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author | MarcoFalke <falke.marco@gmail.com> | 2021-08-30 10:07:28 +0200 |
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committer | MarcoFalke <falke.marco@gmail.com> | 2021-08-30 10:07:31 +0200 |
commit | 7be143a960e2bb9ac81144f55c45731c1bb209c5 (patch) | |
tree | 99c45c32efe997a33db472e88433a81986d98500 /src/validation.h | |
parent | 83daf47898f8a79cb20d20316c64becd564cf54c (diff) | |
parent | 0bd882b7405414b5355e69a9fdcd7a533e504b6b (diff) | |
download | bitcoin-7be143a960e2bb9ac81144f55c45731c1bb209c5.tar.xz |
Merge bitcoin/bitcoin#22824: refactor: remove RecursiveMutex cs_nBlockSequenceId
0bd882b7405414b5355e69a9fdcd7a533e504b6b refactor: remove RecursiveMutex cs_nBlockSequenceId (Sebastian Falbesoner)
Pull request description:
The RecursiveMutex `cs_nBlockSequenceId` is only used at one place in `CChainState::ReceivedBlockTransactions()` to atomically read-and-increment the nBlockSequenceId member:
https://github.com/bitcoin/bitcoin/blob/83daf47898f8a79cb20d20316c64becd564cf54c/src/validation.cpp#L2973-L2976
~~For this simple use-case, we can make the member `std::atomic` instead to achieve the same result (see https://en.cppreference.com/w/cpp/atomic/atomic/operator_arith).~~
~~This is related to #19303. As suggested in the issue, I first planned to change the `RecursiveMutex` to `Mutex` (still possible if the change doesn't get Concept ACKs), but using a Mutex for this simple operation seems to be overkill. Note that at the time when this mutex was introduced (PR #3370, commit 75f51f2a63e0ebe34ab290c2b7141dd240b98c3b) `std::atomic` were not used in the codebase yet -- according to `git log -S std::atomic` they have first appeared in 2016 (commit 7e908c7b826cedbf29560ce7a668af809ee71524), probably also because the compilers didn't support them properly earlier.~~
At this point, the cs_main lock is set, hence we can use a plain int for the member and mark it as guarded by cs_main.
ACKs for top commit:
Zero-1729:
ACK 0bd882b
promag:
Code review ACK 0bd882b7405414b5355e69a9fdcd7a533e504b6b.
hebasto:
ACK 0bd882b7405414b5355e69a9fdcd7a533e504b6b
Tree-SHA512: 435271ac8f877074099ddb31436665b500e555f7cab899e5c8414af299b154d1249996be500e8fdeff64e4639bcaf7386e12510b738ec6f20e415e7e35afaea9
Diffstat (limited to 'src/validation.h')
-rw-r--r-- | src/validation.h | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/src/validation.h b/src/validation.h index b80fa9d328..ef48156309 100644 --- a/src/validation.h +++ b/src/validation.h @@ -558,9 +558,8 @@ protected: * Every received block is assigned a unique and increasing identifier, so we * know which one to give priority in case of a fork. */ - RecursiveMutex cs_nBlockSequenceId; /** Blocks loaded from disk are assigned id 0, so start the counter at 1. */ - int32_t nBlockSequenceId = 1; + int32_t nBlockSequenceId GUARDED_BY(::cs_main) = 1; /** Decreasing counter (used by subsequent preciousblock calls). */ int32_t nBlockReverseSequenceId = -1; /** chainwork for the last block that preciousblock has been applied to. */ @@ -749,7 +748,7 @@ public: void PruneBlockIndexCandidates(); - void UnloadBlockIndex(); + void UnloadBlockIndex() EXCLUSIVE_LOCKS_REQUIRED(::cs_main); /** Check whether we are doing an initial block download (synchronizing from disk or network) */ bool IsInitialBlockDownload() const; |