This new function takes the populated sets of
direct and all conflicts computed in the current
mempool, assuming the replacements are a single
chunk, and computes a diagram check.
The diagram check only works against cluster
sizes of 2 or less, and fails if it encounters
a different topology.
Co-authored-by: Suhas Daftuar <sdaftuar@chaincode.com>
This is done in preparation for the next two commits, where the
CMainSignals are de-globalized.
This avoids adding new constructor arguments to the ChainstateManager
and CTxMemPool classes over the next two commits.
This could also allow future tests that are only interested in the
internal behaviour of the classes to forgo instantiating the signals.
29029df5c7 [doc] v3 signaling in mempool-replacements.md (glozow)
e643ea795e [fuzz] v3 transactions and sigop-adjusted vsize (glozow)
1fd16b5c62 [functional test] v3 transaction submission (glozow)
27c8786ba9 test framework: Add and use option for tx-version in MiniWallet methods (MarcoFalke)
9a1fea55b2 [policy/validation] allow v3 transactions with certain restrictions (glozow)
eb8d5a2e7d [policy] add v3 policy rules (glozow)
9a29d470fb [rpc] return full string for package_msg and package-error (glozow)
158623b8e0 [refactor] change Workspace::m_conflicts and adjacent funcs/structs to use Txid (glozow)
Pull request description:
See #27463 for overall package relay tracking.
Delving Bitcoin discussion thread: https://delvingbitcoin.org/t/v3-transaction-policy-for-anti-pinning/340
Delving Bitcoin discussion for LN usage: https://delvingbitcoin.org/t/lightning-transactions-with-v3-and-ephemeral-anchors/418
Rationale:
- There are various pinning problems with RBF and our general ancestor/descendant limits. These policies help mitigate many pinning attacks and make package RBF feasible (see #28984 which implements package RBF on top of this). I would focus the most here on Rule 3 pinning. [1][2]
- Switching to a cluster-based mempool (see #27677 and #28676) requires the removal of CPFP carve out, which applications depend on. V3 + package RBF + ephemeral anchors + 1-parent-1-child package relay provides an intermediate solution.
V3 policy is for "Priority Transactions." [3][4] It allows users to opt in to more restrictive topological limits for shared transactions, in exchange for the more robust fee-bumping abilities that offers. Even though we don't have cluster limits, we are able to treat these transactions as having as having a maximum cluster size of 2.
Immediate benefits:
- You can presign a transaction with 0 fees (not just 1sat/vB!) and add a fee-bump later.
- Rule 3 pinning is reduced by a significant amount, since the attacker can only attach a maximum of 1000vB to your shared transaction.
This also enables some other cool things (again see #27463 for overall roadmap):
- Ephemeral Anchors
- Package RBF for these 1-parent-1-child packages. That means e.g. a commitment tx + child can replace another commitment tx using the child's fees.
- We can transition to a "single anchor" universe without worrying about package limit pinning. So current users of CPFP carve out would have something else to use.
- We can switch to a cluster-based mempool [5] (#27677#28676), which removes CPFP carve out [6].
[1]: Original mailing list post and discussion about RBF pinning problems https://gist.github.com/glozow/25d9662c52453bd08b4b4b1d3783b9ff, https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-January/019817.html
[2]: A FAQ is "we need this for cluster mempool, but is this still necessary afterwards?" There are some pinning issues that are fixed here and not fully fixed in cluster mempool, so we will still want this or something similar afterward.
[3]: Mailing list post for v3 https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-September/020937.html
[4]: Original PR #25038 also contains a lot of the discussion
[5]: https://delvingbitcoin.org/t/an-overview-of-the-cluster-mempool-proposal/393/7
[6]: https://delvingbitcoin.org/t/an-overview-of-the-cluster-mempool-proposal/393#the-cpfp-carveout-rule-can-no-longer-be-supported-12
ACKs for top commit:
sdaftuar:
ACK 29029df5c7
achow101:
ACK 29029df5c7
instagibbs:
ACK 29029df5c7 modulo that
Tree-SHA512: 9664b078890cfdca2a146439f8835c9d9ab483f43b30af8c7cd6962f09aa557fb1ce7689d5e130a2ec142235dbc8f21213881baa75241c5881660f9008d68450
It's preferable to use type-safe transaction identifiers to avoid
confusing txid and wtxid. The next commit will add a reference to this
set; we use this opportunity to change it to Txid ahead of time instead
of adding new uses of uint256.
