspent in the
  * base CCoinsView, are outputs from any mempool transaction, or are
  * tracked temporarily to allow transaction dependencies in package validation.
  * This allows transaction replacement to work as expected, as you want to
  * have all inputs "available" to check signatures, and any cycles in the
  * dependency graph are checked directly in AcceptToMemoryPool.
  * It also allows you to sign a double-spend directly in
  * signrawtransactionwithkey and signrawtransactionwithwallet,
  * as long as the conflicting transaction is not yet confirmed.
  */
 class CCoinsViewMemPool : public CCoinsViewBacked {
     /**
      * Coins made available by transactions being validated. Tracking these
      * allows for package validation, since we can access transaction outputs
      * without submitting them to mempool.
      */
     std::unordered_map<COutPoint, Coin, SaltedOutpointHasher> m_temp_added;
 
 protected:
     const CTxMemPool &mempool;
 
 public:
     CCoinsViewMemPool(CCoinsView *baseIn, const CTxMemPool &mempoolIn);
     bool GetCoin(const COutPoint &outpoint, Coin &coin) const override;
     /**
      * Add the coins created by this transaction. These coins are only
      * temporarily stored in m_temp_added and cannot be flushed to the back end.
      * Only used for package validation.
      */
     void PackageAddTransaction(const CTransactionRef &tx);
 };
 
 #endif // BITCOIN_TXMEMPOOL_H
diff --git a/src/validation.cpp b/src/validation.cpp
index de191151d..80c674dbe 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1,6559 +1,6545 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2018 The Bitcoin Core developers
 // Copyright (c) 2017-2020 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <validation.h>
 
 #include <kernel/disconnected_transactions.h>
 #include <kernel/mempool_entry.h>
 #include <kernel/mempool_persist.h>
 
 #include <arith_uint256.h>
 #include <avalanche/avalanche.h>
 #include <avalanche/processor.h>
 #include <blockvalidity.h>
 #include <chainparams.h>
 #include <checkpoints.h>
 #include <checkqueue.h>
 #include <config.h>
 #include <consensus/activation.h>
 #include <consensus/amount.h>
 #include <consensus/merkle.h>
 #include <consensus/tx_check.h>
 #include <consensus/tx_verify.h>
 #include <consensus/validation.h>
 #include <deploymentstatus.h>
 #include <fs.h>
 #include <hash.h>
 #include <index/blockfilterindex.h>
 #include <logging.h>
 #include <logging/timer.h>
 #include <minerfund.h>
 #include <node/blockstorage.h>
 #include <node/coinstats.h>
 #include <node/ui_interface.h>
 #include <node/utxo_snapshot.h>
 #include <policy/block/minerfund.h>
 #include <policy/block/preconsensus.h>
 #include <policy/block/stakingrewards.h>
 #include <policy/policy.h>
 #include <policy/settings.h>
 #include <pow/pow.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <random.h>
 #include <reverse_iterator.h>
 #include <script/script.h>
 #include <script/scriptcache.h>
 #include <script/sigcache.h>
 #include <shutdown.h>
 #include <tinyformat.h>
 #include <txdb.h>
 #include <txmempool.h>
 #include <undo.h>
 #include <util/check.h> // For NDEBUG compile time check
 #include <util/strencodings.h>
 #include <util/string.h>
 #include <util/system.h>
 #include <util/time.h>
 #include <util/trace.h>
 #include <util/translation.h>
 #include <validationinterface.h>
 #include <warnings.h>
 
 #include <algorithm>
 #include <atomic>
 #include <cassert>
 #include <chrono>
 #include <deque>
 #include <numeric>
 #include <optional>
 #include <string>
 #include <thread>
 
 using kernel::LoadMempool;
 
 using fsbridge::FopenFn;
 using node::BLOCKFILE_CHUNK_SIZE;
 using node::BlockManager;
 using node::BlockMap;
 using node::CCoinsStats;
 using node::CoinStatsHashType;
 using node::ComputeUTXOStats;
 using node::fReindex;
 using node::nPruneTarget;
 using node::OpenBlockFile;
 using node::ReadBlockFromDisk;
 using node::SnapshotMetadata;
 using node::UNDOFILE_CHUNK_SIZE;
 using node::UndoReadFromDisk;
 using node::UnlinkPrunedFiles;
 
 #define MICRO 0.000001
 #define MILLI 0.001
 
 /** Time to wait between writing blocks/block index to disk. */
 static constexpr std::chrono::hours DATABASE_WRITE_INTERVAL{1};
 /** Time to wait between flushing chainstate to disk. */
 static constexpr std::chrono::hours DATABASE_FLUSH_INTERVAL{24};
 const std::vector<std::string> CHECKLEVEL_DOC{
     "level 0 reads the blocks from disk",
     "level 1 verifies block validity",
     "level 2 verifies undo data",
     "level 3 checks disconnection of tip blocks",
     "level 4 tries to reconnect the blocks",
     "each level includes the checks of the previous levels",
 };
 
-/**
- * Global state
- *
- * Mutex to guard access to validation specific variables, such as reading
- * or changing the chainstate.
- *
- * This may also need to be locked when updating the transaction pool, e.g. on
- * AcceptToMemoryPool. See CTxMemPool::cs comment for details.
- *
- * The transaction pool has a separate lock to allow reading from it and the
- * chainstate at the same time.
- */
-RecursiveMutex cs_main;
-
 GlobalMutex g_best_block_mutex;
 std::condition_variable g_best_block_cv;
 uint256 g_best_block;
 bool fCheckBlockIndex = false;
 bool fCheckpointsEnabled = DEFAULT_CHECKPOINTS_ENABLED;
 int64_t nMaxTipAge = DEFAULT_MAX_TIP_AGE;
 
 BlockHash hashAssumeValid;
 arith_uint256 nMinimumChainWork;
 
 BlockValidationOptions::BlockValidationOptions(const Config &config)
     : excessiveBlockSize(config.GetMaxBlockSize()), checkPoW(true),
       checkMerkleRoot(true) {}
 
 const CBlockIndex *
 Chainstate::FindForkInGlobalIndex(const CBlockLocator &locator) const {
     AssertLockHeld(cs_main);
 
     // Find the latest block common to locator and chain - we expect that
     // locator.vHave is sorted descending by height.
     for (const BlockHash &hash : locator.vHave) {
         const CBlockIndex *pindex{m_blockman.LookupBlockIndex(hash)};
         if (pindex) {
             if (m_chain.Contains(pindex)) {
                 return pindex;
             }
             if (pindex->GetAncestor(m_chain.Height()) == m_chain.Tip()) {
                 return m_chain.Tip();
             }
         }
     }
     return m_chain.Genesis();
 }
 
 static uint32_t GetNextBlockScriptFlags(const Consensus::Params &params,
                                         const CBlockIndex *pindex);
 
 bool CheckSequenceLocksAtTip(CBlockIndex *tip, const CCoinsView &coins_view,
                              const CTransaction &tx, LockPoints *lp,
                              bool useExistingLockPoints) {
     assert(tip != nullptr);
 
     CBlockIndex index;
     index.pprev = tip;
     // CheckSequenceLocksAtTip() uses active_chainstate.m_chain.Height()+1 to
     // evaluate height based locks because when SequenceLocks() is called within
     // ConnectBlock(), the height of the block *being* evaluated is what is
     // used. Thus if we want to know if a transaction can be part of the *next*
     // block, we need to use one more than active_chainstate.m_chain.Height()
     index.nHeight = tip->nHeight + 1;
 
     std::pair<int, int64_t> lockPair;
     if (useExistingLockPoints) {
         assert(lp);
         lockPair.first = lp->height;
         lockPair.second = lp->time;
     } else {
         std::vector<int> prevheights;
         prevheights.resize(tx.vin.size());
         for (size_t txinIndex = 0; txinIndex < tx.vin.size(); txinIndex++) {
             const CTxIn &txin = tx.vin[txinIndex];
             Coin coin;
             if (!coins_view.GetCoin(txin.prevout, coin)) {
                 return error("%s: Missing input", __func__);
             }
             if (coin.GetHeight() == MEMPOOL_HEIGHT) {
                 // Assume all mempool transaction confirm in the next block
                 prevheights[txinIndex] = tip->nHeight + 1;
             } else {
                 prevheights[txinIndex] = coin.GetHeight();
             }
         }
         lockPair = CalculateSequenceLocks(tx, STANDARD_LOCKTIME_VERIFY_FLAGS,
                                           prevheights, index);
         if (lp) {
             lp->height = lockPair.first;
             lp->time = lockPair.second;
         }
     }
     return EvaluateSequenceLocks(index, lockPair);
 }
 
 // Command-line argument "-replayprotectionactivationtime=<timestamp>" will
 // cause the node to switch to replay protected SigHash ForkID value when the
 // median timestamp of the previous 11 blocks is greater than or equal to
 // <timestamp>. Defaults to the pre-defined timestamp when not set.
 static bool IsReplayProtectionEnabled(const Consensus::Params &params,
                                       int64_t nMedianTimePast) {
     return nMedianTimePast >= gArgs.GetIntArg("-replayprotectionactivationtime",
                                               params.leeKuanYewActivationTime);
 }
 
 static bool IsReplayProtectionEnabled(const Consensus::Params &params,
                                       const CBlockIndex *pindexPrev) {
     if (pindexPrev == nullptr) {
         return false;
     }
 
     return IsReplayProtectionEnabled(params, pindexPrev->GetMedianTimePast());
 }
 
 /**
  * Checks to avoid mempool polluting consensus critical paths since cached
  * signature and script validity results will be reused if we validate this
  * transaction again during block validation.
  */
 static bool CheckInputsFromMempoolAndCache(
     const CTransaction &tx, TxValidationState &state,
     const CCoinsViewCache &view, const CTxMemPool &pool, const uint32_t flags,
     PrecomputedTransactionData &txdata, int &nSigChecksOut,
     CCoinsViewCache &coins_tip) EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs) {
     AssertLockHeld(cs_main);
     AssertLockHeld(pool.cs);
 
     assert(!tx.IsCoinBase());
     for (const CTxIn &txin : tx.vin) {
         const Coin &coin = view.AccessCoin(txin.prevout);
 
         // This coin was checked in PreChecks and MemPoolAccept
         // has been holding cs_main since then.
         Assume(!coin.IsSpent());
         if (coin.IsSpent()) {
             return false;
         }
 
         // If the Coin is available, there are 2 possibilities:
         // it is available in our current ChainstateActive UTXO set,
         // or it's a UTXO provided by a transaction in our mempool.
         // Ensure the scriptPubKeys in Coins from CoinsView are correct.
         const CTransactionRef &txFrom = pool.get(txin.prevout.GetTxId());
         if (txFrom) {
             assert(txFrom->GetId() == txin.prevout.GetTxId());
             assert(txFrom->vout.size() > txin.prevout.GetN());
             assert(txFrom->vout[txin.prevout.GetN()] == coin.GetTxOut());
         } else {
             const Coin &coinFromUTXOSet = coins_tip.AccessCoin(txin.prevout);
             assert(!coinFromUTXOSet.IsSpent());
             assert(coinFromUTXOSet.GetTxOut() == coin.GetTxOut());
         }
     }
 
     // Call CheckInputScripts() to cache signature and script validity against
     // current tip consensus rules.
     return CheckInputScripts(tx, state, view, flags, /*sigCacheStore=*/true,
                              /*scriptCacheStore=*/true, txdata, nSigChecksOut);
 }
 
 namespace {
 
 class MemPoolAccept {
 public:
     MemPoolAccept(CTxMemPool &mempool, Chainstate &active_chainstate)
         : m_pool(mempool), m_view(&m_dummy),
           m_viewmempool(&active_chainstate.CoinsTip(), m_pool),
           m_active_chainstate(active_chainstate) {}
 
     // We put the arguments we're handed into a struct, so we can pass them
     // around easier.
     struct ATMPArgs {
         const Config &m_config;
         const int64_t m_accept_time;
         const bool m_bypass_limits;
         /*
          * Return any outpoints which were not previously present in the coins
          * cache, but were added as a result of validating the tx for mempool
          * acceptance. This allows the caller to optionally remove the cache
          * additions if the associated transaction ends up being rejected by
          * the mempool.
          */
         std::vector<COutPoint> &m_coins_to_uncache;
         const bool m_test_accept;
         const unsigned int m_heightOverride;
         /**
          * When true, the mempool will not be trimmed when individual
          * transactions are submitted in Finalize(). Instead, limits should be
          * enforced at the end to ensure the package is not partially submitted.
          */
         const bool m_package_submission;
 
         /** Parameters for single transaction mempool validation. */
         static ATMPArgs SingleAccept(const Config &config, int64_t accept_time,
                                      bool bypass_limits,
                                      std::vector<COutPoint> &coins_to_uncache,
                                      bool test_accept,
                                      unsigned int heightOverride) {
             return ATMPArgs{config,
                             accept_time,
                             bypass_limits,
                             coins_to_uncache,
                             test_accept,
                             heightOverride,
                             /*package_submission=*/false};
         }
 
         /**
          * Parameters for test package mempool validation through
          * testmempoolaccept.
          */
         static ATMPArgs
         PackageTestAccept(const Config &config, int64_t accept_time,
                           std::vector<COutPoint> &coins_to_uncache) {
             return ATMPArgs{config, accept_time,
                             /*bypass_limits=*/false, coins_to_uncache,
                             /*test_accept=*/true,
                             /*height_override=*/0,
                             // not submitting to mempool
                             /*package_submission=*/false};
         }
 
         /** Parameters for child-with-unconfirmed-parents package validation. */
         static ATMPArgs
         PackageChildWithParents(const Config &config, int64_t accept_time,
                                 std::vector<COutPoint> &coins_to_uncache) {
             return ATMPArgs{config,
                             accept_time,
                             /*bypass_limits=*/false,
                             coins_to_uncache,
                             /*test_accept=*/false,
                             /*height_override=*/0,
                             /*package_submission=*/true};
         }
 
     private:
         // Private ctor to avoid exposing details to clients and allowing the
         // possibility of mixing up the order of the arguments. Use static
         // functions above instead.
         ATMPArgs(const Config &config, int64_t accept_time, bool bypass_limits,
                  std::vector<COutPoint> &coins_to_uncache, bool test_accept,
                  unsigned int height_override, bool package_submission)
             : m_config{config}, m_accept_time{accept_time},
               m_bypass_limits{bypass_limits},
               m_coins_to_uncache{coins_to_uncache}, m_test_accept{test_accept},
               m_heightOverride{height_override}, m_package_submission{
                                                      package_submission} {}
     };
 
     // Single transaction acceptance
     MempoolAcceptResult AcceptSingleTransaction(const CTransactionRef &ptx,
                                                 ATMPArgs &args)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Multiple transaction acceptance. Transactions may or may not be
      * interdependent, but must not conflict with each other, and the
      * transactions cannot already be in the mempool. Parents must come
      * before children if any dependencies exist.
      */
     PackageMempoolAcceptResult
     AcceptMultipleTransactions(const std::vector<CTransactionRef> &txns,
                                ATMPArgs &args)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Package (more specific than just multiple transactions) acceptance.
      * Package must be a child with all of its unconfirmed parents, and
      * topologically sorted.
      */
     PackageMempoolAcceptResult AcceptPackage(const Package &package,
                                              ATMPArgs &args)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 private:
     // All the intermediate state that gets passed between the various levels
     // of checking a given transaction.
     struct Workspace {
         Workspace(const CTransactionRef &ptx,
                   const uint32_t next_block_script_verify_flags)
             : m_ptx(ptx),
               m_next_block_script_verify_flags(next_block_script_verify_flags) {
         }
         /**
          * Mempool entry constructed for this transaction.
          * Constructed in PreChecks() but not inserted into the mempool until
          * Finalize().
          */
         std::unique_ptr<CTxMemPoolEntry> m_entry;
 
         /**
          * Virtual size of the transaction as used by the mempool, calculated
          * using serialized size of the transaction and sigchecks.
          */
         int64_t m_vsize;
         /**
          * Fees paid by this transaction: total input amounts subtracted by
          * total output amounts.
          */
         Amount m_base_fees;
 
         /**
          * Base fees + any fee delta set by the user with
          * prioritisetransaction.
          */
         Amount m_modified_fees;
 
         const CTransactionRef &m_ptx;
         TxValidationState m_state;
         /**
          * A temporary cache containing serialized transaction data for
          * signature verification.
          * Reused across PreChecks and ConsensusScriptChecks.
          */
         PrecomputedTransactionData m_precomputed_txdata;
 
         // ABC specific flags that are used in both PreChecks and
         // ConsensusScriptChecks
         const uint32_t m_next_block_script_verify_flags;
         int m_sig_checks_standard;
     };
 
     // Run the policy checks on a given transaction, excluding any script
     // checks. Looks up inputs, calculates feerate, considers replacement,
     // evaluates package limits, etc. As this function can be invoked for "free"
     // by a peer, only tests that are fast should be done here (to avoid CPU
     // DoS).
     bool PreChecks(ATMPArgs &args, Workspace &ws)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
 
     // Re-run the script checks, using consensus flags, and try to cache the
     // result in the scriptcache. This should be done after
     // PolicyScriptChecks(). This requires that all inputs either be in our
     // utxo set or in the mempool.
     bool ConsensusScriptChecks(const ATMPArgs &args, Workspace &ws)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
 
     // Try to add the transaction to the mempool, removing any conflicts first.
     // Returns true if the transaction is in the mempool after any size
     // limiting is performed, false otherwise.
     bool Finalize(const ATMPArgs &args, Workspace &ws)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
 
     // Submit all transactions to the mempool and call ConsensusScriptChecks to
     // add to the script cache - should only be called after successful
     // validation of all transactions in the package.
     // The package may end up partially-submitted after size limiting;
     // returns true if all transactions are successfully added to the mempool,
     // false otherwise.
     bool SubmitPackage(const ATMPArgs &args, std::vector<Workspace> &workspaces,
                        PackageValidationState &package_state,
                        std::map<const TxId, const MempoolAcceptResult> &results)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
 
 private:
     CTxMemPool &m_pool;
     CCoinsViewCache m_view;
     CCoinsViewMemPool m_viewmempool;
     CCoinsView m_dummy;
 
     Chainstate &m_active_chainstate;
 };
 
 bool MemPoolAccept::PreChecks(ATMPArgs &args, Workspace &ws) {
     AssertLockHeld(cs_main);
     AssertLockHeld(m_pool.cs);
     const CTransactionRef &ptx = ws.m_ptx;
     const CTransaction &tx = *ws.m_ptx;
     const TxId &txid = ws.m_ptx->GetId();
 
     // Copy/alias what we need out of args
     const int64_t nAcceptTime = args.m_accept_time;
     const bool bypass_limits = args.m_bypass_limits;
     std::vector<COutPoint> &coins_to_uncache = args.m_coins_to_uncache;
     const unsigned int heightOverride = args.m_heightOverride;
 
     // Alias what we need out of ws
     TxValidationState &state = ws.m_state;
     // Coinbase is only valid in a block, not as a loose transaction.
     if (!CheckRegularTransaction(tx, state)) {
         // state filled in by CheckRegularTransaction.
         return false;
     }
 
     // Rather not work on nonstandard transactions (unless -testnet)
     std::string reason;
     if (m_pool.m_require_standard &&
         !IsStandardTx(tx, m_pool.m_max_datacarrier_bytes,
                       m_pool.m_permit_bare_multisig,
                       m_pool.m_dust_relay_feerate, reason)) {
         return state.Invalid(TxValidationResult::TX_NOT_STANDARD, reason);
     }
 
     // Only accept nLockTime-using transactions that can be mined in the next
     // block; we don't want our mempool filled up with transactions that can't
     // be mined yet.
     TxValidationState ctxState;
     if (!ContextualCheckTransactionForCurrentBlock(
             m_active_chainstate.m_chain.Tip(),
             args.m_config.GetChainParams().GetConsensus(), tx, ctxState)) {
         // We copy the state from a dummy to ensure we don't increase the
         // ban score of peer for transaction that could be valid in the future.
         return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND,
                              ctxState.GetRejectReason(),
                              ctxState.GetDebugMessage());
     }
 
     // Is it already in the memory pool?
     if (m_pool.exists(txid)) {
         return state.Invalid(TxValidationResult::TX_DUPLICATE,
                              "txn-already-in-mempool");
     }
 
     // Check for conflicts with in-memory transactions
     for (const CTxIn &txin : tx.vin) {
         const CTransaction *ptxConflicting = m_pool.GetConflictTx(txin.prevout);
         if (ptxConflicting) {
             // Disable replacement feature for good
             return state.Invalid(TxValidationResult::TX_CONFLICT,
                                  "txn-mempool-conflict");
         }
     }
 
     LockPoints lp;
     m_view.SetBackend(m_viewmempool);
 
     const CCoinsViewCache &coins_cache = m_active_chainstate.CoinsTip();
     // Do all inputs exist?
     for (const CTxIn &txin : tx.vin) {
         if (!coins_cache.HaveCoinInCache(txin.prevout)) {
             coins_to_uncache.push_back(txin.prevout);
         }
 
         // Note: this call may add txin.prevout to the coins cache
         // (coins_cache.cacheCoins) by way of FetchCoin(). It should be
         // removed later (via coins_to_uncache) if this tx turns out to be
         // invalid.
         if (!m_view.HaveCoin(txin.prevout)) {
             // Are inputs missing because we already have the tx?
             for (size_t out = 0; out < tx.vout.size(); out++) {
                 // Optimistically just do efficient check of cache for
                 // outputs.
                 if (coins_cache.HaveCoinInCache(COutPoint(txid, out))) {
                     return state.Invalid(TxValidationResult::TX_DUPLICATE,
                                          "txn-already-known");
                 }
             }
 
             // Otherwise assume this might be an orphan tx for which we just
             // haven't seen parents yet.
             return state.Invalid(TxValidationResult::TX_MISSING_INPUTS,
                                  "bad-txns-inputs-missingorspent");
         }
     }
 
     // Are the actual inputs available?
     if (!m_view.HaveInputs(tx)) {
         return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
                              "bad-txns-inputs-spent");
     }
 
     // Bring the best block into scope.
     m_view.GetBestBlock();
 
     // we have all inputs cached now, so switch back to dummy (to protect
     // against bugs where we pull more inputs from disk that miss being
     // added to coins_to_uncache)
     m_view.SetBackend(m_dummy);
 
     assert(m_active_chainstate.m_blockman.LookupBlockIndex(
                m_view.GetBestBlock()) == m_active_chainstate.m_chain.Tip());
 
     // Only accept BIP68 sequence locked transactions that can be mined in
     // the next block; we don't want our mempool filled up with transactions
     // that can't be mined yet.
     // Pass in m_view which has all of the relevant inputs cached. Note that,
     // since m_view's backend was removed, it no longer pulls coins from the
     // mempool.
     if (!CheckSequenceLocksAtTip(m_active_chainstate.m_chain.Tip(), m_view, tx,
                                  &lp)) {
         return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND,
                              "non-BIP68-final");
     }
 
     // The mempool holds txs for the next block, so pass height+1 to
     // CheckTxInputs
     if (!Consensus::CheckTxInputs(tx, state, m_view,
                                   m_active_chainstate.m_chain.Height() + 1,
                                   ws.m_base_fees)) {
         // state filled in by CheckTxInputs
         return false;
     }
 
     // Check for non-standard pay-to-script-hash in inputs
     if (m_pool.m_require_standard &&
         !AreInputsStandard(tx, m_view, ws.m_next_block_script_verify_flags)) {
         return state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD,
                              "bad-txns-nonstandard-inputs");
     }
 
     // ws.m_modified_fess includes any fee deltas from PrioritiseTransaction
     ws.m_modified_fees = ws.m_base_fees;
     m_pool.ApplyDelta(txid, ws.m_modified_fees);
 
     unsigned int nSize = tx.GetTotalSize();
 
     // No transactions are allowed below the min relay feerate except from
     // disconnected blocks.
     // Do not change this to use virtualsize without coordinating a network
     // policy upgrade.
     if (!bypass_limits &&
         ws.m_modified_fees < m_pool.m_min_relay_feerate.GetFee(nSize)) {
         return state.Invalid(
             TxValidationResult::TX_MEMPOOL_POLICY, "min relay fee not met",
             strprintf("%d < %d", ws.m_modified_fees,
                       m_pool.m_min_relay_feerate.GetFee(nSize)));
     }
 
     // Validate input scripts against standard script flags.
     const uint32_t scriptVerifyFlags =
         ws.m_next_block_script_verify_flags | STANDARD_SCRIPT_VERIFY_FLAGS;
     ws.m_precomputed_txdata = PrecomputedTransactionData{tx};
     if (!CheckInputScripts(tx, state, m_view, scriptVerifyFlags, true, false,
                            ws.m_precomputed_txdata, ws.m_sig_checks_standard)) {
         // State filled in by CheckInputScripts
         return false;
     }
 
     ws.m_entry = std::make_unique<CTxMemPoolEntry>(
         ptx, ws.m_base_fees, nAcceptTime,
         heightOverride ? heightOverride : m_active_chainstate.m_chain.Height(),
         ws.m_sig_checks_standard, lp);
 
     ws.m_vsize = ws.m_entry->GetTxVirtualSize();
 
     Amount mempoolRejectFee = m_pool.GetMinFee().GetFee(ws.m_vsize);
     if (!bypass_limits && mempoolRejectFee > Amount::zero() &&
         ws.m_modified_fees < mempoolRejectFee) {
         return state.Invalid(
             TxValidationResult::TX_MEMPOOL_POLICY, "mempool min fee not met",
             strprintf("%d < %d", ws.m_modified_fees, mempoolRejectFee));
     }
 
     return true;
 }
 
 bool MemPoolAccept::ConsensusScriptChecks(const ATMPArgs &args, Workspace &ws) {
     AssertLockHeld(cs_main);
     AssertLockHeld(m_pool.cs);
     const CTransaction &tx = *ws.m_ptx;
     const TxId &txid = tx.GetId();
     TxValidationState &state = ws.m_state;
 
     // Check again against the next block's script verification flags
     // to cache our script execution flags.
     //
     // This is also useful in case of bugs in the standard flags that cause
     // transactions to pass as valid when they're actually invalid. For
     // instance the STRICTENC flag was incorrectly allowing certain CHECKSIG
     // NOT scripts to pass, even though they were invalid.
     //
     // There is a similar check in CreateNewBlock() to prevent creating
     // invalid blocks (using TestBlockValidity), however allowing such
     // transactions into the mempool can be exploited as a DoS attack.
     int nSigChecksConsensus;
     if (!CheckInputsFromMempoolAndCache(
             tx, state, m_view, m_pool, ws.m_next_block_script_verify_flags,
             ws.m_precomputed_txdata, nSigChecksConsensus,
             m_active_chainstate.CoinsTip())) {
         // This can occur under some circumstances, if the node receives an
         // unrequested tx which is invalid due to new consensus rules not
         // being activated yet (during IBD).
         LogPrintf("BUG! PLEASE REPORT THIS! CheckInputScripts failed against "
                   "latest-block but not STANDARD flags %s, %s\n",
                   txid.ToString(), state.ToString());
         return Assume(false);
     }
 
     if (ws.m_sig_checks_standard != nSigChecksConsensus) {
         // We can't accept this transaction as we've used the standard count
         // for the mempool/mining, but the consensus count will be enforced
         // in validation (we don't want to produce bad block templates).
         return error(
             "%s: BUG! PLEASE REPORT THIS! SigChecks count differed between "
             "standard and consensus flags in %s",
             __func__, txid.ToString());
     }
     return true;
 }
 
 bool MemPoolAccept::Finalize(const ATMPArgs &args, Workspace &ws) {
     AssertLockHeld(cs_main);
     AssertLockHeld(m_pool.cs);
     const TxId &txid = ws.m_ptx->GetId();
     TxValidationState &state = ws.m_state;
     const bool bypass_limits = args.m_bypass_limits;
 
     // Store transaction in memory
     CTxMemPoolEntry *pentry = ws.m_entry.release();
     auto entry = CTxMemPoolEntryRef::acquire(pentry);
     m_pool.addUnchecked(entry);
 
     // Trim mempool and check if tx was trimmed.
     // If we are validating a package, don't trim here because we could evict a
     // previous transaction in the package. LimitMempoolSize() should be called
     // at the very end to make sure the mempool is still within limits and
     // package submission happens atomically.
     if (!args.m_package_submission && !bypass_limits) {
         m_pool.LimitSize(m_active_chainstate.CoinsTip());
         if (!m_pool.exists(txid)) {
             return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
                                  "mempool full");
         }
     }
     return true;
 }
 
 // Get the coins spent by ptx from the coins_view. Assumes coins are present.
 static std::vector<Coin> getSpentCoins(const CTransactionRef &ptx,
                                        const CCoinsViewCache &coins_view) {
     std::vector<Coin> spent_coins;
     spent_coins.reserve(ptx->vin.size());
     for (const CTxIn &input : ptx->vin) {
         Coin coin;
         const bool coinFound = coins_view.GetCoin(input.prevout, coin);
         Assume(coinFound);
         spent_coins.push_back(std::move(coin));
     }
     return spent_coins;
 }
 
 bool MemPoolAccept::SubmitPackage(
     const ATMPArgs &args, std::vector<Workspace> &workspaces,
     PackageValidationState &package_state,
     std::map<const TxId, const MempoolAcceptResult> &results) {
     AssertLockHeld(cs_main);
     AssertLockHeld(m_pool.cs);
     // Sanity check: none of the transactions should be in the mempool.
     assert(std::all_of(
         workspaces.cbegin(), workspaces.cend(),
         [this](const auto &ws) { return !m_pool.exists(ws.m_ptx->GetId()); }));
 
     bool all_submitted = true;
     // ConsensusScriptChecks adds to the script cache and is therefore
     // consensus-critical; CheckInputsFromMempoolAndCache asserts that
     // transactions only spend coins available from the mempool or UTXO set.
     // Submit each transaction to the mempool immediately after calling
     // ConsensusScriptChecks to make the outputs available for subsequent
     // transactions.
     for (Workspace &ws : workspaces) {
         if (!ConsensusScriptChecks(args, ws)) {
             results.emplace(ws.m_ptx->GetId(),
                             MempoolAcceptResult::Failure(ws.m_state));
             // Since PreChecks() passed, this should never fail.
             all_submitted = Assume(false);
         }
 
         // If we call LimitMempoolSize() for each individual Finalize(), the
         // mempool will not take the transaction's descendant feerate into
         // account because it hasn't seen them yet. Also, we risk evicting a
         // transaction that a subsequent package transaction depends on.
         // Instead, allow the mempool to temporarily bypass limits, the maximum
         // package size) while submitting transactions individually and then
         // trim at the very end.
         if (!Finalize(args, ws)) {
             results.emplace(ws.m_ptx->GetId(),
                             MempoolAcceptResult::Failure(ws.m_state));
             // Since LimitMempoolSize() won't be called, this should never fail.
             all_submitted = Assume(false);
         }
     }
 
     // It may or may not be the case that all the transactions made it into the
     // mempool. Regardless, make sure we haven't exceeded max mempool size.
     m_pool.LimitSize(m_active_chainstate.CoinsTip());
     if (!all_submitted) {
         return false;
     }
 
     // Find the txids of the transactions that made it into the mempool. Allow
     // partial submission, but don't report success unless they all made it into
     // the mempool.
     for (Workspace &ws : workspaces) {
         if (m_pool.exists(ws.m_ptx->GetId())) {
             results.emplace(ws.m_ptx->GetId(), MempoolAcceptResult::Success(
                                                    ws.m_vsize, ws.m_base_fees));
             GetMainSignals().TransactionAddedToMempool(
                 ws.m_ptx,
                 std::make_shared<const std::vector<Coin>>(
                     getSpentCoins(ws.m_ptx, m_view)),
                 m_pool.GetAndIncrementSequence());
         } else {
             all_submitted = false;
             ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
                                "mempool full");
             results.emplace(ws.m_ptx->GetId(),
                             MempoolAcceptResult::Failure(ws.m_state));
         }
     }
     return all_submitted;
 }
 
 MempoolAcceptResult
 MemPoolAccept::AcceptSingleTransaction(const CTransactionRef &ptx,
                                        ATMPArgs &args) {
     AssertLockHeld(cs_main);
     // mempool "read lock" (held through
     // GetMainSignals().TransactionAddedToMempool())
     LOCK(m_pool.cs);
 
     const Consensus::Params &consensusParams =
         args.m_config.GetChainParams().GetConsensus();
     const CBlockIndex *tip = m_active_chainstate.m_chain.Tip();
 
     Workspace ws(ptx, GetNextBlockScriptFlags(consensusParams, tip));
 
     // Perform the inexpensive checks first and avoid hashing and signature
     // verification unless those checks pass, to mitigate CPU exhaustion
     // denial-of-service attacks.
     if (!PreChecks(args, ws)) {
         return MempoolAcceptResult::Failure(ws.m_state);
     }
 
     if (!ConsensusScriptChecks(args, ws)) {
         return MempoolAcceptResult::Failure(ws.m_state);
     }
 
     const TxId txid = ptx->GetId();
 
     // Mempool sanity check -- in our new mempool no tx can be added if its
     // outputs are already spent in the mempool (that is, no children before
     // parents allowed; the mempool must be consistent at all times).
     //
     // This means that on reorg, the disconnectpool *must* always import
     // the existing mempool tx's, clear the mempool, and then re-add
     // remaining tx's in topological order via this function. Our new mempool
     // has fast adds, so this is ok.
     if (auto it = m_pool.mapNextTx.lower_bound(COutPoint{txid, 0});
         it != m_pool.mapNextTx.end() && it->first->GetTxId() == txid) {
         LogPrintf("%s: BUG! PLEASE REPORT THIS! Attempt to add txid %s, but "
                   "its outputs are already spent in the "
                   "mempool\n",
                   __func__, txid.ToString());
         ws.m_state.Invalid(TxValidationResult::TX_CHILD_BEFORE_PARENT,
                            "txn-child-before-parent");
         return MempoolAcceptResult::Failure(ws.m_state);
     }
 
     // Tx was accepted, but not added
     if (args.m_test_accept) {
         return MempoolAcceptResult::Success(ws.m_vsize, ws.m_base_fees);
     }
 
     if (!Finalize(args, ws)) {
         return MempoolAcceptResult::Failure(ws.m_state);
     }
 
     GetMainSignals().TransactionAddedToMempool(
         ptx,
         std::make_shared<const std::vector<Coin>>(getSpentCoins(ptx, m_view)),
         m_pool.GetAndIncrementSequence());
 
     return MempoolAcceptResult::Success(ws.m_vsize, ws.m_base_fees);
 }
 
 PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactions(
     const std::vector<CTransactionRef> &txns, ATMPArgs &args) {
     AssertLockHeld(cs_main);
 
     // These context-free package limits can be done before taking the mempool
     // lock.
     PackageValidationState package_state;
     if (!CheckPackage(txns, package_state)) {
         return PackageMempoolAcceptResult(package_state, {});
     }
 
     std::vector<Workspace> workspaces{};
     workspaces.reserve(txns.size());
     std::transform(txns.cbegin(), txns.cend(), std::back_inserter(workspaces),
                    [&args, this](const auto &tx) {
                        return Workspace(
                            tx,
                            GetNextBlockScriptFlags(
                                args.m_config.GetChainParams().GetConsensus(),
                                m_active_chainstate.m_chain.Tip()));
                    });
     std::map<const TxId, const MempoolAcceptResult> results;
 
     LOCK(m_pool.cs);
 
     // Do all PreChecks first and fail fast to avoid running expensive script
     // checks when unnecessary.
     for (Workspace &ws : workspaces) {
         if (!PreChecks(args, ws)) {
             package_state.Invalid(PackageValidationResult::PCKG_TX,
                                   "transaction failed");
             // Exit early to avoid doing pointless work. Update the failed tx
             // result; the rest are unfinished.
             results.emplace(ws.m_ptx->GetId(),
                             MempoolAcceptResult::Failure(ws.m_state));
             return PackageMempoolAcceptResult(package_state,
                                               std::move(results));
         }
         // Make the coins created by this transaction available for subsequent
         // transactions in the package to spend.
         m_viewmempool.PackageAddTransaction(ws.m_ptx);
         if (args.m_test_accept) {
             // When test_accept=true, transactions that pass PreChecks
             // are valid because there are no further mempool checks (passing
             // PreChecks implies passing ConsensusScriptChecks).
             results.emplace(ws.m_ptx->GetId(), MempoolAcceptResult::Success(
                                                    ws.m_vsize, ws.m_base_fees));
         }
     }
 
     if (args.m_test_accept) {
         return PackageMempoolAcceptResult(package_state, std::move(results));
     }
 
     if (!SubmitPackage(args, workspaces, package_state, results)) {
         package_state.Invalid(PackageValidationResult::PCKG_TX,
                               "submission failed");
         return PackageMempoolAcceptResult(package_state, std::move(results));
     }
 
     return PackageMempoolAcceptResult(package_state, std::move(results));
 }
 
 PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package &package,
                                                         ATMPArgs &args) {
     AssertLockHeld(cs_main);
     PackageValidationState package_state;
 
     // Check that the package is well-formed. If it isn't, we won't try to
     // validate any of the transactions and thus won't return any
     // MempoolAcceptResults, just a package-wide error.
 
