ydb/library/cpp/yt/misc, branch mainMirror of YDB github reposhttps://code.mastervirt.ru/ydb/atom?h=main2026-06-06T21:16:49ZCache process/thread id getters and use them in TError origin capture2026-06-06T21:16:49Zbabenkobabenko@yandex-team.com2026-06-06T20:52:00Zurn:sha1:f10c7206fb31af8057446bceef9707aabaa9456e
## Motivation
Profiling the YT master Automaton thread showed TOriginAttributes::Capture (run on every non-OK TError) spending ~60% of its time in a getpid() syscall — uncached on glibc >= 2.25. NYT::GetCurrentThreadId() (gettid) feeds hot thread-affinity / log-manager checks on the same thread.
## Changes
- New library/cpp/yt/system/process_id.* with cached GetProcessId(); GetSystemThreadId() now caches the kernel tid in TLS. Both caches reset in the child after fork.
- Moved thread_name.{h,cpp} from misc to system.
- Removed GetCurrentProcessId/GetCurrentThreadId shims from yt/yt/core/misc/proc.{h,cpp}; migrated all callers to NYT::GetProcessId / NYT::GetSystemThreadId.
- TOriginAttributes::Capture uses the cached getters; recorded Tid is now the real kernel tid (matches perf/ps).
- Added microbenchmarks (library/cpp/yt/system/benchmarks, yt/yt/core/benchmarks/error.cpp).
## Microbenchmarks (release)
| | before | after |
|---|---|---|
| getpid | 101 ns | 0.33 ns |
| gettid | 102 ns | 1.64 ns |
| Capture | 161 ns | 50 ns |
| failed TError | 221 ns | 74 ns |
commit_hash:ee37ae57d61a5a2dd33daee935270f4bb93b7ff9
Add Abseil-compatible support hashers2026-04-27T12:16:34Zbabenkobabenko@yandex-team.com2026-04-27T11:10:55Zurn:sha1:ac1b929087542a400ab0f55f7263c95544baa0b8
commit_hash:2d2808f61599fcfea314ad660585e984d50ffbb3
YT-27872: Refactor BIND to fix ODR violations2026-04-03T12:52:56Zdann239dann239@yandex-team.com2026-04-03T12:15:57Zurn:sha1:57a36bc0bb183d5118c335e84ac02a4f61e257ef
commit_hash:25c6545fed2bffe20f7a008a218b9245896926ec
YT-18571: Drop YT_ATTRIBUTE_NO_UNIQUE_ADDRESS in favor of Y_NO_UNIQUE_ADDRESS2026-03-23T11:26:18Zbabenkobabenko@yandex-team.com2026-03-23T10:39:31Zurn:sha1:db3520530fe5ae9f72f156178374fb6d29b5022f
commit_hash:c574736c9cbb7c6da6502dc751214d8d7f343568
YT-18571: Drop YT_ATTRIBUTE_NO_SANITIZE_ADDRESS in favor of Y_NO_SANITIZE("address")2026-03-23T10:59:36Zbabenkobabenko@yandex-team.com2026-03-23T10:35:56Zurn:sha1:a02cf9a7f69ae1aefc38e1dde65565fab69e733c
commit_hash:30841b1871a64fd6b3cc1eebcc9e4d5f1281c4fa
[yt/misc] remove 64-bit requirement error directive2026-03-11T12:52:40Zvaskovasko@yandex-team.com2026-03-11T11:41:39Zurn:sha1:348ba08d3977cb999eba5ae2df579c24454525f7
commit_hash:5bb34cf1e8e039b59fff79917c694509fff4666c
[yt] make SplitMix & HashCombine bit-independent2026-03-05T10:11:05Zvaskovasko@yandex-team.com2026-03-05T08:17:14Zurn:sha1:d0739058c7dbc0e2e2b8aa6c5bc399522d5e6fca
add realization of hash-functions for 32-bit platforms
commit_hash:3247a0524d3b66d759bf5ebd598be84c8dfb5837
YT-27436 Introduce PP_IS_EMPTY2026-02-18T15:28:10Zdann239dann239@yandex-team.com2026-02-18T14:50:28Zurn:sha1:80feb38637cfcd598a0d734105f1ffb10dc124a2
commit_hash:96d6c16b241e44c6cd7910b16864fd0d037c6e8b
YT-27167: Better TBitwiseUnversionedValueHash2026-02-11T01:27:50Zpavookpavook@yandex-team.com2026-02-11T01:03:48Zurn:sha1:72e2e4fb5634001484795bce3f6ca27e21b24905
+20-30% throughput on UpdateColumnarStatistics benchmark (with large statistics enabled)
- Do not factor in value.Id when calculating column digest
- Pack metadata directly instead of multiple HashCombine calls
- Use SplitMix64 finalizer for proper bit distribution
- Use cheaper xor with metadata instead of HashCombine
- Use XXH3 for strings
- Remove unnecessary copy
- Measured quality increased: on 20 (c=1..20) sequences `{nc | n \in [1..10^6]}` MAE dropped from ~36% to ~20%
HLL digests might temporarily suffer a 2x increase upon merging with the previously computed ones.
commit_hash:0bf661245cf1848ba9ef8b6c840c18dfd05bd2a4
YT-27244: range helpers move to library2026-02-05T09:20:53Zpanesherpanesher@yandex-team.com2026-02-05T08:45:44Zurn:sha1:626d15281a019d018dbb212dedefbc06e78a9edb
commit_hash:f257ebdacfbf0549a0f55cc37df2c059629bac3a