ec6cf49b91blockstorage: Remove cs_LastBlockFile recursive mutex (sedited) Pull request description: The `cs_LastBlockFile` mutex is redundant: all critical sections are already covered by cs_main. This is demonstrated in this patch by replacing all instances of locking `cs_LastBlockFile` with pairs of `AssertLockHeld(::cs_main)` and `EXCLUSIVE_LOCKS_REQUIRED(::cs_main)` annotations. No additional `::cs_main` LOCK(...)s are introduced (besides for test-only code). It is also not clear for which sections `cs_LastBlockFile` is responsible for. It is annotated for `m_blockfile_cursors`, but sporadically and inconsistently also covers `m_blockfile_info` (e.g. in `LoadBlockIndexDB`). Since it has no semantic meaning, and seems confusing to developers, remove it. An alternative to this patch would be expanding the scope of what `cs_LastBlockFile` covers and turning it into a non-recursive mutex. I prepared such a patch some time ago, but found it unsatisfactory. It was not clear to me if the lock was now covering too much or too little, and its purpose remained unclear. If this patch is accepted, I would expect the project to eventually implement a separate, narrowly-scoped block storage lock to allow for a more parallelizable block processing routine. ACKs for top commit: stickies-v: re-ACKec6cf49b91janb84: re- ACKec6cf49b91pablomartin4btc: ACKec6cf49b91Tree-SHA512: e5942bc87300b0db9a0b91d5fe26dab455049e6cef7c96bb12b28141fa04711d46c6af105c0e1a83a9f261edde2c8b8b43ecf577a27d54b4610d784676a85627
src/node/
The src/node/ directory contains code that needs to access node state
(state in CChain, CBlockIndex, CCoinsView, CTxMemPool, and similar
classes).
Code in src/node/ is meant to be segregated from code in
src/wallet/ and src/qt/, to ensure wallet and GUI
code changes don't interfere with node operation, to allow wallet and GUI code
to run in separate processes, and to perhaps eventually allow wallet and GUI
code to be maintained in separate source repositories.
As a rule of thumb, code in one of the src/node/,
src/wallet/, or src/qt/ directories should avoid
calling code in the other directories directly, and only invoke it indirectly
through the more limited src/interfaces/ classes.
This directory is at the moment
sparsely populated. Eventually more substantial files like
src/validation.cpp and
src/txmempool.cpp might be moved there.