     // Context-free package checks.
     if (!CheckPackage(package, package_state)) {
         return PackageMempoolAcceptResult(package_state, {});
     }
 
     // All transactions in the package must be a parent of the last transaction.
     // This is just an opportunity for us to fail fast on a context-free check
     // without taking the mempool lock.
     if (!IsChildWithParents(package)) {
         package_state.Invalid(PackageValidationResult::PCKG_POLICY,
                               "package-not-child-with-parents");
         return PackageMempoolAcceptResult(package_state, {});
     }
 
     // IsChildWithParents() guarantees the package is > 1 transactions.
     assert(package.size() > 1);
     // The package must be 1 child with all of its unconfirmed parents. The
     // package is expected to be sorted, so the last transaction is the child.
     const auto &child = package.back();
     std::unordered_set<TxId, SaltedTxIdHasher> unconfirmed_parent_txids;
     std::transform(
         package.cbegin(), package.cend() - 1,
         std::inserter(unconfirmed_parent_txids, unconfirmed_parent_txids.end()),
         [](const auto &tx) { return tx->GetId(); });
 
     // All child inputs must refer to a preceding package transaction or a
     // confirmed UTXO. The only way to verify this is to look up the child's
     // inputs in our current coins view (not including mempool), and enforce
     // that all parents not present in the package be available at chain tip.
     // Since this check can bring new coins into the coins cache, keep track of
     // these coins and uncache them if we don't end up submitting this package
     // to the mempool.
     const CCoinsViewCache &coins_tip_cache = m_active_chainstate.CoinsTip();
     for (const auto &input : child->vin) {
         if (!coins_tip_cache.HaveCoinInCache(input.prevout)) {
             args.m_coins_to_uncache.push_back(input.prevout);
         }
     }
     // Using the MemPoolAccept m_view cache allows us to look up these same
     // coins faster later. This should be connecting directly to CoinsTip, not
     // to m_viewmempool, because we specifically require inputs to be confirmed
     // if they aren't in the package.
     m_view.SetBackend(m_active_chainstate.CoinsTip());
     const auto package_or_confirmed = [this, &unconfirmed_parent_txids](
                                           const auto &input) {
         return unconfirmed_parent_txids.count(input.prevout.GetTxId()) > 0 ||
                m_view.HaveCoin(input.prevout);
     };
     if (!std::all_of(child->vin.cbegin(), child->vin.cend(),
                      package_or_confirmed)) {
         package_state.Invalid(PackageValidationResult::PCKG_POLICY,
                               "package-not-child-with-unconfirmed-parents");
         return PackageMempoolAcceptResult(package_state, {});
     }
     // Protect against bugs where we pull more inputs from disk that miss being
     // added to coins_to_uncache. The backend will be connected again when
     // needed in PreChecks.
     m_view.SetBackend(m_dummy);
 
     LOCK(m_pool.cs);
     std::map<const TxId, const MempoolAcceptResult> results;
     // Node operators are free to set their mempool policies however they
     // please, nodes may receive transactions in different orders, and malicious
     // counterparties may try to take advantage of policy differences to pin or
     // delay propagation of transactions. As such, it's possible for some
     // package transaction(s) to already be in the mempool, and we don't want to
     // reject the entire package in that case (as that could be a censorship
     // vector). De-duplicate the transactions that are already in the mempool,
     // and only call AcceptMultipleTransactions() with the new transactions.
     // This ensures we don't double-count transaction counts and sizes when
     // checking ancestor/descendant limits, or double-count transaction fees for
     // fee-related policy.
     std::vector<CTransactionRef> txns_new;
     for (const auto &tx : package) {
         const auto &txid = tx->GetId();
         // An already confirmed tx is treated as one not in mempool, because all
         // we know is that the inputs aren't available.
         if (m_pool.exists(txid)) {
             // Exact transaction already exists in the mempool.
             auto iter = m_pool.GetIter(txid);
             assert(iter != std::nullopt);
             results.emplace(txid, MempoolAcceptResult::MempoolTx(
                                       (*iter.value())->GetTxSize(),
                                       (*iter.value())->GetFee()));
         } else {
             // Transaction does not already exist in the mempool.
             txns_new.push_back(tx);
         }
     }
 
     // Nothing to do if the entire package has already been submitted.
     if (txns_new.empty()) {
         return PackageMempoolAcceptResult(package_state, std::move(results));
     }
     // Validate the (deduplicated) transactions as a package.
     auto submission_result = AcceptMultipleTransactions(txns_new, args);
     // Include already-in-mempool transaction results in the final result.
     for (const auto &[txid, mempoolaccept_res] : results) {
         submission_result.m_tx_results.emplace(txid, mempoolaccept_res);
     }
     return submission_result;
 }
 } // namespace
 
 MempoolAcceptResult AcceptToMemoryPool(const Config &config,
                                        Chainstate &active_chainstate,
                                        const CTransactionRef &tx,
                                        int64_t accept_time, bool bypass_limits,
                                        bool test_accept,
                                        unsigned int heightOverride) {
     AssertLockHeld(::cs_main);
     assert(active_chainstate.GetMempool() != nullptr);
     CTxMemPool &pool{*active_chainstate.GetMempool()};
 
     std::vector<COutPoint> coins_to_uncache;
     auto args = MemPoolAccept::ATMPArgs::SingleAccept(
         config, accept_time, bypass_limits, coins_to_uncache, test_accept,
         heightOverride);
     const MempoolAcceptResult result = MemPoolAccept(pool, active_chainstate)
                                            .AcceptSingleTransaction(tx, args);
     if (result.m_result_type != MempoolAcceptResult::ResultType::VALID) {
         // Remove coins that were not present in the coins cache before calling
         // ATMPW; this is to prevent memory DoS in case we receive a large
         // number of invalid transactions that attempt to overrun the in-memory
         // coins cache
         // (`CCoinsViewCache::cacheCoins`).
 
         for (const COutPoint &outpoint : coins_to_uncache) {
             active_chainstate.CoinsTip().Uncache(outpoint);
         }
     }
 
     // After we've (potentially) uncached entries, ensure our coins cache is
     // still within its size limits
     BlockValidationState stateDummy;
     active_chainstate.FlushStateToDisk(stateDummy, FlushStateMode::PERIODIC);
     return result;
 }
 
 PackageMempoolAcceptResult
 ProcessNewPackage(const Config &config, Chainstate &active_chainstate,
                   CTxMemPool &pool, const Package &package, bool test_accept) {
     AssertLockHeld(cs_main);
     assert(!package.empty());
     assert(std::all_of(package.cbegin(), package.cend(),
                        [](const auto &tx) { return tx != nullptr; }));
 
     std::vector<COutPoint> coins_to_uncache;
     const auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
         AssertLockHeld(cs_main);
         if (test_accept) {
             auto args = MemPoolAccept::ATMPArgs::PackageTestAccept(
                 config, GetTime(), coins_to_uncache);
             return MemPoolAccept(pool, active_chainstate)
                 .AcceptMultipleTransactions(package, args);
         } else {
             auto args = MemPoolAccept::ATMPArgs::PackageChildWithParents(
                 config, GetTime(), coins_to_uncache);
             return MemPoolAccept(pool, active_chainstate)
                 .AcceptPackage(package, args);
         }
     }();
 
     // Uncache coins pertaining to transactions that were not submitted to the
     // mempool.
     if (test_accept || result.m_state.IsInvalid()) {
         for (const COutPoint &hashTx : coins_to_uncache) {
             active_chainstate.CoinsTip().Uncache(hashTx);
         }
     }
     // Ensure the coins cache is still within limits.
     BlockValidationState state_dummy;
     active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC);
     return result;
 }
 
 Amount GetBlockSubsidy(int nHeight, const Consensus::Params &consensusParams) {
     int halvings = nHeight / consensusParams.nSubsidyHalvingInterval;
     // Force block reward to zero when right shift is undefined.
     if (halvings >= 64) {
         return Amount::zero();
     }
 
     Amount nSubsidy = 50 * COIN;
     // Subsidy is cut in half every 210,000 blocks which will occur
     // approximately every 4 years.
     return ((nSubsidy / SATOSHI) >> halvings) * SATOSHI;
 }
 
 CoinsViews::CoinsViews(std::string ldb_name, size_t cache_size_bytes,
                        bool in_memory, bool should_wipe)
     : m_dbview(gArgs.GetDataDirNet() / ldb_name, cache_size_bytes, in_memory,
                should_wipe),
       m_catcherview(&m_dbview) {}
 
 void CoinsViews::InitCache() {
     AssertLockHeld(::cs_main);
     m_cacheview = std::make_unique<CCoinsViewCache>(&m_catcherview);
 }
 
 Chainstate::Chainstate(CTxMemPool *mempool, BlockManager &blockman,
                        ChainstateManager &chainman,
                        std::optional<BlockHash> from_snapshot_blockhash)
     : m_mempool(mempool), m_blockman(blockman), m_chainman(chainman),
       m_from_snapshot_blockhash(from_snapshot_blockhash) {}
 
 void Chainstate::InitCoinsDB(size_t cache_size_bytes, bool in_memory,
                              bool should_wipe, std::string leveldb_name) {
     if (m_from_snapshot_blockhash) {
         leveldb_name += node::SNAPSHOT_CHAINSTATE_SUFFIX;
     }
     m_coins_views = std::make_unique<CoinsViews>(leveldb_name, cache_size_bytes,
                                                  in_memory, should_wipe);
 }
 
 void Chainstate::InitCoinsCache(size_t cache_size_bytes) {
     AssertLockHeld(::cs_main);
     assert(m_coins_views != nullptr);
     m_coinstip_cache_size_bytes = cache_size_bytes;
     m_coins_views->InitCache();
 }
 
 // Note that though this is marked const, we may end up modifying
 // `m_cached_finished_ibd`, which is a performance-related implementation
 // detail. This function must be marked `const` so that `CValidationInterface`
 // clients (which are given a `const Chainstate*`) can call it.
 //
 bool Chainstate::IsInitialBlockDownload() const {
     // Optimization: pre-test latch before taking the lock.
     if (m_cached_finished_ibd.load(std::memory_order_relaxed)) {
         return false;
     }
 
     LOCK(cs_main);
     if (m_cached_finished_ibd.load(std::memory_order_relaxed)) {
         return false;
     }
     if (m_chainman.m_blockman.LoadingBlocks()) {
         return true;
     }
     if (m_chain.Tip() == nullptr) {
         return true;
     }
     if (m_chain.Tip()->nChainWork < nMinimumChainWork) {
         return true;
     }
     if (m_chain.Tip()->GetBlockTime() < (GetTime() - nMaxTipAge)) {
         return true;
     }
     LogPrintf("Leaving InitialBlockDownload (latching to false)\n");
     m_cached_finished_ibd.store(true, std::memory_order_relaxed);
     return false;
 }
 
 static void AlertNotify(const std::string &strMessage) {
     uiInterface.NotifyAlertChanged();
 #if defined(HAVE_SYSTEM)
     std::string strCmd = gArgs.GetArg("-alertnotify", "");
     if (strCmd.empty()) {
         return;
     }
 
     // Alert text should be plain ascii coming from a trusted source, but to be
     // safe we first strip anything not in safeChars, then add single quotes
     // around the whole string before passing it to the shell:
     std::string singleQuote("'");
     std::string safeStatus = SanitizeString(strMessage);
     safeStatus = singleQuote + safeStatus + singleQuote;
     ReplaceAll(strCmd, "%s", safeStatus);
 
     std::thread t(runCommand, strCmd);
     // thread runs free
     t.detach();
 #endif
 }
 
 void Chainstate::CheckForkWarningConditions() {
     AssertLockHeld(cs_main);
 
     // Before we get past initial download, we cannot reliably alert about forks
     // (we assume we don't get stuck on a fork before finishing our initial
     // sync)
     if (IsInitialBlockDownload()) {
         return;
     }
 
     // If our best fork is no longer within 72 blocks (+/- 12 hours if no one
     // mines it) of our head, or if it is back on the active chain, drop it
     if (m_best_fork_tip && (m_chain.Height() - m_best_fork_tip->nHeight >= 72 ||
                             m_chain.Contains(m_best_fork_tip))) {
         m_best_fork_tip = nullptr;
     }
 
     if (m_best_fork_tip ||
         (m_chainman.m_best_invalid &&
          m_chainman.m_best_invalid->nChainWork >
              m_chain.Tip()->nChainWork + (GetBlockProof(*m_chain.Tip()) * 6))) {
         if (!GetfLargeWorkForkFound() && m_best_fork_base) {
             std::string warning =
                 std::string("'Warning: Large-work fork detected, forking after "
                             "block ") +
                 m_best_fork_base->phashBlock->ToString() + std::string("'");
             AlertNotify(warning);
         }
 
         if (m_best_fork_tip && m_best_fork_base) {
             LogPrintf("%s: Warning: Large fork found\n  forking the "
                       "chain at height %d (%s)\n  lasting to height %d "
                       "(%s).\nChain state database corruption likely.\n",
                       __func__, m_best_fork_base->nHeight,
                       m_best_fork_base->phashBlock->ToString(),
                       m_best_fork_tip->nHeight,
                       m_best_fork_tip->phashBlock->ToString());
             SetfLargeWorkForkFound(true);
         } else {
             LogPrintf("%s: Warning: Found invalid chain at least ~6 blocks "
                       "longer than our best chain.\nChain state database "
                       "corruption likely.\n",
                       __func__);
             SetfLargeWorkInvalidChainFound(true);
         }
     } else {
         SetfLargeWorkForkFound(false);
         SetfLargeWorkInvalidChainFound(false);
     }
 }
 
 void Chainstate::CheckForkWarningConditionsOnNewFork(
     CBlockIndex *pindexNewForkTip) {
     AssertLockHeld(cs_main);
 
     // If we are on a fork that is sufficiently large, set a warning flag.
     const CBlockIndex *pfork = m_chain.FindFork(pindexNewForkTip);
 
     // We define a condition where we should warn the user about as a fork of at
     // least 7 blocks with a tip within 72 blocks (+/- 12 hours if no one mines
     // it) of ours. We use 7 blocks rather arbitrarily as it represents just
     // under 10% of sustained network hash rate operating on the fork, or a
     // chain that is entirely longer than ours and invalid (note that this
     // should be detected by both). We define it this way because it allows us
     // to only store the highest fork tip (+ base) which meets the 7-block
     // condition and from this always have the most-likely-to-cause-warning fork
     if (pfork &&
         (!m_best_fork_tip ||
          pindexNewForkTip->nHeight > m_best_fork_tip->nHeight) &&
         pindexNewForkTip->nChainWork - pfork->nChainWork >
             (GetBlockProof(*pfork) * 7) &&
         m_chain.Height() - pindexNewForkTip->nHeight < 72) {
         m_best_fork_tip = pindexNewForkTip;
         m_best_fork_base = pfork;
     }
 
     CheckForkWarningConditions();
 }
 
 // Called both upon regular invalid block discovery *and* InvalidateBlock
 void Chainstate::InvalidChainFound(CBlockIndex *pindexNew) {
     AssertLockHeld(cs_main);
     if (!m_chainman.m_best_invalid ||
         pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork) {
         m_chainman.m_best_invalid = pindexNew;
     }
     if (m_chainman.m_best_header != nullptr &&
         m_chainman.m_best_header->GetAncestor(pindexNew->nHeight) ==
             pindexNew) {
         m_chainman.m_best_header = m_chain.Tip();
     }
 
     // If the invalid chain found is supposed to be finalized, we need to move
     // back the finalization point.
     if (IsBlockAvalancheFinalized(pindexNew)) {
         LOCK(cs_avalancheFinalizedBlockIndex);
         m_avalancheFinalizedBlockIndex = pindexNew->pprev;
     }
 
     LogPrintf("%s: invalid block=%s  height=%d  log2_work=%f  date=%s\n",
               __func__, pindexNew->GetBlockHash().ToString(),
               pindexNew->nHeight,
               log(pindexNew->nChainWork.getdouble()) / log(2.0),
               FormatISO8601DateTime(pindexNew->GetBlockTime()));
     CBlockIndex *tip = m_chain.Tip();
     assert(tip);
     LogPrintf("%s:  current best=%s  height=%d  log2_work=%f  date=%s\n",
               __func__, tip->GetBlockHash().ToString(), m_chain.Height(),
               log(tip->nChainWork.getdouble()) / log(2.0),
               FormatISO8601DateTime(tip->GetBlockTime()));
 }
 
 // Same as InvalidChainFound, above, except not called directly from
 // InvalidateBlock, which does its own setBlockIndexCandidates management.
 void Chainstate::InvalidBlockFound(CBlockIndex *pindex,
                                    const BlockValidationState &state) {
     AssertLockHeld(cs_main);
     if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
         pindex->nStatus = pindex->nStatus.withFailed();
         m_chainman.m_failed_blocks.insert(pindex);
         m_blockman.m_dirty_blockindex.insert(pindex);
         InvalidChainFound(pindex);
     }
 }
 
 void SpendCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
                 int nHeight) {
     // Mark inputs spent.
     if (tx.IsCoinBase()) {
         return;
     }
 
     txundo.vprevout.reserve(tx.vin.size());
     for (const CTxIn &txin : tx.vin) {
         txundo.vprevout.emplace_back();
         bool is_spent = view.SpendCoin(txin.prevout, &txundo.vprevout.back());
         assert(is_spent);
     }
 }
 
 void UpdateCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
                  int nHeight) {
     SpendCoins(view, tx, txundo, nHeight);
     AddCoins(view, tx, nHeight);
 }
 
 bool CScriptCheck::operator()() {
     const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
     if (!VerifyScript(scriptSig, m_tx_out.scriptPubKey, nFlags,
                       CachingTransactionSignatureChecker(
                           ptxTo, nIn, m_tx_out.nValue, cacheStore, txdata),
                       metrics, &error)) {
         return false;
     }
     if ((pTxLimitSigChecks &&
          !pTxLimitSigChecks->consume_and_check(metrics.nSigChecks)) ||
         (pBlockLimitSigChecks &&
          !pBlockLimitSigChecks->consume_and_check(metrics.nSigChecks))) {
         // we can't assign a meaningful script error (since the script
         // succeeded), but remove the ScriptError::OK which could be
         // misinterpreted.
         error = ScriptError::SIGCHECKS_LIMIT_EXCEEDED;
         return false;
     }
     return true;
 }
 
 bool CheckInputScripts(const CTransaction &tx, TxValidationState &state,
                        const CCoinsViewCache &inputs, const uint32_t flags,
                        bool sigCacheStore, bool scriptCacheStore,
                        const PrecomputedTransactionData &txdata,
                        int &nSigChecksOut, TxSigCheckLimiter &txLimitSigChecks,
                        CheckInputsLimiter *pBlockLimitSigChecks,
                        std::vector<CScriptCheck> *pvChecks) {
     AssertLockHeld(cs_main);
     assert(!tx.IsCoinBase());
 
     if (pvChecks) {
         pvChecks->reserve(tx.vin.size());
     }
 
     // First check if script executions have been cached with the same flags.
     // Note that this assumes that the inputs provided are correct (ie that the
     // transaction hash which is in tx's prevouts properly commits to the
     // scriptPubKey in the inputs view of that transaction).
     ScriptCacheKey hashCacheEntry(tx, flags);
     if (IsKeyInScriptCache(hashCacheEntry, !scriptCacheStore, nSigChecksOut)) {
         if (!txLimitSigChecks.consume_and_check(nSigChecksOut) ||
             (pBlockLimitSigChecks &&
              !pBlockLimitSigChecks->consume_and_check(nSigChecksOut))) {
             return state.Invalid(TxValidationResult::TX_CONSENSUS,
                                  "too-many-sigchecks");
         }
         return true;
     }
 
     int nSigChecksTotal = 0;
 
     for (size_t i = 0; i < tx.vin.size(); i++) {
         const COutPoint &prevout = tx.vin[i].prevout;
         const Coin &coin = inputs.AccessCoin(prevout);
         assert(!coin.IsSpent());
 
         // We very carefully only pass in things to CScriptCheck which are
         // clearly committed to by tx's hash. This provides a sanity
         // check that our caching is not introducing consensus failures through
         // additional data in, eg, the coins being spent being checked as a part
         // of CScriptCheck.
 
         // Verify signature
         CScriptCheck check(coin.GetTxOut(), tx, i, flags, sigCacheStore, txdata,
                            &txLimitSigChecks, pBlockLimitSigChecks);
 
         // If pvChecks is not null, defer the check execution to the caller.
         if (pvChecks) {
             pvChecks->push_back(std::move(check));
             continue;
         }
 
         if (!check()) {
             ScriptError scriptError = check.GetScriptError();
             // Compute flags without the optional standardness flags.
             // This differs from MANDATORY_SCRIPT_VERIFY_FLAGS as it contains
             // additional upgrade flags (see AcceptToMemoryPoolWorker variable
             // extraFlags).
             uint32_t mandatoryFlags =
                 flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS;
             if (flags != mandatoryFlags) {
                 // Check whether the failure was caused by a non-mandatory
                 // script verification check. If so, ensure we return
                 // NOT_STANDARD instead of CONSENSUS to avoid downstream users
                 // splitting the network between upgraded and non-upgraded nodes
                 // by banning CONSENSUS-failing data providers.
                 CScriptCheck check2(coin.GetTxOut(), tx, i, mandatoryFlags,
                                     sigCacheStore, txdata);
                 if (check2()) {
                     return state.Invalid(
                         TxValidationResult::TX_NOT_STANDARD,
                         strprintf("non-mandatory-script-verify-flag (%s)",
                                   ScriptErrorString(scriptError)));
                 }
                 // update the error message to reflect the mandatory violation.
                 scriptError = check2.GetScriptError();
             }
 
             // MANDATORY flag failures correspond to
             // TxValidationResult::TX_CONSENSUS. Because CONSENSUS failures are
             // the most serious case of validation failures, we may need to
             // consider using RECENT_CONSENSUS_CHANGE for any script failure
             // that could be due to non-upgraded nodes which we may want to
             // support, to avoid splitting the network (but this depends on the
             // details of how net_processing handles such errors).
             return state.Invalid(
                 TxValidationResult::TX_CONSENSUS,
                 strprintf("mandatory-script-verify-flag-failed (%s)",
                           ScriptErrorString(scriptError)));
         }
 
         nSigChecksTotal += check.GetScriptExecutionMetrics().nSigChecks;
     }
 
     nSigChecksOut = nSigChecksTotal;
 
     if (scriptCacheStore && !pvChecks) {
         // We executed all of the provided scripts, and were told to cache the
         // result. Do so now.
         AddKeyInScriptCache(hashCacheEntry, nSigChecksTotal);
     }
 
     return true;
 }
 
 bool AbortNode(BlockValidationState &state, const std::string &strMessage,
                const bilingual_str &userMessage) {
     AbortNode(strMessage, userMessage);
     return state.Error(strMessage);
 }
 
 /** Restore the UTXO in a Coin at a given COutPoint. */
 DisconnectResult UndoCoinSpend(Coin &&undo, CCoinsViewCache &view,
                                const COutPoint &out) {
     bool fClean = true;
 
     if (view.HaveCoin(out)) {
         // Overwriting transaction output.
         fClean = false;
     }
 
     if (undo.GetHeight() == 0) {
         // Missing undo metadata (height and coinbase). Older versions included
         // this information only in undo records for the last spend of a
         // transactions' outputs. This implies that it must be present for some
         // other output of the same tx.
         const Coin &alternate = AccessByTxid(view, out.GetTxId());
         if (alternate.IsSpent()) {
             // Adding output for transaction without known metadata
             return DisconnectResult::FAILED;
         }
 
         // This is somewhat ugly, but hopefully utility is limited. This is only
         // useful when working from legacy on disck data. In any case, putting
         // the correct information in there doesn't hurt.
         const_cast<Coin &>(undo) = Coin(undo.GetTxOut(), alternate.GetHeight(),
                                         alternate.IsCoinBase());
     }
 
     // If the coin already exists as an unspent coin in the cache, then the
     // possible_overwrite parameter to AddCoin must be set to true. We have
     // already checked whether an unspent coin exists above using HaveCoin, so
     // we don't need to guess. When fClean is false, an unspent coin already
     // existed and it is an overwrite.
     view.AddCoin(out, std::move(undo), !fClean);
 
     return fClean ? DisconnectResult::OK : DisconnectResult::UNCLEAN;
 }
 
 /**
  * Undo the effects of this block (with given index) on the UTXO set represented
  * by coins. When FAILED is returned, view is left in an indeterminate state.
  */
 DisconnectResult Chainstate::DisconnectBlock(const CBlock &block,
                                              const CBlockIndex *pindex,
                                              CCoinsViewCache &view) {
     AssertLockHeld(::cs_main);
     CBlockUndo blockUndo;
     if (!UndoReadFromDisk(blockUndo, pindex)) {
         error("DisconnectBlock(): failure reading undo data");
         return DisconnectResult::FAILED;
     }
 
     return ApplyBlockUndo(std::move(blockUndo), block, pindex, view);
 }
 
 DisconnectResult ApplyBlockUndo(CBlockUndo &&blockUndo, const CBlock &block,
                                 const CBlockIndex *pindex,
                                 CCoinsViewCache &view) {
     bool fClean = true;
 
     if (blockUndo.vtxundo.size() + 1 != block.vtx.size()) {
         error("DisconnectBlock(): block and undo data inconsistent");
         return DisconnectResult::FAILED;
     }
 
     // First, restore inputs.
     for (size_t i = 1; i < block.vtx.size(); i++) {
         const CTransaction &tx = *(block.vtx[i]);
         CTxUndo &txundo = blockUndo.vtxundo[i - 1];
         if (txundo.vprevout.size() != tx.vin.size()) {
             error("DisconnectBlock(): transaction and undo data inconsistent");
             return DisconnectResult::FAILED;
         }
 
         for (size_t j = 0; j < tx.vin.size(); j++) {
             const COutPoint &out = tx.vin[j].prevout;
             DisconnectResult res =
                 UndoCoinSpend(std::move(txundo.vprevout[j]), view, out);
             if (res == DisconnectResult::FAILED) {
                 return DisconnectResult::FAILED;
             }
             fClean = fClean && res != DisconnectResult::UNCLEAN;
         }
         // At this point, all of txundo.vprevout should have been moved out.
     }
 
     // Second, revert created outputs.
     for (const auto &ptx : block.vtx) {
         const CTransaction &tx = *ptx;
         const TxId &txid = tx.GetId();
         const bool is_coinbase = tx.IsCoinBase();
 
         // Check that all outputs are available and match the outputs in the
         // block itself exactly.
         for (size_t o = 0; o < tx.vout.size(); o++) {
             if (tx.vout[o].scriptPubKey.IsUnspendable()) {
                 continue;
             }
 
             COutPoint out(txid, o);
             Coin coin;
             bool is_spent = view.SpendCoin(out, &coin);
             if (!is_spent || tx.vout[o] != coin.GetTxOut() ||
                 uint32_t(pindex->nHeight) != coin.GetHeight() ||
                 is_coinbase != coin.IsCoinBase()) {
                 // transaction output mismatch
                 fClean = false;
             }
         }
     }
 
     // Move best block pointer to previous block.
     view.SetBestBlock(block.hashPrevBlock);
 
     return fClean ? DisconnectResult::OK : DisconnectResult::UNCLEAN;
 }
 
 static CCheckQueue<CScriptCheck> scriptcheckqueue(128);
 
 void StartScriptCheckWorkerThreads(int threads_num) {
     scriptcheckqueue.StartWorkerThreads(threads_num);
 }
 
 void StopScriptCheckWorkerThreads() {
     scriptcheckqueue.StopWorkerThreads();
 }
 
 // Returns the script flags which should be checked for the block after
 // the given block.
 static uint32_t GetNextBlockScriptFlags(const Consensus::Params &params,
                                         const CBlockIndex *pindex) {
     uint32_t flags = SCRIPT_VERIFY_NONE;
 
     // Enforce P2SH (BIP16)
     if (DeploymentActiveAfter(pindex, params, Consensus::DEPLOYMENT_P2SH)) {
         flags |= SCRIPT_VERIFY_P2SH;
     }
 
     // Enforce the DERSIG (BIP66) rule.
     if (DeploymentActiveAfter(pindex, params, Consensus::DEPLOYMENT_DERSIG)) {
         flags |= SCRIPT_VERIFY_DERSIG;
     }
 
     // Start enforcing CHECKLOCKTIMEVERIFY (BIP65) rule.
     if (DeploymentActiveAfter(pindex, params, Consensus::DEPLOYMENT_CLTV)) {
         flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
     }
 
     // Start enforcing CSV (BIP68, BIP112 and BIP113) rule.
     if (DeploymentActiveAfter(pindex, params, Consensus::DEPLOYMENT_CSV)) {
         flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
     }
 
     // If the UAHF is enabled, we start accepting replay protected txns
     if (IsUAHFenabled(params, pindex)) {
         flags |= SCRIPT_VERIFY_STRICTENC;
         flags |= SCRIPT_ENABLE_SIGHASH_FORKID;
     }
 
     // If the DAA HF is enabled, we start rejecting transaction that use a high
     // s in their signature. We also make sure that signature that are supposed
     // to fail (for instance in multisig or other forms of smart contracts) are
     // null.
     if (IsDAAEnabled(params, pindex)) {
         flags |= SCRIPT_VERIFY_LOW_S;
         flags |= SCRIPT_VERIFY_NULLFAIL;
     }
 
     // When the magnetic anomaly fork is enabled, we start accepting
     // transactions using the OP_CHECKDATASIG opcode and it's verify
     // alternative. We also start enforcing push only signatures and
     // clean stack.
     if (IsMagneticAnomalyEnabled(params, pindex)) {
         flags |= SCRIPT_VERIFY_SIGPUSHONLY;
         flags |= SCRIPT_VERIFY_CLEANSTACK;
     }
 
     if (IsGravitonEnabled(params, pindex)) {
         flags |= SCRIPT_ENABLE_SCHNORR_MULTISIG;
         flags |= SCRIPT_VERIFY_MINIMALDATA;
     }
 
     if (IsPhononEnabled(params, pindex)) {
         flags |= SCRIPT_ENFORCE_SIGCHECKS;
     }
 
     // We make sure this node will have replay protection during the next hard
     // fork.
     if (IsReplayProtectionEnabled(params, pindex)) {
         flags |= SCRIPT_ENABLE_REPLAY_PROTECTION;
     }
 
     return flags;
 }
 
 static int64_t nTimeCheck = 0;
 static int64_t nTimeForks = 0;
 static int64_t nTimeVerify = 0;
 static int64_t nTimeConnect = 0;
 static int64_t nTimeIndex = 0;
 static int64_t nTimeTotal = 0;
 static int64_t nBlocksTotal = 0;
 
 /**
  * Apply the effects of this block (with given index) on the UTXO set
  * represented by coins. Validity checks that depend on the UTXO set are also
  * done; ConnectBlock() can fail if those validity checks fail (among other
  * reasons).
  */
 bool Chainstate::ConnectBlock(const CBlock &block, BlockValidationState &state,
                               CBlockIndex *pindex, CCoinsViewCache &view,
                               BlockValidationOptions options, Amount *blockFees,
                               bool fJustCheck) {
     AssertLockHeld(cs_main);
     assert(pindex);
 
     const BlockHash block_hash{block.GetHash()};
     assert(*pindex->phashBlock == block_hash);
 
     int64_t nTimeStart = GetTimeMicros();
 
     const CChainParams &params{m_chainman.GetParams()};
     const Consensus::Params &consensusParams = params.GetConsensus();
 
     // Check it again in case a previous version let a bad block in
     // NOTE: We don't currently (re-)invoke ContextualCheckBlock() or
     // ContextualCheckBlockHeader() here. This means that if we add a new
     // consensus rule that is enforced in one of those two functions, then we
     // may have let in a block that violates the rule prior to updating the
     // software, and we would NOT be enforcing the rule here. Fully solving
     // upgrade from one software version to the next after a consensus rule
     // change is potentially tricky and issue-specific.
     // Also, currently the rule against blocks more than 2 hours in the future
     // is enforced in ContextualCheckBlockHeader(); we wouldn't want to
     // re-enforce that rule here (at least until we make it impossible for
     // m_adjusted_time_callback() to go backward).
     if (!CheckBlock(block, state, consensusParams,
                     options.withCheckPoW(!fJustCheck)
                         .withCheckMerkleRoot(!fJustCheck))) {
         if (state.GetResult() == BlockValidationResult::BLOCK_MUTATED) {
             // We don't write down blocks to disk if they may have been
             // corrupted, so this should be impossible unless we're having
             // hardware problems.
             return AbortNode(state, "Corrupt block found indicating potential "
                                     "hardware failure; shutting down");
         }
         return error("%s: Consensus::CheckBlock: %s", __func__,
                      state.ToString());
     }
 
     // Verify that the view's current state corresponds to the previous block
     BlockHash hashPrevBlock =
         pindex->pprev == nullptr ? BlockHash() : pindex->pprev->GetBlockHash();
     assert(hashPrevBlock == view.GetBestBlock());
 
     nBlocksTotal++;
 
     // Special case for the genesis block, skipping connection of its
     // transactions (its coinbase is unspendable)
     if (block_hash == consensusParams.hashGenesisBlock) {
         if (!fJustCheck) {
             view.SetBestBlock(pindex->GetBlockHash());
         }
 
         return true;
     }
 
     bool fScriptChecks = true;
     if (!hashAssumeValid.IsNull()) {
         // We've been configured with the hash of a block which has been
         // externally verified to have a valid history. A suitable default value
         // is included with the software and updated from time to time. Because
         // validity relative to a piece of software is an objective fact these
         // defaults can be easily reviewed. This setting doesn't force the
         // selection of any particular chain but makes validating some faster by
         // effectively caching the result of part of the verification.
         BlockMap::const_iterator it =
             m_blockman.m_block_index.find(hashAssumeValid);
         if (it != m_blockman.m_block_index.end()) {
             if (it->second.GetAncestor(pindex->nHeight) == pindex &&
                 m_chainman.m_best_header->GetAncestor(pindex->nHeight) ==
                     pindex &&
                 m_chainman.m_best_header->nChainWork >= nMinimumChainWork) {
                 // This block is a member of the assumed verified chain and an
                 // ancestor of the best header.
                 // Script verification is skipped when connecting blocks under
                 // the assumevalid block. Assuming the assumevalid block is
                 // valid this is safe because block merkle hashes are still
                 // computed and checked, Of course, if an assumed valid block is
                 // invalid due to false scriptSigs this optimization would allow
                 // an invalid chain to be accepted.
                 // The equivalent time check discourages hash power from
                 // extorting the network via DOS attack into accepting an
                 // invalid block through telling users they must manually set
                 // assumevalid. Requiring a software change or burying the
                 // invalid block, regardless of the setting, makes it hard to
                 // hide the implication of the demand. This also avoids having
                 // release candidates that are hardly doing any signature
                 // verification at all in testing without having to artificially
                 // set the default assumed verified block further back. The test
                 // against nMinimumChainWork prevents the skipping when denied
                 // access to any chain at least as good as the expected chain.
                 fScriptChecks = (GetBlockProofEquivalentTime(
                                      *m_chainman.m_best_header, *pindex,
                                      *m_chainman.m_best_header,
                                      consensusParams) <= 60 * 60 * 24 * 7 * 2);
             }
         }
     }
 
     int64_t nTime1 = GetTimeMicros();
     nTimeCheck += nTime1 - nTimeStart;
     LogPrint(BCLog::BENCH, "    - Sanity checks: %.2fms [%.2fs (%.2fms/blk)]\n",
              MILLI * (nTime1 - nTimeStart), nTimeCheck * MICRO,
              nTimeCheck * MILLI / nBlocksTotal);
 
     // Do not allow blocks that contain transactions which 'overwrite' older
     // transactions, unless those are already completely spent. If such
     // overwrites are allowed, coinbases and transactions depending upon those
     // can be duplicated to remove the ability to spend the first instance --
     // even after being sent to another address.
     // See BIP30, CVE-2012-1909, and http://r6.ca/blog/20120206T005236Z.html
     // for more information. This rule was originally applied to all blocks
     // with a timestamp after March 15, 2012, 0:00 UTC. Now that the whole
     // chain is irreversibly beyond that time it is applied to all blocks
     // except the two in the chain that violate it. This prevents exploiting
     // the issue against nodes during their initial block download.
     bool fEnforceBIP30 = !((pindex->nHeight == 91842 &&
                             pindex->GetBlockHash() ==
                                 uint256S("0x00000000000a4d0a398161ffc163c503763"
                                          "b1f4360639393e0e4c8e300e0caec")) ||
                            (pindex->nHeight == 91880 &&
                             pindex->GetBlockHash() ==
                                 uint256S("0x00000000000743f190a18c5577a3c2d2a1f"
                                          "610ae9601ac046a38084ccb7cd721")));
 
     // Once BIP34 activated it was not possible to create new duplicate
     // coinbases and thus other than starting with the 2 existing duplicate
     // coinbase pairs, not possible to create overwriting txs. But by the time
     // BIP34 activated, in each of the existing pairs the duplicate coinbase had
     // overwritten the first before the first had been spent. Since those
     // coinbases are sufficiently buried it's no longer possible to create
     // further duplicate transactions descending from the known pairs either. If
     // we're on the known chain at height greater than where BIP34 activated, we
     // can save the db accesses needed for the BIP30 check.
 
     // BIP34 requires that a block at height X (block X) has its coinbase
     // scriptSig start with a CScriptNum of X (indicated height X).  The above
     // logic of no longer requiring BIP30 once BIP34 activates is flawed in the
     // case that there is a block X before the BIP34 height of 227,931 which has
     // an indicated height Y where Y is greater than X.  The coinbase for block
     // X would also be a valid coinbase for block Y, which could be a BIP30
     // violation.  An exhaustive search of all mainnet coinbases before the
     // BIP34 height which have an indicated height greater than the block height
     // reveals many occurrences. The 3 lowest indicated heights found are
     // 209,921, 490,897, and 1,983,702 and thus coinbases for blocks at these 3
     // heights would be the first opportunity for BIP30 to be violated.
 
     // The search reveals a great many blocks which have an indicated height
     // greater than 1,983,702, so we simply remove the optimization to skip
     // BIP30 checking for blocks at height 1,983,702 or higher.  Before we reach
     // that block in another 25 years or so, we should take advantage of a
     // future consensus change to do a new and improved version of BIP34 that
     // will actually prevent ever creating any duplicate coinbases in the
     // future.
     static constexpr int BIP34_IMPLIES_BIP30_LIMIT = 1983702;
 
     // There is no potential to create a duplicate coinbase at block 209,921
     // because this is still before the BIP34 height and so explicit BIP30
     // checking is still active.
 
     // The final case is block 176,684 which has an indicated height of
     // 490,897. Unfortunately, this issue was not discovered until about 2 weeks
     // before block 490,897 so there was not much opportunity to address this
     // case other than to carefully analyze it and determine it would not be a
     // problem. Block 490,897 was, in fact, mined with a different coinbase than
     // block 176,684, but it is important to note that even if it hadn't been or
     // is remined on an alternate fork with a duplicate coinbase, we would still
     // not run into a BIP30 violation.  This is because the coinbase for 176,684
     // is spent in block 185,956 in transaction
     // d4f7fbbf92f4a3014a230b2dc70b8058d02eb36ac06b4a0736d9d60eaa9e8781.  This
     // spending transaction can't be duplicated because it also spends coinbase
     // 0328dd85c331237f18e781d692c92de57649529bd5edf1d01036daea32ffde29.  This
     // coinbase has an indicated height of over 4.2 billion, and wouldn't be
     // duplicatable until that height, and it's currently impossible to create a
     // chain that long. Nevertheless we may wish to consider a future soft fork
     // which retroactively prevents block 490,897 from creating a duplicate
     // coinbase. The two historical BIP30 violations often provide a confusing
     // edge case when manipulating the UTXO and it would be simpler not to have
     // another edge case to deal with.
 
