[avalanche] Properly clean up the finalized transactions from the ancestor of the finalized block
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Authored by Fabien on Jul 23 2025, 13:11.

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PiRK

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Restricted Project

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rABCb3484f314c71: [avalanche] Properly clean up the finalized transactions from the ancestor of…

Summary

Make sure that we remove the finalized transaction that are confirmed in a block which is an ancestor of the finalized block.
Otherwise it is possible that several blocks are mined in a row and the tip finalized, causing the transactions from the previous block to remain in the radix tree.

Depends on D18414.

Test Plan

ninja check check-functional

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rABC Bitcoin ABC

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Event Timeline

Fabien created this revision.Jul 23 2025, 13:11

Herald added a reviewer: Restricted Project. · View Herald TranscriptJul 23 2025, 13:11

Harbormaster completed remote builds in B33962: Diff 54980.Jul 23 2025, 13:30

Fabien published this revision for review.Jul 23 2025, 14:00

Fabien added a child revision: D18411: [avalanche] Add preconsensus validation callbacks.Jul 24 2025, 09:38

PiRK added a subscriber: PiRK.Jul 24 2025, 09:53

PiRK added inline comments.

src/txmempool.cpp
341 ↗	(On Diff #54980)

PiRK requested changes to this revision.Jul 24 2025, 11:53

PiRK added inline comments.

src/net_processing.cpp
6963–6968 ↗	(On Diff #54980)	it would be good to assert here that pindex is indeed an ancestor of the active chain tip, or test first that the below call for `m_chainman.ActiveChainstate().AvalancheFinalizeBlock(pindex, *m_avalanche)` (which checks for the block being in the active chain) returns True

This revision now requires changes to proceed.Jul 24 2025, 11:53

Suggested comment improvement.

Other than that, the code logic makes sense to me.

src/net_processing.cpp
6959 ↗	(On Diff #54980)	I find this comment slightly confusing, as the "protect" part doesn't happen here but is later. Suggested rewording to clarify: "If the finalized block is not the tip, we need to keep track of the transactions from the non final block, in case they were finalized by pre-consensus. We build a set of their txids."

Mengerian added inline comments.Jul 24 2025, 17:24

src/net_processing.cpp
6959 ↗	(On Diff #54980)	Or: "If the finalized block is not the tip, we need to keep track of the transactions from the non final block, so that we can check if they were finalized by pre-consensus. We build a set of their txids."