diff --git a/src/avalanche.cpp b/src/avalanche.cpp
index d8bbfe391..2f3e0eb65 100644
--- a/src/avalanche.cpp
+++ b/src/avalanche.cpp
@@ -1,415 +1,417 @@
 // Copyright (c) 2018 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "avalanche.h"
 
 #include "chain.h"
 #include "config/bitcoin-config.h"
 #include "netmessagemaker.h"
 #include "reverse_iterator.h"
 #include "scheduler.h"
 #include "validation.h"
 
 #include <tuple>
 
 /**
  * Run the avalanche event loop every 10ms.
  */
 static const int64_t AVALANCHE_TIME_STEP_MILLISECONDS = 10;
 
 /**
  * Maximum item count that can be polled at once.
  */
 static const size_t AVALANCHE_MAX_ELEMENT_POLL = 4096;
 
 static uint32_t countBits(uint32_t v) {
 #if HAVE_DECL___BUILTIN_POPCOUNT
     return __builtin_popcount(v);
 #else
     /**
      * Computes the number of bits set in each group of 8bits then uses a
      * multiplication to sum all of them in the 8 most significant bits and
      * return these.
      * More detailed explanation can be found at
      * https://www.playingwithpointers.com/blog/swar.html
      */
     v = v - ((v >> 1) & 0x55555555);
     v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
     return (((v + (v >> 4)) & 0xF0F0F0F) * 0x1010101) >> 24;
 #endif
 }
 
 bool VoteRecord::registerVote(uint32_t error) {
     /**
      * The result of the vote is determined from the error code. If the error
      * code is 0, there is no error and therefore the vote is yes. If there is
      * an error, we check the most significant bit to decide if the vote is a no
      * (for instance, the block is invalid) or is the vote inconclusive (for
      * instance, the queried node does not have the block yet).
      */
     votes = (votes << 1) | (error == 0);
     consider = (consider << 1) | (int32_t(error) >= 0);
 
     /**
      * We compute the number of yes and/or no votes as follow:
      *
      * votes:     1010
      * consider:  1100
      *
      * yes votes: 1000 using votes & consider
      * no votes:  0100 using ~votes & consider
      */
     bool yes = countBits(votes & consider & 0xff) > 6;
     if (!yes) {
         bool no = countBits(~votes & consider & 0xff) > 6;
         if (!no) {
             // The round is inconclusive.
             return false;
         }
     }
 
     // If the round is in agreement with previous rounds, increase confidence.
     if (isAccepted() == yes) {
         confidence += 2;
         return getConfidence() == AVALANCHE_FINALIZATION_SCORE;
     }
 
     // The round changed our state. We reset the confidence.
     confidence = yes;
     return true;
 }
 
 static bool IsWorthPolling(const CBlockIndex *pindex) {
     AssertLockHeld(cs_main);
 
     if (pindex->nStatus.isInvalid()) {
         // No point polling invalid blocks.
         return false;
     }
 
     if (IsBlockFinalized(pindex)) {
         // There is no point polling finalized block.
         return false;
     }
 
     return true;
 }
 
 bool AvalancheProcessor::addBlockToReconcile(const CBlockIndex *pindex) {
     bool isAccepted;
 
     {
         LOCK(cs_main);
         if (!IsWorthPolling(pindex)) {
             // There is no point polling this block.
             return false;
         }
 
         isAccepted = chainActive.Contains(pindex);
     }
 
     return vote_records.getWriteView()
         ->insert(std::make_pair(pindex, VoteRecord(isAccepted)))
         .second;
 }
 
 bool AvalancheProcessor::isAccepted(const CBlockIndex *pindex) const {
     auto r = vote_records.getReadView();
     auto it = r->find(pindex);
     if (it == r.end()) {
         return false;
     }
 
     return it->second.isAccepted();
 }
 
 int AvalancheProcessor::getConfidence(const CBlockIndex *pindex) const {
     auto r = vote_records.getReadView();
     auto it = r->find(pindex);
     if (it == r.end()) {
         return -1;
     }
 