     // testnet3 has no blocks before the BIP34 height with indicated heights
     // post BIP34 before approximately height 486,000,000 and presumably will
     // be reset before it reaches block 1,983,702 and starts doing unnecessary
     // BIP30 checking again.
     assert(pindex->pprev);
     CBlockIndex *pindexBIP34height =
         pindex->pprev->GetAncestor(consensusParams.BIP34Height);
     // Only continue to enforce if we're below BIP34 activation height or the
     // block hash at that height doesn't correspond.
     fEnforceBIP30 =
         fEnforceBIP30 &&
         (!pindexBIP34height ||
          !(pindexBIP34height->GetBlockHash() == consensusParams.BIP34Hash));
 
     // TODO: Remove BIP30 checking from block height 1,983,702 on, once we have
     // a consensus change that ensures coinbases at those heights can not
     // duplicate earlier coinbases.
     if (fEnforceBIP30 || pindex->nHeight >= BIP34_IMPLIES_BIP30_LIMIT) {
         for (const auto &tx : block.vtx) {
             for (size_t o = 0; o < tx->vout.size(); o++) {
                 if (view.HaveCoin(COutPoint(tx->GetId(), o))) {
                     LogPrintf("ERROR: ConnectBlock(): tried to overwrite "
                               "transaction\n");
                     return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                          "bad-txns-BIP30");
                 }
             }
         }
     }
 
     // Enforce BIP68 (sequence locks).
     int nLockTimeFlags = 0;
     if (DeploymentActiveAt(*pindex, consensusParams,
                            Consensus::DEPLOYMENT_CSV)) {
         nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE;
     }
 
     const uint32_t flags =
         GetNextBlockScriptFlags(consensusParams, pindex->pprev);
 
     int64_t nTime2 = GetTimeMicros();
     nTimeForks += nTime2 - nTime1;
     LogPrint(BCLog::BENCH, "    - Fork checks: %.2fms [%.2fs (%.2fms/blk)]\n",
              MILLI * (nTime2 - nTime1), nTimeForks * MICRO,
              nTimeForks * MILLI / nBlocksTotal);
 
     std::vector<int> prevheights;
     Amount nFees = Amount::zero();
     int nInputs = 0;
 
     // Limit the total executed signature operations in the block, a consensus
     // rule. Tracking during the CPU-consuming part (validation of uncached
     // inputs) is per-input atomic and validation in each thread stops very
     // quickly after the limit is exceeded, so an adversary cannot cause us to
     // exceed the limit by much at all.
     CheckInputsLimiter nSigChecksBlockLimiter(
         GetMaxBlockSigChecksCount(options.getExcessiveBlockSize()));
 
     std::vector<TxSigCheckLimiter> nSigChecksTxLimiters;
     nSigChecksTxLimiters.resize(block.vtx.size() - 1);
 
     CBlockUndo blockundo;
     blockundo.vtxundo.resize(block.vtx.size() - 1);
 
     CCheckQueueControl<CScriptCheck> control(fScriptChecks ? &scriptcheckqueue
                                                            : nullptr);
 
     // Add all outputs
     try {
         for (const auto &ptx : block.vtx) {
             AddCoins(view, *ptx, pindex->nHeight);
         }
     } catch (const std::logic_error &e) {
         // This error will be thrown from AddCoin if we try to connect a block
         // containing duplicate transactions. Such a thing should normally be
         // caught early nowadays (due to ContextualCheckBlock's CTOR
         // enforcement) however some edge cases can escape that:
         // - ContextualCheckBlock does not get re-run after saving the block to
         // disk, and older versions may have saved a weird block.
         // - its checks are not applied to pre-CTOR chains, which we might visit
         // with checkpointing off.
         LogPrintf("ERROR: ConnectBlock(): tried to overwrite transaction\n");
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "tx-duplicate");
     }
 
     size_t txIndex = 0;
     // nSigChecksRet may be accurate (found in cache) or 0 (checks were
     // deferred into vChecks).
     int nSigChecksRet;
     for (const auto &ptx : block.vtx) {
         const CTransaction &tx = *ptx;
         const bool isCoinBase = tx.IsCoinBase();
         nInputs += tx.vin.size();
 
         {
             Amount txfee = Amount::zero();
             TxValidationState tx_state;
             if (!isCoinBase &&
                 !Consensus::CheckTxInputs(tx, tx_state, view, pindex->nHeight,
                                           txfee)) {
                 // Any transaction validation failure in ConnectBlock is a block
                 // consensus failure.
                 state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                               tx_state.GetRejectReason(),
                               tx_state.GetDebugMessage());
 
                 return error("%s: Consensus::CheckTxInputs: %s, %s", __func__,
                              tx.GetId().ToString(), state.ToString());
             }
             nFees += txfee;
         }
 
         if (!MoneyRange(nFees)) {
             LogPrintf("ERROR: %s: accumulated fee in the block out of range.\n",
                       __func__);
             return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                  "bad-txns-accumulated-fee-outofrange");
         }
 
         // The following checks do not apply to the coinbase.
         if (isCoinBase) {
             continue;
         }
 
         // Check that transaction is BIP68 final BIP68 lock checks (as
         // opposed to nLockTime checks) must be in ConnectBlock because they
         // require the UTXO set.
         prevheights.resize(tx.vin.size());
         for (size_t j = 0; j < tx.vin.size(); j++) {
             prevheights[j] = view.AccessCoin(tx.vin[j].prevout).GetHeight();
         }
 
         if (!SequenceLocks(tx, nLockTimeFlags, prevheights, *pindex)) {
             LogPrintf("ERROR: %s: contains a non-BIP68-final transaction\n",
                       __func__);
             return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                  "bad-txns-nonfinal");
         }
 
         // Don't cache results if we're actually connecting blocks (still
         // consult the cache, though).
         bool fCacheResults = fJustCheck;
 
         const bool fEnforceSigCheck = flags & SCRIPT_ENFORCE_SIGCHECKS;
         if (!fEnforceSigCheck) {
             // Historically, there has been transactions with a very high
             // sigcheck count, so we need to disable this check for such
             // transactions.
             nSigChecksTxLimiters[txIndex] = TxSigCheckLimiter::getDisabled();
         }
 
         std::vector<CScriptCheck> vChecks;
         TxValidationState tx_state;
         if (fScriptChecks &&
             !CheckInputScripts(tx, tx_state, view, flags, fCacheResults,
                                fCacheResults, PrecomputedTransactionData(tx),
                                nSigChecksRet, nSigChecksTxLimiters[txIndex],
                                &nSigChecksBlockLimiter, &vChecks)) {
             // Any transaction validation failure in ConnectBlock is a block
             // consensus failure
             state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                           tx_state.GetRejectReason(),
                           tx_state.GetDebugMessage());
             return error(
                 "ConnectBlock(): CheckInputScripts on %s failed with %s",
                 tx.GetId().ToString(), state.ToString());
         }
 
         control.Add(vChecks);
 
         // Note: this must execute in the same iteration as CheckTxInputs (not
         // in a separate loop) in order to detect double spends. However,
         // this does not prevent double-spending by duplicated transaction
         // inputs in the same transaction (cf. CVE-2018-17144) -- that check is
         // done in CheckBlock (CheckRegularTransaction).
         SpendCoins(view, tx, blockundo.vtxundo.at(txIndex), pindex->nHeight);
         txIndex++;
     }
 
     int64_t nTime3 = GetTimeMicros();
     nTimeConnect += nTime3 - nTime2;
     LogPrint(BCLog::BENCH,
              "      - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) "
              "[%.2fs (%.2fms/blk)]\n",
              (unsigned)block.vtx.size(), MILLI * (nTime3 - nTime2),
              MILLI * (nTime3 - nTime2) / block.vtx.size(),
              nInputs <= 1 ? 0 : MILLI * (nTime3 - nTime2) / (nInputs - 1),
              nTimeConnect * MICRO, nTimeConnect * MILLI / nBlocksTotal);
 
     const Amount blockReward =
         nFees + GetBlockSubsidy(pindex->nHeight, consensusParams);
     if (block.vtx[0]->GetValueOut() > blockReward) {
         LogPrintf("ERROR: ConnectBlock(): coinbase pays too much (actual=%d vs "
                   "limit=%d)\n",
                   block.vtx[0]->GetValueOut(), blockReward);
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "bad-cb-amount");
     }
 
     if (blockFees) {
         *blockFees = nFees;
     }
 
     if (!control.Wait()) {
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "blk-bad-inputs", "parallel script check failed");
     }
 
     int64_t nTime4 = GetTimeMicros();
     nTimeVerify += nTime4 - nTime2;
     LogPrint(
         BCLog::BENCH,
         "    - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs (%.2fms/blk)]\n",
         nInputs - 1, MILLI * (nTime4 - nTime2),
         nInputs <= 1 ? 0 : MILLI * (nTime4 - nTime2) / (nInputs - 1),
         nTimeVerify * MICRO, nTimeVerify * MILLI / nBlocksTotal);
 
     if (fJustCheck) {
         return true;
     }
 
     if (!m_blockman.WriteUndoDataForBlock(blockundo, state, pindex, params)) {
         return false;
     }
 
     if (!pindex->IsValid(BlockValidity::SCRIPTS)) {
         pindex->RaiseValidity(BlockValidity::SCRIPTS);
         m_blockman.m_dirty_blockindex.insert(pindex);
     }
 
     assert(pindex->phashBlock);
     // add this block to the view's block chain
     view.SetBestBlock(pindex->GetBlockHash());
 
     int64_t nTime5 = GetTimeMicros();
     nTimeIndex += nTime5 - nTime4;
     LogPrint(BCLog::BENCH, "    - Index writing: %.2fms [%.2fs (%.2fms/blk)]\n",
              MILLI * (nTime5 - nTime4), nTimeIndex * MICRO,
              nTimeIndex * MILLI / nBlocksTotal);
 
     TRACE6(validation, block_connected, block_hash.data(), pindex->nHeight,
            block.vtx.size(), nInputs, nSigChecksRet,
            // in microseconds (µs)
            nTime5 - nTimeStart);
 
     return true;
 }
 
 CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState() {
     AssertLockHeld(::cs_main);
     return this->GetCoinsCacheSizeState(m_coinstip_cache_size_bytes,
                                         m_mempool ? m_mempool->m_max_size_bytes
                                                   : 0);
 }
 
 CoinsCacheSizeState
 Chainstate::GetCoinsCacheSizeState(size_t max_coins_cache_size_bytes,
                                    size_t max_mempool_size_bytes) {
     AssertLockHeld(::cs_main);
     int64_t nMempoolUsage = m_mempool ? m_mempool->DynamicMemoryUsage() : 0;
     int64_t cacheSize = CoinsTip().DynamicMemoryUsage();
     int64_t nTotalSpace =
         max_coins_cache_size_bytes +
         std::max<int64_t>(int64_t(max_mempool_size_bytes) - nMempoolUsage, 0);
 
     //! No need to periodic flush if at least this much space still available.
     static constexpr int64_t MAX_BLOCK_COINSDB_USAGE_BYTES =
         10 * 1024 * 1024; // 10MB
     int64_t large_threshold = std::max(
         (9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE_BYTES);
 
     if (cacheSize > nTotalSpace) {
         LogPrintf("Cache size (%s) exceeds total space (%s)\n", cacheSize,
                   nTotalSpace);
         return CoinsCacheSizeState::CRITICAL;
     } else if (cacheSize > large_threshold) {
         return CoinsCacheSizeState::LARGE;
     }
     return CoinsCacheSizeState::OK;
 }
 
 bool Chainstate::FlushStateToDisk(BlockValidationState &state,
                                   FlushStateMode mode, int nManualPruneHeight) {
     LOCK(cs_main);
     assert(this->CanFlushToDisk());
     std::set<int> setFilesToPrune;
     bool full_flush_completed = false;
 
     const size_t coins_count = CoinsTip().GetCacheSize();
     const size_t coins_mem_usage = CoinsTip().DynamicMemoryUsage();
 
     try {
         {
             bool fFlushForPrune = false;
             bool fDoFullFlush = false;
 
             CoinsCacheSizeState cache_state = GetCoinsCacheSizeState();
             LOCK(m_blockman.cs_LastBlockFile);
             if (m_blockman.IsPruneMode() &&
                 (m_blockman.m_check_for_pruning || nManualPruneHeight > 0) &&
                 !fReindex) {
                 // Make sure we don't prune above the blockfilterindexes
                 // bestblocks. Pruning is height-based.
                 int last_prune = m_chain.Height();
                 ForEachBlockFilterIndex([&](BlockFilterIndex &index) {
                     last_prune = std::max(
                         1, std::min(last_prune,
                                     index.GetSummary().best_block_height));
                 });
 
                 if (nManualPruneHeight > 0) {
                     LOG_TIME_MILLIS_WITH_CATEGORY(
                         "find files to prune (manual)", BCLog::BENCH);
                     m_blockman.FindFilesToPruneManual(
                         setFilesToPrune,
                         std::min(last_prune, nManualPruneHeight),
                         m_chain.Height());
                 } else {
                     LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune",
                                                   BCLog::BENCH);
                     m_blockman.FindFilesToPrune(
                         setFilesToPrune,
                         m_chainman.GetParams().PruneAfterHeight(),
                         m_chain.Height(), last_prune, IsInitialBlockDownload());
                     m_blockman.m_check_for_pruning = false;
                 }
                 if (!setFilesToPrune.empty()) {
                     fFlushForPrune = true;
                     if (!m_blockman.m_have_pruned) {
                         m_blockman.m_block_tree_db->WriteFlag(
                             "prunedblockfiles", true);
                         m_blockman.m_have_pruned = true;
                     }
                 }
             }
             const auto nNow = GetTime<std::chrono::microseconds>();
             // Avoid writing/flushing immediately after startup.
             if (m_last_write.count() == 0) {
                 m_last_write = nNow;
             }
             if (m_last_flush.count() == 0) {
                 m_last_flush = nNow;
             }
             // The cache is large and we're within 10% and 10 MiB of the limit,
             // but we have time now (not in the middle of a block processing).
             bool fCacheLarge = mode == FlushStateMode::PERIODIC &&
                                cache_state >= CoinsCacheSizeState::LARGE;
             // The cache is over the limit, we have to write now.
             bool fCacheCritical = mode == FlushStateMode::IF_NEEDED &&
                                   cache_state >= CoinsCacheSizeState::CRITICAL;
             // It's been a while since we wrote the block index to disk. Do this
             // frequently, so we don't need to redownload after a crash.
             bool fPeriodicWrite = mode == FlushStateMode::PERIODIC &&
                                   nNow > m_last_write + DATABASE_WRITE_INTERVAL;
             // It's been very long since we flushed the cache. Do this
             // infrequently, to optimize cache usage.
             bool fPeriodicFlush = mode == FlushStateMode::PERIODIC &&
                                   nNow > m_last_flush + DATABASE_FLUSH_INTERVAL;
             // Combine all conditions that result in a full cache flush.
             fDoFullFlush = (mode == FlushStateMode::ALWAYS) || fCacheLarge ||
                            fCacheCritical || fPeriodicFlush || fFlushForPrune;
             // Write blocks and block index to disk.
             if (fDoFullFlush || fPeriodicWrite) {
                 // Ensure we can write block index
                 if (!CheckDiskSpace(gArgs.GetBlocksDirPath())) {
                     return AbortNode(state, "Disk space is too low!",
                                      _("Disk space is too low!"));
                 }
 
                 {
                     LOG_TIME_MILLIS_WITH_CATEGORY(
                         "write block and undo data to disk", BCLog::BENCH);
 
                     // First make sure all block and undo data is flushed to
                     // disk.
                     m_blockman.FlushBlockFile();
                 }
                 // Then update all block file information (which may refer to
                 // block and undo files).
                 {
                     LOG_TIME_MILLIS_WITH_CATEGORY("write block index to disk",
                                                   BCLog::BENCH);
 
                     if (!m_blockman.WriteBlockIndexDB()) {
                         return AbortNode(
                             state, "Failed to write to block index database");
                     }
                 }
 
                 // Finally remove any pruned files
                 if (fFlushForPrune) {
                     LOG_TIME_MILLIS_WITH_CATEGORY("unlink pruned files",
                                                   BCLog::BENCH);
 
                     UnlinkPrunedFiles(setFilesToPrune);
                 }
                 m_last_write = nNow;
             }
             // Flush best chain related state. This can only be done if the
             // blocks / block index write was also done.
             if (fDoFullFlush && !CoinsTip().GetBestBlock().IsNull()) {
                 LOG_TIME_MILLIS_WITH_CATEGORY(
                     strprintf("write coins cache to disk (%d coins, %.2fkB)",
                               coins_count, coins_mem_usage / 1000),
                     BCLog::BENCH);
 
                 // Typical Coin structures on disk are around 48 bytes in size.
                 // Pushing a new one to the database can cause it to be written
                 // twice (once in the log, and once in the tables). This is
                 // already an overestimation, as most will delete an existing
                 // entry or overwrite one. Still, use a conservative safety
                 // factor of 2.
                 if (!CheckDiskSpace(gArgs.GetDataDirNet(),
                                     48 * 2 * 2 * CoinsTip().GetCacheSize())) {
                     return AbortNode(state, "Disk space is too low!",
                                      _("Disk space is too low!"));
                 }
 
                 // Flush the chainstate (which may refer to block index
                 // entries).
                 if (!CoinsTip().Flush()) {
                     return AbortNode(state, "Failed to write to coin database");
                 }
                 m_last_flush = nNow;
                 full_flush_completed = true;
             }
 
             TRACE5(utxocache, flush,
                    // in microseconds (µs)
                    GetTimeMicros() - nNow.count(), uint32_t(mode), coins_count,
                    uint64_t(coins_mem_usage), fFlushForPrune);
         }
 
         if (full_flush_completed) {
             // Update best block in wallet (so we can detect restored wallets).
             GetMainSignals().ChainStateFlushed(m_chain.GetLocator());
         }
     } catch (const std::runtime_error &e) {
         return AbortNode(state, std::string("System error while flushing: ") +
                                     e.what());
     }
     return true;
 }
 
 void Chainstate::ForceFlushStateToDisk() {
     BlockValidationState state;
     if (!this->FlushStateToDisk(state, FlushStateMode::ALWAYS)) {
         LogPrintf("%s: failed to flush state (%s)\n", __func__,
                   state.ToString());
     }
 }
 
 void Chainstate::PruneAndFlush() {
     BlockValidationState state;
     m_blockman.m_check_for_pruning = true;
     if (!this->FlushStateToDisk(state, FlushStateMode::NONE)) {
         LogPrintf("%s: failed to flush state (%s)\n", __func__,
                   state.ToString());
     }
 }
 
 static void UpdateTipLog(const CCoinsViewCache &coins_tip,
                          const CBlockIndex *tip, const CChainParams &params,
                          const std::string &func_name,
                          const std::string &prefix)
     EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
     AssertLockHeld(::cs_main);
     LogPrintf("%s%s: new best=%s height=%d version=0x%08x log2_work=%f tx=%ld "
               "date='%s' progress=%f cache=%.1fMiB(%utxo)\n",
               prefix, func_name, tip->GetBlockHash().ToString(), tip->nHeight,
               tip->nVersion, log(tip->nChainWork.getdouble()) / log(2.0),
               tip->GetChainTxCount(),
               FormatISO8601DateTime(tip->GetBlockTime()),
               GuessVerificationProgress(params.TxData(), tip),
               coins_tip.DynamicMemoryUsage() * (1.0 / (1 << 20)),
               coins_tip.GetCacheSize());
 }
 
 void Chainstate::UpdateTip(const CBlockIndex *pindexNew) {
     AssertLockHeld(::cs_main);
     const auto &coins_tip = CoinsTip();
 
     const CChainParams &params{m_chainman.GetParams()};
 
     // The remainder of the function isn't relevant if we are not acting on
     // the active chainstate, so return if need be.
     if (this != &m_chainman.ActiveChainstate()) {
         // Only log every so often so that we don't bury log messages at the
         // tip.
         constexpr int BACKGROUND_LOG_INTERVAL = 2000;
         if (pindexNew->nHeight % BACKGROUND_LOG_INTERVAL == 0) {
             UpdateTipLog(coins_tip, pindexNew, params, __func__,
                          "[background validation] ");
         }
         return;
     }
 
     // New best block
     if (m_mempool) {
         m_mempool->AddTransactionsUpdated(1);
     }
 
     {
         LOCK(g_best_block_mutex);
         g_best_block = pindexNew->GetBlockHash();
         g_best_block_cv.notify_all();
     }
 
     UpdateTipLog(coins_tip, pindexNew, params, __func__, "");
 }
 
 /**
  * Disconnect m_chain's tip.
  * After calling, the mempool will be in an inconsistent state, with
  * transactions from disconnected blocks being added to disconnectpool. You
  * should make the mempool consistent again by calling updateMempoolForReorg.
  * with cs_main held.
  *
  * If disconnectpool is nullptr, then no disconnected transactions are added to
  * disconnectpool (note that the caller is responsible for mempool consistency
  * in any case).
  */
 bool Chainstate::DisconnectTip(BlockValidationState &state,
                                DisconnectedBlockTransactions *disconnectpool) {
     AssertLockHeld(cs_main);
     if (m_mempool) {
         AssertLockHeld(m_mempool->cs);
     }
 
     CBlockIndex *pindexDelete = m_chain.Tip();
     const Consensus::Params &consensusParams = m_chainman.GetConsensus();
 
     assert(pindexDelete);
 
     // Read block from disk.
     std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
     CBlock &block = *pblock;
     if (!ReadBlockFromDisk(block, pindexDelete, consensusParams)) {
         return error("DisconnectTip(): Failed to read block");
     }
 
     // Apply the block atomically to the chain state.
     int64_t nStart = GetTimeMicros();
     {
         CCoinsViewCache view(&CoinsTip());
         assert(view.GetBestBlock() == pindexDelete->GetBlockHash());
         if (DisconnectBlock(block, pindexDelete, view) !=
             DisconnectResult::OK) {
             return error("DisconnectTip(): DisconnectBlock %s failed",
                          pindexDelete->GetBlockHash().ToString());
         }
 
         bool flushed = view.Flush();
         assert(flushed);
     }
 
     LogPrint(BCLog::BENCH, "- Disconnect block: %.2fms\n",
              (GetTimeMicros() - nStart) * MILLI);
 
     // Write the chain state to disk, if necessary.
     if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) {
         return false;
     }
 
     if (m_mempool) {
         // If this block is deactivating a fork, we move all mempool
         // transactions in front of disconnectpool for reprocessing in a future
         // updateMempoolForReorg call
         if (pindexDelete->pprev != nullptr &&
             GetNextBlockScriptFlags(consensusParams, pindexDelete) !=
                 GetNextBlockScriptFlags(consensusParams, pindexDelete->pprev)) {
             LogPrint(BCLog::MEMPOOL,
                      "Disconnecting mempool due to rewind of upgrade block\n");
             if (disconnectpool) {
                 disconnectpool->importMempool(*m_mempool);
             }
             m_mempool->clear();
         }
 
         if (disconnectpool) {
             disconnectpool->addForBlock(block.vtx, *m_mempool);
         }
     }
 
     m_chain.SetTip(pindexDelete->pprev);
 
     UpdateTip(pindexDelete->pprev);
     // Let wallets know transactions went from 1-confirmed to
     // 0-confirmed or conflicted:
     GetMainSignals().BlockDisconnected(pblock, pindexDelete);
     return true;
 }
 
 static int64_t nTimeReadFromDisk = 0;
 static int64_t nTimeConnectTotal = 0;
 static int64_t nTimeFlush = 0;
 static int64_t nTimeChainState = 0;
 static int64_t nTimePostConnect = 0;
 
 struct PerBlockConnectTrace {
     CBlockIndex *pindex = nullptr;
     std::shared_ptr<const CBlock> pblock;
     PerBlockConnectTrace() {}
 };
 
 /**
  * Used to track blocks whose transactions were applied to the UTXO state as a
  * part of a single ActivateBestChainStep call.
  *
  * This class is single-use, once you call GetBlocksConnected() you have to
  * throw it away and make a new one.
  */
 class ConnectTrace {
 private:
     std::vector<PerBlockConnectTrace> blocksConnected;
 
 public:
     explicit ConnectTrace() : blocksConnected(1) {}
 
     void BlockConnected(CBlockIndex *pindex,
                         std::shared_ptr<const CBlock> pblock) {
         assert(!blocksConnected.back().pindex);
         assert(pindex);
         assert(pblock);
         blocksConnected.back().pindex = pindex;
         blocksConnected.back().pblock = std::move(pblock);
         blocksConnected.emplace_back();
     }
 
     std::vector<PerBlockConnectTrace> &GetBlocksConnected() {
         // We always keep one extra block at the end of our list because blocks
         // are added after all the conflicted transactions have been filled in.
         // Thus, the last entry should always be an empty one waiting for the
         // transactions from the next block. We pop the last entry here to make
         // sure the list we return is sane.
         assert(!blocksConnected.back().pindex);
         blocksConnected.pop_back();
         return blocksConnected;
     }
 };
 
 /**
  * Connect a new block to m_chain. pblock is either nullptr or a pointer to
  * a CBlock corresponding to pindexNew, to bypass loading it again from disk.
  *
  * The block is added to connectTrace if connection succeeds.
  */
 bool Chainstate::ConnectTip(const Config &config, BlockValidationState &state,
                             BlockPolicyValidationState &blockPolicyState,
                             CBlockIndex *pindexNew,
                             const std::shared_ptr<const CBlock> &pblock,
                             ConnectTrace &connectTrace,
                             DisconnectedBlockTransactions &disconnectpool) {
     AssertLockHeld(cs_main);
     if (m_mempool) {
         AssertLockHeld(m_mempool->cs);
     }
 
     const Consensus::Params &consensusParams = m_chainman.GetConsensus();
 
     assert(pindexNew->pprev == m_chain.Tip());
     // Read block from disk.
     int64_t nTime1 = GetTimeMicros();
     std::shared_ptr<const CBlock> pthisBlock;
     if (!pblock) {
         std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>();
         if (!ReadBlockFromDisk(*pblockNew, pindexNew, consensusParams)) {
             return AbortNode(state, "Failed to read block");
         }
         pthisBlock = pblockNew;
     } else {
         pthisBlock = pblock;
     }
 
     const CBlock &blockConnecting = *pthisBlock;
 
     // Apply the block atomically to the chain state.
     int64_t nTime2 = GetTimeMicros();
     nTimeReadFromDisk += nTime2 - nTime1;
     int64_t nTime3;
     LogPrint(BCLog::BENCH, "  - Load block from disk: %.2fms [%.2fs]\n",
              (nTime2 - nTime1) * MILLI, nTimeReadFromDisk * MICRO);
     {
         Amount blockFees{Amount::zero()};
         CCoinsViewCache view(&CoinsTip());
         bool rv = ConnectBlock(blockConnecting, state, pindexNew, view,
                                BlockValidationOptions(config), &blockFees);
         GetMainSignals().BlockChecked(blockConnecting, state);
         if (!rv) {
             if (state.IsInvalid()) {
                 InvalidBlockFound(pindexNew, state);
             }
 
             return error("%s: ConnectBlock %s failed, %s", __func__,
                          pindexNew->GetBlockHash().ToString(),
                          state.ToString());
         }
 
         /**
          * The block is valid by consensus rules so now we check if the block
          * passes all block policy checks. If not, then park the block and bail.
          *
          * We check block parking policies before flushing changes to the UTXO
          * set. This allows us to avoid rewinding everything immediately after.
          *
          * Only check block parking policies the first time the block is
          * connected. Avalanche voting can override the parking decision made by
          * these policies.
          */
         const BlockHash blockhash = pindexNew->GetBlockHash();
         if (!IsInitialBlockDownload() &&
             !m_filterParkingPoliciesApplied.contains(blockhash)) {
             m_filterParkingPoliciesApplied.insert(blockhash);
 
             const Amount blockReward =
                 blockFees +
                 GetBlockSubsidy(pindexNew->nHeight, consensusParams);
 
             std::vector<std::unique_ptr<ParkingPolicy>> parkingPolicies;
             parkingPolicies.emplace_back(std::make_unique<MinerFundPolicy>(
                 consensusParams, *pindexNew, blockConnecting, blockReward));
 
             if (g_avalanche) {
                 parkingPolicies.emplace_back(
                     std::make_unique<StakingRewardsPolicy>(
                         consensusParams, *pindexNew, blockConnecting,
                         blockReward));
 
                 if (m_mempool) {
                     parkingPolicies.emplace_back(
                         std::make_unique<PreConsensusPolicy>(
                             *pindexNew, blockConnecting, m_mempool));
                 }
             }
 
             // If any block policy is violated, bail on the first one found
             if (std::find_if_not(parkingPolicies.begin(), parkingPolicies.end(),
                                  [&](const auto &policy) {
                                      bool ret = (*policy)(blockPolicyState);
                                      if (!ret) {
                                          LogPrintf(
                                              "Park block because it "
                                              "violated a block policy: %s\n",
                                              blockPolicyState.ToString());
                                      }
                                      return ret;
                                  }) != parkingPolicies.end()) {
                 pindexNew->nStatus = pindexNew->nStatus.withParked();
                 m_blockman.m_dirty_blockindex.insert(pindexNew);
                 return false;
             }
         }
 
         nTime3 = GetTimeMicros();
         nTimeConnectTotal += nTime3 - nTime2;
         assert(nBlocksTotal > 0);
         LogPrint(BCLog::BENCH,
                  "  - Connect total: %.2fms [%.2fs (%.2fms/blk)]\n",
                  (nTime3 - nTime2) * MILLI, nTimeConnectTotal * MICRO,
                  nTimeConnectTotal * MILLI / nBlocksTotal);
         bool flushed = view.Flush();
         assert(flushed);
     }
 
     int64_t nTime4 = GetTimeMicros();
     nTimeFlush += nTime4 - nTime3;
     LogPrint(BCLog::BENCH, "  - Flush: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime4 - nTime3) * MILLI, nTimeFlush * MICRO,
              nTimeFlush * MILLI / nBlocksTotal);
 
     // Write the chain state to disk, if necessary.
     if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) {
         return false;
     }
 
     int64_t nTime5 = GetTimeMicros();
     nTimeChainState += nTime5 - nTime4;
     LogPrint(BCLog::BENCH,
              "  - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime5 - nTime4) * MILLI, nTimeChainState * MICRO,
              nTimeChainState * MILLI / nBlocksTotal);
 
     // Remove conflicting transactions from the mempool;
     if (m_mempool) {
         disconnectpool.removeForBlock(blockConnecting.vtx, *m_mempool);
 
         // If this block is activating a fork, we move all mempool transactions
         // in front of disconnectpool for reprocessing in a future
         // updateMempoolForReorg call
         if (pindexNew->pprev != nullptr &&
             GetNextBlockScriptFlags(consensusParams, pindexNew) !=
                 GetNextBlockScriptFlags(consensusParams, pindexNew->pprev)) {
             LogPrint(
                 BCLog::MEMPOOL,
                 "Disconnecting mempool due to acceptance of upgrade block\n");
             disconnectpool.importMempool(*m_mempool);
         }
     }
 
     // Update m_chain & related variables.
     m_chain.SetTip(pindexNew);
     UpdateTip(pindexNew);
 
     int64_t nTime6 = GetTimeMicros();
     nTimePostConnect += nTime6 - nTime5;
     nTimeTotal += nTime6 - nTime1;
     LogPrint(BCLog::BENCH,
              "  - Connect postprocess: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime6 - nTime5) * MILLI, nTimePostConnect * MICRO,
              nTimePostConnect * MILLI / nBlocksTotal);
     LogPrint(BCLog::BENCH, "- Connect block: %.2fms [%.2fs (%.2fms/blk)]\n",
              (nTime6 - nTime1) * MILLI, nTimeTotal * MICRO,
              nTimeTotal * MILLI / nBlocksTotal);
 
     // If we are the background validation chainstate, check to see if we are
     // done validating the snapshot (i.e. our tip has reached the snapshot's
     // base block).
     if (this != &m_chainman.ActiveChainstate()) {
         // This call may set `m_disabled`, which is referenced immediately
         // afterwards in ActivateBestChain, so that we stop connecting blocks
         // past the snapshot base.
         m_chainman.MaybeCompleteSnapshotValidation();
     }
 
     connectTrace.BlockConnected(pindexNew, std::move(pthisBlock));
     return true;
 }
 
 /**
  * Return the tip of the chain with the most work in it, that isn't known to be
  * invalid (it's however far from certain to be valid).
  */
 CBlockIndex *Chainstate::FindMostWorkChain(
     std::vector<const CBlockIndex *> &blocksToReconcile) {
     AssertLockHeld(::cs_main);
     do {
         CBlockIndex *pindexNew = nullptr;
 
         // Find the best candidate header.
         {
             std::set<CBlockIndex *, CBlockIndexWorkComparator>::reverse_iterator
                 it = setBlockIndexCandidates.rbegin();
             if (it == setBlockIndexCandidates.rend()) {
                 return nullptr;
             }
             pindexNew = *it;
         }
 
         // If this block will cause an avalanche finalized block to be reorged,
         // then we park it.
         {
             LOCK(cs_avalancheFinalizedBlockIndex);
             if (m_avalancheFinalizedBlockIndex &&
                 !AreOnTheSameFork(pindexNew, m_avalancheFinalizedBlockIndex)) {
                 LogPrintf("Park block %s because it forks prior to the "
                           "avalanche finalized chaintip.\n",
                           pindexNew->GetBlockHash().ToString());
                 pindexNew->nStatus = pindexNew->nStatus.withParked();
                 m_blockman.m_dirty_blockindex.insert(pindexNew);
             }
         }
 
         const bool fAvalancheEnabled = isAvalancheEnabled(gArgs);
         const bool fAutoUnpark =
             gArgs.GetBoolArg("-automaticunparking", !fAvalancheEnabled);
 
         const CBlockIndex *pindexFork = m_chain.FindFork(pindexNew);
 
         // Check whether all blocks on the path between the currently active
         // chain and the candidate are valid. Just going until the active chain
         // is an optimization, as we know all blocks in it are valid already.
         CBlockIndex *pindexTest = pindexNew;
         bool hasValidAncestor = true;
         while (hasValidAncestor && pindexTest && pindexTest != pindexFork) {
             assert(pindexTest->HaveTxsDownloaded() || pindexTest->nHeight == 0);
 
             // If this is a parked chain, but it has enough PoW, clear the park
             // state.
             bool fParkedChain = pindexTest->nStatus.isOnParkedChain();
             if (fAutoUnpark && fParkedChain) {
                 const CBlockIndex *pindexTip = m_chain.Tip();
 
                 // During initialization, pindexTip and/or pindexFork may be
                 // null. In this case, we just ignore the fact that the chain is
                 // parked.
                 if (!pindexTip || !pindexFork) {
                     UnparkBlock(pindexTest);
                     continue;
                 }
 
                 // A parked chain can be unparked if it has twice as much PoW
                 // accumulated as the main chain has since the fork block.
                 CBlockIndex const *pindexExtraPow = pindexTip;
                 arith_uint256 requiredWork = pindexTip->nChainWork;
                 switch (pindexTip->nHeight - pindexFork->nHeight) {
                     // Limit the penality for depth 1, 2 and 3 to half a block
                     // worth of work to ensure we don't fork accidentally.
                     case 3:
                     case 2:
                         pindexExtraPow = pindexExtraPow->pprev;
                     // FALLTHROUGH
                     case 1: {
                         const arith_uint256 deltaWork =
                             pindexExtraPow->nChainWork - pindexFork->nChainWork;
                         requiredWork += (deltaWork >> 1);
                         break;
                     }
                     default:
                         requiredWork +=
                             pindexExtraPow->nChainWork - pindexFork->nChainWork;
                         break;
                 }
 
                 if (pindexNew->nChainWork > requiredWork) {
                     // We have enough, clear the parked state.
                     LogPrintf("Unpark chain up to block %s as it has "
                               "accumulated enough PoW.\n",
                               pindexNew->GetBlockHash().ToString());
                     fParkedChain = false;
                     UnparkBlock(pindexTest);
                 }
             }
 
             // Pruned nodes may have entries in setBlockIndexCandidates for
             // which block files have been deleted. Remove those as candidates
             // for the most work chain if we come across them; we can't switch
             // to a chain unless we have all the non-active-chain parent blocks.
             bool fInvalidChain = pindexTest->nStatus.isInvalid();
             bool fMissingData = !pindexTest->nStatus.hasData();
             if (!(fInvalidChain || fParkedChain || fMissingData)) {
                 // The current block is acceptable, move to the parent, up to
                 // the fork point.
                 pindexTest = pindexTest->pprev;
                 continue;
             }
 
             // Candidate chain is not usable (either invalid or parked or
             // missing data)
             hasValidAncestor = false;
             setBlockIndexCandidates.erase(pindexTest);
 
             if (fInvalidChain && (m_chainman.m_best_invalid == nullptr ||
                                   pindexNew->nChainWork >
                                       m_chainman.m_best_invalid->nChainWork)) {
                 m_chainman.m_best_invalid = pindexNew;
             }
 
             if (fParkedChain && (m_chainman.m_best_parked == nullptr ||
                                  pindexNew->nChainWork >
                                      m_chainman.m_best_parked->nChainWork)) {
                 m_chainman.m_best_parked = pindexNew;
             }
 
             LogPrintf("Considered switching to better tip %s but that chain "
                       "contains a%s%s%s block.\n",
                       pindexNew->GetBlockHash().ToString(),
                       fInvalidChain ? "n invalid" : "",
                       fParkedChain ? " parked" : "",
                       fMissingData ? " missing-data" : "");
 
             CBlockIndex *pindexFailed = pindexNew;
             // Remove the entire chain from the set.
             while (pindexTest != pindexFailed) {
                 if (fInvalidChain || fParkedChain) {
                     pindexFailed->nStatus =
                         pindexFailed->nStatus.withFailedParent(fInvalidChain)
                             .withParkedParent(fParkedChain);
                 } else if (fMissingData) {
                     // If we're missing data, then add back to
                     // m_blocks_unlinked, so that if the block arrives in the
                     // future we can try adding to setBlockIndexCandidates
                     // again.
                     m_blockman.m_blocks_unlinked.insert(
                         std::make_pair(pindexFailed->pprev, pindexFailed));
                 }
                 setBlockIndexCandidates.erase(pindexFailed);
                 pindexFailed = pindexFailed->pprev;
             }
 
             if (fInvalidChain || fParkedChain) {
                 // We discovered a new chain tip that is either parked or
                 // invalid, we may want to warn.
                 CheckForkWarningConditionsOnNewFork(pindexNew);
             }
         }
 
         if (fAvalancheEnabled && g_avalanche) {
             blocksToReconcile.push_back(pindexNew);
         }
 
         // We found a candidate that has valid ancestors. This is our guy.
         if (hasValidAncestor) {
             return pindexNew;
         }
     } while (true);
 }
 
 /**
  * Delete all entries in setBlockIndexCandidates that are worse than the current
  * tip.
  */
 void Chainstate::PruneBlockIndexCandidates() {
     // Note that we can't delete the current block itself, as we may need to
     // return to it later in case a reorganization to a better block fails.
     auto it = setBlockIndexCandidates.begin();
     while (it != setBlockIndexCandidates.end() &&
            setBlockIndexCandidates.value_comp()(*it, m_chain.Tip())) {
         setBlockIndexCandidates.erase(it++);
     }
 
     // Either the current tip or a successor of it we're working towards is left
     // in setBlockIndexCandidates.
     assert(!setBlockIndexCandidates.empty());
 }
 
 /**
  * Try to make some progress towards making pindexMostWork the active block.
  * pblock is either nullptr or a pointer to a CBlock corresponding to
  * pindexMostWork.
  *
  * @returns true unless a system error occurred
  */
 bool Chainstate::ActivateBestChainStep(
     const Config &config, BlockValidationState &state,
     CBlockIndex *pindexMostWork, const std::shared_ptr<const CBlock> &pblock,
     bool &fInvalidFound, ConnectTrace &connectTrace) {
     AssertLockHeld(cs_main);
     if (m_mempool) {
         AssertLockHeld(m_mempool->cs);
     }
 
     const CBlockIndex *pindexOldTip = m_chain.Tip();
     const CBlockIndex *pindexFork = m_chain.FindFork(pindexMostWork);
 
     // Disconnect active blocks which are no longer in the best chain.
     bool fBlocksDisconnected = false;
     DisconnectedBlockTransactions disconnectpool;
     while (m_chain.Tip() && m_chain.Tip() != pindexFork) {
         if (!fBlocksDisconnected) {
             // Import and clear mempool; we must do this to preserve
             // topological ordering in the mempool index. This is ok since
             // inserts into the mempool are very fast now in our new
             // implementation.
             disconnectpool.importMempool(*m_mempool);
         }
 
         if (!DisconnectTip(state, &disconnectpool)) {
             // This is likely a fatal error, but keep the mempool consistent,
             // just in case. Only remove from the mempool in this case.
             if (m_mempool) {
                 disconnectpool.updateMempoolForReorg(config, *this, false,
                                                      *m_mempool);
             }
 
             // If we're unable to disconnect a block during normal operation,
             // then that is a failure of our local system -- we should abort
             // rather than stay on a less work chain.
             AbortNode(state,
                       "Failed to disconnect block; see debug.log for details");
             return false;
         }
 
         fBlocksDisconnected = true;
     }
 
     // Build list of new blocks to connect.
     std::vector<CBlockIndex *> vpindexToConnect;
     bool fContinue = true;
     int nHeight = pindexFork ? pindexFork->nHeight : -1;
     while (fContinue && nHeight != pindexMostWork->nHeight) {
         // Don't iterate the entire list of potential improvements toward the
         // best tip, as we likely only need a few blocks along the way.
         int nTargetHeight = std::min(nHeight + 32, pindexMostWork->nHeight);
         vpindexToConnect.clear();
         vpindexToConnect.reserve(nTargetHeight - nHeight);
         CBlockIndex *pindexIter = pindexMostWork->GetAncestor(nTargetHeight);
         while (pindexIter && pindexIter->nHeight != nHeight) {
             vpindexToConnect.push_back(pindexIter);
             pindexIter = pindexIter->pprev;
         }
 
         nHeight = nTargetHeight;
 
         // Connect new blocks.
         for (CBlockIndex *pindexConnect : reverse_iterate(vpindexToConnect)) {
             BlockPolicyValidationState blockPolicyState;
             if (!ConnectTip(config, state, blockPolicyState, pindexConnect,
                             pindexConnect == pindexMostWork
                                 ? pblock
                                 : std::shared_ptr<const CBlock>(),
                             connectTrace, disconnectpool)) {
                 if (state.IsInvalid()) {
                     // The block violates a consensus rule.
                     if (state.GetResult() !=
                         BlockValidationResult::BLOCK_MUTATED) {
                         InvalidChainFound(vpindexToConnect.back());
                     }
                     state = BlockValidationState();
                     fInvalidFound = true;
                     fContinue = false;
                     break;
                 }
 
                 if (blockPolicyState.IsInvalid()) {
                     // The block violates a policy rule.
                     fContinue = false;
                     break;
                 }
 
                 // A system error occurred (disk space, database error, ...).
                 // Make the mempool consistent with the current tip, just in
                 // case any observers try to use it before shutdown.
                 if (m_mempool) {
                     disconnectpool.updateMempoolForReorg(config, *this, false,
                                                          *m_mempool);
                 }
                 return false;
             } else {
                 PruneBlockIndexCandidates();
                 if (!pindexOldTip ||
                     m_chain.Tip()->nChainWork > pindexOldTip->nChainWork) {
                     // We're in a better position than we were. Return
                     // temporarily to release the lock.
                     fContinue = false;
                     break;
                 }
             }
         }
     }
 
     if (m_mempool) {
         if (fBlocksDisconnected || !disconnectpool.isEmpty()) {
             // If any blocks were disconnected, we need to update the mempool
             // even if disconnectpool is empty. The disconnectpool may also be
             // non-empty if the mempool was imported due to new validation rules
             // being in effect.
             LogPrint(BCLog::MEMPOOL,
                      "Updating mempool due to reorganization or "
                      "rules upgrade/downgrade\n");
             disconnectpool.updateMempoolForReorg(config, *this, true,
                                                  *m_mempool);
         }
 
         m_mempool->check(this->CoinsTip(), this->m_chain.Height() + 1);
     }
 
     // Callbacks/notifications for a new best chain.
     if (fInvalidFound) {
         CheckForkWarningConditionsOnNewFork(pindexMostWork);
     } else {
         CheckForkWarningConditions();
     }
 
     return true;
 }
 
 static SynchronizationState GetSynchronizationState(bool init) {
     if (!init) {
         return SynchronizationState::POST_INIT;
     }
     if (::fReindex) {
         return SynchronizationState::INIT_REINDEX;
     }
     return SynchronizationState::INIT_DOWNLOAD;
 }
 
 static bool NotifyHeaderTip(Chainstate &chainstate) LOCKS_EXCLUDED(cs_main) {
     bool fNotify = false;
     bool fInitialBlockDownload = false;
     static CBlockIndex *pindexHeaderOld = nullptr;
     CBlockIndex *pindexHeader = nullptr;
     {
         LOCK(cs_main);
         pindexHeader = chainstate.m_chainman.m_best_header;
 
         if (pindexHeader != pindexHeaderOld) {
             fNotify = true;
             fInitialBlockDownload = chainstate.IsInitialBlockDownload();
             pindexHeaderOld = pindexHeader;
         }
     }
 
     // Send block tip changed notifications without cs_main
     if (fNotify) {
         uiInterface.NotifyHeaderTip(
             GetSynchronizationState(fInitialBlockDownload),
             pindexHeader->nHeight, pindexHeader->nTime, false);
     }
     return fNotify;
 }
 
 static void LimitValidationInterfaceQueue() LOCKS_EXCLUDED(cs_main) {
     AssertLockNotHeld(cs_main);
 
     if (GetMainSignals().CallbacksPending() > 10) {
         SyncWithValidationInterfaceQueue();
     }
 }
 
 bool Chainstate::ActivateBestChain(const Config &config,
                                    BlockValidationState &state,
                                    std::shared_ptr<const CBlock> pblock) {
     AssertLockNotHeld(m_chainstate_mutex);
 
     // Note that while we're often called here from ProcessNewBlock, this is
     // far from a guarantee. Things in the P2P/RPC will often end up calling
     // us in the middle of ProcessNewBlock - do not assume pblock is set
     // sanely for performance or correctness!
     AssertLockNotHeld(::cs_main);
 
     // ABC maintains a fair degree of expensive-to-calculate internal state
     // because this function periodically releases cs_main so that it does not
     // lock up other threads for too long during large connects - and to allow
     // for e.g. the callback queue to drain we use m_chainstate_mutex to enforce
     // mutual exclusion so that only one caller may execute this function at a
     // time
     LOCK(m_chainstate_mutex);
 
     // Belt-and-suspenders check that we aren't attempting to advance the
     // background chainstate past the snapshot base block.
     if (WITH_LOCK(::cs_main, return m_disabled)) {
         LogPrintf("m_disabled is set - this chainstate should not be in "
                   "operation. Please report this as a bug. %s\n",
                   PACKAGE_BUGREPORT);
         return false;
     }
 
     CBlockIndex *pindexMostWork = nullptr;
     CBlockIndex *pindexNewTip = nullptr;
     int nStopAtHeight = gArgs.GetIntArg("-stopatheight", DEFAULT_STOPATHEIGHT);
     do {
         // Block until the validation queue drains. This should largely
         // never happen in normal operation, however may happen during
         // reindex, causing memory blowup if we run too far ahead.
         // Note that if a validationinterface callback ends up calling
         // ActivateBestChain this may lead to a deadlock! We should
         // probably have a DEBUG_LOCKORDER test for this in the future.
         LimitValidationInterfaceQueue();
 
         std::vector<const CBlockIndex *> blocksToReconcile;
         bool blocks_connected = false;
 
         {
             LOCK(cs_main);
             // Lock transaction pool for at least as long as it takes for
             // connectTrace to be consumed
             LOCK(MempoolMutex());
             CBlockIndex *starting_tip = m_chain.Tip();
             do {
                 // We absolutely may not unlock cs_main until we've made forward
                 // progress (with the exception of shutdown due to hardware
                 // issues, low disk space, etc).
 
