This refactor does not change any behavior.
However, it is nice to know that no global mocktime leaks from the fuzz
init step to the first fuzz input, or from one fuzz input execution to
the next.
With the clock context, the global is re-set at the end of the context.
fa43897c1d doc: Fix LLM nits in net_processing.cpp (MarcoFalke)
bbbba0fd4b scripted-diff: Use references when nullptr is not possible (MarcoFalke)
fac5415466 refactor: Separate peer/maybe_peer in ProcessMessages and SendMessages (MarcoFalke)
fac529188e refactor: Pass Peer& to ProcessMessage (MarcoFalke)
fa376095a0 refactor: Pass CNode& to ProcessMessages and SendMessages (MarcoFalke)
fada838014 refactor: Make ProcessMessage private again (MarcoFalke)
fa80cd3cee test: [refactor] Avoid calling private ProcessMessage() function (MarcoFalke)
Pull request description:
There is a single unit test, which calls the internal `ProcessMessage` function. This is problematic, because it makes future changes harder, since they will need to carry over this public internal interface each time.
Also, there is a mixed use of pointers and references in p2p code, where just based on context, a pointer may sometimes assumed to be null, or non-null. This is confusing when reading the code, or making or reading future changes.
Fix both issues in a series of commits, to:
* refactor the single unit test to call higher-level functions
* Make `ProcessMessage` private again
* Use references instead of implicit non-null pointers, mostly in a scripted-diff
ACKs for top commit:
optout21:
reACK fa43897c1d
ajtowns:
ACK fa43897c1d
Crypt-iQ:
crACK fa43897c1d
achow101:
ACK fa43897c1d
Tree-SHA512: d03d8ea35490a995f121be3d2f3e4a22d1aadfeab30bc42c4f8383dab0e6e27046260e792d9e5a94faa6777490ba036e39c71c50611a38f70b90e3a01f002c9e
The generic key can also be used in other places
where behavior between different network identities should
be uncorrelated to avoid fingerprinting.
This also changes RANDOMIZER_ID - since it is not
being persisted to disk, there are no compatibility issues.
These remaining miscellaneous changes were identified by commenting out
the `operator const uint256&` conversion and the `Compare(const uint256&)`
method from `transaction_identifier.h`.
This should avoid the remaining non-determistic code coverage paths.
Without this patch, the tool would report a diff (only when running
without libFuzzer):
cargo run --manifest-path ./contrib/devtools/deterministic-fuzz-coverage/Cargo.toml -- $PWD/bld-cmake/ $PWD/../qa-assets/fuzz_corpora/ p2p_headers_presync 32
It should be sufficient to set it once. Especially, if the dynamic value
is only used by ResetAndInitialize.
This also avoids non-determistic code paths, when ResetAndInitialize may
re-initialize m_next_inv_to_inbounds.
Without this patch, the tool would report a diff:
cargo run --manifest-path ./contrib/devtools/deterministic-fuzz-coverage/Cargo.toml -- $PWD/bld-cmake/ $PWD/../qa-assets/fuzz_corpora/ p2p_headers_presync 32
...
- 1126| 3| m_next_inv_to_inbounds = now + m_rng.rand_exp_duration(average_interval);
- 1127| 3| }
+ 1126| 10| m_next_inv_to_inbounds = now + m_rng.rand_exp_duration(average_interval);
+ 1127| 10| }
1128| 491| return m_next_inv_to_inbounds;
...
This allows the clock to be mockable in tests. Also, replace cs_main
with GetMutex() while touching this function.
Also, use the ElapseSteady test helper in the p2p_headers_presync fuzz
target to make it more deterministic.
The m_last_presync_update variable is a global that is not reset in
ResetAndInitialize. However, it is only used for logging, so completely
disable it for now.
Without this patch, the tool would report a diff:
cargo run --manifest-path ./contrib/devtools/deterministic-fuzz-coverage/Cargo.toml -- $PWD/bld-cmake/ $PWD/../qa-assets/fuzz_corpora/ p2p_headers_presync 32
...
4468| 81| auto now = std::chrono::steady_clock::now();
4469| 81| if (now < m_last_presync_update + std::chrono::milliseconds{250}) return;
- ^80
+ ^79
...
The global m_headers_presync_stats is not reset in ResetAndInitialize.
This may lead to non-determinism.
Fix it by incrementing the global node id counter instead.
Without this patch, the tool would report a diff:
cargo run --manifest-path ./contrib/devtools/deterministic-fuzz-coverage/Cargo.toml -- $PWD/bld-cmake/ $PWD/../qa-assets/fuzz_corpora/ p2p_headers_presync 32
...
2587| 3.73k| if (best_it == m_headers_presync_stats.end()) {
------------------
- | Branch (2587:17): [True: 80, False: 3.65k]
+ | Branch (2587:17): [True: 73, False: 3.66k]
------------------
...
The hardcoded nBits range would occasionally produce values for
the difficulty target that were too low, causing the total work
of the test chain to exceed MinimumChainWork. This fix uses
ConsumeArithUInt256InRange to properly generate targets that
will produce header chains with less work than MinimumChainWork.