Update CheckPackageLimits to use util::Result to pass the error message
instead of out parameter.
Also update test to reflect the error message from `CTxMempool`
`CheckPackageLimits` output.
`CBlockPolicyEstimator` will implement `CValidationInterface` and
subscribe to its notification to process transactions added and removed
from the mempool.
Re-delegate calculation of `validForFeeEstimation` from validation to fee estimator.
Also clean up the validForFeeEstimation arg thats no longer needed in `CTxMempool`.
Co-authored-by: Matt Corallo <git@bluematt.me>
43de4d3630 doc: fix typos (Sjors Provoost)
Pull request description:
This PR fixes typos found by lint-spelling.py using codespell 2.2.6.
Our CI linter job uses codespell 2.2.5 and found fewer typos that I did locally. In any case it's happy now.
ACKs for top commit:
pablomartin4btc:
re ACK 43de4d3630
Tree-SHA512: c032fe86cb49c924a468385653b31f309a9db68c478d70335bba3e65a1ff3826abe80284fe00a090ab5a509e1edbf17e476f6922fb15d055e50f1103dad2ccb0
fa6b053b5c mempool: persist with XOR (MarcoFalke)
Pull request description:
Currently the `mempool.dat` file stores data received from remote peers as-is. This may be problematic when a program other than Bitcoin Core tries to interpret them by accident. For example, an anti-virus program or other program may scan the file and move it into quarantine, or delete it, or corrupt it.
While the local wallet is expected to re-submit any pending transactions, unrelated transactions may be missing from the mempool after a restart. This may cause fee estimates to be off, or may cause block relay to be slower.
Fix this, similar to https://github.com/bitcoin/bitcoin/pull/6650, by rolling a random XOR pattern over the dat file when writing or reading it.
Obviously this can only protect against programs that accidentally and unintentionally are trying to mess with the dat file. Any program that intentionally wants to mess with the dat file can still trivially do so.
ACKs for top commit:
achow101:
re-ACK fa6b053b5c
glozow:
reACK fa6b053b5c
ismaelsadeeq:
ACK fa6b053b5c
Tree-SHA512: ded2ce3d81bc944b828263534e3178a1e45a914fe8e024f4a14c6561a73e301820944ecc75dd704b3d4221a7a3a5c0597ccab79546250c1197609ee981fe324e
4313c77400 make DisconnectedBlockTransactions responsible for its own memory management (glozow)
cf5f1faa03 MOVEONLY: DisconnectedBlockTransactions to its own file (glozow)
2765d6f343 rewrite DisconnectedBlockTransactions as a list + map (glozow)
79ce9f0aa4 add std::list to memusage (glozow)
59a35a7398 [bench] DisconnectedBlockTransactions (glozow)
925bb723ca [refactor] batch-add transactions to DisconnectedBlockTransactions (glozow)
Pull request description:
Motivation
- I think it's preferable to use stdlib data structures instead of depending on boost if we can achieve the same thing.
- Also see #28335 for further context/motivation. This PR simplifies that one.
Things done in this PR:
- Add a bench for `DisconnectedBlockTransactions` where we reorg and the new chain has {100%, 90%, 10%} of the same transactions. AFAIU in practice, it's usually close to 100%.
- Rewrite `DisconnectedBlockTransactions` as a `std::list` + `unordered_map` instead of a boost multi index container.
- On my machine, the bench suggests the performance is very similar.
- Move `DisconnectedBlockTransactions` from txmempool.h to its own kernel/disconnected_transactions.h. This struct isn't used by txmempool and doesn't have much to do with txmempool. My guess is that it's been living there for convenience since the boost includes are there.