                 // Destructed before cs_main is unlocked
                 ConnectTrace connectTrace;
 
                 if (pindexMostWork == nullptr) {
                     pindexMostWork = FindMostWorkChain(blocksToReconcile);
                 }
 
                 // Whether we have anything to do at all.
                 if (pindexMostWork == nullptr ||
                     pindexMostWork == m_chain.Tip()) {
                     break;
                 }
 
                 bool fInvalidFound = false;
                 std::shared_ptr<const CBlock> nullBlockPtr;
                 if (!ActivateBestChainStep(
                         config, state, pindexMostWork,
                         pblock && pblock->GetHash() ==
                                       pindexMostWork->GetBlockHash()
                             ? pblock
                             : nullBlockPtr,
                         fInvalidFound, connectTrace)) {
                     // A system error occurred
                     return false;
                 }
                 blocks_connected = true;
 
                 if (fInvalidFound ||
                     (pindexMostWork && pindexMostWork->nStatus.isParked())) {
                     // Wipe cache, we may need another branch now.
                     pindexMostWork = nullptr;
                 }
 
                 pindexNewTip = m_chain.Tip();
                 for (const PerBlockConnectTrace &trace :
                      connectTrace.GetBlocksConnected()) {
                     assert(trace.pblock && trace.pindex);
                     GetMainSignals().BlockConnected(trace.pblock, trace.pindex);
                 }
 
                 // This will have been toggled in
                 // ActivateBestChainStep -> ConnectTip ->
                 // MaybeCompleteSnapshotValidation, if at all, so we should
                 // catch it here.
                 //
                 // Break this do-while to ensure we don't advance past the base
                 // snapshot.
                 if (m_disabled) {
                     break;
                 }
             } while (!m_chain.Tip() ||
                      (starting_tip && CBlockIndexWorkComparator()(
                                           m_chain.Tip(), starting_tip)));
 
             // Check the index once we're done with the above loop, since
             // we're going to release cs_main soon. If the index is in a bad
             // state now, then it's better to know immediately rather than
             // randomly have it cause a problem in a race.
             CheckBlockIndex();
 
             if (blocks_connected) {
                 const CBlockIndex *pindexFork = m_chain.FindFork(starting_tip);
                 bool fInitialDownload = IsInitialBlockDownload();
 
                 // Notify external listeners about the new tip.
                 // Enqueue while holding cs_main to ensure that UpdatedBlockTip
                 // is called in the order in which blocks are connected
                 if (pindexFork != pindexNewTip) {
                     // Notify ValidationInterface subscribers
                     GetMainSignals().UpdatedBlockTip(pindexNewTip, pindexFork,
                                                      fInitialDownload);
 
                     // Always notify the UI if a new block tip was connected
                     uiInterface.NotifyBlockTip(
                         GetSynchronizationState(fInitialDownload),
                         pindexNewTip);
                 }
             }
         }
         // When we reach this point, we switched to a new tip (stored in
         // pindexNewTip).
         if (g_avalanche) {
             for (const CBlockIndex *pindex : blocksToReconcile) {
                 g_avalanche->addToReconcile(pindex);
                 g_avalanche->computeStakingReward(pindex);
             }
         }
 
         if (!blocks_connected) {
             return true;
         }
 
         if (nStopAtHeight && pindexNewTip &&
             pindexNewTip->nHeight >= nStopAtHeight) {
             StartShutdown();
         }
 
         if (WITH_LOCK(::cs_main, return m_disabled)) {
             // Background chainstate has reached the snapshot base block, so
             // exit.
             break;
         }
 
         // We check shutdown only after giving ActivateBestChainStep a chance to
         // run once so that we never shutdown before connecting the genesis
         // block during LoadChainTip(). Previously this caused an assert()
         // failure during shutdown in such cases as the UTXO DB flushing checks
         // that the best block hash is non-null.
         if (ShutdownRequested()) {
             break;
         }
     } while (pindexNewTip != pindexMostWork);
 
     // Write changes periodically to disk, after relay.
     if (!FlushStateToDisk(state, FlushStateMode::PERIODIC)) {
         return false;
     }
 
     return true;
 }
 
 bool Chainstate::PreciousBlock(const Config &config,
                                BlockValidationState &state,
                                CBlockIndex *pindex) {
     AssertLockNotHeld(m_chainstate_mutex);
     AssertLockNotHeld(::cs_main);
     {
         LOCK(cs_main);
         if (pindex->nChainWork < m_chain.Tip()->nChainWork) {
             // Nothing to do, this block is not at the tip.
             return true;
         }
 
         if (m_chain.Tip()->nChainWork > nLastPreciousChainwork) {
             // The chain has been extended since the last call, reset the
             // counter.
             nBlockReverseSequenceId = -1;
         }
 
         nLastPreciousChainwork = m_chain.Tip()->nChainWork;
         setBlockIndexCandidates.erase(pindex);
         pindex->nSequenceId = nBlockReverseSequenceId;
         if (nBlockReverseSequenceId > std::numeric_limits<int32_t>::min()) {
             // We can't keep reducing the counter if somebody really wants to
             // call preciousblock 2**31-1 times on the same set of tips...
             nBlockReverseSequenceId--;
         }
 
         // In case this was parked, unpark it.
         UnparkBlock(pindex);
 
         // Make sure it is added to the candidate list if appropriate.
         if (pindex->IsValid(BlockValidity::TRANSACTIONS) &&
             pindex->HaveTxsDownloaded()) {
             setBlockIndexCandidates.insert(pindex);
             PruneBlockIndexCandidates();
         }
     }
 
     return ActivateBestChain(config, state);
 }
 
 namespace {
 // Leverage RAII to run a functor at scope end
 template <typename Func> struct Defer {
     Func func;
     Defer(Func &&f) : func(std::move(f)) {}
     ~Defer() { func(); }
 };
 } // namespace
 
 bool Chainstate::UnwindBlock(const Config &config, BlockValidationState &state,
                              CBlockIndex *pindex, bool invalidate) {
     // Genesis block can't be invalidated or parked
     assert(pindex);
     if (pindex->nHeight == 0) {
         return false;
     }
 
     CBlockIndex *to_mark_failed_or_parked = pindex;
     bool pindex_was_in_chain = false;
     int disconnected = 0;
 
     // We do not allow ActivateBestChain() to run while UnwindBlock() is
     // running, as that could cause the tip to change while we disconnect
     // blocks. (Note for backport of Core PR16849: we acquire
     // LOCK(m_chainstate_mutex) in the Park, Invalidate and FinalizeBlock
     // functions due to differences in our code)
     AssertLockHeld(m_chainstate_mutex);
 
     // We'll be acquiring and releasing cs_main below, to allow the validation
     // callbacks to run. However, we should keep the block index in a
     // consistent state as we disconnect blocks -- in particular we need to
     // add equal-work blocks to setBlockIndexCandidates as we disconnect.
     // To avoid walking the block index repeatedly in search of candidates,
     // build a map once so that we can look up candidate blocks by chain
     // work as we go.
     std::multimap<const arith_uint256, CBlockIndex *> candidate_blocks_by_work;
 
     {
         LOCK(cs_main);
         for (auto &entry : m_blockman.m_block_index) {
             CBlockIndex *candidate = &entry.second;
             // We don't need to put anything in our active chain into the
             // multimap, because those candidates will be found and considered
             // as we disconnect.
             // Instead, consider only non-active-chain blocks that have at
             // least as much work as where we expect the new tip to end up.
             if (!m_chain.Contains(candidate) &&
                 !CBlockIndexWorkComparator()(candidate, pindex->pprev) &&
                 candidate->IsValid(BlockValidity::TRANSACTIONS) &&
                 candidate->HaveTxsDownloaded()) {
                 candidate_blocks_by_work.insert(
                     std::make_pair(candidate->nChainWork, candidate));
             }
         }
     }
 
     {
         LOCK(cs_main);
         // Lock for as long as disconnectpool is in scope to make sure
         // UpdateMempoolForReorg is called after DisconnectTip without unlocking
         // in between
         LOCK(MempoolMutex());
 
         constexpr int maxDisconnectPoolBlocks = 10;
         bool ret = false;
         DisconnectedBlockTransactions disconnectpool;
         // After 10 blocks this becomes nullptr, so that DisconnectTip will
         // stop giving us unwound block txs if we are doing a deep unwind.
         DisconnectedBlockTransactions *optDisconnectPool = &disconnectpool;
 
         // Disable thread safety analysis because we can't require m_mempool->cs
         // as m_mempool can be null. We keep the runtime analysis though.
         Defer deferred([&]() NO_THREAD_SAFETY_ANALYSIS {
             AssertLockHeld(cs_main);
             if (m_mempool && !disconnectpool.isEmpty()) {
                 AssertLockHeld(m_mempool->cs);
                 // DisconnectTip will add transactions to disconnectpool.
                 // When all unwinding is done and we are on a new tip, we must
                 // add all transactions back to the mempool against the new tip.
                 disconnectpool.updateMempoolForReorg(config, *this,
                                                      /* fAddToMempool = */ ret,
                                                      *m_mempool);
             }
         });
 
         // Disconnect (descendants of) pindex, and mark them invalid.
         while (true) {
             if (ShutdownRequested()) {
                 break;
             }
 
             // Make sure the queue of validation callbacks doesn't grow
             // unboundedly.
             // FIXME this commented code is a regression and could cause OOM if
             // a very old block is invalidated via the invalidateblock RPC.
             // This can be uncommented if the main signals are moved away from
             // cs_main or this code is refactored so that cs_main can be
             // released at this point.
             //
             // LimitValidationInterfaceQueue();
 
             if (!m_chain.Contains(pindex)) {
                 break;
             }
 
             if (m_mempool && disconnected == 0) {
                 // On first iteration, we grab all the mempool txs to preserve
                 // topological ordering. This has the side-effect of temporarily
                 // clearing the mempool, but we will re-add later in
                 // updateMempoolForReorg() (above). This technique guarantees
                 // mempool consistency as well as ensures that our topological
                 // entry_id index is always correct.
                 disconnectpool.importMempool(*m_mempool);
             }
 
             pindex_was_in_chain = true;
             CBlockIndex *invalid_walk_tip = m_chain.Tip();
 
             // ActivateBestChain considers blocks already in m_chain
             // unconditionally valid already, so force disconnect away from it.
 
             ret = DisconnectTip(state, optDisconnectPool);
             ++disconnected;
 
             if (optDisconnectPool && disconnected > maxDisconnectPoolBlocks) {
                 // Stop using the disconnect pool after 10 blocks. After 10
                 // blocks we no longer add block tx's to the disconnectpool.
                 // However, when this scope ends we will reconcile what's
                 // in the pool with the new tip (in the deferred d'tor above).
                 optDisconnectPool = nullptr;
             }
 
             if (!ret) {
                 return false;
             }
 
             assert(invalid_walk_tip->pprev == m_chain.Tip());
 
             // We immediately mark the disconnected blocks as invalid.
             // This prevents a case where pruned nodes may fail to
             // invalidateblock and be left unable to start as they have no tip
             // candidates (as there are no blocks that meet the "have data and
             // are not invalid per nStatus" criteria for inclusion in
             // setBlockIndexCandidates).
 
             invalid_walk_tip->nStatus =
                 invalidate ? invalid_walk_tip->nStatus.withFailed()
                            : invalid_walk_tip->nStatus.withParked();
 
             m_blockman.m_dirty_blockindex.insert(invalid_walk_tip);
             setBlockIndexCandidates.insert(invalid_walk_tip->pprev);
 
             if (invalid_walk_tip == to_mark_failed_or_parked->pprev &&
                 (invalidate ? to_mark_failed_or_parked->nStatus.hasFailed()
                             : to_mark_failed_or_parked->nStatus.isParked())) {
                 // We only want to mark the last disconnected block as
                 // Failed (or Parked); its children need to be FailedParent (or
                 // ParkedParent) instead.
                 to_mark_failed_or_parked->nStatus =
                     (invalidate
                          ? to_mark_failed_or_parked->nStatus.withFailed(false)
                                .withFailedParent()
                          : to_mark_failed_or_parked->nStatus.withParked(false)
                                .withParkedParent());
 
                 m_blockman.m_dirty_blockindex.insert(to_mark_failed_or_parked);
             }
 
             // Add any equal or more work headers to setBlockIndexCandidates
             auto candidate_it = candidate_blocks_by_work.lower_bound(
                 invalid_walk_tip->pprev->nChainWork);
             while (candidate_it != candidate_blocks_by_work.end()) {
                 if (!CBlockIndexWorkComparator()(candidate_it->second,
                                                  invalid_walk_tip->pprev)) {
                     setBlockIndexCandidates.insert(candidate_it->second);
                     candidate_it = candidate_blocks_by_work.erase(candidate_it);
                 } else {
                     ++candidate_it;
                 }
             }
 
             // Track the last disconnected block, so we can correct its
             // FailedParent (or ParkedParent) status in future iterations, or,
             // if it's the last one, call InvalidChainFound on it.
             to_mark_failed_or_parked = invalid_walk_tip;
         }
     }
 
     CheckBlockIndex();
 
     {
         LOCK(cs_main);
         if (m_chain.Contains(to_mark_failed_or_parked)) {
             // If the to-be-marked invalid block is in the active chain,
             // something is interfering and we can't proceed.
             return false;
         }
 
         // Mark pindex (or the last disconnected block) as invalid (or parked),
         // even when it never was in the main chain.
         to_mark_failed_or_parked->nStatus =
             invalidate ? to_mark_failed_or_parked->nStatus.withFailed()
                        : to_mark_failed_or_parked->nStatus.withParked();
         m_blockman.m_dirty_blockindex.insert(to_mark_failed_or_parked);
         if (invalidate) {
             m_chainman.m_failed_blocks.insert(to_mark_failed_or_parked);
         }
 
         // If any new blocks somehow arrived while we were disconnecting
         // (above), then the pre-calculation of what should go into
         // setBlockIndexCandidates may have missed entries. This would
         // technically be an inconsistency in the block index, but if we clean
         // it up here, this should be an essentially unobservable error.
         // Loop back over all block index entries and add any missing entries
         // to setBlockIndexCandidates.
         for (auto &[_, block_index] : m_blockman.m_block_index) {
             if (block_index.IsValid(BlockValidity::TRANSACTIONS) &&
                 block_index.HaveTxsDownloaded() &&
                 !setBlockIndexCandidates.value_comp()(&block_index,
                                                       m_chain.Tip())) {
                 setBlockIndexCandidates.insert(&block_index);
             }
         }
 
         if (invalidate) {
             InvalidChainFound(to_mark_failed_or_parked);
         }
     }
 
     // Only notify about a new block tip if the active chain was modified.
     if (pindex_was_in_chain) {
         uiInterface.NotifyBlockTip(
             GetSynchronizationState(IsInitialBlockDownload()),
             to_mark_failed_or_parked->pprev);
     }
     return true;
 }
 
 bool Chainstate::InvalidateBlock(const Config &config,
                                  BlockValidationState &state,
                                  CBlockIndex *pindex) {
     AssertLockNotHeld(m_chainstate_mutex);
     AssertLockNotHeld(::cs_main);
     // See 'Note for backport of Core PR16849' in Chainstate::UnwindBlock
     LOCK(m_chainstate_mutex);
 
     return UnwindBlock(config, state, pindex, true);
 }
 
 bool Chainstate::ParkBlock(const Config &config, BlockValidationState &state,
                            CBlockIndex *pindex) {
     AssertLockNotHeld(m_chainstate_mutex);
     AssertLockNotHeld(::cs_main);
     // See 'Note for backport of Core PR16849' in Chainstate::UnwindBlock
     LOCK(m_chainstate_mutex);
 
     return UnwindBlock(config, state, pindex, false);
 }
 
 template <typename F>
 bool Chainstate::UpdateFlagsForBlock(CBlockIndex *pindexBase,
                                      CBlockIndex *pindex, F f) {
     BlockStatus newStatus = f(pindex->nStatus);
     if (pindex->nStatus != newStatus &&
         (!pindexBase ||
          pindex->GetAncestor(pindexBase->nHeight) == pindexBase)) {
         pindex->nStatus = newStatus;
         m_blockman.m_dirty_blockindex.insert(pindex);
         if (newStatus.isValid()) {
             m_chainman.m_failed_blocks.erase(pindex);
         }
 
         if (pindex->IsValid(BlockValidity::TRANSACTIONS) &&
             pindex->HaveTxsDownloaded() &&
             setBlockIndexCandidates.value_comp()(m_chain.Tip(), pindex)) {
             setBlockIndexCandidates.insert(pindex);
         }
         return true;
     }
     return false;
 }
 
 template <typename F, typename C, typename AC>
 void Chainstate::UpdateFlags(CBlockIndex *pindex, CBlockIndex *&pindexReset,
                              F f, C fChild, AC fAncestorWasChanged) {
     AssertLockHeld(cs_main);
 
     // Update the current block and ancestors; while we're doing this, identify
     // which was the deepest ancestor we changed.
     CBlockIndex *pindexDeepestChanged = pindex;
     for (auto pindexAncestor = pindex; pindexAncestor != nullptr;
          pindexAncestor = pindexAncestor->pprev) {
         if (UpdateFlagsForBlock(nullptr, pindexAncestor, f)) {
             pindexDeepestChanged = pindexAncestor;
         }
     }
 
     if (pindexReset &&
         pindexReset->GetAncestor(pindexDeepestChanged->nHeight) ==
             pindexDeepestChanged) {
         // reset pindexReset if it had a modified ancestor.
         pindexReset = nullptr;
     }
 
     // Update all blocks under modified blocks.
     for (auto &[_, block_index] : m_blockman.m_block_index) {
         UpdateFlagsForBlock(pindex, &block_index, fChild);
         UpdateFlagsForBlock(pindexDeepestChanged, &block_index,
                             fAncestorWasChanged);
     }
 }
 
 void Chainstate::ResetBlockFailureFlags(CBlockIndex *pindex) {
     AssertLockHeld(cs_main);
 
     UpdateFlags(
         pindex, m_chainman.m_best_invalid,
         [](const BlockStatus status) {
             return status.withClearedFailureFlags();
         },
         [](const BlockStatus status) {
             return status.withClearedFailureFlags();
         },
         [](const BlockStatus status) {
             return status.withFailedParent(false);
         });
 }
 
 void Chainstate::UnparkBlockImpl(CBlockIndex *pindex, bool fClearChildren) {
     AssertLockHeld(cs_main);
 
     UpdateFlags(
         pindex, m_chainman.m_best_parked,
         [](const BlockStatus status) {
             return status.withClearedParkedFlags();
         },
         [fClearChildren](const BlockStatus status) {
             return fClearChildren ? status.withClearedParkedFlags()
                                   : status.withParkedParent(false);
         },
         [](const BlockStatus status) {
             return status.withParkedParent(false);
         });
 }
 
 void Chainstate::UnparkBlockAndChildren(CBlockIndex *pindex) {
     return UnparkBlockImpl(pindex, true);
 }
 
 void Chainstate::UnparkBlock(CBlockIndex *pindex) {
     return UnparkBlockImpl(pindex, false);
 }
 
 bool Chainstate::AvalancheFinalizeBlock(CBlockIndex *pindex) {
     if (!pindex) {
         return false;
     }
 
     if (!m_chain.Contains(pindex)) {
         LogPrint(BCLog::AVALANCHE,
                  "The block to mark finalized by avalanche is not on the "
                  "active chain: %s\n",
                  pindex->GetBlockHash().ToString());
         return false;
     }
 
     if (g_avalanche) {
         g_avalanche->cleanupStakingRewards(pindex->nHeight);
     }
 
     if (IsBlockAvalancheFinalized(pindex)) {
         return true;
     }
 
     {
         LOCK(cs_avalancheFinalizedBlockIndex);
         m_avalancheFinalizedBlockIndex = pindex;
     }
 
     GetMainSignals().BlockFinalized(pindex);
 
     return true;
 }
 
 void Chainstate::ClearAvalancheFinalizedBlock() {
     LOCK(cs_avalancheFinalizedBlockIndex);
     m_avalancheFinalizedBlockIndex = nullptr;
 }
 
 bool Chainstate::IsBlockAvalancheFinalized(const CBlockIndex *pindex) const {
     LOCK(cs_avalancheFinalizedBlockIndex);
     return pindex && m_avalancheFinalizedBlockIndex &&
            m_avalancheFinalizedBlockIndex->GetAncestor(pindex->nHeight) ==
                pindex;
 }
 
 /**
  * Mark a block as having its data received and checked (up to
  * BLOCK_VALID_TRANSACTIONS).
  */
 void Chainstate::ReceivedBlockTransactions(const CBlock &block,
                                            CBlockIndex *pindexNew,
                                            const FlatFilePos &pos) {
     pindexNew->nTx = block.vtx.size();
     pindexNew->nSize = ::GetSerializeSize(block, PROTOCOL_VERSION);
     pindexNew->nFile = pos.nFile;
     pindexNew->nDataPos = pos.nPos;
     pindexNew->nUndoPos = 0;
     pindexNew->nStatus = pindexNew->nStatus.withData();
     pindexNew->RaiseValidity(BlockValidity::TRANSACTIONS);
     m_blockman.m_dirty_blockindex.insert(pindexNew);
 
     if (pindexNew->UpdateChainStats()) {
         // If pindexNew is the genesis block or all parents are
         // BLOCK_VALID_TRANSACTIONS.
         std::deque<CBlockIndex *> queue;
         queue.push_back(pindexNew);
 
         // Recursively process any descendant blocks that now may be eligible to
         // be connected.
         while (!queue.empty()) {
             CBlockIndex *pindex = queue.front();
             queue.pop_front();
             pindex->UpdateChainStats();
             if (pindex->nSequenceId == 0) {
                 // We assign a sequence is when transaction are received to
                 // prevent a miner from being able to broadcast a block but not
                 // its content. However, a sequence id may have been set
                 // manually, for instance via PreciousBlock, in which case, we
                 // don't need to assign one.
                 pindex->nSequenceId = nBlockSequenceId++;
             }
 
             if (m_chain.Tip() == nullptr ||
                 !setBlockIndexCandidates.value_comp()(pindex, m_chain.Tip())) {
                 setBlockIndexCandidates.insert(pindex);
             }
 
             std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                       std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
                 range = m_blockman.m_blocks_unlinked.equal_range(pindex);
             while (range.first != range.second) {
                 std::multimap<CBlockIndex *, CBlockIndex *>::iterator it =
                     range.first;
                 queue.push_back(it->second);
                 range.first++;
                 m_blockman.m_blocks_unlinked.erase(it);
             }
         }
     } else if (pindexNew->pprev &&
                pindexNew->pprev->IsValid(BlockValidity::TREE)) {
         m_blockman.m_blocks_unlinked.insert(
             std::make_pair(pindexNew->pprev, pindexNew));
     }
 }
 
 /**
  * Return true if the provided block header is valid.
  * Only verify PoW if blockValidationOptions is configured to do so.
  * This allows validation of headers on which the PoW hasn't been done.
  * For example: to validate template handed to mining software.
  * Do not call this for any check that depends on the context.
  * For context-dependent calls, see ContextualCheckBlockHeader.
  */
 static bool CheckBlockHeader(const CBlockHeader &block,
                              BlockValidationState &state,
                              const Consensus::Params &params,
                              BlockValidationOptions validationOptions) {
     // Check proof of work matches claimed amount
     if (validationOptions.shouldValidatePoW() &&
         !CheckProofOfWork(block.GetHash(), block.nBits, params)) {
         return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER,
                              "high-hash", "proof of work failed");
     }
 
     return true;
 }
 
 bool CheckBlock(const CBlock &block, BlockValidationState &state,
                 const Consensus::Params &params,
                 BlockValidationOptions validationOptions) {
     // These are checks that are independent of context.
     if (block.fChecked) {
         return true;
     }
 
     // Check that the header is valid (particularly PoW).  This is mostly
     // redundant with the call in AcceptBlockHeader.
     if (!CheckBlockHeader(block, state, params, validationOptions)) {
         return false;
     }
 
     // Check the merkle root.
     if (validationOptions.shouldValidateMerkleRoot()) {
         bool mutated;
         uint256 hashMerkleRoot2 = BlockMerkleRoot(block, &mutated);
         if (block.hashMerkleRoot != hashMerkleRoot2) {
             return state.Invalid(BlockValidationResult::BLOCK_MUTATED,
                                  "bad-txnmrklroot", "hashMerkleRoot mismatch");
         }
 
         // Check for merkle tree malleability (CVE-2012-2459): repeating
         // sequences of transactions in a block without affecting the merkle
         // root of a block, while still invalidating it.
         if (mutated) {
             return state.Invalid(BlockValidationResult::BLOCK_MUTATED,
                                  "bad-txns-duplicate", "duplicate transaction");
         }
     }
 
     // All potential-corruption validation must be done before we do any
     // transaction validation, as otherwise we may mark the header as invalid
     // because we receive the wrong transactions for it.
 
     // First transaction must be coinbase.
     if (block.vtx.empty()) {
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "bad-cb-missing", "first tx is not coinbase");
     }
 
     // Size limits.
     auto nMaxBlockSize = validationOptions.getExcessiveBlockSize();
 
     // Bail early if there is no way this block is of reasonable size.
     if ((block.vtx.size() * MIN_TRANSACTION_SIZE) > nMaxBlockSize) {
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "bad-blk-length", "size limits failed");
     }
 
     auto currentBlockSize = ::GetSerializeSize(block, PROTOCOL_VERSION);
     if (currentBlockSize > nMaxBlockSize) {
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              "bad-blk-length", "size limits failed");
     }
 
     // And a valid coinbase.
     TxValidationState tx_state;
     if (!CheckCoinbase(*block.vtx[0], tx_state)) {
         return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                              tx_state.GetRejectReason(),
                              strprintf("Coinbase check failed (txid %s) %s",
                                        block.vtx[0]->GetId().ToString(),
                                        tx_state.GetDebugMessage()));
     }
 
     // Check transactions for regularity, skipping the first. Note that this
     // is the first time we check that all after the first are !IsCoinBase.
     for (size_t i = 1; i < block.vtx.size(); i++) {
         auto *tx = block.vtx[i].get();
         if (!CheckRegularTransaction(*tx, tx_state)) {
             return state.Invalid(
                 BlockValidationResult::BLOCK_CONSENSUS,
                 tx_state.GetRejectReason(),
                 strprintf("Transaction check failed (txid %s) %s",
                           tx->GetId().ToString(), tx_state.GetDebugMessage()));
         }
     }
 
     if (validationOptions.shouldValidatePoW() &&
         validationOptions.shouldValidateMerkleRoot()) {
         block.fChecked = true;
     }
 
     return true;
 }
 
 bool HasValidProofOfWork(const std::vector<CBlockHeader> &headers,
                          const Consensus::Params &consensusParams) {
     return std::all_of(headers.cbegin(), headers.cend(),
                        [&](const auto &header) {
                            return CheckProofOfWork(
                                header.GetHash(), header.nBits, consensusParams);
                        });
 }
 
 arith_uint256 CalculateHeadersWork(const std::vector<CBlockHeader> &headers) {
     arith_uint256 total_work{0};
     for (const CBlockHeader &header : headers) {
         CBlockIndex dummy(header);
         total_work += GetBlockProof(dummy);
     }
     return total_work;
 }
 
 /**
  * Context-dependent validity checks.
  * By "context", we mean only the previous block headers, but not the UTXO
  * set; UTXO-related validity checks are done in ConnectBlock().
  * NOTE: This function is not currently invoked by ConnectBlock(), so we
  * should consider upgrade issues if we change which consensus rules are
  * enforced in this function (eg by adding a new consensus rule). See comment
  * in ConnectBlock().
  * Note that -reindex-chainstate skips the validation that happens here!
  */
 static bool ContextualCheckBlockHeader(const CChainParams &params,
                                        const CBlockHeader &block,
                                        BlockValidationState &state,
                                        BlockManager &blockman,
                                        const CBlockIndex *pindexPrev,
                                        NodeClock::time_point now)
     EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
     AssertLockHeld(::cs_main);
     assert(pindexPrev != nullptr);
     const int nHeight = pindexPrev->nHeight + 1;
 
     // Check proof of work
     if (block.nBits != GetNextWorkRequired(pindexPrev, &block, params)) {
         LogPrintf("bad bits after height: %d\n", pindexPrev->nHeight);
         return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER,
                              "bad-diffbits", "incorrect proof of work");
     }
 
     // Check against checkpoints
     if (fCheckpointsEnabled) {
         const CCheckpointData &checkpoints = params.Checkpoints();
 
         // Check that the block chain matches the known block chain up to a
         // checkpoint.
         if (!Checkpoints::CheckBlock(checkpoints, nHeight, block.GetHash())) {
             LogPrint(BCLog::VALIDATION,
                      "ERROR: %s: rejected by checkpoint lock-in at %d\n",
                      __func__, nHeight);
             return state.Invalid(BlockValidationResult::BLOCK_CHECKPOINT,
                                  "checkpoint mismatch");
         }
 
         // Don't accept any forks from the main chain prior to last checkpoint.
         // GetLastCheckpoint finds the last checkpoint in MapCheckpoints that's
         // in our BlockIndex().
 
         const CBlockIndex *pcheckpoint =
             blockman.GetLastCheckpoint(checkpoints);
         if (pcheckpoint && nHeight < pcheckpoint->nHeight) {
             LogPrint(BCLog::VALIDATION,
                      "ERROR: %s: forked chain older than last checkpoint "
                      "(height %d)\n",
                      __func__, nHeight);
             return state.Invalid(BlockValidationResult::BLOCK_CHECKPOINT,
                                  "bad-fork-prior-to-checkpoint");
         }
     }
 
     // Check timestamp against prev
     if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast()) {
         return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER,
                              "time-too-old", "block's timestamp is too early");
     }
 
     // Check timestamp
     if (block.Time() > now + std::chrono::seconds{MAX_FUTURE_BLOCK_TIME}) {
         return state.Invalid(BlockValidationResult::BLOCK_TIME_FUTURE,
                              "time-too-new",
                              "block timestamp too far in the future");
     }
 
     const Consensus::Params &consensusParams = params.GetConsensus();
     // Reject blocks with outdated version
     if ((block.nVersion < 2 &&
          DeploymentActiveAfter(pindexPrev, consensusParams,
                                Consensus::DEPLOYMENT_HEIGHTINCB)) ||
         (block.nVersion < 3 &&
          DeploymentActiveAfter(pindexPrev, consensusParams,
                                Consensus::DEPLOYMENT_DERSIG)) ||
         (block.nVersion < 4 &&
          DeploymentActiveAfter(pindexPrev, consensusParams,
                                Consensus::DEPLOYMENT_CLTV))) {
         return state.Invalid(
             BlockValidationResult::BLOCK_INVALID_HEADER,
             strprintf("bad-version(0x%08x)", block.nVersion),
             strprintf("rejected nVersion=0x%08x block", block.nVersion));
     }
 
     return true;
 }
 
 bool ContextualCheckTransactionForCurrentBlock(
     const CBlockIndex *active_chain_tip, const Consensus::Params &params,
     const CTransaction &tx, TxValidationState &state) {
     AssertLockHeld(cs_main);
     // TODO: Make active_chain_tip a reference
     assert(active_chain_tip);
 
     // ContextualCheckTransactionForCurrentBlock() uses
     // active_chain_tip.Height()+1 to evaluate nLockTime because when
     // IsFinalTx() is called within AcceptBlock(), the height of the
     // block *being* evaluated is what is used. Thus if we want to know if a
     // transaction can be part of the *next* block, we need to call
     // ContextualCheckTransaction() with one more than
     // active_chain_tip.Height().
     const int nBlockHeight = active_chain_tip->nHeight + 1;
 
     // BIP113 will require that time-locked transactions have nLockTime set to
     // less than the median time of the previous block they're contained in.
     // When the next block is created its previous block will be the current
     // chain tip, so we use that to calculate the median time passed to
     // ContextualCheckTransaction().
     // This time can also be used for consensus upgrades.
     const int64_t nMedianTimePast{active_chain_tip->GetMedianTimePast()};
 
     return ContextualCheckTransaction(params, tx, state, nBlockHeight,
                                       nMedianTimePast);
 }
 
 /**
  * NOTE: This function is not currently invoked by ConnectBlock(), so we
  * should consider upgrade issues if we change which consensus rules are
  * enforced in this function (eg by adding a new consensus rule). See comment
  * in ConnectBlock().
  * Note that -reindex-chainstate skips the validation that happens here!
  */
 static bool ContextualCheckBlock(const CBlock &block,
                                  BlockValidationState &state,
                                  const Consensus::Params &params,
                                  const CBlockIndex *pindexPrev) {
     const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1;
 
     // Enforce BIP113 (Median Time Past).
     bool enforce_locktime_median_time_past{false};
     if (DeploymentActiveAfter(pindexPrev, params, Consensus::DEPLOYMENT_CSV)) {
         assert(pindexPrev != nullptr);
         enforce_locktime_median_time_past = true;
     }
 
     const int64_t nMedianTimePast =
         pindexPrev == nullptr ? 0 : pindexPrev->GetMedianTimePast();
 
     const int64_t nLockTimeCutoff{enforce_locktime_median_time_past
                                       ? nMedianTimePast
                                       : block.GetBlockTime()};
 
     const bool fIsMagneticAnomalyEnabled =
         IsMagneticAnomalyEnabled(params, pindexPrev);
 
     // Check transactions:
     // - canonical ordering
     // - ensure they are finalized
     // - check they have the minimum size
     const CTransaction *prevTx = nullptr;
     for (const auto &ptx : block.vtx) {
         const CTransaction &tx = *ptx;
         if (fIsMagneticAnomalyEnabled) {
             if (prevTx && (tx.GetId() <= prevTx->GetId())) {
                 if (tx.GetId() == prevTx->GetId()) {
                     return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                          "tx-duplicate",
                                          strprintf("Duplicated transaction %s",
                                                    tx.GetId().ToString()));
                 }
 
                 return state.Invalid(
                     BlockValidationResult::BLOCK_CONSENSUS, "tx-ordering",
                     strprintf("Transaction order is invalid (%s < %s)",
                               tx.GetId().ToString(),
                               prevTx->GetId().ToString()));
             }
 
             if (prevTx || !tx.IsCoinBase()) {
                 prevTx = &tx;
             }
         }
 
         TxValidationState tx_state;
         if (!ContextualCheckTransaction(params, tx, tx_state, nHeight,
                                         nLockTimeCutoff)) {
             return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                  tx_state.GetRejectReason(),
                                  tx_state.GetDebugMessage());
         }
     }
 
