diff options
author | Abseil Team <absl-team@google.com> | 2020-09-18 15:55:15 -0700 |
---|---|---|
committer | Derek Mauro <dmauro@google.com> | 2020-09-24 13:47:15 -0400 |
commit | b56cbdd23834a65682c0b46f367f8679e83bc894 (patch) | |
tree | dacab9a64dd1a9e9668737e511d1a5420ff96001 /absl/container/internal/hashtablez_sampler.h | |
parent | b832dce8489ef7b6231384909fd9b68d5a5ff2b7 (diff) |
Abseil LTS 2020092320200923
What's New:
* `absl::StatusOr<T>` has been released. See our [blog
post](https://abseil.io/blog/2020-091021-status) for more
information.
* Abseil Flags reflection interfaces have been released.
* Abseil Flags memory usage has been significantly optimized.
* Abseil now supports a "hardened" build mode. This build mode enables
runtime checks that guard against programming errors that may lead
to security vulnerabilities.
Notable Fixes:
* Sanitizer dynamic annotations like `AnnotateRWLockCreate` that are
also defined by the compiler sanitizer implementation are no longer
also defined by Abseil.
* Sanitizer macros are now prefixed with `ABSL_` to avoid naming collisions.
* Sanitizer usage is now automatically detected and no longer requires
macros like `ADDRESS_SANITIZER` to be defined on the command line.
Breaking Changes:
* Abseil no longer contains a `dynamic_annotations` library. Users
using a supported build system (Bazel or CMake) are unaffected by
this, but users manually specifying link libraries may get an error
about a missing linker input.
Baseline: 7680a5f8efe32de4753baadbd63e74e59d95bac1
Cherry picks: None
Diffstat (limited to 'absl/container/internal/hashtablez_sampler.h')
-rw-r--r-- | absl/container/internal/hashtablez_sampler.h | 46 |
1 files changed, 35 insertions, 11 deletions
diff --git a/absl/container/internal/hashtablez_sampler.h b/absl/container/internal/hashtablez_sampler.h index 34d5e572..394348da 100644 --- a/absl/container/internal/hashtablez_sampler.h +++ b/absl/container/internal/hashtablez_sampler.h @@ -73,6 +73,7 @@ struct HashtablezInfo { std::atomic<size_t> capacity; std::atomic<size_t> size; std::atomic<size_t> num_erases; + std::atomic<size_t> num_rehashes; std::atomic<size_t> max_probe_length; std::atomic<size_t> total_probe_length; std::atomic<size_t> hashes_bitwise_or; @@ -98,13 +99,18 @@ struct HashtablezInfo { }; inline void RecordRehashSlow(HashtablezInfo* info, size_t total_probe_length) { -#if SWISSTABLE_HAVE_SSE2 +#if ABSL_INTERNAL_RAW_HASH_SET_HAVE_SSE2 total_probe_length /= 16; #else total_probe_length /= 8; #endif info->total_probe_length.store(total_probe_length, std::memory_order_relaxed); info->num_erases.store(0, std::memory_order_relaxed); + // There is only one concurrent writer, so `load` then `store` is sufficient + // instead of using `fetch_add`. + info->num_rehashes.store( + 1 + info->num_rehashes.load(std::memory_order_relaxed), + std::memory_order_relaxed); } inline void RecordStorageChangedSlow(HashtablezInfo* info, size_t size, @@ -113,7 +119,8 @@ inline void RecordStorageChangedSlow(HashtablezInfo* info, size_t size, info->capacity.store(capacity, std::memory_order_relaxed); if (size == 0) { // This is a clear, reset the total/num_erases too. - RecordRehashSlow(info, 0); + info->total_probe_length.store(0, std::memory_order_relaxed); + info->num_erases.store(0, std::memory_order_relaxed); } } @@ -122,12 +129,21 @@ void RecordInsertSlow(HashtablezInfo* info, size_t hash, inline void RecordEraseSlow(HashtablezInfo* info) { info->size.fetch_sub(1, std::memory_order_relaxed); - info->num_erases.fetch_add(1, std::memory_order_relaxed); + // There is only one concurrent writer, so `load` then `store` is sufficient + // instead of using `fetch_add`. + info->num_erases.store( + 1 + info->num_erases.load(std::memory_order_relaxed), + std::memory_order_relaxed); } HashtablezInfo* SampleSlow(int64_t* next_sample); void UnsampleSlow(HashtablezInfo* info); +#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) +#error ABSL_INTERNAL_HASHTABLEZ_SAMPLE cannot be directly set +#endif // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) + +#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) class HashtablezInfoHandle { public: explicit HashtablezInfoHandle() : info_(nullptr) {} @@ -179,19 +195,27 @@ class HashtablezInfoHandle { friend class HashtablezInfoHandlePeer; HashtablezInfo* info_; }; +#else +// Ensure that when Hashtablez is turned off at compile time, HashtablezInfo can +// be removed by the linker, in order to reduce the binary size. +class HashtablezInfoHandle { + public: + explicit HashtablezInfoHandle() = default; + explicit HashtablezInfoHandle(std::nullptr_t) {} -#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) -#error ABSL_INTERNAL_HASHTABLEZ_SAMPLE cannot be directly set -#endif // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) + inline void RecordStorageChanged(size_t /*size*/, size_t /*capacity*/) {} + inline void RecordRehash(size_t /*total_probe_length*/) {} + inline void RecordInsert(size_t /*hash*/, size_t /*distance_from_desired*/) {} + inline void RecordErase() {} -#if (ABSL_PER_THREAD_TLS == 1) && !defined(ABSL_BUILD_DLL) && \ - !defined(ABSL_CONSUME_DLL) -#define ABSL_INTERNAL_HASHTABLEZ_SAMPLE -#endif + friend inline void swap(HashtablezInfoHandle& /*lhs*/, + HashtablezInfoHandle& /*rhs*/) {} +}; +#endif // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) #if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) extern ABSL_PER_THREAD_TLS_KEYWORD int64_t global_next_sample; -#endif // ABSL_PER_THREAD_TLS +#endif // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) // Returns an RAII sampling handle that manages registration and unregistation // with the global sampler. |