Since #28280, the cost of a non-wiping sync of the UTXO cache is only proportional to the number of dirty entries, rather than proportional to the size of the entire cache. Because of that, there is no reason to perform a wiping flush in case the contents of the cache is still useful.
Split the FlushStateMode::ALWAYS mode into a FORCE_SYNC (non-wiping) and a FORCE_FLUSH (wiping), and then use the former in scantxoutset, gettxoutsetinfo, snapshot creation.
Co-authored-by: l0rinc <pap.lorinc@gmail.com>
Co-authored-by: cedwies <141683552+cedwies@users.noreply.github.com>
This prepares the addition of `FORCE_SYNC`.
`empty_cache` in `FlushStateToDisk` was moved up to be reusable and `FlushStateMode::FORCE_FLUSH` was used as a placeholder before we properly split the two new states.
`log_utxocache_flush.py` was regenerated and the alignment adjusted for the wider `FlushStateMode` values.
Co-authored-by: Pieter Wuille <pieter@wuille.net>
Co-authored-by: optout <13562139+optout21@users.noreply.github.com>
BCC needs the PID of a bitcoind process to attach to the tracepoints
(instead of the binary path used before) when the tracepoints have a
semaphore.
For reference, we already use the PID in our tracepoint interface
tests. See 220a5a2841.
799968e8b3 tracing: misc follow-ups to 22902 (0xb10c)
36a6584703 tracing: correctly scope utxocache:flush tracepoint (Arnab Sen)
Pull request description:
This PR is a follow-up to the [#22902](https://github.com/bitcoin/bitcoin/pull/22902).
Previously, the tracepoint `utxocache:flush` was called, even when it was not flushing. So, the tracepoint is now scoped to write only when coins cache to disk.
ACKs for top commit:
0xB10C:
ACK 799968e8b3
Tree-SHA512: ebb096cbf991c551c81e4339821f10d9768c14cf3d8cb14d0ad851acff5980962228a1c746914c6aba3bdb27e8be53b33349c41efe8bab5542f639916e437b5f
- mention 'Lost X events' workaround
- clarify flush tracepoint docs
- fix typo in tracepoint context
- clarify flush for prune
The documentation and examples for the `fFlushForPrune` argument
of the utxocache flush tracepoint weren't clear without looking
at the code.
See these comments: https://github.com/bitcoin/bitcoin/pull/22902#issuecomment-987094612
- doc: note that there can be temporary UTXO caches
Bitcoin Core uses temporary clones of it's _main_ UTXO cache in some
places. The utxocache:add and :spent tracepoints are triggered when
temporary caches are changed too. This is documented.
Previously, the `utxocache:flush` tracepoint was in the wrong scope and
reached every time `CChainState::FlushStateToDisk` was called, even when
there was no flushing of the cache. The tracepoint is now properly scoped
and will be reached during a full flush.
Inside the scope, the `fDoFullFlush` value will always be `true`, so it
doesn't need to be logged separately. Hence, it's dropped from the
tracepoint arguments.