     // Enforce rule that the coinbase starts with serialized block height
     if (DeploymentActiveAfter(pindexPrev, params,
                               Consensus::DEPLOYMENT_HEIGHTINCB)) {
         CScript expect = CScript() << nHeight;
         if (block.vtx[0]->vin[0].scriptSig.size() < expect.size() ||
             !std::equal(expect.begin(), expect.end(),
                         block.vtx[0]->vin[0].scriptSig.begin())) {
             return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
                                  "bad-cb-height",
                                  "block height mismatch in coinbase");
         }
     }
 
     return true;
 }
 
 /**
  * If the provided block header is valid, add it to the block index.
  *
  * Returns true if the block is successfully added to the block index.
  */
 bool ChainstateManager::AcceptBlockHeader(const Config &config,
                                           const CBlockHeader &block,
                                           BlockValidationState &state,
                                           CBlockIndex **ppindex,
                                           bool min_pow_checked) {
     AssertLockHeld(cs_main);
     const CChainParams &chainparams = config.GetChainParams();
 
     // Check for duplicate
     BlockHash hash = block.GetHash();
     BlockMap::iterator miSelf{m_blockman.m_block_index.find(hash)};
     if (hash != chainparams.GetConsensus().hashGenesisBlock) {
         if (miSelf != m_blockman.m_block_index.end()) {
             // Block header is already known.
             CBlockIndex *pindex = &(miSelf->second);
             if (ppindex) {
                 *ppindex = pindex;
             }
 
             if (pindex->nStatus.isInvalid()) {
                 LogPrint(BCLog::VALIDATION, "%s: block %s is marked invalid\n",
                          __func__, hash.ToString());
                 return state.Invalid(
                     BlockValidationResult::BLOCK_CACHED_INVALID, "duplicate");
             }
 
             return true;
         }
 
         if (!CheckBlockHeader(block, state, chainparams.GetConsensus(),
                               BlockValidationOptions(config))) {
             LogPrint(BCLog::VALIDATION,
                      "%s: Consensus::CheckBlockHeader: %s, %s\n", __func__,
                      hash.ToString(), state.ToString());
             return false;
         }
 
         // Get prev block index
         BlockMap::iterator mi{
             m_blockman.m_block_index.find(block.hashPrevBlock)};
         if (mi == m_blockman.m_block_index.end()) {
             LogPrint(BCLog::VALIDATION,
                      "header %s has prev block not found: %s\n",
                      hash.ToString(), block.hashPrevBlock.ToString());
             return state.Invalid(BlockValidationResult::BLOCK_MISSING_PREV,
                                  "prev-blk-not-found");
         }
 
         CBlockIndex *pindexPrev = &((*mi).second);
         assert(pindexPrev);
         if (pindexPrev->nStatus.isInvalid()) {
             LogPrint(BCLog::VALIDATION,
                      "header %s has prev block invalid: %s\n", hash.ToString(),
                      block.hashPrevBlock.ToString());
             return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV,
                                  "bad-prevblk");
         }
 
         if (!ContextualCheckBlockHeader(chainparams, block, state, m_blockman,
                                         pindexPrev,
                                         m_options.adjusted_time_callback())) {
             LogPrint(BCLog::VALIDATION,
                      "%s: Consensus::ContextualCheckBlockHeader: %s, %s\n",
                      __func__, hash.ToString(), state.ToString());
             return false;
         }
 
         /* Determine if this block descends from any block which has been found
          * invalid (m_failed_blocks), then mark pindexPrev and any blocks
          * between them as failed. For example:
          *
          *                D3
          *              /
          *      B2 - C2
          *    /         \
          *  A             D2 - E2 - F2
          *    \
          *      B1 - C1 - D1 - E1
          *
          * In the case that we attempted to reorg from E1 to F2, only to find
          * C2 to be invalid, we would mark D2, E2, and F2 as BLOCK_FAILED_CHILD
          * but NOT D3 (it was not in any of our candidate sets at the time).
          *
          * In any case D3 will also be marked as BLOCK_FAILED_CHILD at restart
          * in LoadBlockIndex.
          */
         if (!pindexPrev->IsValid(BlockValidity::SCRIPTS)) {
             // The above does not mean "invalid": it checks if the previous
             // block hasn't been validated up to BlockValidity::SCRIPTS. This is
             // a performance optimization, in the common case of adding a new
             // block to the tip, we don't need to iterate over the failed blocks
             // list.
             for (const CBlockIndex *failedit : m_failed_blocks) {
                 if (pindexPrev->GetAncestor(failedit->nHeight) == failedit) {
                     assert(failedit->nStatus.hasFailed());
                     CBlockIndex *invalid_walk = pindexPrev;
                     while (invalid_walk != failedit) {
                         invalid_walk->nStatus =
                             invalid_walk->nStatus.withFailedParent();
                         m_blockman.m_dirty_blockindex.insert(invalid_walk);
                         invalid_walk = invalid_walk->pprev;
                     }
                     LogPrint(BCLog::VALIDATION,
                              "header %s has prev block invalid: %s\n",
                              hash.ToString(), block.hashPrevBlock.ToString());
                     return state.Invalid(
                         BlockValidationResult::BLOCK_INVALID_PREV,
                         "bad-prevblk");
                 }
             }
         }
     }
     if (!min_pow_checked) {
         LogPrint(BCLog::VALIDATION,
                  "%s: not adding new block header %s, missing anti-dos "
                  "proof-of-work validation\n",
                  __func__, hash.ToString());
         return state.Invalid(BlockValidationResult::BLOCK_HEADER_LOW_WORK,
                              "too-little-chainwork");
     }
     CBlockIndex *pindex{m_blockman.AddToBlockIndex(block, m_best_header)};
 
     if (ppindex) {
         *ppindex = pindex;
     }
 
     return true;
 }
 
 // Exposed wrapper for AcceptBlockHeader
 bool ChainstateManager::ProcessNewBlockHeaders(
     const Config &config, const std::vector<CBlockHeader> &headers,
     bool min_pow_checked, BlockValidationState &state,
     const CBlockIndex **ppindex) {
     AssertLockNotHeld(cs_main);
     {
         LOCK(cs_main);
         for (const CBlockHeader &header : headers) {
             // Use a temp pindex instead of ppindex to avoid a const_cast
             CBlockIndex *pindex = nullptr;
             bool accepted = AcceptBlockHeader(config, header, state, &pindex,
                                               min_pow_checked);
             ActiveChainstate().CheckBlockIndex();
 
             if (!accepted) {
                 return false;
             }
 
             if (ppindex) {
                 *ppindex = pindex;
             }
         }
     }
 
     if (NotifyHeaderTip(ActiveChainstate())) {
         if (ActiveChainstate().IsInitialBlockDownload() && ppindex &&
             *ppindex) {
             const CBlockIndex &last_accepted{**ppindex};
             const int64_t blocks_left{
                 (GetTime() - last_accepted.GetBlockTime()) /
                 config.GetChainParams().GetConsensus().nPowTargetSpacing};
             const double progress{100.0 * last_accepted.nHeight /
                                   (last_accepted.nHeight + blocks_left)};
             LogPrintf("Synchronizing blockheaders, height: %d (~%.2f%%)\n",
                       last_accepted.nHeight, progress);
         }
     }
     return true;
 }
 
 void ChainstateManager::ReportHeadersPresync(const arith_uint256 &work,
                                              int64_t height,
                                              int64_t timestamp) {
     AssertLockNotHeld(cs_main);
     const auto &chainstate = ActiveChainstate();
     {
         LOCK(cs_main);
         // Don't report headers presync progress if we already have a
         // post-minchainwork header chain.
         // This means we lose reporting for potentially legimate, but unlikely,
         // deep reorgs, but prevent attackers that spam low-work headers from
         // filling our logs.
         if (m_best_header->nChainWork >=
             UintToArith256(GetConsensus().nMinimumChainWork)) {
             return;
         }
         // Rate limit headers presync updates to 4 per second, as these are not
         // subject to DoS protection.
         auto now = Now<SteadyMilliseconds>();
         if (now < m_last_presync_update + 250ms) {
             return;
         }
         m_last_presync_update = now;
     }
     bool initial_download = chainstate.IsInitialBlockDownload();
     uiInterface.NotifyHeaderTip(GetSynchronizationState(initial_download),
                                 height, timestamp, /*presync=*/true);
     if (initial_download) {
         const int64_t blocks_left{(GetTime() - timestamp) /
                                   GetConsensus().nPowTargetSpacing};
         const double progress{100.0 * height / (height + blocks_left)};
         LogPrintf("Pre-synchronizing blockheaders, height: %d (~%.2f%%)\n",
                   height, progress);
     }
 }
 
 /**
  * Store a block on disk.
  *
  * @param[in]     config     The global config.
  * @param[in,out] pblock     The block we want to accept.
  * @param[in]     fRequested A boolean to indicate if this block was requested
  *                           from our peers.
  * @param[in]     dbp        If non-null, the disk position of the block.
  * @param[in,out] fNewBlock  True if block was first received via this call.
  * @param[in]     min_pow_checked  True if proof-of-work anti-DoS checks have
  *                                 been done by caller for headers chain
  * @return True if the block is accepted as a valid block and written to disk.
  */
 bool Chainstate::AcceptBlock(const Config &config,
                              const std::shared_ptr<const CBlock> &pblock,
                              BlockValidationState &state, bool fRequested,
                              const FlatFilePos *dbp, bool *fNewBlock,
                              bool min_pow_checked) {
     AssertLockHeld(cs_main);
 
     const CBlock &block = *pblock;
     if (fNewBlock) {
         *fNewBlock = false;
     }
 
     CBlockIndex *pindex = nullptr;
 
     bool accepted_header{m_chainman.AcceptBlockHeader(
         config, block, state, &pindex, min_pow_checked)};
     CheckBlockIndex();
 
     if (!accepted_header) {
         return false;
     }
 
     // Try to process all requested blocks that we don't have, but only
     // process an unrequested block if it's new and has enough work to
     // advance our tip, and isn't too many blocks ahead.
     bool fAlreadyHave = pindex->nStatus.hasData();
 
     // TODO: deal better with return value and error conditions for duplicate
     // and unrequested blocks.
     if (fAlreadyHave) {
         return true;
     }
 
     // Compare block header timestamps and received times of the block and the
     // chaintip.  If they have the same chain height, use these diffs as a
     // tie-breaker, attempting to pick the more honestly-mined block.
     int64_t newBlockTimeDiff = std::llabs(pindex->GetReceivedTimeDiff());
     int64_t chainTipTimeDiff =
         m_chain.Tip() ? std::llabs(m_chain.Tip()->GetReceivedTimeDiff()) : 0;
 
     bool isSameHeight =
         m_chain.Tip() && (pindex->nChainWork == m_chain.Tip()->nChainWork);
     if (isSameHeight) {
         LogPrintf("Chain tip timestamp-to-received-time difference: hash=%s, "
                   "diff=%d\n",
                   m_chain.Tip()->GetBlockHash().ToString(), chainTipTimeDiff);
         LogPrintf("New block timestamp-to-received-time difference: hash=%s, "
                   "diff=%d\n",
                   pindex->GetBlockHash().ToString(), newBlockTimeDiff);
     }
 
     bool fHasMoreOrSameWork =
         (m_chain.Tip() ? pindex->nChainWork >= m_chain.Tip()->nChainWork
                        : true);
 
     // Blocks that are too out-of-order needlessly limit the effectiveness of
     // pruning, because pruning will not delete block files that contain any
     // blocks which are too close in height to the tip.  Apply this test
     // regardless of whether pruning is enabled; it should generally be safe to
     // not process unrequested blocks.
     bool fTooFarAhead{pindex->nHeight >
                       m_chain.Height() + int(MIN_BLOCKS_TO_KEEP)};
 
     // TODO: Decouple this function from the block download logic by removing
     // fRequested
     // This requires some new chain data structure to efficiently look up if a
     // block is in a chain leading to a candidate for best tip, despite not
     // being such a candidate itself.
     // Note that this would break the getblockfrompeer RPC
 
     // If we didn't ask for it:
     if (!fRequested) {
         // This is a previously-processed block that was pruned.
         if (pindex->nTx != 0) {
             return true;
         }
 
         // Don't process less-work chains.
         if (!fHasMoreOrSameWork) {
             return true;
         }
 
         // Block height is too high.
         if (fTooFarAhead) {
             return true;
         }
 
         // Protect against DoS attacks from low-work chains.
         // If our tip is behind, a peer could try to send us
         // low-work blocks on a fake chain that we would never
         // request; don't process these.
         if (pindex->nChainWork < nMinimumChainWork) {
             return true;
         }
     }
 
     const CChainParams &params{m_chainman.GetParams()};
     const Consensus::Params &consensusParams = params.GetConsensus();
 
     if (!CheckBlock(block, state, consensusParams,
                     BlockValidationOptions(config)) ||
         !ContextualCheckBlock(block, state, consensusParams, pindex->pprev)) {
         if (state.IsInvalid() &&
             state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
             pindex->nStatus = pindex->nStatus.withFailed();
             m_blockman.m_dirty_blockindex.insert(pindex);
         }
 
         return error("%s: %s (block %s)", __func__, state.ToString(),
                      block.GetHash().ToString());
     }
 
     // If connecting the new block would require rewinding more than one block
     // from the active chain (i.e., a "deep reorg"), then mark the new block as
     // parked. If it has enough work then it will be automatically unparked
     // later, during FindMostWorkChain. We mark the block as parked at the very
     // last minute so we can make sure everything is ready to be reorged if
     // needed.
     if (gArgs.GetBoolArg("-parkdeepreorg", true)) {
         const CBlockIndex *pindexFork = m_chain.FindFork(pindex);
         if (pindexFork && pindexFork->nHeight + 1 < m_chain.Height()) {
             LogPrintf("Park block %s as it would cause a deep reorg.\n",
                       pindex->GetBlockHash().ToString());
             pindex->nStatus = pindex->nStatus.withParked();
             m_blockman.m_dirty_blockindex.insert(pindex);
         }
     }
 
     // Header is valid/has work and the merkle tree is good.
     // Relay now, but if it does not build on our best tip, let the
     // SendMessages loop relay it.
     if (!IsInitialBlockDownload() && m_chain.Tip() == pindex->pprev) {
         GetMainSignals().NewPoWValidBlock(pindex, pblock);
     }
 
     // Write block to history file
     if (fNewBlock) {
         *fNewBlock = true;
     }
     try {
         FlatFilePos blockPos{m_blockman.SaveBlockToDisk(block, pindex->nHeight,
                                                         m_chain, params, dbp)};
         if (blockPos.IsNull()) {
             state.Error(strprintf(
                 "%s: Failed to find position to write new block to disk",
                 __func__));
             return false;
         }
         ReceivedBlockTransactions(block, pindex, blockPos);
     } catch (const std::runtime_error &e) {
         return AbortNode(state, std::string("System error: ") + e.what());
     }
 
     FlushStateToDisk(state, FlushStateMode::NONE);
 
     CheckBlockIndex();
 
     return true;
 }
 
 bool ChainstateManager::ProcessNewBlock(
     const Config &config, const std::shared_ptr<const CBlock> &block,
     bool force_processing, bool min_pow_checked, bool *new_block) {
     AssertLockNotHeld(cs_main);
 
     {
         if (new_block) {
             *new_block = false;
         }
 
         BlockValidationState state;
 
         // CheckBlock() does not support multi-threaded block validation
         // because CBlock::fChecked can cause data race.
         // Therefore, the following critical section must include the
         // CheckBlock() call as well.
         LOCK(cs_main);
 
         // Skipping AcceptBlock() for CheckBlock() failures means that we will
         // never mark a block as invalid if CheckBlock() fails.  This is
         // protective against consensus failure if there are any unknown form
         // s of block malleability that cause CheckBlock() to fail; see e.g.
         // CVE-2012-2459 and
         // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-February/016697.html.
         // Because CheckBlock() is not very expensive, the anti-DoS benefits of
         // caching failure (of a definitely-invalid block) are not substantial.
         bool ret =
             CheckBlock(*block, state, config.GetChainParams().GetConsensus(),
                        BlockValidationOptions(config));
         if (ret) {
             // Store to disk
             ret = ActiveChainstate().AcceptBlock(config, block, state,
                                                  force_processing, nullptr,
                                                  new_block, min_pow_checked);
         }
 
         if (!ret) {
             GetMainSignals().BlockChecked(*block, state);
             return error("%s: AcceptBlock FAILED (%s)", __func__,
                          state.ToString());
         }
     }
 
     NotifyHeaderTip(ActiveChainstate());
 
     // Only used to report errors, not invalidity - ignore it
     BlockValidationState state;
     if (!ActiveChainstate().ActivateBestChain(config, state, block)) {
         return error("%s: ActivateBestChain failed (%s)", __func__,
                      state.ToString());
     }
 
     return true;
 }
 
 MempoolAcceptResult
 ChainstateManager::ProcessTransaction(const CTransactionRef &tx,
                                       bool test_accept) {
     AssertLockHeld(cs_main);
     Chainstate &active_chainstate = ActiveChainstate();
     if (!active_chainstate.GetMempool()) {
         TxValidationState state;
         state.Invalid(TxValidationResult::TX_NO_MEMPOOL, "no-mempool");
         return MempoolAcceptResult::Failure(state);
     }
     // Use GetConfig() temporarily. It will be removed in a follow-up by
     // making AcceptToMemoryPool take a CChainParams instead of a Config.
     // This avoids passing an extra Config argument to this function that will
     // be removed soon.
     auto result =
         AcceptToMemoryPool(::GetConfig(), active_chainstate, tx, GetTime(),
                            /*bypass_limits=*/false, test_accept);
     active_chainstate.GetMempool()->check(
         active_chainstate.CoinsTip(), active_chainstate.m_chain.Height() + 1);
     return result;
 }
 
 bool TestBlockValidity(
     BlockValidationState &state, const CChainParams &params,
     Chainstate &chainstate, const CBlock &block, CBlockIndex *pindexPrev,
     const std::function<NodeClock::time_point()> &adjusted_time_callback,
     BlockValidationOptions validationOptions) {
     AssertLockHeld(cs_main);
     assert(pindexPrev && pindexPrev == chainstate.m_chain.Tip());
     CCoinsViewCache viewNew(&chainstate.CoinsTip());
     BlockHash block_hash(block.GetHash());
     CBlockIndex indexDummy(block);
     indexDummy.pprev = pindexPrev;
     indexDummy.nHeight = pindexPrev->nHeight + 1;
     indexDummy.phashBlock = &block_hash;
 
     // NOTE: CheckBlockHeader is called by CheckBlock
     if (!ContextualCheckBlockHeader(params, block, state, chainstate.m_blockman,
                                     pindexPrev, adjusted_time_callback())) {
         return error("%s: Consensus::ContextualCheckBlockHeader: %s", __func__,
                      state.ToString());
     }
 
     if (!CheckBlock(block, state, params.GetConsensus(), validationOptions)) {
         return error("%s: Consensus::CheckBlock: %s", __func__,
                      state.ToString());
     }
 
     if (!ContextualCheckBlock(block, state, params.GetConsensus(),
                               pindexPrev)) {
         return error("%s: Consensus::ContextualCheckBlock: %s", __func__,
                      state.ToString());
     }
 
     if (!chainstate.ConnectBlock(block, state, &indexDummy, viewNew,
                                  validationOptions, nullptr, true)) {
         return false;
     }
 
     assert(state.IsValid());
     return true;
 }
 
 /* This function is called from the RPC code for pruneblockchain */
 void PruneBlockFilesManual(Chainstate &active_chainstate,
                            int nManualPruneHeight) {
     BlockValidationState state;
     if (active_chainstate.FlushStateToDisk(state, FlushStateMode::NONE,
                                            nManualPruneHeight)) {
         LogPrintf("%s: failed to flush state (%s)\n", __func__,
                   state.ToString());
     }
 }
 
 void Chainstate::LoadMempool(const Config &config, const fs::path &load_path,
                              FopenFn mockable_fopen_function) {
     if (!m_mempool) {
         return;
     }
     ::LoadMempool(config, *m_mempool, load_path, *this,
                   mockable_fopen_function);
     m_mempool->SetLoadTried(!ShutdownRequested());
 }
 
 bool Chainstate::LoadChainTip() {
     AssertLockHeld(cs_main);
     const CCoinsViewCache &coins_cache = CoinsTip();
     // Never called when the coins view is empty
     assert(!coins_cache.GetBestBlock().IsNull());
     const CBlockIndex *tip = m_chain.Tip();
 
     if (tip && tip->GetBlockHash() == coins_cache.GetBestBlock()) {
         return true;
     }
 
     // Load pointer to end of best chain
     CBlockIndex *pindex =
         m_blockman.LookupBlockIndex(coins_cache.GetBestBlock());
     if (!pindex) {
         return false;
     }
     m_chain.SetTip(pindex);
     PruneBlockIndexCandidates();
 
     tip = m_chain.Tip();
     LogPrintf(
         "Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n",
         tip->GetBlockHash().ToString(), m_chain.Height(),
         FormatISO8601DateTime(tip->GetBlockTime()),
         GuessVerificationProgress(m_chainman.GetParams().TxData(), tip));
     return true;
 }
 
 CVerifyDB::CVerifyDB() {
     uiInterface.ShowProgress(_("Verifying blocks...").translated, 0, false);
 }
 
 CVerifyDB::~CVerifyDB() {
     uiInterface.ShowProgress("", 100, false);
 }
 
 VerifyDBResult CVerifyDB::VerifyDB(Chainstate &chainstate, const Config &config,
                                    CCoinsView &coinsview, int nCheckLevel,
                                    int nCheckDepth) {
     AssertLockHeld(cs_main);
 
     const CChainParams &params = config.GetChainParams();
     const Consensus::Params &consensusParams = params.GetConsensus();
 
     if (chainstate.m_chain.Tip() == nullptr ||
         chainstate.m_chain.Tip()->pprev == nullptr) {
         return VerifyDBResult::SUCCESS;
     }
 
     // Verify blocks in the best chain
     if (nCheckDepth <= 0 || nCheckDepth > chainstate.m_chain.Height()) {
         nCheckDepth = chainstate.m_chain.Height();
     }
 
     nCheckLevel = std::max(0, std::min(4, nCheckLevel));
     LogPrintf("Verifying last %i blocks at level %i\n", nCheckDepth,
               nCheckLevel);
 
     CCoinsViewCache coins(&coinsview);
     CBlockIndex *pindex;
     CBlockIndex *pindexFailure = nullptr;
     int nGoodTransactions = 0;
     BlockValidationState state;
     int reportDone = 0;
     bool skipped_no_block_data{false};
     bool skipped_l3_checks{false};
     LogPrintf("Verification progress: 0%%\n");
 
     const bool is_snapshot_cs{!chainstate.m_from_snapshot_blockhash};
 
     for (pindex = chainstate.m_chain.Tip(); pindex && pindex->pprev;
          pindex = pindex->pprev) {
         const int percentageDone = std::max(
             1, std::min(99, (int)(((double)(chainstate.m_chain.Height() -
                                             pindex->nHeight)) /
                                   (double)nCheckDepth *
                                   (nCheckLevel >= 4 ? 50 : 100))));
         if (reportDone < percentageDone / 10) {
             // report every 10% step
             LogPrintf("Verification progress: %d%%\n", percentageDone);
             reportDone = percentageDone / 10;
         }
 
         uiInterface.ShowProgress(_("Verifying blocks...").translated,
                                  percentageDone, false);
         if (pindex->nHeight <= chainstate.m_chain.Height() - nCheckDepth) {
             break;
         }
 
         if ((chainstate.m_blockman.IsPruneMode() || is_snapshot_cs) &&
             !pindex->nStatus.hasData()) {
             // If pruning or running under an assumeutxo snapshot, only go
             // back as far as we have data.
             LogPrintf("VerifyDB(): block verification stopping at height %d "
                       "(no data). This could be due to pruning or use of an "
                       "assumeutxo snapshot.\n",
                       pindex->nHeight);
             skipped_no_block_data = true;
             break;
         }
 
         CBlock block;
 
         // check level 0: read from disk
         if (!ReadBlockFromDisk(block, pindex, consensusParams)) {
             LogPrintf(
                 "Verification error: ReadBlockFromDisk failed at %d, hash=%s\n",
                 pindex->nHeight, pindex->GetBlockHash().ToString());
             return VerifyDBResult::CORRUPTED_BLOCK_DB;
         }
 
         // check level 1: verify block validity
         if (nCheckLevel >= 1 && !CheckBlock(block, state, consensusParams,
                                             BlockValidationOptions(config))) {
             LogPrintf(
                 "Verification error: found bad block at %d, hash=%s (%s)\n",
                 pindex->nHeight, pindex->GetBlockHash().ToString(),
                 state.ToString());
             return VerifyDBResult::CORRUPTED_BLOCK_DB;
         }
 
         // check level 2: verify undo validity
         if (nCheckLevel >= 2 && pindex) {
             CBlockUndo undo;
             if (!pindex->GetUndoPos().IsNull()) {
                 if (!UndoReadFromDisk(undo, pindex)) {
                     LogPrintf("Verification error: found bad undo data at %d, "
                               "hash=%s\n",
                               pindex->nHeight,
                               pindex->GetBlockHash().ToString());
                     return VerifyDBResult::CORRUPTED_BLOCK_DB;
                 }
             }
         }
         // check level 3: check for inconsistencies during memory-only
         // disconnect of tip blocks
         size_t curr_coins_usage = coins.DynamicMemoryUsage() +
                                   chainstate.CoinsTip().DynamicMemoryUsage();
 
         if (nCheckLevel >= 3) {
             if (curr_coins_usage <= chainstate.m_coinstip_cache_size_bytes) {
                 assert(coins.GetBestBlock() == pindex->GetBlockHash());
                 DisconnectResult res =
                     chainstate.DisconnectBlock(block, pindex, coins);
                 if (res == DisconnectResult::FAILED) {
                     LogPrintf("Verification error: irrecoverable inconsistency "
                               "in block data at %d, hash=%s\n",
                               pindex->nHeight,
                               pindex->GetBlockHash().ToString());
                     return VerifyDBResult::CORRUPTED_BLOCK_DB;
                 }
                 if (res == DisconnectResult::UNCLEAN) {
                     nGoodTransactions = 0;
                     pindexFailure = pindex;
                 } else {
                     nGoodTransactions += block.vtx.size();
                 }
             } else {
                 skipped_l3_checks = true;
             }
         }
 
         if (ShutdownRequested()) {
             return VerifyDBResult::INTERRUPTED;
         }
     }
 
     if (pindexFailure) {
         LogPrintf("Verification error: coin database inconsistencies found "
                   "(last %i blocks, %i good transactions before that)\n",
                   chainstate.m_chain.Height() - pindexFailure->nHeight + 1,
                   nGoodTransactions);
         return VerifyDBResult::CORRUPTED_BLOCK_DB;
     }
     if (skipped_l3_checks) {
         LogPrintf("Skipped verification of level >=3 (insufficient database "
                   "cache size). Consider increasing -dbcache.\n");
     }
 
     // store block count as we move pindex at check level >= 4
     int block_count = chainstate.m_chain.Height() - pindex->nHeight;
 
     // check level 4: try reconnecting blocks
     if (nCheckLevel >= 4 && !skipped_l3_checks) {
         while (pindex != chainstate.m_chain.Tip()) {
             const int percentageDone = std::max(
                 1, std::min(99, 100 - int(double(chainstate.m_chain.Height() -
                                                  pindex->nHeight) /
                                           double(nCheckDepth) * 50)));
             if (reportDone < percentageDone / 10) {
                 // report every 10% step
                 LogPrintf("Verification progress: %d%%\n", percentageDone);
                 reportDone = percentageDone / 10;
             }
             uiInterface.ShowProgress(_("Verifying blocks...").translated,
                                      percentageDone, false);
             pindex = chainstate.m_chain.Next(pindex);
             CBlock block;
             if (!ReadBlockFromDisk(block, pindex, consensusParams)) {
                 LogPrintf("Verification error: ReadBlockFromDisk failed at %d, "
                           "hash=%s\n",
                           pindex->nHeight, pindex->GetBlockHash().ToString());
                 return VerifyDBResult::CORRUPTED_BLOCK_DB;
             }
             if (!chainstate.ConnectBlock(block, state, pindex, coins,
                                          BlockValidationOptions(config))) {
                 LogPrintf("Verification error: found unconnectable block at "
                           "%d, hash=%s (%s)\n",
                           pindex->nHeight, pindex->GetBlockHash().ToString(),
                           state.ToString());
                 return VerifyDBResult::CORRUPTED_BLOCK_DB;
             }
             if (ShutdownRequested()) {
                 return VerifyDBResult::INTERRUPTED;
             }
         }
     }
 
     LogPrintf("Verification: No coin database inconsistencies in last %i "
               "blocks (%i transactions)\n",
               block_count, nGoodTransactions);
 
     if (skipped_l3_checks) {
         return VerifyDBResult::SKIPPED_L3_CHECKS;
     }
     if (skipped_no_block_data) {
         return VerifyDBResult::SKIPPED_MISSING_BLOCKS;
     }
     return VerifyDBResult::SUCCESS;
 }
 
 /**
  * Apply the effects of a block on the utxo cache, ignoring that it may already
  * have been applied.
  */
 bool Chainstate::RollforwardBlock(const CBlockIndex *pindex,
                                   CCoinsViewCache &view) {
     AssertLockHeld(cs_main);
     // TODO: merge with ConnectBlock
     CBlock block;
     if (!ReadBlockFromDisk(block, pindex, m_chainman.GetConsensus())) {
         return error("ReplayBlock(): ReadBlockFromDisk failed at %d, hash=%s",
                      pindex->nHeight, pindex->GetBlockHash().ToString());
     }
 
     for (const CTransactionRef &tx : block.vtx) {
         // Pass check = true as every addition may be an overwrite.
         AddCoins(view, *tx, pindex->nHeight, true);
     }
 
     for (const CTransactionRef &tx : block.vtx) {
         if (tx->IsCoinBase()) {
             continue;
         }
 
         for (const CTxIn &txin : tx->vin) {
             view.SpendCoin(txin.prevout);
         }
     }
 
     return true;
 }
 
 bool Chainstate::ReplayBlocks() {
     LOCK(cs_main);
 
     CCoinsView &db = this->CoinsDB();
     CCoinsViewCache cache(&db);
 
     std::vector<BlockHash> hashHeads = db.GetHeadBlocks();
     if (hashHeads.empty()) {
         // We're already in a consistent state.
         return true;
     }
     if (hashHeads.size() != 2) {
         return error("ReplayBlocks(): unknown inconsistent state");
     }
 
     uiInterface.ShowProgress(_("Replaying blocks...").translated, 0, false);
     LogPrintf("Replaying blocks\n");
 
     // Old tip during the interrupted flush.
     const CBlockIndex *pindexOld = nullptr;
     // New tip during the interrupted flush.
     const CBlockIndex *pindexNew;
     // Latest block common to both the old and the new tip.
     const CBlockIndex *pindexFork = nullptr;
 
     if (m_blockman.m_block_index.count(hashHeads[0]) == 0) {
         return error(
             "ReplayBlocks(): reorganization to unknown block requested");
     }
 
     pindexNew = &(m_blockman.m_block_index[hashHeads[0]]);
 
     if (!hashHeads[1].IsNull()) {
         // The old tip is allowed to be 0, indicating it's the first flush.
         if (m_blockman.m_block_index.count(hashHeads[1]) == 0) {
             return error(
                 "ReplayBlocks(): reorganization from unknown block requested");
         }
 
         pindexOld = &(m_blockman.m_block_index[hashHeads[1]]);
         pindexFork = LastCommonAncestor(pindexOld, pindexNew);
         assert(pindexFork != nullptr);
     }
 
     // Rollback along the old branch.
     while (pindexOld != pindexFork) {
         if (pindexOld->nHeight > 0) {
             // Never disconnect the genesis block.
             CBlock block;
             if (!ReadBlockFromDisk(block, pindexOld,
                                    m_chainman.GetConsensus())) {
                 return error("RollbackBlock(): ReadBlockFromDisk() failed at "
                              "%d, hash=%s",
                              pindexOld->nHeight,
                              pindexOld->GetBlockHash().ToString());
             }
 
             LogPrintf("Rolling back %s (%i)\n",
                       pindexOld->GetBlockHash().ToString(), pindexOld->nHeight);
             DisconnectResult res = DisconnectBlock(block, pindexOld, cache);
             if (res == DisconnectResult::FAILED) {
                 return error(
                     "RollbackBlock(): DisconnectBlock failed at %d, hash=%s",
                     pindexOld->nHeight, pindexOld->GetBlockHash().ToString());
             }
 
             // If DisconnectResult::UNCLEAN is returned, it means a non-existing
             // UTXO was deleted, or an existing UTXO was overwritten. It
             // corresponds to cases where the block-to-be-disconnect never had
             // all its operations applied to the UTXO set. However, as both
             // writing a UTXO and deleting a UTXO are idempotent operations, the
             // result is still a version of the UTXO set with the effects of
             // that block undone.
         }
         pindexOld = pindexOld->pprev;
     }
 
     // Roll forward from the forking point to the new tip.
     int nForkHeight = pindexFork ? pindexFork->nHeight : 0;
     for (int nHeight = nForkHeight + 1; nHeight <= pindexNew->nHeight;
          ++nHeight) {
         const CBlockIndex &pindex{*Assert(pindexNew->GetAncestor(nHeight))};
         LogPrintf("Rolling forward %s (%i)\n", pindex.GetBlockHash().ToString(),
                   nHeight);
         uiInterface.ShowProgress(_("Replaying blocks...").translated,
                                  (int)((nHeight - nForkHeight) * 100.0 /
                                        (pindexNew->nHeight - nForkHeight)),
                                  false);
         if (!RollforwardBlock(&pindex, cache)) {
             return false;
         }
     }
 
     cache.SetBestBlock(pindexNew->GetBlockHash());
     cache.Flush();
     uiInterface.ShowProgress("", 100, false);
     return true;
 }
 
 // May NOT be used after any connections are up as much of the peer-processing
 // logic assumes a consistent block index state
 void Chainstate::UnloadBlockIndex() {
     AssertLockHeld(::cs_main);
     nBlockSequenceId = 1;
     m_best_fork_tip = nullptr;
     m_best_fork_base = nullptr;
     setBlockIndexCandidates.clear();
 }
 
 bool ChainstateManager::LoadBlockIndex() {
     AssertLockHeld(cs_main);
     // Load block index from databases
     bool needs_init = fReindex;
     if (!fReindex) {
         bool ret = m_blockman.LoadBlockIndexDB(GetConsensus());
         if (!ret) {
             return false;
         }
 
         std::vector<CBlockIndex *> vSortedByHeight{
             m_blockman.GetAllBlockIndices()};
         std::sort(vSortedByHeight.begin(), vSortedByHeight.end(),
                   CBlockIndexHeightOnlyComparator());
 
         // Find start of assumed-valid region.
         int first_assumed_valid_height = std::numeric_limits<int>::max();
 
         for (const CBlockIndex *block : vSortedByHeight) {
             if (block->IsAssumedValid()) {
                 auto chainstates = GetAll();
 
                 // If we encounter an assumed-valid block index entry, ensure
                 // that we have one chainstate that tolerates assumed-valid
                 // entries and another that does not (i.e. the background
                 // validation chainstate), since assumed-valid entries should
                 // always be pending validation by a fully-validated chainstate.
                 auto any_chain = [&](auto fnc) {
                     return std::any_of(chainstates.cbegin(), chainstates.cend(),
                                        fnc);
                 };
                 assert(any_chain([](auto chainstate) {
                     return chainstate->reliesOnAssumedValid();
                 }));
                 assert(any_chain([](auto chainstate) {
                     return !chainstate->reliesOnAssumedValid();
                 }));
 
                 first_assumed_valid_height = block->nHeight;
                 LogPrintf("Saw first assumedvalid block at height %d (%s)\n",
                           first_assumed_valid_height, block->ToString());
                 break;
             }
         }
 
         for (CBlockIndex *pindex : vSortedByHeight) {
             if (ShutdownRequested()) {
                 return false;
             }
             if (pindex->IsAssumedValid() ||
                 (pindex->IsValid(BlockValidity::TRANSACTIONS) &&
                  (pindex->HaveTxsDownloaded() || pindex->pprev == nullptr))) {
                 // Fill each chainstate's block candidate set. Only add
                 // assumed-valid blocks to the tip candidate set if the
                 // chainstate is allowed to rely on assumed-valid blocks.
                 //
                 // If all setBlockIndexCandidates contained the assumed-valid
                 // blocks, the background chainstate's ActivateBestChain() call
                 // would add assumed-valid blocks to the chain (based on how
                 // FindMostWorkChain() works). Obviously we don't want this
                 // since the purpose of the background validation chain is to
                 // validate assumed-valid blocks.
                 //
                 // Note: This is considering all blocks whose height is greater
                 // or equal to the first assumed-valid block to be assumed-valid
                 // blocks, and excluding them from the background chainstate's
                 // setBlockIndexCandidates set. This does mean that some blocks
                 // which are not technically assumed-valid (later blocks on a
                 // fork beginning before the first assumed-valid block) might
                 // not get added to the background chainstate, but this is ok,
                 // because they will still be attached to the active chainstate
                 // if they actually contain more work.
                 //
                 // Instead of this height-based approach, an earlier attempt was
                 // made at detecting "holistically" whether the block index
                 // under consideration relied on an assumed-valid ancestor, but
                 // this proved to be too slow to be practical.
                 for (Chainstate *chainstate : GetAll()) {
                     if (chainstate->reliesOnAssumedValid() ||
                         pindex->nHeight < first_assumed_valid_height) {
                         chainstate->setBlockIndexCandidates.insert(pindex);
                     }
                 }
             }
 
             if (pindex->nStatus.isInvalid() &&
                 (!m_best_invalid ||
                  pindex->nChainWork > m_best_invalid->nChainWork)) {
                 m_best_invalid = pindex;
             }
 
             if (pindex->nStatus.isOnParkedChain() &&
                 (!m_best_parked ||
                  pindex->nChainWork > m_best_parked->nChainWork)) {
                 m_best_parked = pindex;
             }
 
             if (pindex->IsValid(BlockValidity::TREE) &&
                 (m_best_header == nullptr ||
                  CBlockIndexWorkComparator()(m_best_header, pindex))) {
                 m_best_header = pindex;
             }
         }
 
         needs_init = m_blockman.m_block_index.empty();
     }
 
     if (needs_init) {
         // Everything here is for *new* reindex/DBs. Thus, though
         // LoadBlockIndexDB may have set fReindex if we shut down
         // mid-reindex previously, we don't check fReindex and
         // instead only check it prior to LoadBlockIndexDB to set
         // needs_init.
 
