diff options
| -rw-r--r-- | CMake/AbseilDll.cmake | 2 | ||||
| -rw-r--r-- | absl/container/BUILD.bazel | 2 | ||||
| -rw-r--r-- | absl/container/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | absl/container/internal/hashtablez_sampler.cc | 104 | ||||
| -rw-r--r-- | absl/container/internal/hashtablez_sampler.h | 81 | ||||
| -rw-r--r-- | absl/container/internal/hashtablez_sampler_test.cc | 3 | ||||
| -rw-r--r-- | absl/container/internal/raw_hash_set_test.cc | 4 | ||||
| -rw-r--r-- | absl/profiling/BUILD.bazel | 34 | ||||
| -rw-r--r-- | absl/profiling/CMakeLists.txt | 25 | ||||
| -rw-r--r-- | absl/profiling/internal/sample_recorder.h | 231 | ||||
| -rw-r--r-- | absl/profiling/internal/sample_recorder_test.cc | 171 |
11 files changed, 482 insertions, 176 deletions
diff --git a/CMake/AbseilDll.cmake b/CMake/AbseilDll.cmake index ea45c8a2..056343e5 100644 --- a/CMake/AbseilDll.cmake +++ b/CMake/AbseilDll.cmake @@ -133,6 +133,7 @@ set(ABSL_INTERNAL_DLL_FILES "numeric/int128.h" "numeric/internal/bits.h" "numeric/internal/representation.h" + "profiling/internal/sample_recorder.h" "random/bernoulli_distribution.h" "random/beta_distribution.h" "random/bit_gen_ref.h" @@ -457,6 +458,7 @@ set(ABSL_INTERNAL_DLL_TARGETS "raw_hash_set" "layout" "tracked" + "sample_recorder" ) function(absl_internal_dll_contains) diff --git a/absl/container/BUILD.bazel b/absl/container/BUILD.bazel index cf55f4bb..c9d387d6 100644 --- a/absl/container/BUILD.bazel +++ b/absl/container/BUILD.bazel @@ -513,6 +513,7 @@ cc_library( "//absl/base:exponential_biased", "//absl/debugging:stacktrace", "//absl/memory", + "//absl/profiling:sample_recorder", "//absl/synchronization", "//absl/utility", ], @@ -526,6 +527,7 @@ cc_test( ":hashtablez_sampler", ":have_sse", "//absl/base:core_headers", + "//absl/profiling:sample_recorder", "//absl/synchronization", "//absl/synchronization:thread_pool", "//absl/time", diff --git a/absl/container/CMakeLists.txt b/absl/container/CMakeLists.txt index 691a05c0..9b8a7509 100644 --- a/absl/container/CMakeLists.txt +++ b/absl/container/CMakeLists.txt @@ -548,6 +548,7 @@ absl_cc_library( absl::base absl::exponential_biased absl::have_sse + absl::sample_recorder absl::synchronization ) diff --git a/absl/container/internal/hashtablez_sampler.cc b/absl/container/internal/hashtablez_sampler.cc index 5a29bed7..ca03d9b6 100644 --- a/absl/container/internal/hashtablez_sampler.cc +++ b/absl/container/internal/hashtablez_sampler.cc @@ -25,6 +25,7 @@ #include "absl/container/internal/have_sse.h" #include "absl/debugging/stacktrace.h" #include "absl/memory/memory.h" +#include "absl/profiling/internal/sample_recorder.h" #include "absl/synchronization/mutex.h" namespace absl { @@ -37,7 +38,6 @@ ABSL_CONST_INIT std::atomic<bool> g_hashtablez_enabled{ false }; ABSL_CONST_INIT std::atomic<int32_t> g_hashtablez_sample_parameter{1 << 10}; -ABSL_CONST_INIT std::atomic<int32_t> g_hashtablez_max_samples{1 << 20}; #if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) ABSL_PER_THREAD_TLS_KEYWORD absl::base_internal::ExponentialBiased @@ -50,16 +50,11 @@ ABSL_PER_THREAD_TLS_KEYWORD absl::base_internal::ExponentialBiased ABSL_PER_THREAD_TLS_KEYWORD int64_t global_next_sample = 0; #endif // defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) -HashtablezSampler& HashtablezSampler::Global() { +HashtablezSampler& GlobalHashtablezSampler() { static auto* sampler = new HashtablezSampler(); return *sampler; } -HashtablezSampler::DisposeCallback HashtablezSampler::SetDisposeCallback( - DisposeCallback f) { - return dispose_.exchange(f, std::memory_order_relaxed); -} - HashtablezInfo::HashtablezInfo() { PrepareForSampling(); } HashtablezInfo::~HashtablezInfo() = default; @@ -80,93 +75,6 @@ void HashtablezInfo::PrepareForSampling() { // instead. depth = absl::GetStackTrace(stack, HashtablezInfo::kMaxStackDepth, /* skip_count= */ 0); - dead = nullptr; -} - -HashtablezSampler::HashtablezSampler() - : dropped_samples_(0), size_estimate_(0), all_(nullptr), dispose_(nullptr) { - absl::MutexLock l(&graveyard_.init_mu); - graveyard_.dead = &graveyard_; -} - -HashtablezSampler::~HashtablezSampler() { - HashtablezInfo* s = all_.load(std::memory_order_acquire); - while (s != nullptr) { - HashtablezInfo* next = s->next; - delete s; - s = next; - } -} - -void HashtablezSampler::PushNew(HashtablezInfo* sample) { - sample->next = all_.load(std::memory_order_relaxed); - while (!all_.compare_exchange_weak(sample->next, sample, - std::memory_order_release, - std::memory_order_relaxed)) { - } -} - -void HashtablezSampler::PushDead(HashtablezInfo* sample) { - if (auto* dispose = dispose_.load(std::memory_order_relaxed)) { - dispose(*sample); - } - - absl::MutexLock graveyard_lock(&graveyard_.init_mu); - absl::MutexLock sample_lock(&sample->init_mu); - sample->dead = graveyard_.dead; - graveyard_.dead = sample; -} - -HashtablezInfo* HashtablezSampler::PopDead() { - absl::MutexLock graveyard_lock(&graveyard_.init_mu); - - // The list is circular, so eventually it collapses down to - // graveyard_.dead == &graveyard_ - // when it is empty. - HashtablezInfo* sample = graveyard_.dead; - if (sample == &graveyard_) return nullptr; - - absl::MutexLock sample_lock(&sample->init_mu); - graveyard_.dead = sample->dead; - sample->PrepareForSampling(); - return sample; -} - -HashtablezInfo* HashtablezSampler::Register() { - int64_t size = size_estimate_.fetch_add(1, std::memory_order_relaxed); - if (size > g_hashtablez_max_samples.load(std::memory_order_relaxed)) { - size_estimate_.fetch_sub(1, std::memory_order_relaxed); - dropped_samples_.fetch_add(1, std::memory_order_relaxed); - return nullptr; - } - - HashtablezInfo* sample = PopDead(); - if (sample == nullptr) { - // Resurrection failed. Hire a new warlock. - sample = new HashtablezInfo(); - PushNew(sample); - } - - return sample; -} - -void HashtablezSampler::Unregister(HashtablezInfo* sample) { - PushDead(sample); - size_estimate_.fetch_sub(1, std::memory_order_relaxed); -} - -int64_t HashtablezSampler::Iterate( - const std::function<void(const HashtablezInfo& stack)>& f) { - HashtablezInfo* s = all_.load(std::memory_order_acquire); - while (s != nullptr) { - absl::MutexLock l(&s->init_mu); - if (s->dead == nullptr) { - f(*s); - } - s = s->next; - } - - return dropped_samples_.load(std::memory_order_relaxed); } static bool ShouldForceSampling() { @@ -192,7 +100,7 @@ static bool ShouldForceSampling() { HashtablezInfo* SampleSlow(int64_t* next_sample) { if (ABSL_PREDICT_FALSE(ShouldForceSampling())) { *next_sample = 1; - return HashtablezSampler::Global().Register(); + return GlobalHashtablezSampler().Register(); } #if !defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE) @@ -217,12 +125,12 @@ HashtablezInfo* SampleSlow(int64_t* next_sample) { return SampleSlow(next_sample); } - return HashtablezSampler::Global().Register(); + return GlobalHashtablezSampler().Register(); #endif } void UnsampleSlow(HashtablezInfo* info) { - HashtablezSampler::Global().Unregister(info); + GlobalHashtablezSampler().Unregister(info); } void RecordInsertSlow(HashtablezInfo* info, size_t hash, @@ -262,7 +170,7 @@ void SetHashtablezSampleParameter(int32_t rate) { void SetHashtablezMaxSamples(int32_t max) { if (max > 0) { - g_hashtablez_max_samples.store(max, std::memory_order_release); + GlobalHashtablezSampler().SetMaxSamples(max); } else { ABSL_RAW_LOG(ERROR, "Invalid hashtablez max samples: %lld", static_cast<long long>(max)); // NOLINT(runtime/int) diff --git a/absl/container/internal/hashtablez_sampler.h b/absl/container/internal/hashtablez_sampler.h