     return it->second.getConfidence();
 }
 
 bool AvalancheProcessor::registerVotes(
     NodeId nodeid, const AvalancheResponse &response,
     std::vector<AvalancheBlockUpdate> &updates) {
     {
         // Save the time at which we can query again.
         auto w = peerSet.getWriteView();
         auto it = w->find(nodeid);
         if (it != w->end()) {
             w->modify(it, [&response](Peer &p) {
                 // FIXME: This will override the time even when we received an
                 // old stale message. This should check that the message is
                 // indeed the most up to date one before updating the time.
                 p.nextRequestTime =
                     std::chrono::steady_clock::now() +
                     std::chrono::milliseconds(response.getCooldown());
             });
         }
     }
 
     std::vector<CInv> invs;
 
     {
         // Check that the query exists.
         auto w = queries.getWriteView();
         auto it = w->find(std::make_tuple(nodeid, response.getRound()));
         if (it == w.end()) {
             // NB: The request may be old, so we don't increase banscore.
             return false;
         }
 
         invs = std::move(it->invs);
         w->erase(it);
     }
 
     // Verify that the request and the vote are consistent.
     const std::vector<AvalancheVote> &votes = response.GetVotes();
     size_t size = invs.size();
     if (votes.size() != size) {
         // TODO: increase banscore for inconsistent response.
         // NB: This isn't timeout but actually node misbehaving.
         return false;
     }
 
     for (size_t i = 0; i < size; i++) {
         if (invs[i].hash != votes[i].GetHash()) {
             // TODO: increase banscore for inconsistent response.
             // NB: This isn't timeout but actually node misbehaving.
             return false;
         }
     }
 
     std::map<CBlockIndex *, AvalancheVote> responseIndex;
 
     {
         LOCK(cs_main);
         for (auto &v : votes) {
             BlockMap::iterator mi = mapBlockIndex.find(v.GetHash());
             if (mi == mapBlockIndex.end()) {
                 // This should not happen, but just in case...
                 continue;
             }
 
             CBlockIndex *pindex = mi->second;
             if (!IsWorthPolling(pindex)) {
                 // There is no point polling this block.
                 continue;
             }
 
             responseIndex.insert(std::make_pair(pindex, v));
         }
     }
 
     {
         // Register votes.
         auto w = vote_records.getWriteView();
         for (auto &p : responseIndex) {
             CBlockIndex *pindex = p.first;
             const AvalancheVote &v = p.second;
 
             auto it = w->find(pindex);
             if (it == w.end()) {
                 // We are not voting on that item anymore.
                 continue;
             }
 
             auto &vr = it->second;
             if (!vr.registerVote(v.GetError())) {
                 // This vote did not provide any extra information, move on.
                 continue;
             }
 
             if (!vr.hasFinalized()) {
                 // This item has note been finalized, so we have nothing more to
                 // do.
                 updates.emplace_back(
                     pindex, vr.isAccepted()
                                 ? AvalancheBlockUpdate::Status::Accepted
                                 : AvalancheBlockUpdate::Status::Rejected);
                 continue;
             }
 
             // We just finalized a vote. If it is valid, then let the caller
             // know. Either way, remove the item from the map.
             updates.emplace_back(pindex,
                                  vr.isAccepted()
                                      ? AvalancheBlockUpdate::Status::Finalized
                                      : AvalancheBlockUpdate::Status::Invalid);
             w->erase(it);
         }
     }
 
     return true;
 }
 
 bool AvalancheProcessor::addPeer(NodeId nodeid, int64_t score) {
     return peerSet.getWriteView()
         ->insert({nodeid, score, std::chrono::steady_clock::now()})
         .second;
 }
 
 bool AvalancheProcessor::startEventLoop(CScheduler &scheduler) {
     LOCK(cs_running);
     if (running) {
         // Do not start the event loop twice.
         return false;
     }
 
     running = true;
 
     // Start the event loop.
     scheduler.scheduleEvery(
         [this]() -> bool {
             runEventLoop();
             if (!stopRequest) {
                 return true;
             }
 
             LOCK(cs_running);
             running = false;
 
             cond_running.notify_all();
 
             // A stop request was made.
             return false;
         },
         AVALANCHE_TIME_STEP_MILLISECONDS);
 
     return true;
 }
 
 bool AvalancheProcessor::stopEventLoop() {
     WAIT_LOCK(cs_running, lock);
     if (!running) {
         return false;
     }
 