         LogPrintf("Initializing databases...\n");
     }
     return true;
 }
 
 bool Chainstate::LoadGenesisBlock() {
     LOCK(cs_main);
 
     const CChainParams &params{m_chainman.GetParams()};
 
     // Check whether we're already initialized by checking for genesis in
     // m_blockman.m_block_index. Note that we can't use m_chain here, since it
     // is set based on the coins db, not the block index db, which is the only
     // thing loaded at this point.
     if (m_blockman.m_block_index.count(params.GenesisBlock().GetHash())) {
         return true;
     }
 
     try {
         const CBlock &block = params.GenesisBlock();
         FlatFilePos blockPos{
             m_blockman.SaveBlockToDisk(block, 0, m_chain, params, nullptr)};
         if (blockPos.IsNull()) {
             return error("%s: writing genesis block to disk failed", __func__);
         }
         CBlockIndex *pindex =
             m_blockman.AddToBlockIndex(block, m_chainman.m_best_header);
         ReceivedBlockTransactions(block, pindex, blockPos);
     } catch (const std::runtime_error &e) {
         return error("%s: failed to write genesis block: %s", __func__,
                      e.what());
     }
 
     return true;
 }
 
 void Chainstate::LoadExternalBlockFile(
     const Config &config, FILE *fileIn, FlatFilePos *dbp,
     std::multimap<BlockHash, FlatFilePos> *blocks_with_unknown_parent) {
     AssertLockNotHeld(m_chainstate_mutex);
 
     // Either both should be specified (-reindex), or neither (-loadblock).
     assert(!dbp == !blocks_with_unknown_parent);
 
     int64_t nStart = GetTimeMillis();
     const CChainParams &params{m_chainman.GetParams()};
 
     int nLoaded = 0;
     try {
         // This takes over fileIn and calls fclose() on it in the CBufferedFile
         // destructor. Make sure we have at least 2*MAX_TX_SIZE space in there
         // so any transaction can fit in the buffer.
         CBufferedFile blkdat(fileIn, 2 * MAX_TX_SIZE, MAX_TX_SIZE + 8, SER_DISK,
                              CLIENT_VERSION);
         uint64_t nRewind = blkdat.GetPos();
         while (!blkdat.eof()) {
             if (ShutdownRequested()) {
                 return;
             }
 
             blkdat.SetPos(nRewind);
             // Start one byte further next time, in case of failure.
             nRewind++;
             // Remove former limit.
             blkdat.SetLimit();
             unsigned int nSize = 0;
             try {
                 // Locate a header.
                 uint8_t buf[CMessageHeader::MESSAGE_START_SIZE];
                 blkdat.FindByte(char(params.DiskMagic()[0]));
                 nRewind = blkdat.GetPos() + 1;
                 blkdat >> buf;
                 if (memcmp(buf, params.DiskMagic().data(),
                            CMessageHeader::MESSAGE_START_SIZE)) {
                     continue;
                 }
 
                 // Read size.
                 blkdat >> nSize;
                 if (nSize < 80) {
                     continue;
                 }
             } catch (const std::exception &) {
                 // No valid block header found; don't complain.
                 break;
             }
 
             try {
                 // read block
                 uint64_t nBlockPos = blkdat.GetPos();
                 if (dbp) {
                     dbp->nPos = nBlockPos;
                 }
                 blkdat.SetLimit(nBlockPos + nSize);
                 std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
                 CBlock &block = *pblock;
                 blkdat >> block;
                 nRewind = blkdat.GetPos();
 
                 const BlockHash hash = block.GetHash();
                 {
                     LOCK(cs_main);
                     // detect out of order blocks, and store them for later
                     if (hash != params.GetConsensus().hashGenesisBlock &&
                         !m_blockman.LookupBlockIndex(block.hashPrevBlock)) {
                         LogPrint(
                             BCLog::REINDEX,
                             "%s: Out of order block %s, parent %s not known\n",
                             __func__, hash.ToString(),
                             block.hashPrevBlock.ToString());
                         if (dbp && blocks_with_unknown_parent) {
                             blocks_with_unknown_parent->emplace(
                                 block.hashPrevBlock, *dbp);
                         }
                         continue;
                     }
 
                     // process in case the block isn't known yet
                     const CBlockIndex *pindex =
                         m_blockman.LookupBlockIndex(hash);
                     if (!pindex || !pindex->nStatus.hasData()) {
                         BlockValidationState state;
                         if (AcceptBlock(config, pblock, state, true, dbp,
                                         nullptr, true)) {
                             nLoaded++;
                         }
                         if (state.IsError()) {
                             break;
                         }
                     } else if (hash != params.GetConsensus().hashGenesisBlock &&
                                pindex->nHeight % 1000 == 0) {
                         LogPrint(
                             BCLog::REINDEX,
                             "Block Import: already had block %s at height %d\n",
                             hash.ToString(), pindex->nHeight);
                     }
                 }
 
                 // Activate the genesis block so normal node progress can
                 // continue
                 if (hash == params.GetConsensus().hashGenesisBlock) {
                     BlockValidationState state;
                     if (!ActivateBestChain(config, state, nullptr)) {
                         break;
                     }
                 }
 
                 if (m_blockman.IsPruneMode() && !fReindex && pblock) {
                     // Must update the tip for pruning to work while importing
                     // with -loadblock. This is a tradeoff to conserve disk
                     // space at the expense of time spent updating the tip to be
                     // able to prune. Otherwise, ActivateBestChain won't be
                     // called by the import process until after all of the block
                     // files are loaded. ActivateBestChain can be called by
                     // concurrent network message processing, but that is not
                     // reliable for the purpose of pruning while importing.
                     BlockValidationState state;
                     if (!ActivateBestChain(config, state, pblock)) {
                         LogPrint(BCLog::REINDEX,
                                  "failed to activate chain (%s)\n",
                                  state.ToString());
                         break;
                     }
                 }
 
                 NotifyHeaderTip(*this);
 
                 if (!blocks_with_unknown_parent) {
                     continue;
                 }
 
                 // Recursively process earlier encountered successors of this
                 // block
                 std::deque<BlockHash> queue;
                 queue.push_back(hash);
                 while (!queue.empty()) {
                     BlockHash head = queue.front();
                     queue.pop_front();
                     auto range = blocks_with_unknown_parent->equal_range(head);
                     while (range.first != range.second) {
                         std::multimap<BlockHash, FlatFilePos>::iterator it =
                             range.first;
                         std::shared_ptr<CBlock> pblockrecursive =
                             std::make_shared<CBlock>();
                         if (ReadBlockFromDisk(*pblockrecursive, it->second,
                                               params.GetConsensus())) {
                             LogPrint(
                                 BCLog::REINDEX,
                                 "%s: Processing out of order child %s of %s\n",
                                 __func__, pblockrecursive->GetHash().ToString(),
                                 head.ToString());
                             LOCK(cs_main);
                             BlockValidationState dummy;
                             if (AcceptBlock(config, pblockrecursive, dummy,
                                             true, &it->second, nullptr, true)) {
                                 nLoaded++;
                                 queue.push_back(pblockrecursive->GetHash());
                             }
                         }
                         range.first++;
                         blocks_with_unknown_parent->erase(it);
                         NotifyHeaderTip(*this);
                     }
                 }
             } catch (const std::exception &e) {
                 // Historical bugs added extra data to the block files that does
                 // not deserialize cleanly. Commonly this data is between
                 // readable blocks, but it does not really matter. Such data is
                 // not fatal to the import process. The code that reads the
                 // block files deals with invalid data by simply ignoring it. It
                 // continues to search for the next {4 byte magic message start
                 // bytes + 4 byte length + block} that does deserialize cleanly
                 // and passes all of the other block validation checks dealing
                 // with POW and the merkle root, etc... We merely note with this
                 // informational log message when unexpected data is
                 // encountered. We could also be experiencing a storage system
                 // read error, or a read of a previous bad write. These are
                 // possible, but less likely scenarios. We don't have enough
                 // information to tell a difference here. The reindex process is
                 // not the place to attempt to clean and/or compact the block
                 // files. If so desired, a studious node operator may use
                 // knowledge of the fact that the block files are not entirely
                 // pristine in order to prepare a set of pristine, and perhaps
                 // ordered, block files for later reindexing.
                 LogPrint(BCLog::REINDEX,
                          "%s: unexpected data at file offset 0x%x - %s. "
                          "continuing\n",
                          __func__, (nRewind - 1), e.what());
             }
         }
     } catch (const std::runtime_error &e) {
         AbortNode(std::string("System error: ") + e.what());
     }
 
     LogPrintf("Loaded %i blocks from external file in %dms\n", nLoaded,
               GetTimeMillis() - nStart);
 }
 
 void Chainstate::CheckBlockIndex() {
     if (!fCheckBlockIndex) {
         return;
     }
 
     LOCK(cs_main);
 
     // During a reindex, we read the genesis block and call CheckBlockIndex
     // before ActivateBestChain, so we have the genesis block in
     // m_blockman.m_block_index but no active chain. (A few of the tests when
     // iterating the block tree require that m_chain has been initialized.)
     if (m_chain.Height() < 0) {
         assert(m_blockman.m_block_index.size() <= 1);
         return;
     }
 
     // Build forward-pointing map of the entire block tree.
     std::multimap<CBlockIndex *, CBlockIndex *> forward;
     for (auto &[_, block_index] : m_blockman.m_block_index) {
         forward.emplace(block_index.pprev, &block_index);
     }
 
     assert(forward.size() == m_blockman.m_block_index.size());
 
     std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
               std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
         rangeGenesis = forward.equal_range(nullptr);
     CBlockIndex *pindex = rangeGenesis.first->second;
     rangeGenesis.first++;
     // There is only one index entry with parent nullptr.
     assert(rangeGenesis.first == rangeGenesis.second);
 
     // Iterate over the entire block tree, using depth-first search.
     // Along the way, remember whether there are blocks on the path from genesis
     // block being explored which are the first to have certain properties.
     size_t nNodes = 0;
     int nHeight = 0;
     // Oldest ancestor of pindex which is invalid.
     CBlockIndex *pindexFirstInvalid = nullptr;
     // Oldest ancestor of pindex which is parked.
     CBlockIndex *pindexFirstParked = nullptr;
     // Oldest ancestor of pindex which does not have data available.
     CBlockIndex *pindexFirstMissing = nullptr;
     // Oldest ancestor of pindex for which nTx == 0.
     CBlockIndex *pindexFirstNeverProcessed = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_TREE
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotTreeValid = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_TRANSACTIONS
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotTransactionsValid = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_CHAIN
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotChainValid = nullptr;
     // Oldest ancestor of pindex which does not have BLOCK_VALID_SCRIPTS
     // (regardless of being valid or not).
     CBlockIndex *pindexFirstNotScriptsValid = nullptr;
     while (pindex != nullptr) {
         nNodes++;
         if (pindexFirstInvalid == nullptr && pindex->nStatus.hasFailed()) {
             pindexFirstInvalid = pindex;
         }
         if (pindexFirstParked == nullptr && pindex->nStatus.isParked()) {
             pindexFirstParked = pindex;
         }
         // Assumed-valid index entries will not have data since we haven't
         // downloaded the full block yet.
         if (pindexFirstMissing == nullptr && !pindex->nStatus.hasData() &&
             !pindex->IsAssumedValid()) {
             pindexFirstMissing = pindex;
         }
         if (pindexFirstNeverProcessed == nullptr && pindex->nTx == 0) {
             pindexFirstNeverProcessed = pindex;
         }
         if (pindex->pprev != nullptr && pindexFirstNotTreeValid == nullptr &&
             pindex->nStatus.getValidity() < BlockValidity::TREE) {
             pindexFirstNotTreeValid = pindex;
         }
         if (pindex->pprev != nullptr && !pindex->IsAssumedValid()) {
             if (pindexFirstNotTransactionsValid == nullptr &&
                 pindex->nStatus.getValidity() < BlockValidity::TRANSACTIONS) {
                 pindexFirstNotTransactionsValid = pindex;
             }
             if (pindexFirstNotChainValid == nullptr &&
                 pindex->nStatus.getValidity() < BlockValidity::CHAIN) {
                 pindexFirstNotChainValid = pindex;
             }
             if (pindexFirstNotScriptsValid == nullptr &&
                 pindex->nStatus.getValidity() < BlockValidity::SCRIPTS) {
                 pindexFirstNotScriptsValid = pindex;
             }
         }
 
         // Begin: actual consistency checks.
         if (pindex->pprev == nullptr) {
             // Genesis block checks.
             // Genesis block's hash must match.
             assert(pindex->GetBlockHash() ==
                    m_chainman.GetConsensus().hashGenesisBlock);
             // The current active chain's genesis block must be this block.
             assert(pindex == m_chain.Genesis());
         }
         if (!pindex->HaveTxsDownloaded()) {
             // nSequenceId can't be set positive for blocks that aren't linked
             // (negative is used for preciousblock)
             assert(pindex->nSequenceId <= 0);
         }
         // VALID_TRANSACTIONS is equivalent to nTx > 0 for all nodes (whether or
         // not pruning has occurred). HAVE_DATA is only equivalent to nTx > 0
         // (or VALID_TRANSACTIONS) if no pruning has occurred.
         // Unless these indexes are assumed valid and pending block download on
         // a background chainstate.
         if (!m_blockman.m_have_pruned && !pindex->IsAssumedValid()) {
             // If we've never pruned, then HAVE_DATA should be equivalent to nTx
             // > 0
             assert(pindex->nStatus.hasData() == (pindex->nTx > 0));
             assert(pindexFirstMissing == pindexFirstNeverProcessed);
         } else if (pindex->nStatus.hasData()) {
             // If we have pruned, then we can only say that HAVE_DATA implies
             // nTx > 0
             assert(pindex->nTx > 0);
         }
         if (pindex->nStatus.hasUndo()) {
             assert(pindex->nStatus.hasData());
         }
         if (pindex->IsAssumedValid()) {
             // Assumed-valid blocks should have some nTx value.
             assert(pindex->nTx > 0);
             // Assumed-valid blocks should connect to the main chain.
             assert(pindex->nStatus.getValidity() >= BlockValidity::TREE);
         } else {
             // Otherwise there should only be an nTx value if we have
             // actually seen a block's transactions.
             // This is pruning-independent.
             assert((pindex->nStatus.getValidity() >=
                     BlockValidity::TRANSACTIONS) == (pindex->nTx > 0));
         }
         // All parents having had data (at some point) is equivalent to all
         // parents being VALID_TRANSACTIONS, which is equivalent to
         // HaveTxsDownloaded(). All parents having had data (at some point) is
         // equivalent to all parents being VALID_TRANSACTIONS, which is
         // equivalent to HaveTxsDownloaded().
         assert((pindexFirstNeverProcessed == nullptr) ==
                (pindex->HaveTxsDownloaded()));
         assert((pindexFirstNotTransactionsValid == nullptr) ==
                (pindex->HaveTxsDownloaded()));
         // nHeight must be consistent.
         assert(pindex->nHeight == nHeight);
         // For every block except the genesis block, the chainwork must be
         // larger than the parent's.
         assert(pindex->pprev == nullptr ||
                pindex->nChainWork >= pindex->pprev->nChainWork);
         // The pskip pointer must point back for all but the first 2 blocks.
         assert(nHeight < 2 ||
                (pindex->pskip && (pindex->pskip->nHeight < nHeight)));
         // All m_blockman.m_block_index entries must at least be TREE valid
         assert(pindexFirstNotTreeValid == nullptr);
         if (pindex->nStatus.getValidity() >= BlockValidity::TREE) {
             // TREE valid implies all parents are TREE valid
             assert(pindexFirstNotTreeValid == nullptr);
         }
         if (pindex->nStatus.getValidity() >= BlockValidity::CHAIN) {
             // CHAIN valid implies all parents are CHAIN valid
             assert(pindexFirstNotChainValid == nullptr);
         }
         if (pindex->nStatus.getValidity() >= BlockValidity::SCRIPTS) {
             // SCRIPTS valid implies all parents are SCRIPTS valid
             assert(pindexFirstNotScriptsValid == nullptr);
         }
         if (pindexFirstInvalid == nullptr) {
             // Checks for not-invalid blocks.
             // The failed mask cannot be set for blocks without invalid parents.
             assert(!pindex->nStatus.isInvalid());
         }
         if (pindexFirstParked == nullptr) {
             // Checks for not-parked blocks.
             // The parked mask cannot be set for blocks without parked parents.
             // (i.e., hasParkedParent only if an ancestor is properly parked).
             assert(!pindex->nStatus.isOnParkedChain());
         }
         if (!CBlockIndexWorkComparator()(pindex, m_chain.Tip()) &&
             pindexFirstNeverProcessed == nullptr) {
             if (pindexFirstInvalid == nullptr) {
                 // Don't perform this check for the background chainstate since
                 // its setBlockIndexCandidates shouldn't have some entries (i.e.
                 // those past the snapshot block) which do exist in the block
                 // index for the active chainstate.
                 if (this == &m_chainman.ActiveChainstate()) {
                     // If this block sorts at least as good as the current tip
                     // and is valid and we have all data for its parents, it
                     // must be in setBlockIndexCandidates or be parked.
                     if (pindexFirstMissing == nullptr) {
                         assert(pindex->nStatus.isOnParkedChain() ||
                                setBlockIndexCandidates.count(pindex));
                     }
                     // m_chain.Tip() must also be there even if some data has
                     // been pruned.
                     if (pindex == m_chain.Tip()) {
                         assert(setBlockIndexCandidates.count(pindex));
                     }
                 }
                 // If some parent is missing, then it could be that this block
                 // was in setBlockIndexCandidates but had to be removed because
                 // of the missing data. In this case it must be in
                 // m_blocks_unlinked -- see test below.
             }
         } else {
             // If this block sorts worse than the current tip or some ancestor's
             // block has never been seen, it cannot be in
             // setBlockIndexCandidates.
             assert(setBlockIndexCandidates.count(pindex) == 0);
         }
         // Check whether this block is in m_blocks_unlinked.
         std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                   std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
             rangeUnlinked =
                 m_blockman.m_blocks_unlinked.equal_range(pindex->pprev);
         bool foundInUnlinked = false;
         while (rangeUnlinked.first != rangeUnlinked.second) {
             assert(rangeUnlinked.first->first == pindex->pprev);
             if (rangeUnlinked.first->second == pindex) {
                 foundInUnlinked = true;
                 break;
             }
             rangeUnlinked.first++;
         }
         if (pindex->pprev && pindex->nStatus.hasData() &&
             pindexFirstNeverProcessed != nullptr &&
             pindexFirstInvalid == nullptr) {
             // If this block has block data available, some parent was never
             // received, and has no invalid parents, it must be in
             // m_blocks_unlinked.
             assert(foundInUnlinked);
         }
         if (!pindex->nStatus.hasData()) {
             // Can't be in m_blocks_unlinked if we don't HAVE_DATA
             assert(!foundInUnlinked);
         }
         if (pindexFirstMissing == nullptr) {
             // We aren't missing data for any parent -- cannot be in
             // m_blocks_unlinked.
             assert(!foundInUnlinked);
         }
         if (pindex->pprev && pindex->nStatus.hasData() &&
             pindexFirstNeverProcessed == nullptr &&
             pindexFirstMissing != nullptr) {
             // We HAVE_DATA for this block, have received data for all parents
             // at some point, but we're currently missing data for some parent.
             // We must have pruned.
             assert(m_blockman.m_have_pruned);
             // This block may have entered m_blocks_unlinked if:
             //  - it has a descendant that at some point had more work than the
             //    tip, and
             //  - we tried switching to that descendant but were missing
             //    data for some intermediate block between m_chain and the
             //    tip.
             // So if this block is itself better than m_chain.Tip() and it
             // wasn't in
             // setBlockIndexCandidates, then it must be in m_blocks_unlinked.
             if (!CBlockIndexWorkComparator()(pindex, m_chain.Tip()) &&
                 setBlockIndexCandidates.count(pindex) == 0) {
                 if (pindexFirstInvalid == nullptr) {
                     assert(foundInUnlinked);
                 }
             }
         }
         // Perhaps too slow
         // assert(pindex->GetBlockHash() == pindex->GetBlockHeader().GetHash());
         // End: actual consistency checks.
 
         // Try descending into the first subnode.
         std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                   std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
             range = forward.equal_range(pindex);
         if (range.first != range.second) {
             // A subnode was found.
             pindex = range.first->second;
             nHeight++;
             continue;
         }
         // This is a leaf node. Move upwards until we reach a node of which we
         // have not yet visited the last child.
         while (pindex) {
             // We are going to either move to a parent or a sibling of pindex.
             // If pindex was the first with a certain property, unset the
             // corresponding variable.
             if (pindex == pindexFirstInvalid) {
                 pindexFirstInvalid = nullptr;
             }
             if (pindex == pindexFirstParked) {
                 pindexFirstParked = nullptr;
             }
             if (pindex == pindexFirstMissing) {
                 pindexFirstMissing = nullptr;
             }
             if (pindex == pindexFirstNeverProcessed) {
                 pindexFirstNeverProcessed = nullptr;
             }
             if (pindex == pindexFirstNotTreeValid) {
                 pindexFirstNotTreeValid = nullptr;
             }
             if (pindex == pindexFirstNotTransactionsValid) {
                 pindexFirstNotTransactionsValid = nullptr;
             }
             if (pindex == pindexFirstNotChainValid) {
                 pindexFirstNotChainValid = nullptr;
             }
             if (pindex == pindexFirstNotScriptsValid) {
                 pindexFirstNotScriptsValid = nullptr;
             }
             // Find our parent.
             CBlockIndex *pindexPar = pindex->pprev;
             // Find which child we just visited.
             std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
                       std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
                 rangePar = forward.equal_range(pindexPar);
             while (rangePar.first->second != pindex) {
                 // Our parent must have at least the node we're coming from as
                 // child.
                 assert(rangePar.first != rangePar.second);
                 rangePar.first++;
             }
             // Proceed to the next one.
             rangePar.first++;
             if (rangePar.first != rangePar.second) {
                 // Move to the sibling.
                 pindex = rangePar.first->second;
                 break;
             } else {
                 // Move up further.
                 pindex = pindexPar;
                 nHeight--;
                 continue;
             }
         }
     }
 
     // Check that we actually traversed the entire map.
     assert(nNodes == forward.size());
 }
 
 std::string Chainstate::ToString() {
     AssertLockHeld(::cs_main);
     CBlockIndex *tip = m_chain.Tip();
     return strprintf("Chainstate [%s] @ height %d (%s)",
                      m_from_snapshot_blockhash ? "snapshot" : "ibd",
                      tip ? tip->nHeight : -1,
                      tip ? tip->GetBlockHash().ToString() : "null");
 }
 
 bool Chainstate::ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size) {
     AssertLockHeld(::cs_main);
     if (coinstip_size == m_coinstip_cache_size_bytes &&
         coinsdb_size == m_coinsdb_cache_size_bytes) {
         // Cache sizes are unchanged, no need to continue.
         return true;
     }
     size_t old_coinstip_size = m_coinstip_cache_size_bytes;
     m_coinstip_cache_size_bytes = coinstip_size;
     m_coinsdb_cache_size_bytes = coinsdb_size;
     CoinsDB().ResizeCache(coinsdb_size);
 
     LogPrintf("[%s] resized coinsdb cache to %.1f MiB\n", this->ToString(),
               coinsdb_size * (1.0 / 1024 / 1024));
     LogPrintf("[%s] resized coinstip cache to %.1f MiB\n", this->ToString(),
               coinstip_size * (1.0 / 1024 / 1024));
 
     BlockValidationState state;
     bool ret;
 
     if (coinstip_size > old_coinstip_size) {
         // Likely no need to flush if cache sizes have grown.
         ret = FlushStateToDisk(state, FlushStateMode::IF_NEEDED);
     } else {
         // Otherwise, flush state to disk and deallocate the in-memory coins
         // map.
         ret = FlushStateToDisk(state, FlushStateMode::ALWAYS);
         CoinsTip().ReallocateCache();
     }
     return ret;
 }
 
 //! Guess how far we are in the verification process at the given block index
 //! require cs_main if pindex has not been validated yet (because the chain's
 //! transaction count might be unset) This conditional lock requirement might be
 //! confusing, see: https://github.com/bitcoin/bitcoin/issues/15994
 double GuessVerificationProgress(const ChainTxData &data,
                                  const CBlockIndex *pindex) {
     if (pindex == nullptr) {
         return 0.0;
     }
 
     int64_t nNow = time(nullptr);
 
     double fTxTotal;
     if (pindex->GetChainTxCount() <= data.nTxCount) {
         fTxTotal = data.nTxCount + (nNow - data.nTime) * data.dTxRate;
     } else {
         fTxTotal = pindex->GetChainTxCount() +
                    (nNow - pindex->GetBlockTime()) * data.dTxRate;
     }
 
     return std::min<double>(pindex->GetChainTxCount() / fTxTotal, 1.0);
 }
 
 std::optional<BlockHash> ChainstateManager::SnapshotBlockhash() const {
     LOCK(::cs_main);
     if (m_active_chainstate && m_active_chainstate->m_from_snapshot_blockhash) {
         // If a snapshot chainstate exists, it will always be our active.
         return m_active_chainstate->m_from_snapshot_blockhash;
     }
     return std::nullopt;
 }
 
 std::vector<Chainstate *> ChainstateManager::GetAll() {
     LOCK(::cs_main);
     std::vector<Chainstate *> out;
 
     for (Chainstate *pchainstate :
          {m_ibd_chainstate.get(), m_snapshot_chainstate.get()}) {
         if (this->IsUsable(pchainstate)) {
             out.push_back(pchainstate);
         }
     }
 
     return out;
 }
 
 Chainstate &ChainstateManager::InitializeChainstate(CTxMemPool *mempool) {
     AssertLockHeld(::cs_main);
     assert(!m_ibd_chainstate);
     assert(!m_active_chainstate);
 
     m_ibd_chainstate = std::make_unique<Chainstate>(mempool, m_blockman, *this);
     m_active_chainstate = m_ibd_chainstate.get();
     return *m_active_chainstate;
 }
 
 const AssumeutxoData *ExpectedAssumeutxo(const int height,
                                          const CChainParams &chainparams) {
     const MapAssumeutxo &valid_assumeutxos_map = chainparams.Assumeutxo();
     const auto assumeutxo_found = valid_assumeutxos_map.find(height);
 
     if (assumeutxo_found != valid_assumeutxos_map.end()) {
         return &assumeutxo_found->second;
     }
     return nullptr;
 }
 
 static bool DeleteCoinsDBFromDisk(const fs::path &db_path, bool is_snapshot)
     EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
     AssertLockHeld(::cs_main);
 
     if (is_snapshot) {
         fs::path base_blockhash_path =
             db_path / node::SNAPSHOT_BLOCKHASH_FILENAME;
 
         try {
             const bool existed{fs::remove(base_blockhash_path)};
             if (!existed) {
                 LogPrintf("[snapshot] snapshot chainstate dir being removed "
                           "lacks %s file\n",
                           fs::PathToString(node::SNAPSHOT_BLOCKHASH_FILENAME));
             }
         } catch (const fs::filesystem_error &e) {
             LogPrintf("[snapshot] failed to remove file %s: %s\n",
                       fs::PathToString(base_blockhash_path),
                       fsbridge::get_filesystem_error_message(e));
         }
     }
 
     std::string path_str = fs::PathToString(db_path);
     LogPrintf("Removing leveldb dir at %s\n", path_str);
 
     // We have to destruct before this call leveldb::DB in order to release the
     // db lock, otherwise `DestroyDB` will fail. See `leveldb::~DBImpl()`.
     const bool destroyed = dbwrapper::DestroyDB(path_str, {}).ok();
 
     if (!destroyed) {
         LogPrintf("error: leveldb DestroyDB call failed on %s\n", path_str);
     }
 
     // Datadir should be removed from filesystem; otherwise initialization may
     // detect it on subsequent statups and get confused.
     //
     // If the base_blockhash_path removal above fails in the case of snapshot
     // chainstates, this will return false since leveldb won't remove a
     // non-empty directory.
     return destroyed && !fs::exists(db_path);
 }
 
 bool ChainstateManager::ActivateSnapshot(AutoFile &coins_file,
                                          const SnapshotMetadata &metadata,
                                          bool in_memory) {
     BlockHash base_blockhash = metadata.m_base_blockhash;
 
     if (this->SnapshotBlockhash()) {
         LogPrintf("[snapshot] can't activate a snapshot-based chainstate more "
                   "than once\n");
         return false;
     }
 
     int64_t current_coinsdb_cache_size{0};
     int64_t current_coinstip_cache_size{0};
 
     // Cache percentages to allocate to each chainstate.
     //
     // These particular percentages don't matter so much since they will only be
     // relevant during snapshot activation; caches are rebalanced at the
     // conclusion of this function. We want to give (essentially) all available
     // cache capacity to the snapshot to aid the bulk load later in this
     // function.
     static constexpr double IBD_CACHE_PERC = 0.01;
     static constexpr double SNAPSHOT_CACHE_PERC = 0.99;
 
     {
         LOCK(::cs_main);
         // Resize the coins caches to ensure we're not exceeding memory limits.
         //
         // Allocate the majority of the cache to the incoming snapshot
         // chainstate, since (optimistically) getting to its tip will be the top
         // priority. We'll need to call `MaybeRebalanceCaches()` once we're done
         // with this function to ensure the right allocation (including the
         // possibility that no snapshot was activated and that we should restore
         // the active chainstate caches to their original size).
         //
         current_coinsdb_cache_size =
             this->ActiveChainstate().m_coinsdb_cache_size_bytes;
         current_coinstip_cache_size =
             this->ActiveChainstate().m_coinstip_cache_size_bytes;
 
         // Temporarily resize the active coins cache to make room for the
         // newly-created snapshot chain.
         this->ActiveChainstate().ResizeCoinsCaches(
             static_cast<size_t>(current_coinstip_cache_size * IBD_CACHE_PERC),
             static_cast<size_t>(current_coinsdb_cache_size * IBD_CACHE_PERC));
     }
 
     auto snapshot_chainstate =
         WITH_LOCK(::cs_main, return std::make_unique<Chainstate>(
                                  /* mempool */ nullptr, m_blockman, *this,
                                  base_blockhash));
 
     {
         LOCK(::cs_main);
         snapshot_chainstate->InitCoinsDB(
             static_cast<size_t>(current_coinsdb_cache_size *
                                 SNAPSHOT_CACHE_PERC),
             in_memory, false, "chainstate");
         snapshot_chainstate->InitCoinsCache(static_cast<size_t>(
             current_coinstip_cache_size * SNAPSHOT_CACHE_PERC));
     }
 
     bool snapshot_ok = this->PopulateAndValidateSnapshot(*snapshot_chainstate,
                                                          coins_file, metadata);
 
     // If not in-memory, persist the base blockhash for use during subsequent
     // initialization.
     if (!in_memory) {
         LOCK(::cs_main);
         if (!node::WriteSnapshotBaseBlockhash(*snapshot_chainstate)) {
             snapshot_ok = false;
         }
     }
     if (!snapshot_ok) {
         LOCK(::cs_main);
         this->MaybeRebalanceCaches();
 
         // PopulateAndValidateSnapshot can return (in error) before the leveldb
         // datadir has been created, so only attempt removal if we got that far.
         if (auto snapshot_datadir = node::FindSnapshotChainstateDir()) {
             // We have to destruct leveldb::DB in order to release the db lock,
             // otherwise DestroyDB() (in DeleteCoinsDBFromDisk()) will fail. See
             // `leveldb::~DBImpl()`. Destructing the chainstate (and so
             // resetting the coinsviews object) does this.
             snapshot_chainstate.reset();
             bool removed =
                 DeleteCoinsDBFromDisk(*snapshot_datadir, /*is_snapshot=*/true);
             if (!removed) {
                 AbortNode(
                     strprintf("Failed to remove snapshot chainstate dir (%s). "
                               "Manually remove it before restarting.\n",
                               fs::PathToString(*snapshot_datadir)));
             }
         }
         return false;
     }
 
     {
         LOCK(::cs_main);
         assert(!m_snapshot_chainstate);
         m_snapshot_chainstate.swap(snapshot_chainstate);
         const bool chaintip_loaded = m_snapshot_chainstate->LoadChainTip();
         assert(chaintip_loaded);
 
         m_active_chainstate = m_snapshot_chainstate.get();
 
         LogPrintf("[snapshot] successfully activated snapshot %s\n",
                   base_blockhash.ToString());
         LogPrintf("[snapshot] (%.2f MB)\n",
                   m_snapshot_chainstate->CoinsTip().DynamicMemoryUsage() /
                       (1000 * 1000));
 
         this->MaybeRebalanceCaches();
     }
     return true;
 }
 
 static void FlushSnapshotToDisk(CCoinsViewCache &coins_cache,
                                 bool snapshot_loaded) {
     LOG_TIME_MILLIS_WITH_CATEGORY_MSG_ONCE(
         strprintf("%s (%.2f MB)",
                   snapshot_loaded ? "saving snapshot chainstate"
                                   : "flushing coins cache",
                   coins_cache.DynamicMemoryUsage() / (1000 * 1000)),
         BCLog::LogFlags::ALL);
 
     coins_cache.Flush();
 }
 
 struct StopHashingException : public std::exception {
     const char *what() const throw() override {
         return "ComputeUTXOStats interrupted by shutdown.";
     }
 };
 
 static void SnapshotUTXOHashBreakpoint() {
     if (ShutdownRequested()) {
         throw StopHashingException();
     }
 }
 
 bool ChainstateManager::PopulateAndValidateSnapshot(
     Chainstate &snapshot_chainstate, AutoFile &coins_file,
     const SnapshotMetadata &metadata) {
     // It's okay to release cs_main before we're done using `coins_cache`
     // because we know that nothing else will be referencing the newly created
     // snapshot_chainstate yet.
     CCoinsViewCache &coins_cache =
         *WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsTip());
 
     BlockHash base_blockhash = metadata.m_base_blockhash;
 
     CBlockIndex *snapshot_start_block = WITH_LOCK(
         ::cs_main, return m_blockman.LookupBlockIndex(base_blockhash));
 
     if (!snapshot_start_block) {
         // Needed for ComputeUTXOStats and ExpectedAssumeutxo to determine the
         // height and to avoid a crash when base_blockhash.IsNull()
         LogPrintf("[snapshot] Did not find snapshot start blockheader %s\n",
                   base_blockhash.ToString());
         return false;
     }
 
     int base_height = snapshot_start_block->nHeight;
     auto maybe_au_data = ExpectedAssumeutxo(base_height, GetParams());
 
     if (!maybe_au_data) {
         LogPrintf("[snapshot] assumeutxo height in snapshot metadata not "
                   "recognized (%d) - refusing to load snapshot\n",
                   base_height);
         return false;
     }
 
     const AssumeutxoData &au_data = *maybe_au_data;
 
     COutPoint outpoint;
     Coin coin;
     const uint64_t coins_count = metadata.m_coins_count;
     uint64_t coins_left = metadata.m_coins_count;
 
     LogPrintf("[snapshot] loading coins from snapshot %s\n",
               base_blockhash.ToString());
     int64_t coins_processed{0};
 
     while (coins_left > 0) {
         try {
             coins_file >> outpoint;
             coins_file >> coin;
         } catch (const std::ios_base::failure &) {
             LogPrintf("[snapshot] bad snapshot format or truncated snapshot "
                       "after deserializing %d coins\n",
                       coins_count - coins_left);
             return false;
         }
         if (coin.GetHeight() > uint32_t(base_height) ||
             // Avoid integer wrap-around in coinstats.cpp:ApplyHash
             outpoint.GetN() >=
                 std::numeric_limits<decltype(outpoint.GetN())>::max()) {
             LogPrintf(
                 "[snapshot] bad snapshot data after deserializing %d coins\n",
                 coins_count - coins_left);
             return false;
         }
         coins_cache.EmplaceCoinInternalDANGER(std::move(outpoint),
                                               std::move(coin));
 
         --coins_left;
         ++coins_processed;
 
         if (coins_processed % 1000000 == 0) {
             LogPrintf("[snapshot] %d coins loaded (%.2f%%, %.2f MB)\n",
                       coins_processed,
                       static_cast<float>(coins_processed) * 100 /
                           static_cast<float>(coins_count),
                       coins_cache.DynamicMemoryUsage() / (1000 * 1000));
         }
 
         // Batch write and flush (if we need to) every so often.
         //
         // If our average Coin size is roughly 41 bytes, checking every 120,000
         // coins means <5MB of memory imprecision.
         if (coins_processed % 120000 == 0) {
             if (ShutdownRequested()) {
                 return false;
             }
 
             const auto snapshot_cache_state = WITH_LOCK(
                 ::cs_main, return snapshot_chainstate.GetCoinsCacheSizeState());
 
             if (snapshot_cache_state >= CoinsCacheSizeState::CRITICAL) {
                 // This is a hack - we don't know what the actual best block is,
                 // but that doesn't matter for the purposes of flushing the
                 // cache here. We'll set this to its correct value
                 // (`base_blockhash`) below after the coins are loaded.
                 coins_cache.SetBestBlock(BlockHash{GetRandHash()});
 
                 // No need to acquire cs_main since this chainstate isn't being
                 // used yet.
                 FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/false);
             }
         }
     }
 
     // Important that we set this. This and the coins_cache accesses above are
     // sort of a layer violation, but either we reach into the innards of
     // CCoinsViewCache here or we have to invert some of the Chainstate to
     // embed them in a snapshot-activation-specific CCoinsViewCache bulk load
     // method.
     coins_cache.SetBestBlock(base_blockhash);
 
     bool out_of_coins{false};
     try {
         coins_file >> outpoint;
     } catch (const std::ios_base::failure &) {
         // We expect an exception since we should be out of coins.
         out_of_coins = true;
     }
     if (!out_of_coins) {
         LogPrintf("[snapshot] bad snapshot - coins left over after "
                   "deserializing %d coins\n",
                   coins_count);
         return false;
     }
 
     LogPrintf("[snapshot] loaded %d (%.2f MB) coins from snapshot %s\n",
               coins_count, coins_cache.DynamicMemoryUsage() / (1000 * 1000),
               base_blockhash.ToString());
 
     // No need to acquire cs_main since this chainstate isn't being used yet.
     FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/true);
 
     assert(coins_cache.GetBestBlock() == base_blockhash);
 
     // As above, okay to immediately release cs_main here since no other context
     // knows about the snapshot_chainstate.
     CCoinsViewDB *snapshot_coinsdb =
         WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsDB());
 
     std::optional<CCoinsStats> maybe_stats;
 
     try {
         maybe_stats = ComputeUTXOStats(CoinStatsHashType::HASH_SERIALIZED,
                                        snapshot_coinsdb, m_blockman,
                                        SnapshotUTXOHashBreakpoint);
     } catch (StopHashingException const &) {
         return false;
     }
     if (!maybe_stats.has_value()) {
         LogPrintf("[snapshot] failed to generate coins stats\n");
         return false;
     }
 
     // Assert that the deserialized chainstate contents match the expected
     // assumeutxo value.
     if (AssumeutxoHash{maybe_stats->hashSerialized} !=
         au_data.hash_serialized) {
         LogPrintf("[snapshot] bad snapshot content hash: expected %s, got %s\n",
                   au_data.hash_serialized.ToString(),
                   maybe_stats->hashSerialized.ToString());
         return false;
     }
 
     snapshot_chainstate.m_chain.SetTip(snapshot_start_block);
 
     // The remainder of this function requires modifying data protected by
     // cs_main.
     LOCK(::cs_main);
 
     // Fake various pieces of CBlockIndex state:
     CBlockIndex *index = nullptr;
 
     // Don't make any modifications to the genesis block.
     // This is especially important because we don't want to erroneously
     // apply ASSUMED_VALID_FLAG to genesis, which would happen if we didn't
     // skip it here (since it apparently isn't BlockValidity::SCRIPTS).
     constexpr int AFTER_GENESIS_START{1};
 
     for (int i = AFTER_GENESIS_START; i <= snapshot_chainstate.m_chain.Height();
          ++i) {
         index = snapshot_chainstate.m_chain[i];
 
         // Fake nTx so that LoadBlockIndex() loads assumed-valid CBlockIndex
         // entries (among other things)
         if (!index->nTx) {
             index->nTx = 1;
         }
         // Fake nChainTx so that GuessVerificationProgress reports accurately
         index->nChainTx = index->pprev->nChainTx + index->nTx;
 
         // Mark unvalidated block index entries beneath the snapshot base block
         // as assumed-valid.
         if (!index->IsValid(BlockValidity::SCRIPTS)) {
             // This flag will be removed once the block is fully validated by a
             // background chainstate.
             index->nStatus = index->nStatus.withAssumedValid();
         }
 
         m_blockman.m_dirty_blockindex.insert(index);
         // Changes to the block index will be flushed to disk after this call
         // returns in `ActivateSnapshot()`, when `MaybeRebalanceCaches()` is
         // called, since we've added a snapshot chainstate and therefore will
         // have to downsize the IBD chainstate, which will result in a call to
         // `FlushStateToDisk(ALWAYS)`.
     }
 
     assert(index);
     index->nChainTx = au_data.nChainTx;
     snapshot_chainstate.setBlockIndexCandidates.insert(snapshot_start_block);
 
     LogPrintf("[snapshot] validated snapshot (%.2f MB)\n",
               coins_cache.DynamicMemoryUsage() / (1000 * 1000));
     return true;
 }
 