index 85685f72..d86207f5 100644 --- a/absl/container/internal/hashtablez_sampler.h +++ b/absl/container/internal/hashtablez_sampler.h @@ -47,6 +47,7 @@ #include "absl/base/internal/per_thread_tls.h" #include "absl/base/optimization.h" #include "absl/container/internal/have_sse.h" +#include "absl/profiling/internal/sample_recorder.h" #include "absl/synchronization/mutex.h" #include "absl/utility/utility.h" @@ -57,7 +58,7 @@ namespace container_internal { // Stores information about a sampled hashtable. All mutations to this *must* // be made through `Record*` functions below. All reads from this *must* only // occur in the callback to `HashtablezSampler::Iterate`. -struct HashtablezInfo { +struct HashtablezInfo : public profiling_internal::Sample<HashtablezInfo> { // Constructs the object but does not fill in any fields. HashtablezInfo(); ~HashtablezInfo(); @@ -80,14 +81,6 @@ struct HashtablezInfo { std::atomic<size_t> hashes_bitwise_and; std::atomic<size_t> hashes_bitwise_xor; - // `HashtablezSampler` maintains intrusive linked lists for all samples. See - // comments on `HashtablezSampler::all_` for details on these. `init_mu` - // guards the ability to restore the sample to a pristine state. This - // prevents races with sampling and resurrecting an object. - absl::Mutex init_mu; - HashtablezInfo* next; - HashtablezInfo* dead ABSL_GUARDED_BY(init_mu); - // All of the fields below are set by `PrepareForSampling`, they must not be // mutated in `Record*` functions. They are logically `const` in that sense. // These are guarded by init_mu, but that is not externalized to clients, who @@ -231,73 +224,11 @@ inline HashtablezInfoHandle Sample() { #endif // !ABSL_PER_THREAD_TLS } -// Holds samples and their associated stack traces with a soft limit of -// `SetHashtablezMaxSamples()`. -// -// Thread safe. -class HashtablezSampler { - public: - // Returns a global Sampler. - static HashtablezSampler& Global(); - - HashtablezSampler(); - ~HashtablezSampler(); - - // Registers for sampling. Returns an opaque registration info. - HashtablezInfo* Register(); +using HashtablezSampler = + ::absl::profiling_internal::SampleRecorder<HashtablezInfo>; - // Unregisters the sample. - void Unregister(HashtablezInfo* sample); - - // The dispose callback will be called on all samples the moment they are - // being unregistered. Only affects samples that are unregistered after the - // callback has been set. - // Returns the previous callback. - using DisposeCallback = void (*)(const HashtablezInfo&); - DisposeCallback SetDisposeCallback(DisposeCallback f); - - // Iterates over all the registered `StackInfo`s. Returning the number of - // samples that have been dropped. - int64_t Iterate(const std::function<void(const HashtablezInfo& stack)>& f); - - private: - void PushNew(HashtablezInfo* sample); - void PushDead(HashtablezInfo* sample); - HashtablezInfo* PopDead(); - - std::atomic<size_t> dropped_samples_; - std::atomic<size_t> size_estimate_; - - // Intrusive lock free linked lists for tracking samples. - // - // `all_` records all samples (they are never removed from this list) and is - // terminated with a `nullptr`. - // - // `graveyard_.dead` is a circular linked list. When it is empty, - // `graveyard_.dead == &graveyard`. The list is circular so that - // every item on it (even the last) has a non-null dead pointer. This allows - // `Iterate` to determine if a given sample is live or dead using only - // information on the sample itself. - // - // For example, nodes [A, B, C, D, E] with [A, C, E] alive and [B, D] dead - // looks like this (G is the Graveyard): - // - // +---+ +---+ +---+ +---+ +---+ - // all -->| A |--->| B |--->| C |--->| D |--->| E | - // | | | | | | | | | | - // +---+ | | +->| |-+ | | +->| |-+ | | - // | G | +---+ | +---+ | +---+ | +---+ | +---+ - // | | | | | | - // | | --------+ +--------+ | - // +---+ | - // ^ | - // +--------------------------------------+ - // - std::atomic<HashtablezInfo*> all_; - HashtablezInfo graveyard_; - - std::atomic<DisposeCallback> dispose_; -}; +// Returns a global Sampler. +HashtablezSampler& GlobalHashtablezSampler(); // Enables or disables sampling for Swiss tables. void SetHashtablezEnabled(bool enabled); diff --git a/absl/container/internal/hashtablez_sampler_test.cc b/absl/container/internal/hashtablez_sampler_test.cc index 5f4c83b7..53fcfe6f 100644 --- a/absl/container/internal/hashtablez_sampler_test.cc +++ b/absl/container/internal/hashtablez_sampler_test.cc @@ -22,6 +22,7 @@ #include "gtest/gtest.h" #include "absl/base/attributes.h" #include "absl/container/internal/have_sse.h" +#include "absl/profiling/internal/sample_recorder.h" #include "absl/synchronization/blocking_counter.h" #include "absl/synchronization/internal/thread_pool.h" #include "absl/synchronization/mutex.h" @@ -232,7 +233,7 @@ TEST(HashtablezSamplerTest, Sample) { } TEST(HashtablezSamplerTest, Handle) { - auto& sampler = HashtablezSampler::Global(); + auto& sampler = GlobalHashtablezSampler(); HashtablezInfoHandle h(sampler.Register()); auto* info = HashtablezInfoHandlePeer::GetInfo(&h); info->hashes_bitwise_and.store(0x12345678, std::memory_order_relaxed); diff --git a/absl/container/internal/raw_hash_set_test.cc b/absl/container/internal/raw_hash_set_test.cc index 4fb31fad..4012a3aa 100644 --- a/absl/container/internal/raw_hash_set_test.cc +++ b/absl/container/internal/raw_hash_set_test.cc @@ -2038,7 +2038,7 @@ TEST(RawHashSamplerTest, Sample) { SetHashtablezEnabled(true); SetHashtablezSampleParameter(100); - auto& sampler = HashtablezSampler::Global(); + auto& sampler = GlobalHashtablezSampler(); size_t start_size = 0; std::unordered_set<const HashtablezInfo*> preexisting_info; start_size += sampler.Iterate([&](const HashtablezInfo& info) { @@ -2076,7 +2076,7 @@ TEST(RawHashSamplerTest, DoNotSampleCustomAllocators) { SetHashtablezEnabled(true); SetHashtablezSampleParameter(100); - auto& sampler = HashtablezSampler::Global(); + auto& sampler = GlobalHashtablezSampler(); size_t start_size = 0; start_size += sampler.Iterate([&](const HashtablezInfo&) { ++start_size; }); diff --git a/absl/profiling/BUILD.bazel b/absl/profiling/BUILD.bazel index 10b256d6..5f3a1030 100644 --- a/absl/profiling/BUILD.bazel +++ b/absl/profiling/BUILD.bazel @@ -12,6 +12,40 @@ # See the License for the specific language governing permissions and # limitations under the License. +load( + "//absl:copts/configure_copts.bzl", + "ABSL_DEFAULT_COPTS", + "ABSL_DEFAULT_LINKOPTS", +) + package(default_visibility = ["//visibility:private"]) licenses(["notice"]) + +cc_library( + name = "sample_recorder", + hdrs = ["internal/sample_recorder.h"], + copts = ABSL_DEFAULT_COPTS, + linkopts = ABSL_DEFAULT_LINKOPTS, + visibility = ["//absl:__subpackages__"], + deps = [ + "//absl/base:config", + "//absl/base:core_headers", + "//absl/synchronization", + "//absl/time", + ], +) + +cc_test( + name = "sample_recorder_test", + srcs = ["internal/sample_recorder_test.cc"], + linkopts = ABSL_DEFAULT_LINKOPTS, + deps = [ + ":sample_recorder", + "//absl/base:core_headers", + "//absl/synchronization", + "//absl/synchronization:thread_pool", + "//absl/time", + "@com_google_googletest//:gtest_main", + ], +) diff --git a/absl/profiling/CMakeLists.txt b/absl/profiling/CMakeLists.txt index 3c37491e..7b6a7780 100644 --- a/absl/profiling/CMakeLists.txt +++ b/absl/profiling/CMakeLists.txt @@ -12,3 +12,28 @@ # See the License for the specific language governing permissions and # limitations under the License. +absl_cc_library( + NAME + sample_recorder + HDRS + "internal/sample_recorder.h" + COPTS + ${ABSL_DEFAULT_COPTS} + DEPS + absl::base + absl::synchronization +) + +absl_cc_test( + NAME + sample_recorder_test + SRCS + "internal/sample_recorder_test.cc" + COPTS + ${ABSL_TEST_COPTS} + DEPS + absl::sample_recorder + absl::time + GTest::gmock_main +) + diff --git a/absl/profiling/internal/sample_recorder.h b/absl/profiling/internal/sample_recorder.h new file mode 100644 index 00000000..a257ea5d --- /dev/null +++ b/absl/profiling/internal/sample_recorder.h @@ -0,0 +1,231 @@ +// Copyright 2018 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// +// ----------------------------------------------------------------------------- +// File: sample_recorder.h +// ----------------------------------------------------------------------------- +// +// This header file defines a lock-free linked list for recording samples +// collected from a random/stochastic process. +// +// This utility is internal-only. Use at your own risk. + +#ifndef ABSL_PROFILING_INTERNAL_SAMPLE_RECORDER_H_ +#define ABSL_PROFILING_INTERNAL_SAMPLE_RECORDER_H_ + +#include <atomic> +#include <cstddef> +#include <functional> + +#include "absl/base/config.h" +#include "absl/base/thread_annotations.h" +#include "absl/synchronization/mutex.h" +#include "absl/time/time.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace profiling_internal { + +// Sample<T> that has members required for linking samples in the linked list of +// samples maintained by the SampleRecorder. Type T defines the sampled data. +template <typename T> +struct Sample { + public: + // Guards the ability to restore the sample to a pristine state. This + // prevents races with sampling and resurrecting an object. + absl::Mutex init_mu; + T* next = nullptr; + T* dead ABSL_GUARDED_BY(init_mu) = nullptr; +}; + +// Holds samples and their associated stack traces with a soft limit of +// `SetHashtablezMaxSamples()`. +// +// Thread safe. +template <typename T> +class SampleRecorder { + public: + SampleRecorder(); + ~SampleRecorder(); + + // Registers for sampling. Returns an opaque registration info. + T* Register(); + + // Unregisters the sample. + void Unregister(T* sample); + + // The dispose callback will be called on all samples the moment they are + // being unregistered. Only affects samples that are unregistered after the + // callback has been set. + // Returns the previous callback. + using DisposeCallback = void (*)(const T&); + DisposeCallback SetDisposeCallback(DisposeCallback f); + + // Iterates over all the registered `StackInfo`s. Returning the number of + // samples that have been dropped. + int64_t Iterate(const std::function<void(const T& stack)>& f); + + void SetMaxSamples(int32_t max); + + private: + void PushNew(T* sample); + void PushDead(T* sample); + T* PopDead(); + + std::atomic<size_t> dropped_samples_; + std::atomic<size_t> size_estimate_; + std::atomic<int32_t> max_samples_{1 << 20}; + + // Intrusive lock free linked lists for tracking samples. + // + // `all_` records all samples (they are never removed from this list) and is + // terminated with a `nullptr`. + // + // `graveyard_.dead` is a circular linked list. When it is empty, + // `graveyard_.dead == &graveyard`. The list is circular so that + // every item on it (even the last) has a non-null dead pointer. This allows + // `Iterate` to determine if a given sample is live or dead using only + // information on the sample itself. + // + // For example, nodes [A, B, C, D, E] with [A, C, E] alive and [B, D] dead + // looks like this (G is the Graveyard): + // + // +---+ +---+ +---+ +---+ +---+ + // all -->| A |--->| B |--->| C |--->| D |--->| E | + // | | | | | | | | | | + // +---+ | | +->| |-+ | | +->| |-+ | | + // | G | +---+ | +---+ | +---+ | +---+ | +---+ + // | | | | | | + // | | --------+ +--------+ | + // +---+ | + // ^ | + // +--------------------------------------+ + // + std::atomic<T*> all_; + T graveyard_; + + std::atomic<DisposeCallback> dispose_; +}; + +template <typename T> +typename SampleRecorder<T>::DisposeCallback +SampleRecorder<T>::SetDisposeCallback(DisposeCallback f) { + return dispose_.exchange(f, std::memory_order_relaxed); +} + +template <typename T> +SampleRecorder<T>::SampleRecorder() + : dropped_samples_(0), size_estimate_(0), all_(nullptr), dispose_(nullptr) { + absl::MutexLock l(&graveyard_.init_mu); + graveyard_.dead = &graveyard_; +} + +template <typename T> +SampleRecorder<T>::~SampleRecorder() { + T* s = all_.load(std::memory_order_acquire); + while (s != nullptr) { + T* next = s->next; + delete s; + s = next; + } +} + +template <typename T> +void SampleRecorder<T>::PushNew(T* sample) { + sample->next = all_.load(std::memory_order_relaxed); + while (!all_.compare_exchange_weak(sample->next, sample, + std::memory_order_release, + std::memory_order_relaxed)) { + } +} + +template <typename T> +void SampleRecorder<T>::PushDead(T* sample) { + if (auto* dispose = dispose_.load(std::memory_order_relaxed)) { + dispose(*sample); + } + + absl::MutexLock graveyard_lock(&graveyard_.init_mu); + absl::MutexLock sample_lock(&sample->init_mu); + sample->dead = graveyard_.dead; + graveyard_.dead = sample; +} + +template <typename T> +T* SampleRecorder<T>::PopDead() { + absl::MutexLock graveyard_lock(&graveyard_.init_mu); + + // The list is circular, so eventually it collapses down to + // graveyard_.dead == &graveyard_ + // when it is empty. + T* sample = graveyard_.dead; + if (sample == &graveyard_) return nullptr; + + absl::MutexLock sample_lock(&sample->init_mu); + graveyard_.dead = sample->dead; + sample->dead = nullptr; + sample->PrepareForSampling(); + return sample; +} + +template <typename T> +T* SampleRecorder<T>::Register() { + int64_t size = size_estimate_.fetch_add(1, std::memory_order_relaxed); + if (size > max_samples_.load(std::memory_order_relaxed)) { + size_estimate_.fetch_sub(1, std::memory_order_relaxed); + dropped_samples_.fetch_add(1, std::memory_order_relaxed); + return nullptr; + } + + T* sample = PopDead(); + if (sample == nullptr) { + // Resurrection failed. Hire a new warlock. + sample = new T(); + PushNew(sample); + } + + return sample; +} + +template <typename T> +void SampleRecorder<T>::Unregister(T* sample) { + PushDead(sample); + size_estimate_.fetch_sub(1, std::memory_order_relaxed); +} + +template <typename T> +int64_t SampleRecorder<T>::Iterate( + const std::function<void(const T& stack)>& f) { + T* s = all_.load(std::memory_order_acquire); + while (s != nullptr) { + absl::MutexLock l(&s->init_mu); + if (s->dead == nullptr) { + f(*s); + } + s = s->next; + } + + return dropped_samples_.load(std::memory_order_relaxed); +} + +template <typename T> +void SampleRecorder<T>::SetMaxSamples(int32_t max) { + max_samples_.store(max, std::memory_order_release); +} + +} // namespace profiling_internal +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_PROFILING_INTERNAL_SAMPLE_RECORDER_H_ diff --git a/absl/profiling/internal/sample_recorder_test.cc b/absl/profiling/internal/sample_recorder_test.cc new file mode 100644 index 00000000..ec6e0fa2 --- /dev/null +++ b/absl/profiling/internal/sample_recorder_test.cc @@ -0,0 +1,171 @@ +// Copyright 2018 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include "absl/profiling/internal/sample_recorder.h" + +#include <atomic> +#include <random> +#include <vector> + +#include "gmock/gmock.h" +#include "absl/base/thread_annotations.h" +#include "absl/synchronization/internal/thread_pool.h" +#include "absl/synchronization/mutex.h" +#include "absl/synchronization/notification.h" +#include "absl/time/time.