     // Request avalanche to stop.
     stopRequest = true;
 
     // Wait for avalanche to stop.
     cond_running.wait(lock, [this]() EXCLUSIVE_LOCKS_REQUIRED(cs_running) {
         return !running;
     });
 
     stopRequest = false;
     return true;
 }
 
 std::vector<CInv> AvalancheProcessor::getInvsForNextPoll() const {
     std::vector<CInv> invs;
 
-    LOCK(cs_main);
-
     auto r = vote_records.getReadView();
-    for (const std::pair<const CBlockIndex *, VoteRecord> &p :
+    for (const std::pair<const CBlockIndex *const, VoteRecord> &p :
          reverse_iterate(r)) {
         const CBlockIndex *pindex = p.first;
-        if (!IsWorthPolling(pindex)) {
-            // Obviously do not poll if the block is not worth polling.
-            continue;
+
+        {
+            LOCK(cs_main);
+            if (!IsWorthPolling(pindex)) {
+                // Obviously do not poll if the block is not worth polling.
+                continue;
+            }
         }
 
         // We don't have a decision, we need more votes.
-        invs.emplace_back(MSG_BLOCK, p.first->GetBlockHash());
+        invs.emplace_back(MSG_BLOCK, pindex->GetBlockHash());
         if (invs.size() >= AVALANCHE_MAX_ELEMENT_POLL) {
             // Make sure we do not produce more invs than specified by the
             // protocol.
             return invs;
         }
     }
 
     return invs;
 }
 
 NodeId AvalancheProcessor::getSuitableNodeToQuery() {
     auto r = peerSet.getReadView();
     auto it = r->get<next_request_time>().begin();
     if (it == r->get<next_request_time>().end()) {
         return NO_NODE;
     }
 
     if (it->nextRequestTime <= std::chrono::steady_clock::now()) {
         return it->nodeid;
     }
 
     return NO_NODE;
 }
 
 void AvalancheProcessor::clearTimedoutRequests() {
     auto now = std::chrono::steady_clock::now();
 
     // Clear expired requests.
     auto w = queries.getWriteView();
     auto it = w->get<query_timeout>().begin();
     while (it != w->get<query_timeout>().end() && it->timeout < now) {
         w->get<query_timeout>().erase(it++);
     }
 }
 
 void AvalancheProcessor::runEventLoop() {
     // First things first, check if we have requests that timed out and clear
     // them.
     clearTimedoutRequests();
 
     std::vector<CInv> invs = getInvsForNextPoll();
     if (invs.empty()) {
         // If there are no invs to poll, we are done.
         return;
     }
 
     while (true) {
         NodeId nodeid = getSuitableNodeToQuery();
         if (nodeid == NO_NODE) {
             return;
         }
 
         /**
          * If we lost contact to that node, then we remove it from nodeids, but
          * never add the request to queries, which ensures bad nodes get cleaned
          * up over time.
          */
         bool hasSent = connman->ForNode(nodeid, [this, &invs](CNode *pnode) {
             uint64_t current_round = round++;
 
             {
                 // Compute the time at which this requests times out.
                 auto timeout =
                     std::chrono::steady_clock::now() + queryTimeoutDuration;
                 // Register the query.
                 queries.getWriteView()->insert(
                     {pnode->GetId(), current_round, timeout, invs});
                 // Set the timeout.
                 auto w = peerSet.getWriteView();
                 auto it = w->find(pnode->GetId());
                 if (it != w->end()) {
                     w->modify(it, [&timeout](Peer &p) {
                         p.nextRequestTime = timeout;
                     });
                 }
             }
 
             // Send the query to the node.
             connman->PushMessage(
                 pnode,
                 CNetMsgMaker(pnode->GetSendVersion())
                     .Make(NetMsgType::AVAPOLL,
                           AvalanchePoll(current_round, std::move(invs))));
             return true;
         });
 
         // Success!
         if (hasSent) {
             return;
         }
 
         // This node is obsolete, delete it.
         peerSet.getWriteView()->erase(nodeid);
     }
 }