fa818e103c txmempool: Remove unused clear() member function (MarcoFalke)
Pull request description:
Seems odd to have code in Bitcoin Core that is unused.
Moreover the function was broken (see https://github.com/bitcoin/bitcoin/pull/24145) and is brittle, as there is nothing that prevents similar bugs from re-appearing.
Fix both issues by replacing it with C++11 member initializers.
ACKs for top commit:
glozow:
ACK fa818e103c
Tree-SHA512: e79e44cac7d5a84d9ecc8e3f3b0b9a50e1e3ebec358b20ba5dac175ef07d1fbe338a20f83ee80f746f7c726c79e77f8be49e14bca57a41063da8a5302123c3a9
47c4b1f52a mempool: log/halt when CalculateMemPoolAncestors fails unexpectedly (stickies-v)
5481f65849 mempool: add AssumeCalculateMemPoolAncestors helper function (stickies-v)
f911bdfff9 mempool: use util::Result for CalculateMemPoolAncestors (stickies-v)
66e028f739 mempool: use util::Result for CalculateAncestorsAndCheckLimits (stickies-v)
Pull request description:
Upon reviewing the documentation for `CTxMemPool::CalculateMemPoolAncestors`, I noticed `setAncestors` was meant to be an `out` parameter but actually is an `in,out` parameter, as can be observed by adding `assert(setAncestors.empty());` as the first line in the function and running `make check`. This PR fixes this unexpected behaviour and introduces refactoring improvements to make intents and effects of the code more clear.
## Unexpected behaviour
This behaviour occurs only in the package acceptance path, currently only triggered by `testmempoolaccept` and `submitpackage` RPCs.
In `MemPoolAccept::AcceptMultipleTransactions()`, we first call `PreChecks()` and then `SubmitPackage()` with the same `Workspace ws` reference. `PreChecks` leaves `ws.m_ancestors` in a potentially non-empty state, before it is passed on to `MemPoolAccept::SubmitPackage`. `SubmitPackage` is the only place where `setAncestors` isn't guaranteed to be empty before calling `CalculateMemPoolAncestors`. The most straightforward fix is to just forcefully clear `setAncestors` at the beginning of CalculateMemPoolAncestors, which is done in the first bugfix commit.
## Improvements
### Return value instead of out-parameters
This PR updates the function signatures for `CTxMemPool::CalculateMemPoolAncestors` and `CTxMemPool::CalculateAncestorsAndCheckLimits` to use a `util::Result` return type and eliminate both the `setAncestors` `in,out`-parameter as well as the error string. It simplifies the code and makes the intent and effects more explicit.
### Observability
There are 7 instances where we currently call `CalculateMemPoolAncestors` without actually checking if the function succeeded because we assume that it can't fail, such as in [miner.cpp](69b10212ea/src/node/miner.cpp (L399)). This PR adds a new wrapper `AssumeCalculateMemPoolAncestors` function that logs such unexpected failures, or in case of debug builds even halts the program. It's not crucial to the objective, more of an observability improvement that seems sensible to add on here.
ACKs for top commit:
achow101:
ACK 47c4b1f52a
w0xlt:
ACK https://github.com/bitcoin/bitcoin/pull/26289/commits/47c4b1f52ab8d95d7deef83050bad49d1e3e5990
glozow:
ACK 47c4b1f52a
furszy:
light code review ACK 47c4b1f5
aureleoules:
ACK 47c4b1f52a
Tree-SHA512: d908dad00d1a5645eb865c4877cc0bae74b9cd3332a3641eb4a285431aef119f9fc78172d38b55c592168a73dae83242e6af3348815f7b37cbe2d448a3a58648
When CalculateMemPoolAncestors fails unexpectedly (e.g. it exceeds
ancestor/descendant limits even though we expect no limits to be applied),
add an error log entry for increased visibility. For debug builds,
the application will even halt completely since this is not supposed
to happen.
There are quite a few places that assume CalculateMemPoolAncestors
will return a value without raising an error. This helper function
adds logging (and Assume for debug builds) that ensures robustness
but increases visibility in case of unexpected failures
c8dc0e3eaa refactor: Inline `CTxMemPoolEntry` class's functions (Hennadii Stepanov)
75bbe594e5 refactor: Move `CTxMemPoolEntry` class to its own module (Hennadii Stepanov)
Pull request description:
This PR:
- gets rid of the `policy/fees` -> `txmempool` -> `policy/fees` circular dependency
- is an alternative to #13949, which nukes only one circular dependency
ACKs for top commit:
ryanofsky:
Code review ACK c8dc0e3eaa. Just include and whitespace changes since last review, and there's a moveonly commit now so it's very easy to review
theStack:
Code-review ACK c8dc0e3eaa
glozow:
utACK c8dc0e3eaa, agree these changes are an improvement.
Tree-SHA512: 36ece824e6ed3ab1a1e198b30a906c8ac12de24545f840eb046958a17315ac9260c7de26e11e2fbab7208adc3d74918db7a7e389444130f8810548ca2e81af41
Currently the exact reason a transaction is removed from the mempool isn't
logged. It is sometimes detectable from context, but adding the `reason` to
the validation interface logs (where it is already passed) seems like an easy
way to disambiguate.
For example, in the case of mempool expiry, the logs look like this:
```
[validationinterface.cpp:220] [TransactionRemovedFromMempool] [validation] Enqueuing TransactionRemovedFromMempool: txid=<txid> wtxid=<wtxid>
[txmempool.cpp:1050] [RemoveUnbroadcastTx] [mempool] Removed <txid> from set of unbroadcast txns before confirmation that txn was sent out
[validationinterface.cpp:220] [operator()] [validation] TransactionRemovedFromMempool: txid=<txid> wtxid=<wtxid>
[validation.cpp:267] [LimitMempoolSize] [mempool] Expired 1 transactions from the memory pool
```
There is no context-free way to know $txid was evicted on the basis of expiry.
This change will make that case (and probably others) clear.
33b12e5df6 docs: improve docs where MemPoolLimits is used (stickies-v)
6945853c0b test: use NoLimits() in MempoolIndexingTest (stickies-v)
3a86f24a4c refactor: mempool: use CTxMempool::Limits (stickies-v)
b85af25f87 refactor: mempool: add MemPoolLimits::NoLimits() (stickies-v)
Pull request description:
Mempool currently considers 4 limits regarding ancestor and descendant count and size, which get passed around between functions quite a bit. This PR uses `CTxMemPool::Limits` introduced in https://github.com/bitcoin/bitcoin/pull/25290 to simplify those signatures and callsites.
The purpose of this PR is to improve readability and maintenance, without behaviour change.
As noted in the first commit "refactor: mempool: change MemPoolLimits members to uint", we currently have an underflow issue where a user could pass a negative `-limitancestorsize`, which is eventually cast to an unsigned integer. This behaviour already exists. Because it's orthogonal and to minimize scope, I think this should be fixed in a separate PR.
ACKs for top commit:
hebasto:
ACK 33b12e5df6, I have reviewed the code and it looks OK, I agree it can be merged.
glozow:
reACK 33b12e5df6
Tree-SHA512: 591c6dcee1894f1c3ca28b34a680eeadcf0d40cda92451b4a422c03087b27d682b5e30ba4367abd75a99b5ccb115b7884b0026958d3c7dddab030549db5a4056
Simplifies function signatures by removing repetition of all the
ancestor/descendant limits, and increases readability by being
more verbose by naming the limits, while still reducing the LoC.