 // Currently, this function holds cs_main for its duration, which could be for
 // multiple minutes due to the ComputeUTXOStats call. This hold is necessary
 // because we need to avoid advancing the background validation chainstate
 // farther than the snapshot base block - and this function is also invoked
 // from within ConnectTip, i.e. from within ActivateBestChain, so cs_main is
 // held anyway.
 //
 // Eventually (TODO), we could somehow separate this function's runtime from
 // maintenance of the active chain, but that will either require
 //
 //  (i) setting `m_disabled` immediately and ensuring all chainstate accesses go
 //      through IsUsable() checks, or
 //
 //  (ii) giving each chainstate its own lock instead of using cs_main for
 //  everything.
 SnapshotCompletionResult ChainstateManager::MaybeCompleteSnapshotValidation(
     std::function<void(bilingual_str)> shutdown_fnc) {
     AssertLockHeld(cs_main);
     if (m_ibd_chainstate.get() == &this->ActiveChainstate() ||
         !this->IsUsable(m_snapshot_chainstate.get()) ||
         !this->IsUsable(m_ibd_chainstate.get()) ||
         !m_ibd_chainstate->m_chain.Tip()) {
         // Nothing to do - this function only applies to the background
         // validation chainstate.
         return SnapshotCompletionResult::SKIPPED;
     }
     const int snapshot_tip_height = this->ActiveHeight();
     const int snapshot_base_height = *Assert(this->GetSnapshotBaseHeight());
     const CBlockIndex &index_new = *Assert(m_ibd_chainstate->m_chain.Tip());
 
     if (index_new.nHeight < snapshot_base_height) {
         // Background IBD not complete yet.
         return SnapshotCompletionResult::SKIPPED;
     }
 
     assert(SnapshotBlockhash());
     BlockHash snapshot_blockhash = *Assert(SnapshotBlockhash());
 
     auto handle_invalid_snapshot = [&]() EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         bilingual_str user_error = strprintf(
             _("%s failed to validate the -assumeutxo snapshot state. "
               "This indicates a hardware problem, or a bug in the software, or "
               "a bad software modification that allowed an invalid snapshot to "
               "be loaded. As a result of this, the node will shut down and "
               "stop using any state that was built on the snapshot, resetting "
               "the chain height from %d to %d. On the next restart, the node "
               "will resume syncing from %d without using any snapshot data. "
               "Please report this incident to %s, including how you obtained "
               "the snapshot. The invalid snapshot chainstate has been left on "
               "disk in case it is helpful in diagnosing the issue that caused "
               "this error."),
             PACKAGE_NAME, snapshot_tip_height, snapshot_base_height,
             snapshot_base_height, PACKAGE_BUGREPORT);
 
         LogPrintf("[snapshot] !!! %s\n", user_error.original);
         LogPrintf("[snapshot] deleting snapshot, reverting to validated chain, "
                   "and stopping node\n");
 
         m_active_chainstate = m_ibd_chainstate.get();
         m_snapshot_chainstate->m_disabled = true;
         assert(!this->IsUsable(m_snapshot_chainstate.get()));
         assert(this->IsUsable(m_ibd_chainstate.get()));
 
         m_snapshot_chainstate->InvalidateCoinsDBOnDisk();
 
         shutdown_fnc(user_error);
     };
 
     if (index_new.GetBlockHash() != snapshot_blockhash) {
         LogPrintf(
             "[snapshot] supposed base block %s does not match the "
             "snapshot base block %s (height %d). Snapshot is not valid.\n",
             index_new.ToString(), snapshot_blockhash.ToString(),
             snapshot_base_height);
         handle_invalid_snapshot();
         return SnapshotCompletionResult::BASE_BLOCKHASH_MISMATCH;
     }
 
     assert(index_new.nHeight == snapshot_base_height);
 
     int curr_height = m_ibd_chainstate->m_chain.Height();
 
     assert(snapshot_base_height == curr_height);
     assert(snapshot_base_height == index_new.nHeight);
     assert(this->IsUsable(m_snapshot_chainstate.get()));
     assert(this->GetAll().size() == 2);
 
     CCoinsViewDB &ibd_coins_db = m_ibd_chainstate->CoinsDB();
     m_ibd_chainstate->ForceFlushStateToDisk();
 
     auto maybe_au_data = ExpectedAssumeutxo(curr_height, GetParams());
     if (!maybe_au_data) {
         LogPrintf("[snapshot] assumeutxo data not found for height "
                   "(%d) - refusing to validate snapshot\n",
                   curr_height);
         handle_invalid_snapshot();
         return SnapshotCompletionResult::MISSING_CHAINPARAMS;
     }
 
     const AssumeutxoData &au_data = *maybe_au_data;
     std::optional<CCoinsStats> maybe_ibd_stats;
     LogPrintf(
         "[snapshot] computing UTXO stats for background chainstate to validate "
         "snapshot - this could take a few minutes\n");
     try {
         maybe_ibd_stats =
             ComputeUTXOStats(CoinStatsHashType::HASH_SERIALIZED, &ibd_coins_db,
                              m_blockman, SnapshotUTXOHashBreakpoint);
     } catch (StopHashingException const &) {
         return SnapshotCompletionResult::STATS_FAILED;
     }
 
     if (!maybe_ibd_stats) {
         LogPrintf(
             "[snapshot] failed to generate stats for validation coins db\n");
         // While this isn't a problem with the snapshot per se, this condition
         // prevents us from validating the snapshot, so we should shut down and
         // let the user handle the issue manually.
         handle_invalid_snapshot();
         return SnapshotCompletionResult::STATS_FAILED;
     }
     const auto &ibd_stats = *maybe_ibd_stats;
 
     // Compare the background validation chainstate's UTXO set hash against the
     // hard-coded assumeutxo hash we expect.
     //
     // TODO: For belt-and-suspenders, we could cache the UTXO set
     // hash for the snapshot when it's loaded in its chainstate's leveldb. We
     // could then reference that here for an additional check.
     if (AssumeutxoHash{ibd_stats.hashSerialized} != au_data.hash_serialized) {
         LogPrintf("[snapshot] hash mismatch: actual=%s, expected=%s\n",
                   ibd_stats.hashSerialized.ToString(),
                   au_data.hash_serialized.ToString());
         handle_invalid_snapshot();
         return SnapshotCompletionResult::HASH_MISMATCH;
     }
 
     LogPrintf("[snapshot] snapshot beginning at %s has been fully validated\n",
               snapshot_blockhash.ToString());
 
     m_ibd_chainstate->m_disabled = true;
     this->MaybeRebalanceCaches();
 
     return SnapshotCompletionResult::SUCCESS;
 }
 
 Chainstate &ChainstateManager::ActiveChainstate() const {
     LOCK(::cs_main);
     assert(m_active_chainstate);
     return *m_active_chainstate;
 }
 
 bool ChainstateManager::IsSnapshotActive() const {
     LOCK(::cs_main);
     return m_snapshot_chainstate &&
            m_active_chainstate == m_snapshot_chainstate.get();
 }
 void ChainstateManager::MaybeRebalanceCaches() {
     AssertLockHeld(::cs_main);
     bool ibd_usable = this->IsUsable(m_ibd_chainstate.get());
     bool snapshot_usable = this->IsUsable(m_snapshot_chainstate.get());
     assert(ibd_usable || snapshot_usable);
 
     if (ibd_usable && !snapshot_usable) {
         LogPrintf("[snapshot] allocating all cache to the IBD chainstate\n");
         // Allocate everything to the IBD chainstate.
         m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache,
                                             m_total_coinsdb_cache);
     } else if (snapshot_usable && !ibd_usable) {
         // If background validation has completed and snapshot is our active
         // chain...
         LogPrintf(
             "[snapshot] allocating all cache to the snapshot chainstate\n");
         // Allocate everything to the snapshot chainstate.
         m_snapshot_chainstate->ResizeCoinsCaches(m_total_coinstip_cache,
                                                  m_total_coinsdb_cache);
     } else if (ibd_usable && snapshot_usable) {
         // If both chainstates exist, determine who needs more cache based on
         // IBD status.
         //
         // Note: shrink caches first so that we don't inadvertently overwhelm
         // available memory.
         if (m_snapshot_chainstate->IsInitialBlockDownload()) {
             m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache * 0.05,
                                                 m_total_coinsdb_cache * 0.05);
             m_snapshot_chainstate->ResizeCoinsCaches(
                 m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95);
         } else {
             m_snapshot_chainstate->ResizeCoinsCaches(
                 m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05);
             m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache * 0.95,
                                                 m_total_coinsdb_cache * 0.95);
         }
     }
 }
 
 void ChainstateManager::ResetChainstates() {
     m_ibd_chainstate.reset();
     m_snapshot_chainstate.reset();
     m_active_chainstate = nullptr;
 }
 
 bool ChainstateManager::DetectSnapshotChainstate(CTxMemPool *mempool) {
     assert(!m_snapshot_chainstate);
     std::optional<fs::path> path = node::FindSnapshotChainstateDir();
     if (!path) {
         return false;
     }
     std::optional<BlockHash> base_blockhash =
         node::ReadSnapshotBaseBlockhash(*path);
     if (!base_blockhash) {
         return false;
     }
     LogPrintf("[snapshot] detected active snapshot chainstate (%s) - loading\n",
               fs::PathToString(*path));
 
     this->ActivateExistingSnapshot(mempool, *base_blockhash);
     return true;
 }
 
 Chainstate &
 ChainstateManager::ActivateExistingSnapshot(CTxMemPool *mempool,
                                             BlockHash base_blockhash) {
     assert(!m_snapshot_chainstate);
     m_snapshot_chainstate = std::make_unique<Chainstate>(mempool, m_blockman,
                                                          *this, base_blockhash);
     LogPrintf("[snapshot] switching active chainstate to %s\n",
               m_snapshot_chainstate->ToString());
     m_active_chainstate = m_snapshot_chainstate.get();
     return *m_snapshot_chainstate;
 }
 
 void Chainstate::InvalidateCoinsDBOnDisk() {
     AssertLockHeld(::cs_main);
     // Should never be called on a non-snapshot chainstate.
     assert(m_from_snapshot_blockhash);
     auto storage_path_maybe = this->CoinsDB().StoragePath();
     // Should never be called with a non-existent storage path.
     assert(storage_path_maybe);
     fs::path snapshot_datadir = *storage_path_maybe;
 
     // Coins views no longer usable.
     m_coins_views.reset();
 
     auto invalid_path = snapshot_datadir + "_INVALID";
     std::string dbpath = fs::PathToString(snapshot_datadir);
     std::string target = fs::PathToString(invalid_path);
     LogPrintf("[snapshot] renaming snapshot datadir %s to %s\n", dbpath,
               target);
 
     // The invalid snapshot datadir is simply moved and not deleted because we
     // may want to do forensics later during issue investigation. The user is
     // instructed accordingly in MaybeCompleteSnapshotValidation().
     try {
         fs::rename(snapshot_datadir, invalid_path);
     } catch (const fs::filesystem_error &e) {
         auto src_str = fs::PathToString(snapshot_datadir);
         auto dest_str = fs::PathToString(invalid_path);
 
         LogPrintf("%s: error renaming file '%s' -> '%s': %s\n", __func__,
                   src_str, dest_str, e.what());
         AbortNode(strprintf("Rename of '%s' -> '%s' failed. "
                             "You should resolve this by manually moving or "
                             "deleting the invalid "
                             "snapshot directory %s, otherwise you will "
                             "encounter the same error again "
                             "on the next startup.",
                             src_str, dest_str, src_str));
     }
 }
 
 const CBlockIndex *ChainstateManager::GetSnapshotBaseBlock() const {
     const auto blockhash_op = this->SnapshotBlockhash();
     if (!blockhash_op) {
         return nullptr;
     }
     return Assert(m_blockman.LookupBlockIndex(*blockhash_op));
 }
 
 std::optional<int> ChainstateManager::GetSnapshotBaseHeight() const {
     const CBlockIndex *base = this->GetSnapshotBaseBlock();
     return base ? std::make_optional(base->nHeight) : std::nullopt;
 }
 
 bool ChainstateManager::ValidatedSnapshotCleanup() {
     AssertLockHeld(::cs_main);
     auto get_storage_path = [](auto &chainstate) EXCLUSIVE_LOCKS_REQUIRED(
                                 ::cs_main) -> std::optional<fs::path> {
         if (!(chainstate && chainstate->HasCoinsViews())) {
             return {};
         }
         return chainstate->CoinsDB().StoragePath();
     };
     std::optional<fs::path> ibd_chainstate_path_maybe =
         get_storage_path(m_ibd_chainstate);
     std::optional<fs::path> snapshot_chainstate_path_maybe =
         get_storage_path(m_snapshot_chainstate);
 
     if (!this->IsSnapshotValidated()) {
         // No need to clean up.
         return false;
     }
     // If either path doesn't exist, that means at least one of the chainstates
     // is in-memory, in which case we can't do on-disk cleanup. You'd better be
     // in a unittest!
     if (!ibd_chainstate_path_maybe || !snapshot_chainstate_path_maybe) {
         LogPrintf("[snapshot] snapshot chainstate cleanup cannot happen with "
                   "in-memory chainstates. You are testing, right?\n");
         return false;
     }
 
     const auto &snapshot_chainstate_path = *snapshot_chainstate_path_maybe;
     const auto &ibd_chainstate_path = *ibd_chainstate_path_maybe;
 
     // Since we're going to be moving around the underlying leveldb filesystem
     // content for each chainstate, make sure that the chainstates (and their
     // constituent CoinsViews members) have been destructed first.
     //
     // The caller of this method will be responsible for reinitializing
     // chainstates if they want to continue operation.
     this->ResetChainstates();
 
     // No chainstates should be considered usable.
     assert(this->GetAll().size() == 0);
 
     LogPrintf("[snapshot] deleting background chainstate directory (now "
               "unnecessary) (%s)\n",
               fs::PathToString(ibd_chainstate_path));
 
     fs::path tmp_old{ibd_chainstate_path + "_todelete"};
 
     auto rename_failed_abort = [](fs::path p_old, fs::path p_new,
                                   const fs::filesystem_error &err) {
         LogPrintf("Error renaming file (%s): %s\n", fs::PathToString(p_old),
                   err.what());
         AbortNode(strprintf(
             "Rename of '%s' -> '%s' failed. "
             "Cannot clean up the background chainstate leveldb directory.",
             fs::PathToString(p_old), fs::PathToString(p_new)));
     };
 
     try {
         fs::rename(ibd_chainstate_path, tmp_old);
     } catch (const fs::filesystem_error &e) {
         rename_failed_abort(ibd_chainstate_path, tmp_old, e);
         throw;
     }
 
     LogPrintf("[snapshot] moving snapshot chainstate (%s) to "
               "default chainstate directory (%s)\n",
               fs::PathToString(snapshot_chainstate_path),
               fs::PathToString(ibd_chainstate_path));
 
     try {
         fs::rename(snapshot_chainstate_path, ibd_chainstate_path);
     } catch (const fs::filesystem_error &e) {
         rename_failed_abort(snapshot_chainstate_path, ibd_chainstate_path, e);
         throw;
     }
 
     if (!DeleteCoinsDBFromDisk(tmp_old, /*is_snapshot=*/false)) {
         // No need to AbortNode because once the unneeded bg chainstate data is
         // moved, it will not interfere with subsequent initialization.
         LogPrintf("Deletion of %s failed. Please remove it manually, as the "
                   "directory is now unnecessary.\n",
                   fs::PathToString(tmp_old));
     } else {
         LogPrintf("[snapshot] deleted background chainstate directory (%s)\n",
                   fs::PathToString(ibd_chainstate_path));
     }
     return true;
 }
diff --git a/src/validation.h b/src/validation.h
index 17d310f95..3cf895279 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -1,1508 +1,1508 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2019 The Bitcoin Core developers
 // Copyright (c) 2017-2020 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_VALIDATION_H
 #define BITCOIN_VALIDATION_H
 
 #if defined(HAVE_CONFIG_H)
 #include <config/bitcoin-config.h>
 #endif
 
 #include <arith_uint256.h>
 #include <attributes.h>
 #include <blockfileinfo.h>
 #include <blockindexcomparators.h>
 #include <bloom.h>
 #include <chain.h>
 #include <chainparams.h>
 #include <config.h>
 #include <consensus/amount.h>
 #include <consensus/consensus.h>
 #include <disconnectresult.h>
 #include <flatfile.h>
 #include <fs.h>
 #include <kernel/chainstatemanager_opts.h>
+#include <kernel/cs_main.h>
 #include <node/blockstorage.h>
 #include <policy/packages.h>
 #include <script/script_error.h>
 #include <script/script_metrics.h>
 #include <shutdown.h>
 #include <sync.h>
 #include <txdb.h>
 #include <txmempool.h> // For CTxMemPool::cs
 #include <uint256.h>
 #include <util/check.h>
 #include <util/translation.h>
 
 #include <atomic>
 #include <cstdint>
 #include <map>
 #include <memory>
 #include <optional>
 #include <set>
 #include <string>
 #include <thread>
 #include <utility>
 #include <vector>
 
 class BlockPolicyValidationState;
 class CChainParams;
 class Chainstate;
 class ChainstateManager;
 class CScriptCheck;
 class CTxMemPool;
 class CTxUndo;
 class DisconnectedBlockTransactions;
 
 struct ChainTxData;
 struct FlatFilePos;
 struct PrecomputedTransactionData;
 struct LockPoints;
 struct AssumeutxoData;
 namespace node {
 class SnapshotMetadata;
 } // namespace node
 namespace Consensus {
 struct Params;
 } // namespace Consensus
 
 namespace Consensus {
 struct Params;
 }
 
 #define MIN_TRANSACTION_SIZE                                                   \
     (::GetSerializeSize(CTransaction(), PROTOCOL_VERSION))
 
 /** Maximum number of dedicated script-checking threads allowed */
 static const int MAX_SCRIPTCHECK_THREADS = 15;
 /** -par default (number of script-checking threads, 0 = auto) */
 static const int DEFAULT_SCRIPTCHECK_THREADS = 0;
 static const int64_t DEFAULT_MAX_TIP_AGE = 24 * 60 * 60;
 static const bool DEFAULT_CHECKPOINTS_ENABLED = true;
 static const bool DEFAULT_TXINDEX = false;
 static constexpr bool DEFAULT_COINSTATSINDEX{false};
 static const char *const DEFAULT_BLOCKFILTERINDEX = "0";
 
 static const bool DEFAULT_PEERBLOOMFILTERS = true;
 
 /** Default for -stopatheight */
 static const int DEFAULT_STOPATHEIGHT = 0;
 /**
  * Block files containing a block-height within MIN_BLOCKS_TO_KEEP of
  * ActiveChain().Tip() will not be pruned.
  */
 static const unsigned int MIN_BLOCKS_TO_KEEP = 288;
 static const signed int DEFAULT_CHECKBLOCKS = 6;
 static const unsigned int DEFAULT_CHECKLEVEL = 3;
 /**
  * Require that user allocate at least 550 MiB for block & undo files
  * (blk???.dat and rev???.dat)
  * At 1MB per block, 288 blocks = 288MB.
  * Add 15% for Undo data = 331MB
  * Add 20% for Orphan block rate = 397MB
  * We want the low water mark after pruning to be at least 397 MB and since we
  * prune in full block file chunks, we need the high water mark which triggers
  * the prune to be one 128MB block file + added 15% undo data = 147MB greater
  * for a total of 545MB
  * Setting the target to >= 550 MiB will make it likely we can respect the
  * target.
  */
 static const uint64_t MIN_DISK_SPACE_FOR_BLOCK_FILES = 550 * 1024 * 1024;
 
 /** Current sync state passed to tip changed callbacks. */
 enum class SynchronizationState { INIT_REINDEX, INIT_DOWNLOAD, POST_INIT };
 
-extern RecursiveMutex cs_main;
 extern GlobalMutex g_best_block_mutex;
 extern std::condition_variable g_best_block_cv;
 /** Used to notify getblocktemplate RPC of new tips. */
 extern uint256 g_best_block;
 extern bool fCheckBlockIndex;
 extern bool fCheckpointsEnabled;
 
 /**
  * If the tip is older than this (in seconds), the node is considered to be in
  * initial block download.
  */
 extern int64_t nMaxTipAge;
 
 /**
  * Block hash whose ancestors we will assume to have valid scripts without
  * checking them.
  */
 extern BlockHash hashAssumeValid;
 
 /**
  * Minimum work we will assume exists on some valid chain.
  */
 extern arith_uint256 nMinimumChainWork;
 
 /** Documentation for argument 'checklevel'. */
 extern const std::vector<std::string> CHECKLEVEL_DOC;
 
 class BlockValidationOptions {
 private:
     uint64_t excessiveBlockSize;
     bool checkPoW : 1;
     bool checkMerkleRoot : 1;
 
 public:
     // Do full validation by default
     explicit BlockValidationOptions(const Config &config);
     explicit BlockValidationOptions(uint64_t _excessiveBlockSize,
                                     bool _checkPow = true,
                                     bool _checkMerkleRoot = true)
         : excessiveBlockSize(_excessiveBlockSize), checkPoW(_checkPow),
           checkMerkleRoot(_checkMerkleRoot) {}
 
     BlockValidationOptions withCheckPoW(bool _checkPoW = true) const {
         BlockValidationOptions ret = *this;
         ret.checkPoW = _checkPoW;
         return ret;
     }
 
     BlockValidationOptions
     withCheckMerkleRoot(bool _checkMerkleRoot = true) const {
         BlockValidationOptions ret = *this;
         ret.checkMerkleRoot = _checkMerkleRoot;
         return ret;
     }
 
     bool shouldValidatePoW() const { return checkPoW; }
     bool shouldValidateMerkleRoot() const { return checkMerkleRoot; }
     uint64_t getExcessiveBlockSize() const { return excessiveBlockSize; }
 };
 
 /**
  * Run instances of script checking worker threads
  */
 void StartScriptCheckWorkerThreads(int threads_num);
 
 /**
  * Stop all of the script checking worker threads
  */
 void StopScriptCheckWorkerThreads();
 
 Amount GetBlockSubsidy(int nHeight, const Consensus::Params &consensusParams);
 
 bool AbortNode(BlockValidationState &state, const std::string &strMessage,
                const bilingual_str &userMessage = bilingual_str{});
 
 /**
  * Guess verification progress (as a fraction between 0.0=genesis and
  * 1.0=current tip).
  */
 double GuessVerificationProgress(const ChainTxData &data,
                                  const CBlockIndex *pindex);
 
 /** Prune block files up to a given height */
 void PruneBlockFilesManual(Chainstate &active_chainstate,
                            int nManualPruneHeight);
 
 /**
  * Validation result for a single transaction mempool acceptance.
  */
 struct MempoolAcceptResult {
     /** Used to indicate the results of mempool validation. */
     enum class ResultType {
         //! Fully validated, valid.
         VALID,
         //! Invalid.
         INVALID,
         //! Valid, transaction was already in the mempool.
         MEMPOOL_ENTRY,
     };
     const ResultType m_result_type;
     const TxValidationState m_state;
 
     // The following fields are only present when m_result_type =
     // ResultType::VALID or MEMPOOL_ENTRY
     /**
      * Virtual size as used by the mempool, calculated using serialized size
      * and sigchecks.
      */
     const std::optional<int64_t> m_vsize;
     /** Raw base fees in satoshis. */
     const std::optional<Amount> m_base_fees;
     static MempoolAcceptResult Failure(TxValidationState state) {
         return MempoolAcceptResult(state);
     }
 
     /** Constructor for success case */
     static MempoolAcceptResult Success(int64_t vsize, Amount fees) {
         return MempoolAcceptResult(ResultType::VALID, vsize, fees);
     }
 
     /**
      * Constructor for already-in-mempool case. It wouldn't replace any
      * transactions.
      */
     static MempoolAcceptResult MempoolTx(int64_t vsize, Amount fees) {
         return MempoolAcceptResult(ResultType::MEMPOOL_ENTRY, vsize, fees);
     }
 
     // Private constructors. Use static methods MempoolAcceptResult::Success,
     // etc. to construct.
 private:
     /** Constructor for failure case */
     explicit MempoolAcceptResult(TxValidationState state)
         : m_result_type(ResultType::INVALID), m_state(state),
           m_base_fees(std::nullopt) {
         // Can be invalid or error
         Assume(!state.IsValid());
     }
 
     /** Generic constructor for success cases */
     explicit MempoolAcceptResult(ResultType result_type, int64_t vsize,
                                  Amount fees)
         : m_result_type(result_type), m_vsize{vsize}, m_base_fees(fees) {}
 };
 
 /**
  * Validation result for package mempool acceptance.
  */
 struct PackageMempoolAcceptResult {
     const PackageValidationState m_state;
     /**
      * Map from txid to finished MempoolAcceptResults. The client is
      * responsible for keeping track of the transaction objects themselves.
      * If a result is not present, it means validation was unfinished for that
      * transaction. If there was a package-wide error (see result in m_state),
      * m_tx_results will be empty.
      */
     std::map<const TxId, const MempoolAcceptResult> m_tx_results;
 
     explicit PackageMempoolAcceptResult(
         PackageValidationState state,
         std::map<const TxId, const MempoolAcceptResult> &&results)
         : m_state{state}, m_tx_results(std::move(results)) {}
 
     /**
      * Constructor to create a PackageMempoolAcceptResult from a
      * MempoolAcceptResult
      */
     explicit PackageMempoolAcceptResult(const TxId &txid,
                                         const MempoolAcceptResult &result)
         : m_tx_results{{txid, result}} {}
 };
 
 /**
  * Try to add a transaction to the mempool. This is an internal function and is
  * exposed only for testing. Client code should use
  * ChainstateManager::ProcessTransaction()
  *
  * @param[in]  config             The global configuration.
  * @param[in]  active_chainstate  Reference to the active chainstate.
  * @param[in]  tx                 The transaction to submit for mempool
  *                                acceptance.
  * @param[in]  accept_time        The timestamp for adding the transaction to
  *                                the mempool.
  *                                It is also used to determine when the entry
  *                                expires.
  * @param[in]  bypass_limits      When true, don't enforce mempool fee and
  *                                capacity limits.
  * @param[in]  test_accept        When true, run validation checks but don't
  *                                submit to mempool.
  * @param[in]  heightOverride     Override the block height of the transaction.
  *                                Used only upon reorg.
  *
  * @returns a MempoolAcceptResult indicating whether the transaction was
  *     accepted/rejected with reason.
  */
 MempoolAcceptResult
 AcceptToMemoryPool(const Config &config, Chainstate &active_chainstate,
                    const CTransactionRef &tx, int64_t accept_time,
                    bool bypass_limits, bool test_accept = false,
                    unsigned int heightOverride = 0)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 /**
  * Validate (and maybe submit) a package to the mempool.
  * See doc/policy/packages.md for full detailson package validation rules.
  *
  * @param[in]    test_accept     When true, run validation checks but don't
  *                               submit to mempool.
  * @returns a PackageMempoolAcceptResult which includes a MempoolAcceptResult
  *     for each transaction. If a transaction fails, validation will exit early
  *     and some results may be missing. It is also possible for the package to
  *     be partially submitted.
  */
 PackageMempoolAcceptResult
 ProcessNewPackage(const Config &config, Chainstate &active_chainstate,
                   CTxMemPool &pool, const Package &txns, bool test_accept)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 /**
  * Simple class for regulating resource usage during CheckInputScripts (and
  * CScriptCheck), atomic so as to be compatible with parallel validation.
  */
 class CheckInputsLimiter {
 protected:
     std::atomic<int64_t> remaining;
 
 public:
     explicit CheckInputsLimiter(int64_t limit) : remaining(limit) {}
 
     bool consume_and_check(int consumed) {
         auto newvalue = (remaining -= consumed);
         return newvalue >= 0;
     }
 
     bool check() { return remaining >= 0; }
 };
 
 class TxSigCheckLimiter : public CheckInputsLimiter {
 public:
     TxSigCheckLimiter() : CheckInputsLimiter(MAX_TX_SIGCHECKS) {}
 
     // Let's make this bad boy copiable.
     TxSigCheckLimiter(const TxSigCheckLimiter &rhs)
         : CheckInputsLimiter(rhs.remaining.load()) {}
 
     TxSigCheckLimiter &operator=(const TxSigCheckLimiter &rhs) {
         remaining = rhs.remaining.load();
         return *this;
     }
 
     static TxSigCheckLimiter getDisabled() {
         TxSigCheckLimiter txLimiter;
         // Historically, there has not been a transaction with more than 20k sig
         // checks on testnet or mainnet, so this effectively disable sigchecks.
         txLimiter.remaining = 20000;
         return txLimiter;
     }
 };
 
 class ConnectTrace;
 
 /**
  * Check whether all of this transaction's input scripts succeed.
  *
  * This involves ECDSA signature checks so can be computationally intensive.
  * This function should only be called after the cheap sanity checks in
  * CheckTxInputs passed.
  *
  * If pvChecks is not nullptr, script checks are pushed onto it instead of being
  * performed inline. Any script checks which are not necessary (eg due to script
  * execution cache hits) are, obviously, not pushed onto pvChecks/run.
  *
  * Upon success nSigChecksOut will be filled in with either:
  * - correct total for all inputs, or,
  * - 0, in the case when checks were pushed onto pvChecks (i.e., a cache miss
  * with pvChecks non-null), in which case the total can be found by executing
  * pvChecks and adding the results.
  *
  * Setting sigCacheStore/scriptCacheStore to false will remove elements from the
  * corresponding cache which are matched. This is useful for checking blocks
  * where we will likely never need the cache entry again.
  *
  * pLimitSigChecks can be passed to limit the sigchecks count either in parallel
  * or serial validation. With pvChecks null (serial validation), breaking the
  * pLimitSigChecks limit will abort evaluation early and return false. With
  * pvChecks not-null (parallel validation): the cached nSigChecks may itself
  * break the limit in which case false is returned, OR, each entry in the
  * returned pvChecks must be executed exactly once in order to probe the limit
  * accurately.
  */
 bool CheckInputScripts(const CTransaction &tx, TxValidationState &state,
                        const CCoinsViewCache &view, const uint32_t flags,
                        bool sigCacheStore, bool scriptCacheStore,
                        const PrecomputedTransactionData &txdata,
                        int &nSigChecksOut, TxSigCheckLimiter &txLimitSigChecks,
                        CheckInputsLimiter *pBlockLimitSigChecks,
                        std::vector<CScriptCheck> *pvChecks)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 /**
  * Handy shortcut to full fledged CheckInputScripts call.
  */
 static inline bool
 CheckInputScripts(const CTransaction &tx, TxValidationState &state,
                   const CCoinsViewCache &view, const uint32_t flags,
                   bool sigCacheStore, bool scriptCacheStore,
                   const PrecomputedTransactionData &txdata, int &nSigChecksOut)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     TxSigCheckLimiter nSigChecksTxLimiter;
     return CheckInputScripts(tx, state, view, flags, sigCacheStore,
                              scriptCacheStore, txdata, nSigChecksOut,
                              nSigChecksTxLimiter, nullptr, nullptr);
 }
 
 /**
  * Mark all the coins corresponding to a given transaction inputs as spent.
  */
 void SpendCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
                 int nHeight);
 
 /**
  * Apply the effects of this transaction on the UTXO set represented by view.
  */
 void UpdateCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
                  int nHeight);
 
 /**
  * Check if transaction will be BIP68 final in the next block to be created on
  * top of tip.
  * @param[in]   tip             Chain tip to check tx sequence locks against.
  *     For example, the tip of the current active chain.
  * @param[in]   coins_view      Any CCoinsView that provides access to the
  *     relevant coins for checking sequence locks. For example, it can be a
  *     CCoinsViewCache that isn't connected to anything but contains all the
  *     relevant coins, or a CCoinsViewMemPool that is connected to the mempool
  *     and chainstate UTXO set. In the latter case, the caller is responsible
  *     for holding the appropriate locks to ensure that calls to GetCoin()
  *     return correct coins.
  * Simulates calling SequenceLocks() with data from the tip passed in.
  * Optionally stores in LockPoints the resulting height and time
  * calculated and the hash of the block needed for calculation or skips the
  * calculation and uses the LockPoints passed in for evaluation. The LockPoints
  * should not be considered valid if CheckSequenceLocksAtTip returns false.
  */
 bool CheckSequenceLocksAtTip(CBlockIndex *tip, const CCoinsView &coins_view,
                              const CTransaction &tx, LockPoints *lp = nullptr,
                              bool useExistingLockPoints = false);
 
 /**
  * Closure representing one script verification.
  * Note that this stores references to the spending transaction.
  *
  * Note that if pLimitSigChecks is passed, then failure does not imply that
  * scripts have failed.
  */
 class CScriptCheck {
 private:
     CTxOut m_tx_out;
     const CTransaction *ptxTo;
     unsigned int nIn;
     uint32_t nFlags;
     bool cacheStore;
     ScriptError error;
     ScriptExecutionMetrics metrics;
     PrecomputedTransactionData txdata;
     TxSigCheckLimiter *pTxLimitSigChecks;
     CheckInputsLimiter *pBlockLimitSigChecks;
 
 public:
     CScriptCheck()
         : ptxTo(nullptr), nIn(0), nFlags(0), cacheStore(false),
           error(ScriptError::UNKNOWN), txdata(), pTxLimitSigChecks(nullptr),
           pBlockLimitSigChecks(nullptr) {}
 
     CScriptCheck(const CTxOut &outIn, const CTransaction &txToIn,
                  unsigned int nInIn, uint32_t nFlagsIn, bool cacheIn,
                  const PrecomputedTransactionData &txdataIn,
                  TxSigCheckLimiter *pTxLimitSigChecksIn = nullptr,
                  CheckInputsLimiter *pBlockLimitSigChecksIn = nullptr)
         : m_tx_out(outIn), ptxTo(&txToIn), nIn(nInIn), nFlags(nFlagsIn),
           cacheStore(cacheIn), error(ScriptError::UNKNOWN), txdata(txdataIn),
           pTxLimitSigChecks(pTxLimitSigChecksIn),
           pBlockLimitSigChecks(pBlockLimitSigChecksIn) {}
 
     bool operator()();
 
     void swap(CScriptCheck &check) noexcept {
         std::swap(ptxTo, check.ptxTo);
         std::swap(m_tx_out, check.m_tx_out);
         std::swap(nIn, check.nIn);
         std::swap(nFlags, check.nFlags);
         std::swap(cacheStore, check.cacheStore);
         std::swap(error, check.error);
         std::swap(metrics, check.metrics);
         std::swap(txdata, check.txdata);
         std::swap(pTxLimitSigChecks, check.pTxLimitSigChecks);
         std::swap(pBlockLimitSigChecks, check.pBlockLimitSigChecks);
     }
 
     ScriptError GetScriptError() const { return error; }
 
     ScriptExecutionMetrics GetScriptExecutionMetrics() const { return metrics; }
 };
 
 /** Functions for validating blocks and updating the block tree */
 
 /**
  * Context-independent validity checks.
  *
  * Returns true if the provided block is valid (has valid header,
  * transactions are valid, block is a valid size, etc.)
  */
 bool CheckBlock(const CBlock &block, BlockValidationState &state,
                 const Consensus::Params &params,
                 BlockValidationOptions validationOptions);
 
 /**
  * This is a variant of ContextualCheckTransaction which computes the contextual
  * check for a transaction based on the chain tip.
  *
  * See consensus/consensus.h for flag definitions.
  */
 bool ContextualCheckTransactionForCurrentBlock(
     const CBlockIndex *active_chain_tip, const Consensus::Params &params,
     const CTransaction &tx, TxValidationState &state)
     EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
 /**
  * Check a block is completely valid from start to finish (only works on top of
  * our current best block)
  */
 bool TestBlockValidity(
     BlockValidationState &state, const CChainParams &params,
     Chainstate &chainstate, const CBlock &block, CBlockIndex *pindexPrev,
     const std::function<NodeClock::time_point()> &adjusted_time_callback,
     BlockValidationOptions validationOptions) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 /**
  * Check with the proof of work on each blockheader matches the value in nBits
  */
 bool HasValidProofOfWork(const std::vector<CBlockHeader> &headers,
                          const Consensus::Params &consensusParams);
 
 /** Return the sum of the work on a given set of headers */
 arith_uint256 CalculateHeadersWork(const std::vector<CBlockHeader> &headers);
 
 enum class VerifyDBResult {
     SUCCESS,
     CORRUPTED_BLOCK_DB,
     INTERRUPTED,
     SKIPPED_L3_CHECKS,
     SKIPPED_MISSING_BLOCKS,
 };
 
 /**
  * RAII wrapper for VerifyDB: Verify consistency of the block and coin
  * databases.
  */
 class CVerifyDB {
 public:
     CVerifyDB();
 
     ~CVerifyDB();
 
     [[nodiscard]] VerifyDBResult
     VerifyDB(Chainstate &chainstate, const Config &config,
              CCoinsView &coinsview, int nCheckLevel, int nCheckDepth)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 };
 
 /** @see Chainstate::FlushStateToDisk */
 enum class FlushStateMode { NONE, IF_NEEDED, PERIODIC, ALWAYS };
 
 /**
  * A convenience class for constructing the CCoinsView* hierarchy used
  * to facilitate access to the UTXO set.
  *
  * This class consists of an arrangement of layered CCoinsView objects,
  * preferring to store and retrieve coins in memory via `m_cacheview` but
  * ultimately falling back on cache misses to the canonical store of UTXOs on
  * disk, `m_dbview`.
  */
 class CoinsViews {
 public:
     //! The lowest level of the CoinsViews cache hierarchy sits in a leveldb
     //! database on disk. All unspent coins reside in this store.
     CCoinsViewDB m_dbview GUARDED_BY(cs_main);
 
     //! This view wraps access to the leveldb instance and handles read errors
     //! gracefully.
     CCoinsViewErrorCatcher m_catcherview GUARDED_BY(cs_main);
 
     //! This is the top layer of the cache hierarchy - it keeps as many coins in
     //! memory as can fit per the dbcache setting.
     std::unique_ptr<CCoinsViewCache> m_cacheview GUARDED_BY(cs_main);
 
     //! This constructor initializes CCoinsViewDB and CCoinsViewErrorCatcher
     //! instances, but it *does not* create a CCoinsViewCache instance by
     //! default. This is done separately because the presence of the cache has
     //! implications on whether or not we're allowed to flush the cache's state
     //! to disk, which should not be done until the health of the database is
     //! verified.
     //!
     //! All arguments forwarded onto CCoinsViewDB.
     CoinsViews(std::string ldb_name, size_t cache_size_bytes, bool in_memory,
                bool should_wipe);
 
     //! Initialize the CCoinsViewCache member.
     void InitCache() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 };
 
 enum class CoinsCacheSizeState {
     //! The coins cache is in immediate need of a flush.
     CRITICAL = 2,
     //! The cache is at >= 90% capacity.
     LARGE = 1,
     OK = 0
 };
 
 /**
  * Chainstate stores and provides an API to update our local knowledge of the
  * current best chain.
  *
  * Eventually, the API here is targeted at being exposed externally as a
  * consumable libconsensus library, so any functions added must only call
  * other class member functions, pure functions in other parts of the consensus
  * library, callbacks via the validation interface, or read/write-to-disk
  * functions (eventually this will also be via callbacks).
  *
  * Anything that is contingent on the current tip of the chain is stored here,
  * whereas block information and metadata independent of the current tip is
  * kept in `BlockManager`.
  */
 class Chainstate {
 protected:
     /**
      * The ChainState Mutex.
      * A lock that must be held when modifying this ChainState.
      */
     Mutex m_chainstate_mutex;
 
     /**
      * Every received block is assigned a unique and increasing identifier, so
      * we know which one to give priority in case of a fork.
      * Blocks loaded from disk are assigned id 0, so start the counter at 1.
      */
     std::atomic<int32_t> nBlockSequenceId{1};
     /** Decreasing counter (used by subsequent preciousblock calls). */
     int32_t nBlockReverseSequenceId = -1;
     /** chainwork for the last block that preciousblock has been applied to. */
     arith_uint256 nLastPreciousChainwork = 0;
 
     /**
      * Whether this chainstate is undergoing initial block download.
      *
      * Mutable because we need to be able to mark IsInitialBlockDownload()
      * const, which latches this for caching purposes.
      */
     mutable std::atomic<bool> m_cached_finished_ibd{false};
 
     //! Optional mempool that is kept in sync with the chain.
     //! Only the active chainstate has a mempool.
     CTxMemPool *m_mempool;
 
     //! Manages the UTXO set, which is a reflection of the contents of
     //! `m_chain`.
     std::unique_ptr<CoinsViews> m_coins_views;
 