ACKs for top commit:
ismaelsadeeq:
Tested ACK 4313c77400
stickies-v:
ACK 4313c77400
TheCharlatan:
ACK 4313c77400
Tree-SHA512: 273c80866bf3acd39b2a039dc082b7719d2d82e0940e1eb6c402f1c0992e997256722b85c7e310c9811238a770cfbdeb122ea4babbc23835d17128f214a1ef9e
32c1dd1ad6 [test] mempool coins disappearing mid-package evaluation (glozow)
a67f460c3f [refactor] split setup in mempool_limit test (glozow)
d08696120e [test framework] add ability to spend only confirmed utxos (glozow)
3ea71feb11 [validation] don't LimitMempoolSize in any subpackage submissions (glozow)
d227b7234c [validation] return correct result when already-in-mempool tx gets evicted (glozow)
9698b81828 [refactor] back-fill results in AcceptPackage (glozow)
8ad7ad3392 [validation] make PackageMempoolAcceptResult members mutable (glozow)
03b87c11ca [validation] add AcceptSubPackage to delegate Accept* calls and clean up m_view (glozow)
3f01a3dab1 [CCoinsViewMemPool] track non-base coins and allow Reset (glozow)
7d7f7a1189 [policy] check for duplicate txids in package (glozow)
Pull request description:
While we are evaluating a package, we split it into "subpackages" for evaluation (currently subpackages all have size 1 except the last one). If a subpackage has size 1, we may add a tx to mempool and call `LimitMempoolSize()`, which evicts transactions if the mempool gets full. We handle the case where the just-submitted transaction is evicted immediately, but we don't handle the case in which a transaction from a previous subpackage (either just submitted or already in mempool) is evicted. Mainly, since the coins created by the evicted transaction are cached in `m_view`, we don't realize the UTXO has disappeared until `CheckInputsFromMempoolAndCache` asserts that they exist. Also, the returned `PackageMempoolAcceptResult` reports that the transaction is in mempool even though it isn't anymore.
Fix this by not calling `LimitMempoolSize()` until the very end, and editing the results map with "mempool full" if things fall out.
Pointed out by instagibbs in faeed687e5 on top of the v3 PR.
ACKs for top commit:
instagibbs:
reACK 32c1dd1ad6
Tree-SHA512: 61e7f69db4712e5e5bfa27d037ab66bdd97f1bf60a8d9ffb96adb1f0609af012c810d681102ee5c7baec7b5fe8cb7c304a60c63ccc445d00d86a2b7f0e7ddb90
Temporary coins should not be available in separate subpackage submissions.
Any mempool coins that are cached in m_view should be removed whenever
mempool contents change, as they may be spent or no longer exist.
And encapsulate underlying data structures to avoid misuse.
It's better to use stdlib instead of boost when we can achieve the same thing.
Behavior change: the number returned by DynamicMemoryUsage for the same
transactions is higher (due to change in usage or more accurate
accounting), which effectively decreases the maximum amount of
transactions kept for resubmission in a reorg.
Co-authored-by: Cory Fields <cory-nospam-@coryfields.com>
... and move them to where they are really needed.
This was found by IWYU:
txmempool.h should remove these lines:
- #include <random.h> // lines 29-29
- class CBlockIndex; // lines 43-43
- class Chainstate; // lines 45-45
Also, move the stdlib section to the right place. Can be reviewed with:
--color-moved=dimmed-zebra
fb02ba3c5f mempool_entry: improve struct packing (Anthony Towns)
1a118062fb net_processing: Clean up INVENTORY_BROADCAST_MAX constants (Anthony Towns)
6fa49937e4 test: Check tx from disconnected block is immediately requestable (glozow)
e4ffabbffa net_processing: don't add txids to m_tx_inventory_known_filter (Anthony Towns)
6ec1809d33 net_processing: drop m_recently_announced_invs bloom filter (Anthony Towns)
a70beafdb2 validation: when adding txs due to a block reorg, allow immediate relay (Anthony Towns)
1e9684f39f mempool_entry: add mempool entry sequence number (Anthony Towns)
Pull request description:
This PR replaces the `m_recently_announced_invs` bloom filter with a simple sequence number tracking the mempool state when we last considered sending an INV message to a node. This saves 33kB per peer (or more if we raise the rate at which we relay transactions over the network, in which case we would need to increase the size of the bloom filter proportionally).
