It's not allowed to use WaitForSingleObject with _beginthread, because the thread closes its own handle before exiting.
So the wait function will either wait on an invalid handle, or on a different handle used by something else.
Or, if it starts waiting before the thread exits, the behavior is undefined according to MS: "If this handle is closed while the wait is still pending, the function's behavior is undefined."
In my test sync I observed threads getting stuck infinitely on WaitForSingleObject, and then rx_set_main_seedhash spamming new threads when RandomX seed changes again. Eventually the system ran out of resources, and monerod aborted with "Couldn't start RandomX seed thread" message.
This PR fixes it by using `_beginthreadex` instead and explicitly closing the handle when it's safe.
- Straight-forward call interface: `void rx_slow_hash(const char *seedhash, const void *data, size_t length, char *result_hash)`
- Consensus chain seed hash is now updated by calling `rx_set_main_seedhash` whenever a block is added/removed or a reorg happens
- `rx_slow_hash` will compute correct hash no matter if `rx_set_main_seedhash` was called or not (the only difference is performance)
- New environment variable `MONERO_RANDOMX_FULL_MEM` to force use the full dataset for PoW verification (faster block verification)
- When dataset is used for PoW verification, dataset updates don't stall other threads (verification is done in light mode then)
- When mining is running, PoW checks now also use dataset for faster verification
All tests were conducted on the same PC (Ryzen 5 5600X running at fixed 4.65 GHz).
Before:
test_cn_fast_hash<32> (100000 calls) - OK: 1 us/call
test_cn_fast_hash<16384> (1000 calls) - OK: 164 us/call
After:
test_cn_fast_hash<32> (100000 calls) - OK: 0 us/call
test_cn_fast_hash<16384> (1000 calls) - OK: 31 us/call
More than 5 times speedup for cn_fast_hash.
Also noticed consistent 1-2% improvement in test_construct_tx results.
Implements view tags as proposed by @UkoeHB in MRL issue
https://github.com/monero-project/research-lab/issues/73
At tx construction, the sender adds a 1-byte view tag to each
output. The view tag is derived from the sender-receiver
shared secret. When scanning for outputs, the receiver can
check the view tag for a match, in order to reduce scanning
time. When the view tag does not match, the wallet avoids the
more expensive EC operations when deriving the output public
key using the shared secret.
d20ff4f64 functional_tests: add a large (many randomx epochs) p2p reorg test (moneromooo-monero)
6a0b3b1f8 functional_tests: add randomx tests (moneromooo-monero)
9d42649d5 core: fix mining from a block that's not the current top (moneromooo-monero)
Some tools report the alignment check as UB, which seems a bit
dubious, but since the performance difference between the two
versions is minimal, I'll go with the safe version
- New flag in NOTIFY_NEW_TRANSACTION to indicate stem mode
- Stem loops detected in tx_pool.cpp
- Embargo timeout for a blackhole attack during stem phase
* Faster cache initialization with SSSE3/AVX2
* Automatic detection of CPU capabilities in RandomX
* Fixed a possible out-of-bounds access in superscalar program generator
* Use MONERO_RANDOMX_UMASK to manually disable RandomX flags in monerod
2cd4fd8 Changed the use of boost:value_initialized for C++ list initializer (JesusRami)
4ad191f Removed unused boost/value_init header (whyamiroot)
928f4be Make null hash constants constexpr (whyamiroot)