     //! This toggle exists for use when doing background validation for UTXO
     //! snapshots.
     //!
     //! In the expected case, it is set once the background validation chain
     //! reaches the same height as the base of the snapshot and its UTXO set is
     //! found to hash to the expected assumeutxo value. It signals that we
     //! should no longer connect blocks to the background chainstate. When set
     //! on the background validation chainstate, it signifies that we have fully
     //! validated the snapshot chainstate.
     //!
     //! In the unlikely case that the snapshot chainstate is found to be
     //! invalid, this is set to true on the snapshot chainstate.
     bool m_disabled GUARDED_BY(::cs_main){false};
 
     mutable Mutex cs_avalancheFinalizedBlockIndex;
 
     /**
      * The best block via avalanche voting.
      * This block cannot be reorged in any way except by explicit user action.
      */
     const CBlockIndex *m_avalancheFinalizedBlockIndex
         GUARDED_BY(cs_avalancheFinalizedBlockIndex) = nullptr;
 
     /**
      * Filter to prevent parking a block due to block policies more than once.
      * After first application of block policies, Avalanche voting will
      * determine the final acceptance state. Rare false positives will be
      * reconciled by the network and should not have any negative impact.
      */
     CRollingBloomFilter m_filterParkingPoliciesApplied =
         CRollingBloomFilter{1000, 0.000001};
 
     CBlockIndex const *m_best_fork_tip = nullptr;
     CBlockIndex const *m_best_fork_base = nullptr;
 
 public:
     //! Reference to a BlockManager instance which itself is shared across all
     //! Chainstate instances.
     node::BlockManager &m_blockman;
 
     //! The chainstate manager that owns this chainstate. The reference is
     //! necessary so that this instance can check whether it is the active
     //! chainstate within deeply nested method calls.
     ChainstateManager &m_chainman;
 
     explicit Chainstate(
         CTxMemPool *mempool, node::BlockManager &blockman,
         ChainstateManager &chainman,
         std::optional<BlockHash> from_snapshot_blockhash = std::nullopt);
 
     /**
      * Initialize the CoinsViews UTXO set database management data structures.
      * The in-memory cache is initialized separately.
      *
      * All parameters forwarded to CoinsViews.
      */
     void InitCoinsDB(size_t cache_size_bytes, bool in_memory, bool should_wipe,
                      std::string leveldb_name = "chainstate");
 
     //! Initialize the in-memory coins cache (to be done after the health of the
     //! on-disk database is verified).
     void InitCoinsCache(size_t cache_size_bytes)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! @returns whether or not the CoinsViews object has been fully initialized
     //! and we can
     //!          safely flush this object to disk.
     bool CanFlushToDisk() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         AssertLockHeld(::cs_main);
         return m_coins_views && m_coins_views->m_cacheview;
     }
 
     //! The current chain of blockheaders we consult and build on.
     //! @see CChain, CBlockIndex.
     CChain m_chain;
 
     /**
      * The blockhash which is the base of the snapshot this chainstate was
      * created from.
      *
      * std::nullopt if this chainstate was not created from a snapshot.
      */
     const std::optional<BlockHash> m_from_snapshot_blockhash{};
 
     //! Return true if this chainstate relies on blocks that are assumed-valid.
     //! In practice this means it was created based on a UTXO snapshot.
     bool reliesOnAssumedValid() {
         return m_from_snapshot_blockhash.has_value();
     }
 
     /**
      * The set of all CBlockIndex entries with either BLOCK_VALID_TRANSACTIONS
      * (for itself and all ancestors) *or* BLOCK_ASSUMED_VALID (if using
      * background chainstates) and as good as our current tip or better.
      * Entries may be failed, though, and pruning nodes may be missing the data
      * for the block.
      */
     std::set<CBlockIndex *, CBlockIndexWorkComparator> setBlockIndexCandidates;
 
     //! @returns A reference to the in-memory cache of the UTXO set.
     CCoinsViewCache &CoinsTip() EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         AssertLockHeld(::cs_main);
         Assert(m_coins_views);
         return *Assert(m_coins_views->m_cacheview);
     }
 
     //! @returns A reference to the on-disk UTXO set database.
     CCoinsViewDB &CoinsDB() EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         AssertLockHeld(::cs_main);
         return Assert(m_coins_views)->m_dbview;
     }
 
     //! @returns A pointer to the mempool.
     CTxMemPool *GetMempool() { return m_mempool; }
 
     //! @returns A reference to a wrapped view of the in-memory UTXO set that
     //!     handles disk read errors gracefully.
     CCoinsViewErrorCatcher &CoinsErrorCatcher()
         EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
         AssertLockHeld(::cs_main);
         return Assert(m_coins_views)->m_catcherview;
     }
 
     //! Destructs all objects related to accessing the UTXO set.
     void ResetCoinsViews() { m_coins_views.reset(); }
 
     //! Does this chainstate have a UTXO set attached?
     bool HasCoinsViews() const { return (bool)m_coins_views; }
 
     //! The cache size of the on-disk coins view.
     size_t m_coinsdb_cache_size_bytes{0};
 
     //! The cache size of the in-memory coins view.
     size_t m_coinstip_cache_size_bytes{0};
 
     //! Resize the CoinsViews caches dynamically and flush state to disk.
     //! @returns true unless an error occurred during the flush.
     bool ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     /**
      * Import blocks from an external file
      *
      * During reindexing, this function is called for each block file
      * (datadir/blocks/blk?????.dat). It reads all blocks contained in the given
      * file and attempts to process them (add them to the block index). The
      * blocks may be out of order within each file and across files. Often this
      * function reads a block but finds that its parent hasn't been read yet, so
      * the block can't be processed yet. The function will add an entry to the
      * blocks_with_unknown_parent map (which is passed as an argument), so that
      * when the block's parent is later read and processed, this function can
      * re-read the child block from disk and process it.
      *
      * Because a block's parent may be in a later file, not just later in the
      * same file, the blocks_with_unknown_parent map must be passed in and out
      * with each call. It's a multimap, rather than just a map, because multiple
      * blocks may have the same parent (when chain splits or stale blocks
      * exist). It maps from parent-hash to child-disk-position.
      *
      * This function can also be used to read blocks from user-specified block
      * files using the -loadblock= option. There's no unknown-parent tracking,
      * so the last two arguments are omitted.
      *
      *
      * @param[in]     fileIn  FILE handle to file containing blocks to read
      * @param[in]     dbp     (optional) Disk block position (only for reindex)
      * @param[in,out] blocks_with_unknown_parent
      *                        (optional) Map of disk positions for blocks with
      *                        unknown parent, key is parent block hash
      *                        (only used for reindex)
      */
     void LoadExternalBlockFile(
         const Config &config, FILE *fileIn, FlatFilePos *dbp = nullptr,
         std::multimap<BlockHash, FlatFilePos> *blocks_with_unknown_parent =
             nullptr) EXCLUSIVE_LOCKS_REQUIRED(!m_chainstate_mutex,
                                               !cs_avalancheFinalizedBlockIndex);
 
     /**
      * Update the on-disk chain state.
      * The caches and indexes are flushed depending on the mode we're called
      * with if they're too large, if it's been a while since the last write, or
      * always and in all cases if we're in prune mode and are deleting files.
      *
      * If FlushStateMode::NONE is used, then FlushStateToDisk(...) won't do
      * anything besides checking if we need to prune.
      *
      * @returns true unless a system error occurred
      */
     bool FlushStateToDisk(BlockValidationState &state, FlushStateMode mode,
                           int nManualPruneHeight = 0);
 
     //! Unconditionally flush all changes to disk.
     void ForceFlushStateToDisk();
 
     //! Prune blockfiles from the disk if necessary and then flush chainstate
     //! changes if we pruned.
     void PruneAndFlush();
 
     /**
      * Find the best known block, and make it the tip of the block chain. The
      * result is either failure or an activated best chain. pblock is either
      * nullptr or a pointer to a block that is already loaded (to avoid loading
      * it again from disk).
      *
      * ActivateBestChain is split into steps (see ActivateBestChainStep) so that
      * we avoid holding cs_main for an extended period of time; the length of
      * this call may be quite long during reindexing or a substantial reorg.
      *
      * May not be called with cs_main held. May not be called in a
      * validationinterface callback.
      *
      * Note that if this is called while a snapshot chainstate is active, and if
      * it is called on a background chainstate whose tip has reached the base
      * block of the snapshot, its execution will take *MINUTES* while it hashes
      * the background UTXO set to verify the assumeutxo value the snapshot was
      * activated with. `cs_main` will be held during this time.
      *
      * @returns true unless a system error occurred
      */
     bool ActivateBestChain(const Config &config, BlockValidationState &state,
                            std::shared_ptr<const CBlock> pblock = nullptr)
         EXCLUSIVE_LOCKS_REQUIRED(!m_chainstate_mutex,
                                  !cs_avalancheFinalizedBlockIndex)
             LOCKS_EXCLUDED(cs_main);
 
     bool AcceptBlock(const Config &config,
                      const std::shared_ptr<const CBlock> &pblock,
                      BlockValidationState &state, bool fRequested,
                      const FlatFilePos *dbp, bool *fNewBlock,
                      bool min_pow_checked) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     // Block (dis)connection on a given view:
     DisconnectResult DisconnectBlock(const CBlock &block,
                                      const CBlockIndex *pindex,
                                      CCoinsViewCache &view)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
     bool ConnectBlock(const CBlock &block, BlockValidationState &state,
                       CBlockIndex *pindex, CCoinsViewCache &view,
                       BlockValidationOptions options,
                       Amount *blockFees = nullptr, bool fJustCheck = false)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     // Apply the effects of a block disconnection on the UTXO set.
     bool DisconnectTip(BlockValidationState &state,
                        DisconnectedBlockTransactions *disconnectpool)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool->cs);
 
     // Manual block validity manipulation:
     /**
      * Mark a block as precious and reorganize.
      *
      * May not be called in a validationinterface callback.
      */
     bool PreciousBlock(const Config &config, BlockValidationState &state,
                        CBlockIndex *pindex)
         EXCLUSIVE_LOCKS_REQUIRED(!m_chainstate_mutex,
                                  !cs_avalancheFinalizedBlockIndex)
             LOCKS_EXCLUDED(cs_main);
     /** Mark a block as invalid. */
     bool InvalidateBlock(const Config &config, BlockValidationState &state,
                          CBlockIndex *pindex) LOCKS_EXCLUDED(cs_main)
         EXCLUSIVE_LOCKS_REQUIRED(!m_chainstate_mutex,
                                  !cs_avalancheFinalizedBlockIndex);
     /** Park a block. */
     bool ParkBlock(const Config &config, BlockValidationState &state,
                    CBlockIndex *pindex) LOCKS_EXCLUDED(cs_main)
         EXCLUSIVE_LOCKS_REQUIRED(!m_chainstate_mutex,
                                  !cs_avalancheFinalizedBlockIndex);
 
     /**
      * Mark a block as finalized by avalanche.
      */
     bool AvalancheFinalizeBlock(CBlockIndex *pindex)
         EXCLUSIVE_LOCKS_REQUIRED(!cs_avalancheFinalizedBlockIndex);
 
     /**
      * Clear avalanche finalization.
      */
     void ClearAvalancheFinalizedBlock()
         EXCLUSIVE_LOCKS_REQUIRED(!cs_avalancheFinalizedBlockIndex);
 
     /**
      * Checks if a block is finalized by avalanche voting.
      */
     bool IsBlockAvalancheFinalized(const CBlockIndex *pindex) const
         EXCLUSIVE_LOCKS_REQUIRED(!cs_avalancheFinalizedBlockIndex);
 
     /** Remove invalidity status from a block and its descendants. */
     void ResetBlockFailureFlags(CBlockIndex *pindex)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     template <typename F>
     bool UpdateFlagsForBlock(CBlockIndex *pindexBase, CBlockIndex *pindex, F f)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     template <typename F, typename C, typename AC>
     void UpdateFlags(CBlockIndex *pindex, CBlockIndex *&pindexReset, F f,
                      C fChild, AC fAncestorWasChanged)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** Remove parked status from a block and its descendants. */
     void UnparkBlockAndChildren(CBlockIndex *pindex)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** Remove parked status from a block. */
     void UnparkBlock(CBlockIndex *pindex) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /** Replay blocks that aren't fully applied to the database. */
     bool ReplayBlocks();
 
     /**
      * Ensures we have a genesis block in the block tree, possibly writing one
      * to disk.
      */
     bool LoadGenesisBlock();
 
     void PruneBlockIndexCandidates();
 
     void UnloadBlockIndex() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Check whether we are doing an initial block download (synchronizing from
      * disk or network)
      */
     bool IsInitialBlockDownload() const;
 
     /** Find the last common block of this chain and a locator. */
     const CBlockIndex *FindForkInGlobalIndex(const CBlockLocator &locator) const
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Make various assertions about the state of the block index.
      *
      * By default this only executes fully when using the Regtest chain; see:
      * fCheckBlockIndex.
      */
     void CheckBlockIndex();
 
     /** Load the persisted mempool from disk */
     void
     LoadMempool(const Config &config, const fs::path &load_path,
                 fsbridge::FopenFn mockable_fopen_function = fsbridge::fopen);
 
     /** Update the chain tip based on database information, i.e. CoinsTip()'s
      * best block. */
     bool LoadChainTip() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     //! Dictates whether we need to flush the cache to disk or not.
     //!
     //! @return the state of the size of the coins cache.
     CoinsCacheSizeState GetCoinsCacheSizeState()
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     CoinsCacheSizeState
     GetCoinsCacheSizeState(size_t max_coins_cache_size_bytes,
                            size_t max_mempool_size_bytes)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     std::string ToString() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! Indirection necessary to make lock annotations work with an optional
     //! mempool.
     RecursiveMutex *MempoolMutex() const LOCK_RETURNED(m_mempool->cs) {
         return m_mempool ? &m_mempool->cs : nullptr;
     }
 
 private:
     bool ActivateBestChainStep(const Config &config,
                                BlockValidationState &state,
                                CBlockIndex *pindexMostWork,
                                const std::shared_ptr<const CBlock> &pblock,
                                bool &fInvalidFound, ConnectTrace &connectTrace)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool->cs,
                                  !cs_avalancheFinalizedBlockIndex);
     bool ConnectTip(const Config &config, BlockValidationState &state,
                     BlockPolicyValidationState &blockPolicyState,
                     CBlockIndex *pindexNew,
                     const std::shared_ptr<const CBlock> &pblock,
                     ConnectTrace &connectTrace,
                     DisconnectedBlockTransactions &disconnectpool)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_mempool->cs,
                                  !cs_avalancheFinalizedBlockIndex);
     void InvalidBlockFound(CBlockIndex *pindex,
                            const BlockValidationState &state)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, !cs_avalancheFinalizedBlockIndex);
     CBlockIndex *
     FindMostWorkChain(std::vector<const CBlockIndex *> &blocksToReconcile)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, !cs_avalancheFinalizedBlockIndex);
     void ReceivedBlockTransactions(const CBlock &block, CBlockIndex *pindexNew,
                                    const FlatFilePos &pos)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     bool RollforwardBlock(const CBlockIndex *pindex, CCoinsViewCache &inputs)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     void UnparkBlockImpl(CBlockIndex *pindex, bool fClearChildren)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     bool UnwindBlock(const Config &config, BlockValidationState &state,
                      CBlockIndex *pindex, bool invalidate)
         EXCLUSIVE_LOCKS_REQUIRED(m_chainstate_mutex,
                                  !cs_avalancheFinalizedBlockIndex);
 
     void CheckForkWarningConditions() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     void CheckForkWarningConditionsOnNewFork(CBlockIndex *pindexNewForkTip)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     void InvalidChainFound(CBlockIndex *pindexNew)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main, !cs_avalancheFinalizedBlockIndex);
 
     const CBlockIndex *FindBlockToFinalize(CBlockIndex *pindexNew)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     /**
      * Check warning conditions and do some notifications on new chain tip set.
      */
     void UpdateTip(const CBlockIndex *pindexNew)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     std::chrono::microseconds m_last_write{0};
     std::chrono::microseconds m_last_flush{0};
 
     /**
      * In case of an invalid snapshot, rename the coins leveldb directory so
      * that it can be examined for issue diagnosis.
      */
     void InvalidateCoinsDBOnDisk() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     friend ChainstateManager;
 };
 
 enum class SnapshotCompletionResult {
     SUCCESS,
     SKIPPED,
 
     // Expected assumeutxo configuration data is not found for the height of the
     // base block.
     MISSING_CHAINPARAMS,
 
     // Failed to generate UTXO statistics (to check UTXO set hash) for the
     // background chainstate.
     STATS_FAILED,
 
     // The UTXO set hash of the background validation chainstate does not match
     // the one expected by assumeutxo chainparams.
     HASH_MISMATCH,
 
     // The blockhash of the current tip of the background validation chainstate
     // does not match the one expected by the snapshot chainstate.
     BASE_BLOCKHASH_MISMATCH,
 };
 
 /**
  * Provides an interface for creating and interacting with one or two
  * chainstates: an IBD chainstate generated by downloading blocks, and
  * an optional snapshot chainstate loaded from a UTXO snapshot. Managed
  * chainstates can be maintained at different heights simultaneously.
  *
  * This class provides abstractions that allow the retrieval of the current
  * most-work chainstate ("Active") as well as chainstates which may be in
  * background use to validate UTXO snapshots.
  *
  * Definitions:
  *
  * *IBD chainstate*: a chainstate whose current state has been "fully"
  *   validated by the initial block download process.
  *
  * *Snapshot chainstate*: a chainstate populated by loading in an
  *    assumeutxo UTXO snapshot.
  *
  * *Active chainstate*: the chainstate containing the current most-work
  *    chain. Consulted by most parts of the system (net_processing,
  *    wallet) as a reflection of the current chain and UTXO set.
  *    This may either be an IBD chainstate or a snapshot chainstate.
  *
  * *Background IBD chainstate*: an IBD chainstate for which the
  *    IBD process is happening in the background while use of the
  *    active (snapshot) chainstate allows the rest of the system to function.
  */
 class ChainstateManager {
 private:
     //! The chainstate used under normal operation (i.e. "regular" IBD) or, if
     //! a snapshot is in use, for background validation.
     //!
     //! Its contents (including on-disk data) will be deleted *upon shutdown*
     //! after background validation of the snapshot has completed. We do not
     //! free the chainstate contents immediately after it finishes validation
     //! to cautiously avoid a case where some other part of the system is still
     //! using this pointer (e.g. net_processing).
     //!
     //! Once this pointer is set to a corresponding chainstate, it will not
     //! be reset until init.cpp:Shutdown().
     //!
     //! This is especially important when, e.g., calling ActivateBestChain()
     //! on all chainstates because we are not able to hold ::cs_main going into
     //! that call.
     std::unique_ptr<Chainstate> m_ibd_chainstate GUARDED_BY(::cs_main);
 
     //! A chainstate initialized on the basis of a UTXO snapshot. If this is
     //! non-null, it is always our active chainstate.
     //!
     //! Once this pointer is set to a corresponding chainstate, it will not
     //! be reset until init.cpp:Shutdown().
     //!
     //! This is especially important when, e.g., calling ActivateBestChain()
     //! on all chainstates because we are not able to hold ::cs_main going into
     //! that call.
     std::unique_ptr<Chainstate> m_snapshot_chainstate GUARDED_BY(::cs_main);
 
     //! Points to either the ibd or snapshot chainstate; indicates our
     //! most-work chain.
     //!
     //! Once this pointer is set to a corresponding chainstate, it will not
     //! be reset until init.cpp:Shutdown().
     //!
     //! This is especially important when, e.g., calling ActivateBestChain()
     //! on all chainstates because we are not able to hold ::cs_main going into
     //! that call.
     Chainstate *m_active_chainstate GUARDED_BY(::cs_main){nullptr};
 
     CBlockIndex *m_best_invalid GUARDED_BY(::cs_main){nullptr};
     CBlockIndex *m_best_parked GUARDED_BY(::cs_main){nullptr};
 
     //! Internal helper for ActivateSnapshot().
     [[nodiscard]] bool
     PopulateAndValidateSnapshot(Chainstate &snapshot_chainstate,
                                 AutoFile &coins_file,
                                 const node::SnapshotMetadata &metadata);
     /**
      * If a block header hasn't already been seen, call CheckBlockHeader on it,
      * ensure that it doesn't descend from an invalid block, and then add it to
      * m_block_index.
      * Caller must set min_pow_checked=true in order to add a new header to the
      * block index (permanent memory storage), indicating that the header is
      * known to be part of a sufficiently high-work chain (anti-dos check).
      */
     bool AcceptBlockHeader(const Config &config, const CBlockHeader &block,
                            BlockValidationState &state, CBlockIndex **ppindex,
                            bool min_pow_checked)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
     friend Chainstate;
 
     //! Returns nullptr if no snapshot has been loaded.
     const CBlockIndex *GetSnapshotBaseBlock() const
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! Return the height of the base block of the snapshot in use, if one
     //! exists, else nullopt.
     std::optional<int> GetSnapshotBaseHeight() const
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! Return true if a chainstate is considered usable.
     //!
     //! This is false when a background validation chainstate has completed its
     //! validation of an assumed-valid chainstate, or when a snapshot
     //! chainstate has been found to be invalid.
     bool IsUsable(const Chainstate *const pchainstate) const
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         return pchainstate && !pchainstate->m_disabled;
     }
 
     /** Most recent headers presync progress update, for rate-limiting. */
     SteadyMilliseconds m_last_presync_update GUARDED_BY(::cs_main){};
 
 public:
     using Options = kernel::ChainstateManagerOpts;
 
     explicit ChainstateManager(Options options)
         : m_options{std::move(options)} {
         Assert(m_options.adjusted_time_callback);
     }
 
     const CChainParams &GetParams() const {
         return m_options.config.GetChainParams();
     }
     const Consensus::Params &GetConsensus() const {
         return m_options.config.GetChainParams().GetConsensus();
     }
 
     /**
      * Alias for ::cs_main.
      * Should be used in new code to make it easier to make ::cs_main a member
      * of this class.
      * Generally, methods of this class should be annotated to require this
      * mutex. This will make calling code more verbose, but also help to:
      * - Clarify that the method will acquire a mutex that heavily affects
      *   overall performance.
      * - Force call sites to think how long they need to acquire the mutex to
      *   get consistent results.
      */
     RecursiveMutex &GetMutex() const LOCK_RETURNED(::cs_main) {
         return ::cs_main;
     }
 
     const Options m_options;
     std::thread m_load_block;
     //! A single BlockManager instance is shared across each constructed
     //! chainstate to avoid duplicating block metadata.
     node::BlockManager m_blockman;
 
     /**
      * In order to efficiently track invalidity of headers, we keep the set of
      * blocks which we tried to connect and found to be invalid here (ie which
      * were set to BLOCK_FAILED_VALID since the last restart). We can then
      * walk this set and check if a new header is a descendant of something in
      * this set, preventing us from having to walk m_block_index when we try
      * to connect a bad block and fail.
      *
      * While this is more complicated than marking everything which descends
      * from an invalid block as invalid at the time we discover it to be
      * invalid, doing so would require walking all of m_block_index to find all
      * descendants. Since this case should be very rare, keeping track of all
      * BLOCK_FAILED_VALID blocks in a set should be just fine and work just as
      * well.
      *
      * Because we already walk m_block_index in height-order at startup, we go
      * ahead and mark descendants of invalid blocks as FAILED_CHILD at that
      * time, instead of putting things in this set.
      */
     std::set<CBlockIndex *> m_failed_blocks;
 
     /**
      * Best header we've seen so far (used for getheaders queries' starting
      * points).
      */
     CBlockIndex *m_best_header GUARDED_BY(::cs_main){nullptr};
 
     //! The total number of bytes available for us to use across all in-memory
     //! coins caches. This will be split somehow across chainstates.
     int64_t m_total_coinstip_cache{0};
     //
     //! The total number of bytes available for us to use across all leveldb
     //! coins databases. This will be split somehow across chainstates.
     int64_t m_total_coinsdb_cache{0};
 
     //! Instantiate a new chainstate.
     //!
     //! @param[in] mempool              The mempool to pass to the chainstate
     //                                  constructor
     Chainstate &InitializeChainstate(CTxMemPool *mempool)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! Get all chainstates currently being used.
     std::vector<Chainstate *> GetAll();
 
     //! Construct and activate a Chainstate on the basis of UTXO snapshot data.
     //!
     //! Steps:
     //!
     //! - Initialize an unused Chainstate.
     //! - Load its `CoinsViews` contents from `coins_file`.
     //! - Verify that the hash of the resulting coinsdb matches the expected
     //!   hash per assumeutxo chain parameters.
     //! - Wait for our headers chain to include the base block of the snapshot.
     //! - "Fast forward" the tip of the new chainstate to the base of the
     //!   snapshot, faking nTx* block index data along the way.
     //! - Move the new chainstate to `m_snapshot_chainstate` and make it our
     //!   ActiveChainstate().
     [[nodiscard]] bool ActivateSnapshot(AutoFile &coins_file,
                                         const node::SnapshotMetadata &metadata,
                                         bool in_memory);
 
     //! Once the background validation chainstate has reached the height which
     //! is the base of the UTXO snapshot in use, compare its coins to ensure
     //! they match those expected by the snapshot.
     //!
     //! If the coins match (expected), then mark the validation chainstate for
     //! deletion and continue using the snapshot chainstate as active.
     //! Otherwise, revert to using the ibd chainstate and shutdown.
     SnapshotCompletionResult MaybeCompleteSnapshotValidation(
         std::function<void(bilingual_str)> shutdown_fnc =
             [](bilingual_str msg) { AbortNode(msg.original, msg); })
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! The most-work chain.
     Chainstate &ActiveChainstate() const;
     CChain &ActiveChain() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex()) {
         return ActiveChainstate().m_chain;
     }
     int ActiveHeight() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex()) {
         return ActiveChain().Height();
     }
     CBlockIndex *ActiveTip() const EXCLUSIVE_LOCKS_REQUIRED(GetMutex()) {
         return ActiveChain().Tip();
     }
 
     node::BlockMap &BlockIndex() EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         AssertLockHeld(::cs_main);
         return m_blockman.m_block_index;
     }
 
     //! @returns true if a snapshot-based chainstate is in use. Also implies
     //!          that a background validation chainstate is also in use.
     bool IsSnapshotActive() const;
 
     std::optional<BlockHash> SnapshotBlockhash() const;
 
     //! Is there a snapshot in use and has it been fully validated?
     bool IsSnapshotValidated() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
         return m_snapshot_chainstate && m_ibd_chainstate &&
                m_ibd_chainstate->m_disabled;
     }
 
     /**
      * Process an incoming block. This only returns after the best known valid
      * block is made active. Note that it does not, however, guarantee that the
      * specific block passed to it has been checked for validity!
      *
      * If you want to *possibly* get feedback on whether block is valid, you
      * must install a CValidationInterface (see validationinterface.h) - this
      * will have its BlockChecked method called whenever *any* block completes
      * validation.
      *
      * Note that we guarantee that either the proof-of-work is valid on block,
      * or (and possibly also) BlockChecked will have been called.
      *
      * May not be called in a validationinterface callback.
      *
      * @param[in]   config  The global config.
      * @param[in]   block  The block we want to process.
      * @param[in]   force_processing Process this block even if unrequested;
      *                               used for non-network block sources.
      * @param[in]   min_pow_checked  True if proof-of-work anti-DoS checks have
      *                               been done by caller for headers chain
      *                               (note: only affects headers acceptance; if
      *                               block header is already present in block
      *                               index then this parameter has no effect)
      * @param[out]  new_block A boolean which is set to indicate if the block
      * was first received via this call.
      * @returns     If the block was processed, independently of block validity
      */
     bool ProcessNewBlock(const Config &config,
                          const std::shared_ptr<const CBlock> &block,
                          bool force_processing, bool min_pow_checked,
                          bool *new_block) LOCKS_EXCLUDED(cs_main);
 
     /**
      * Process incoming block headers.
      *
      * May not be called in a validationinterface callback.
      *
      * @param[in]  config        The config.
      * @param[in]  block         The block headers themselves.
      * @param[in]  min_pow_checked  True if proof-of-work anti-DoS checks have
      *                              been done by caller for headers chain
      * @param[out] state         This may be set to an Error state if any error
      *                           occurred processing them.
      * @param[out] ppindex       If set, the pointer will be set to point to the
      *                           last new block index object for the given
      * headers.
      * @return True if block headers were accepted as valid.
      */
     bool ProcessNewBlockHeaders(const Config &config,
                                 const std::vector<CBlockHeader> &block,
                                 bool min_pow_checked,
                                 BlockValidationState &state,
                                 const CBlockIndex **ppindex = nullptr)
         LOCKS_EXCLUDED(cs_main);
 
     /**
      * Try to add a transaction to the memory pool.
      *
      * @param[in]  tx              The transaction to submit for mempool
      *                             acceptance.
      * @param[in]  test_accept     When true, run validation checks but don't
      *                             submit to mempool.
      */
     [[nodiscard]] MempoolAcceptResult
     ProcessTransaction(const CTransactionRef &tx, bool test_accept = false)
         EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     //! Load the block tree and coins database from disk, initializing state if
     //! we're running with -reindex
     bool LoadBlockIndex() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     //! Check to see if caches are out of balance and if so, call
     //! ResizeCoinsCaches() as needed.
     void MaybeRebalanceCaches() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     /**
      * This is used by net_processing to report pre-synchronization progress of
      * headers, as headers are not yet fed to validation during that time, but
      * validation is (for now) responsible for logging and signalling through
      * NotifyHeaderTip, so it needs this information.
      */
     void ReportHeadersPresync(const arith_uint256 &work, int64_t height,
                               int64_t timestamp);
 
     //! When starting up, search the datadir for a chainstate based on a UTXO
     //! snapshot that is in the process of being validated.
     bool DetectSnapshotChainstate(CTxMemPool *mempool)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     void ResetChainstates() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! Switch the active chainstate to one based on a UTXO snapshot that was
     //! loaded previously.
     Chainstate &ActivateExistingSnapshot(CTxMemPool *mempool,
                                          BlockHash base_blockhash)
         EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
     //! If we have validated a snapshot chain during this runtime, copy its
     //! chainstate directory over to the main `chainstate` location, completing
     //! validation of the snapshot.
     //!
     //! If the cleanup succeeds, the caller will need to ensure chainstates are
     //! reinitialized, since ResetChainstates() will be called before leveldb
     //! directories are moved or deleted.
     //!
     //! @sa node/chainstate:LoadChainstate()
     bool ValidatedSnapshotCleanup() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 };
 
 /**
  * Return the expected assumeutxo value for a given height, if one exists.
  *
  * @param[in] height Get the assumeutxo value for this height.
  *
  * @returns empty if no assumeutxo configuration exists for the given height.
  */
 const AssumeutxoData *ExpectedAssumeutxo(const int height,
                                          const CChainParams &params);
 
 #endif // BITCOIN_VALIDATION_H
diff --git a/src/validationinterface.h b/src/validationinterface.h
index 690d8bf4a..ab3bc4adf 100644
--- a/src/validationinterface.h
+++ b/src/validationinterface.h
@@ -1,249 +1,249 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_VALIDATIONINTERFACE_H
 #define BITCOIN_VALIDATIONINTERFACE_H
 
+#include <kernel/cs_main.h>
 #include <primitives/transaction.h> // CTransaction(Ref)
 #include <sync.h>
 
 #include <functional>
 #include <memory>
 
-extern RecursiveMutex cs_main;
 class BlockValidationState;
 class CBlock;
 class CBlockIndex;
 struct CBlockLocator;
 class Coin;
 class CValidationInterface;
 class CScheduler;
 enum class MemPoolRemovalReason;
 
 /** Register subscriber */
 void RegisterValidationInterface(CValidationInterface *callbacks);
 /**
  * Unregister subscriber. DEPRECATED. This is not safe to use when the RPC
  * server or main message handler thread is running.
  */
 void UnregisterValidationInterface(CValidationInterface *callbacks);
 /** Unregister all subscribers */
 void UnregisterAllValidationInterfaces();
 
 // Alternate registration functions that release a shared_ptr after the last
 // notification is sent. These are useful for race-free cleanup, since
 // unregistration is nonblocking and can return before the last notification is
 // processed.
 /** Register subscriber */
 void RegisterSharedValidationInterface(
     std::shared_ptr<CValidationInterface> callbacks);
 /** Unregister subscriber */
 void UnregisterSharedValidationInterface(
     std::shared_ptr<CValidationInterface> callbacks);
 
 /**
  * Pushes a function to callback onto the notification queue, guaranteeing any
  * callbacks generated prior to now are finished when the function is called.
  *
  * Be very careful blocking on func to be called if any locks are held -
  * validation interface clients may not be able to make progress as they often
  * wait for things like cs_main, so blocking until func is called with cs_main
  * will result in a deadlock (that DEBUG_LOCKORDER will miss).
  */
 void CallFunctionInValidationInterfaceQueue(std::function<void()> func);
 /**
  * This is a synonym for the following, which asserts certain locks are not
  * held:
  *     std::promise<void> promise;
  *     CallFunctionInValidationInterfaceQueue([&promise] {
  *         promise.set_value();
  *     });
  *     promise.get_future().wait();
  */
 void SyncWithValidationInterfaceQueue() LOCKS_EXCLUDED(cs_main);
 
 /**
  * Implement this to subscribe to events generated in validation
  *
  * Each CValidationInterface() subscriber will receive event callbacks
  * in the order in which the events were generated by validation.
  * Furthermore, each ValidationInterface() subscriber may assume that
  * callbacks effectively run in a single thread with single-threaded
  * memory consistency. That is, for a given ValidationInterface()
  * instantiation, each callback will complete before the next one is
  * invoked. This means, for example when a block is connected that the
  * UpdatedBlockTip() callback may depend on an operation performed in
  * the BlockConnected() callback without worrying about explicit
  * synchronization. No ordering should be assumed across
  * ValidationInterface() subscribers.
  */
 class CValidationInterface {
 protected:
     /**
      * Protected destructor so that instances can only be deleted by derived
      * classes. If that restriction is no longer desired, this should be made
      * public and virtual.
      */
     ~CValidationInterface() = default;
     /**
      * Notifies listeners when the block chain tip advances.
      *
      * When multiple blocks are connected at once, UpdatedBlockTip will be
      * called on the final tip but may not be called on every intermediate tip.
      * If the latter behavior is desired, subscribe to BlockConnected() instead.
      *
      * Called on a background thread.
      */
     virtual void UpdatedBlockTip(const CBlockIndex *pindexNew,
                                  const CBlockIndex *pindexFork,
                                  bool fInitialDownload) {}
     /**
      * Notifies listeners of a transaction having been added to mempool.
      *
      * Called on a background thread.
      */
     virtual void TransactionAddedToMempool(
         const CTransactionRef &tx,
         std::shared_ptr<const std::vector<Coin>> spent_coins,
         uint64_t mempool_sequence) {}
 
     /**
      * Notifies listeners of a transaction leaving mempool.
      *
      * This notification fires for transactions that are removed from the
      * mempool for the following reasons:
      *
      * - EXPIRY (expired from mempool after -mempoolexpiry hours)
      * - SIZELIMIT (removed in size limiting if the mempool exceeds -maxmempool
      *   megabytes)
      * - REORG (removed during a reorg)
      * - CONFLICT (removed because it conflicts with in-block transaction)
      *
      * This does not fire for transactions that are removed from the mempool
      * because they have been included in a block. Any client that is interested
      * in transactions removed from the mempool for inclusion in a block can
      * learn about those transactions from the BlockConnected notification.
      *
      * Transactions that are removed from the mempool because they conflict
      * with a transaction in the new block will have
      * TransactionRemovedFromMempool events fired *before* the BlockConnected
      * event is fired. If multiple blocks are connected in one step, then the
      * ordering could be:
      *
      * - TransactionRemovedFromMempool(tx1 from block A)
      * - TransactionRemovedFromMempool(tx2 from block A)
      * - TransactionRemovedFromMempool(tx1 from block B)
      * - TransactionRemovedFromMempool(tx2 from block B)
      * - BlockConnected(A)
      * - BlockConnected(B)
      *
      * Called on a background thread.
      */
     virtual void TransactionRemovedFromMempool(const CTransactionRef &tx,
                                                MemPoolRemovalReason reason,
                                                uint64_t mempool_sequence) {}
     /**
      * Notifies listeners of a block being connected.
      * Provides a vector of transactions evicted from the mempool as a result.
      *
      * Called on a background thread.
      */
     virtual void BlockConnected(const std::shared_ptr<const CBlock> &block,
                                 const CBlockIndex *pindex) {}
     /**
      * Notifies listeners of a block being disconnected
      *
      * Called on a background thread.
      */
     virtual void BlockDisconnected(const std::shared_ptr<const CBlock> &block,
                                    const CBlockIndex *pindex) {}
     /**
      * Notifies listeners of the new active block chain on-disk.
      *
      * Prior to this callback, any updates are not guaranteed to persist on disk
      * (ie clients need to handle shutdown/restart safety by being able to
      * understand when some updates were lost due to unclean shutdown).
      *
      * When this callback is invoked, the validation changes done by any prior
      * callback are guaranteed to exist on disk and survive a restart, including
      * an unclean shutdown.
      *
      * Provides a locator describing the best chain, which is likely useful for
      * storing current state on disk in client DBs.
      *
      * Called on a background thread.
      */
     virtual void ChainStateFlushed(const CBlockLocator &locator) {}
     /**
      * Notifies listeners of a block validation result.
      * If the provided BlockValidationState IsValid, the provided block
      * is guaranteed to be the current best block at the time the
      * callback was generated (not necessarily now)
      */
     virtual void BlockChecked(const CBlock &, const BlockValidationState &) {}
     /**
      * Notifies listeners that a block which builds directly on our current tip
      * has been received and connected to the headers tree, though not validated
      * yet.
      */
     virtual void NewPoWValidBlock(const CBlockIndex *pindex,
                                   const std::shared_ptr<const CBlock> &block){};
 
     virtual void BlockFinalized(const CBlockIndex *pindex){};
 
     friend class CMainSignals;
     friend class ValidationInterfaceTest;
 };
 
 class MainSignalsImpl;
 class CMainSignals {
 private:
     std::unique_ptr<MainSignalsImpl> m_internals;
 
     friend void ::RegisterSharedValidationInterface(
         std::shared_ptr<CValidationInterface>);
     friend void ::UnregisterValidationInterface(CValidationInterface *);
     friend void ::UnregisterAllValidationInterfaces();
     friend void ::CallFunctionInValidationInterfaceQueue(
         std::function<void()> func);
 
 public:
     /**
      * Register a CScheduler to give callbacks which should run in the
      * background (may only be called once)
      */
     void RegisterBackgroundSignalScheduler(CScheduler &scheduler);
     /**
      * Unregister a CScheduler to give callbacks which should run in the
      * background - these callbacks will now be dropped!
      */
     void UnregisterBackgroundSignalScheduler();
     /** Call any remaining callbacks on the calling thread */
     void FlushBackgroundCallbacks();
 
     size_t CallbacksPending();
 
     void UpdatedBlockTip(const CBlockIndex *, const CBlockIndex *,
                          bool fInitialDownload);
     void TransactionAddedToMempool(const CTransactionRef &,
                                    std::shared_ptr<const std::vector<Coin>>,
                                    uint64_t mempool_sequence);
     void TransactionRemovedFromMempool(const CTransactionRef &,
                                        MemPoolRemovalReason,
                                        uint64_t mempool_sequence);
     void BlockConnected(const std::shared_ptr<const CBlock> &,
                         const CBlockIndex *pindex);
     void BlockDisconnected(const std::shared_ptr<const CBlock> &,
                            const CBlockIndex *pindex);
     void ChainStateFlushed(const CBlockLocator &);
     void BlockChecked(const CBlock &, const BlockValidationState &);
     void NewPoWValidBlock(const CBlockIndex *,
                           const std::shared_ptr<const CBlock> &);
     void BlockFinalized(const CBlockIndex *);
 };
 
 CMainSignals &GetMainSignals();
 
 #endif // BITCOIN_VALIDATIONINTERFACE_H