refactor: replace RecursiveMutex cs_SubVer with Mutex (and rename)
#24079
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cs SubVer with Mutex (and rename)cs_SubVer with Mutex (and rename)
hebasto
reviewed
Jan 16, 2022
36 tasks
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This mutex was added in 22b4966 back in 2017. Maybe it is out of this PR scope, but in the current codebase I see no reasons for it because a write operation is executed once only during processing the received VERSION message. |
-BEGIN VERIFY SCRIPT- sed -i 's/cs_SubVer/m_subver_mutex/g' ./src/net.h ./src/net.cpp ./src/net_processing.cpp -END VERIFY SCRIPT-
In each of the critical sections, only the the guarded variable is accessed, without any chance that within one section another one is called. Hence, we can use an ordinary Mutex instead of RecursiveMutex.
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I agree that it's unlikely, but isn't there still a non-zero probability that access could happen concurrently? Processing of a VERSION message could in theory happen during a getpeerinfo RPC call -- a peer is already in the nodes list before the version exchange is completed. |
sidhujag
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to syscoin/syscoin
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Jan 18, 2022
…h Mutex (and rename) 30927cb refactor: replace RecursiveMutex `m_subver_mutex` with Mutex (Sebastian Falbesoner) 0639aba scripted-diff: rename `cs_SubVer` -> `m_subver_mutex` (Sebastian Falbesoner) Pull request description: This PR is related to bitcoin#19303 and gets rid of the RecursiveMutex `cs_SubVer`. Both of the critical sections only directly access the guarded variable, i.e. it is not possible that within one section another one is called, and we can use a regular Mutex. ACKs for top commit: hebasto: ACK 30927cb, I have reviewed the code and it looks OK, I agree it can be merged. Tree-SHA512: 2faead792ea0b2f79f9f7fe99acde5cf2bfcd2f15c51fbb6cb1099d4f81276001a492f7d46a5139055f4366c2d58a36a8ba19f21d56df20e0ed93af3141dbe11
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This PR is related to #19303 and gets rid of the RecursiveMutex
cs_SubVer. Both of the critical sections only directly access the guarded variable, i.e. it is not possible that within one section another one is called, and we can use a regular Mutex.