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace profiling_internal { + +namespace { +using ::absl::synchronization_internal::ThreadPool; +using ::testing::IsEmpty; +using ::testing::UnorderedElementsAre; + +struct Info : public Sample<Info> { + public: + void PrepareForSampling() {} + std::atomic<size_t> size; + absl::Time create_time; +}; + +std::vector<size_t> GetSizes(SampleRecorder<Info>* s) { + std::vector<size_t> res; + s->Iterate([&](const Info& info) { + res.push_back(info.size.load(std::memory_order_acquire)); + }); + return res; +} + +Info* Register(SampleRecorder<Info>* s, size_t size) { + auto* info = s->Register(); + assert(info != nullptr); + info->size.store(size); + return info; +} + +TEST(SampleRecorderTest, Registration) { + SampleRecorder<Info> sampler; + auto* info1 = Register(&sampler, 1); + EXPECT_THAT(GetSizes(&sampler), UnorderedElementsAre(1)); + + auto* info2 = Register(&sampler, 2); + EXPECT_THAT(GetSizes(&sampler), UnorderedElementsAre(1, 2)); + info1->size.store(3); + EXPECT_THAT(GetSizes(&sampler), UnorderedElementsAre(3, 2)); + + sampler.Unregister(info1); + sampler.Unregister(info2); +} + +TEST(SampleRecorderTest, Unregistration) { + SampleRecorder<Info> sampler; + std::vector<Info*> infos; + for (size_t i = 0; i < 3; ++i) { + infos.push_back(Register(&sampler, i)); + } + EXPECT_THAT(GetSizes(&sampler), UnorderedElementsAre(0, 1, 2)); + + sampler.Unregister(infos[1]); + EXPECT_THAT(GetSizes(&sampler), UnorderedElementsAre(0, 2)); + + infos.push_back(Register(&sampler, 3)); + infos.push_back(Register(&sampler, 4)); + EXPECT_THAT(GetSizes(&sampler), UnorderedElementsAre(0, 2, 3, 4)); + sampler.Unregister(infos[3]); + EXPECT_THAT(GetSizes(&sampler), UnorderedElementsAre(0, 2, 4)); + + sampler.Unregister(infos[0]); + sampler.Unregister(infos[2]); + sampler.Unregister(infos[4]); + EXPECT_THAT(GetSizes(&sampler), IsEmpty()); +} + +TEST(SampleRecorderTest, MultiThreaded) { + SampleRecorder<Info> sampler; + Notification stop; + ThreadPool pool(10); + + for (int i = 0; i < 10; ++i) { + pool.Schedule([&sampler, &stop]() { + std::random_device rd; + std::mt19937 gen(rd()); + + std::vector<Info*> infoz; + while (!stop.HasBeenNotified()) { + if (infoz.empty()) { + infoz.push_back(sampler.Register()); + } + switch (std::uniform_int_distribution<>(0, 2)(gen)) { + case 0: { + infoz.push_back(sampler.Register()); + break; + } + case 1: { + size_t p = + std::uniform_int_distribution<>(0, infoz.size() - 1)(gen); + Info* info = infoz[p]; + infoz[p] = infoz.back(); + infoz.pop_back(); + sampler.Unregister(info); + break; + } + case 2: { + absl::Duration oldest = absl::ZeroDuration(); + sampler.Iterate([&](const Info& info) { + oldest = std::max(oldest, absl::Now() - info.create_time); + }); + ASSERT_GE(oldest, absl::ZeroDuration()); + break; + } + } + } + }); + } + // The threads will hammer away. Give it a little bit of time for tsan to + // spot errors. + absl::SleepFor(absl::Seconds(3)); + stop.Notify(); +} + +TEST(SampleRecorderTest, Callback) { + SampleRecorder<Info> sampler; + + auto* info1 = Register(&sampler, 1); + auto* info2 = Register(&sampler, 2); + + static const Info* expected; + + auto callback = [](const Info& info) { + // We can't use `info` outside of this callback because the object will be + // disposed as soon as we return from here. + EXPECT_EQ(&info, expected); + }; + + // Set the callback. + EXPECT_EQ(sampler.SetDisposeCallback(callback), nullptr); + expected = info1; + sampler.Unregister(info1); + + // Unset the callback. + EXPECT_EQ(callback, sampler.SetDisposeCallback(nullptr)); + expected = nullptr; // no more calls. + sampler.Unregister(info2); +} + +} // namespace +} // namespace profiling_internal +ABSL_NAMESPACE_END +} // namespace absl |