The philosophy here (compare with #18861 and #19109) is that we consider the rate limiting on INV messages to only be about saving bandwidth and not protecting privacy, and therefore after you receive an INV message, it's immediately fair game to request any transaction that was in the mempool at the time the INV message was sent. We likewise consider the BIP 133 feefilter and BIP 37 bloom filters to be bandwidth optimisations here, and treat transactions as requestable if they would have been announced without those filters. Given that philosophy, tracking the timestamp of the last INV message and comparing that against the mempool entry time allows removal of each of `m_recently_announced_invs`, `m_last_mempool_req` and `UNCONDITIONAL_RELAY_DELAY` and associated logic.
ACKs for top commit:
naumenkogs:
ACK fb02ba3c5f
amitiuttarwar:
review ACK fb02ba3c5f
glozow:
reACK fb02ba3c5f
Tree-SHA512: cbba5ee04c86df26b6057f3654c00a2b45ec94d354f4f157a769cecdaa0b509edaac02b3128afba39b023e82473fc5e28c915a787f84457ffe66638c6ac9c2d4
Rather than using a bloom filter to track announced invs, simply allow
a peer to request any tx that entered the mempool prior to the last INV
message we sent them. This also obsoletes the UNCONDITIONAL_RELAY_DELAY.
67b7fecacd [mempool] clear mapDeltas entry if prioritisetransaction sets delta to 0 (glozow)
c1061acb9d [functional test] prioritisation is not removed during replacement and expiry (glozow)
0e5874f0b0 [functional test] getprioritisedtransactions RPC (glozow)
99f8046829 [rpc] add getprioritisedtransactions (glozow)
9e9ca36c80 [mempool] add GetPrioritisedTransactions (glozow)
Pull request description:
Add an RPC to get prioritised transactions (also tells you whether the tx is in mempool or not), helping users clean up `mapDeltas` manually. When `CTxMemPool::PrioritiseTransaction` sets a delta to 0, remove the entry from `mapDeltas`.
Motivation / Background
- `mapDeltas` entries are never removed from mapDeltas except when the tx is mined in a block or conflicted.
- Mostly it is a feature to allow `prioritisetransaction` for a tx that isn't in the mempool {yet, anymore}. A user can may resbumit a tx and it retains its priority, or mark a tx as "definitely accept" before it is seen.
- Since #8448, `mapDeltas` is persisted to mempool.dat and loaded on restart. This is also good, otherwise we lose prioritisation on restart.
- Note the removal due to block/conflict is only done when `removeForBlock` is called, i.e. when the block is received. If you load a mempool.dat containing `mapDeltas` with transactions that were mined already (e.g. the file was saved prior to the last few blocks), you don't delete them.
- Related: #4818 and #6464.
- There is no way to query the node for not-in-mempool `mapDeltas`. If you add a priority and forget what the value was, the only way to get that information is to inspect mempool.dat.
- Calling `prioritisetransaction` with an inverse value does not remove it from `mapDeltas`, it just sets the value to 0. It disappears on a restart (`LoadMempool` checks if delta is 0), but that might not happen for a while.
Added together, if a user calls `prioritisetransaction` very regularly and not all those transactions get mined/conflicted, `mapDeltas` might keep lots of entries of delta=0 around. A user should clean up the not-in-mempool prioritisations, but that's currently difficult without keeping track of what those txids/amounts are.
ACKs for top commit:
achow101:
ACK 67b7fecacd
theStack:
Code-review ACK 67b7fecacd
instagibbs:
code review ACK 67b7fecacd
ajtowns:
ACK 67b7fecacd code review only, some nits
Tree-SHA512: 9df48b622ef27f33db1a2748f682bb3f16abe8172fcb7ac3c1a3e1654121ffb9b31aeaad5570c4162261f7e2ff5b5912ddc61a1b8beac0e9f346a86f5952260a
We limit GatherClusters’s result to a maximum of 500 transactions as
clusters can be made arbitrarily large by third parties.
Co-authored-by: Murch <murch@murch.one>
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 47c4b1f52a
glozow:
ACK 47c4b1f52a
furszy:
light code review ACK 47c4b1f5
aureleoules:
ACK 47c4b1f52a
Tree-SHA512: d908dad00d1a5645eb865c4877cc0bae74b9cd3332a3641eb4a285431aef119f9fc78172d38b55c592168a73dae83242e6af3348815f7b37cbe2d448a3a58648
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.
