From 5aa5d282eac56a21e74611c1cdbaa97bb5db2dca Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Tue, 8 Feb 2022 02:05:36 +0300 Subject: chore(3p/abseil_cpp): unvendor abseil_cpp we weren't actually using these sources anymore, okay? Change-Id: If701571d9716de308d3512e1eb22c35db0877a66 Reviewed-on: https://cl.tvl.fyi/c/depot/+/5248 Tested-by: BuildkiteCI Reviewed-by: grfn Autosubmit: tazjin --- .../absl/synchronization/mutex_benchmark.cc | 224 --------------------- 1 file changed, 224 deletions(-) delete mode 100644 third_party/abseil_cpp/absl/synchronization/mutex_benchmark.cc (limited to 'third_party/abseil_cpp/absl/synchronization/mutex_benchmark.cc') diff --git a/third_party/abseil_cpp/absl/synchronization/mutex_benchmark.cc b/third_party/abseil_cpp/absl/synchronization/mutex_benchmark.cc deleted file mode 100644 index 933ea14f8f..0000000000 --- a/third_party/abseil_cpp/absl/synchronization/mutex_benchmark.cc +++ /dev/null @@ -1,224 +0,0 @@ -// Copyright 2017 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 -#include // NOLINT(build/c++11) -#include - -#include "absl/base/config.h" -#include "absl/base/internal/cycleclock.h" -#include "absl/base/internal/spinlock.h" -#include "absl/synchronization/blocking_counter.h" -#include "absl/synchronization/internal/thread_pool.h" -#include "absl/synchronization/mutex.h" -#include "benchmark/benchmark.h" - -namespace { - -void BM_Mutex(benchmark::State& state) { - static absl::Mutex* mu = new absl::Mutex; - for (auto _ : state) { - absl::MutexLock lock(mu); - } -} -BENCHMARK(BM_Mutex)->UseRealTime()->Threads(1)->ThreadPerCpu(); - -static void DelayNs(int64_t ns, int* data) { - int64_t end = absl::base_internal::CycleClock::Now() + - ns * absl::base_internal::CycleClock::Frequency() / 1e9; - while (absl::base_internal::CycleClock::Now() < end) { - ++(*data); - benchmark::DoNotOptimize(*data); - } -} - -template -class RaiiLocker { - public: - explicit RaiiLocker(MutexType* mu) : mu_(mu) { mu_->Lock(); } - ~RaiiLocker() { mu_->Unlock(); } - private: - MutexType* mu_; -}; - -template <> -class RaiiLocker { - public: - explicit RaiiLocker(std::mutex* mu) : mu_(mu) { mu_->lock(); } - ~RaiiLocker() { mu_->unlock(); } - private: - std::mutex* mu_; -}; - -template -void BM_Contended(benchmark::State& state) { - struct Shared { - MutexType mu; - int data = 0; - }; - static auto* shared = new Shared; - int local = 0; - for (auto _ : state) { - // Here we model both local work outside of the critical section as well as - // some work inside of the critical section. The idea is to capture some - // more or less realisitic contention levels. - // If contention is too low, the benchmark won't measure anything useful. - // If contention is unrealistically high, the benchmark will favor - // bad mutex implementations that block and otherwise distract threads - // from the mutex and shared state for as much as possible. - // To achieve this amount of local work is multiplied by number of threads - // to keep ratio between local work and critical section approximately - // equal regardless of number of threads. - DelayNs(100 * state.threads, &local); - RaiiLocker locker(&shared->mu); - DelayNs(state.range(0), &shared->data); - } -} - -BENCHMARK_TEMPLATE(BM_Contended, absl::Mutex) - ->UseRealTime() - // ThreadPerCpu poorly handles non-power-of-two CPU counts. - ->Threads(1) - ->Threads(2) - ->Threads(4) - ->Threads(6) - ->Threads(8) - ->Threads(12) - ->Threads(16) - ->Threads(24) - ->Threads(32) - ->Threads(48) - ->Threads(64) - ->Threads(96) - ->Threads(128) - ->Threads(192) - ->Threads(256) - // Some empirically chosen amounts of work in critical section. - // 1 is low contention, 200 is high contention and few values in between. - ->Arg(1) - ->Arg(20) - ->Arg(50) - ->Arg(200); - -BENCHMARK_TEMPLATE(BM_Contended, absl::base_internal::SpinLock) - ->UseRealTime() - // ThreadPerCpu poorly handles non-power-of-two CPU counts. - ->Threads(1) - ->Threads(2) - ->Threads(4) - ->Threads(6) - ->Threads(8) - ->Threads(12) - ->Threads(16) - ->Threads(24) - ->Threads(32) - ->Threads(48) - ->Threads(64) - ->Threads(96) - ->Threads(128) - ->Threads(192) - ->Threads(256) - // Some empirically chosen amounts of work in critical section. - // 1 is low contention, 200 is high contention and few values in between. - ->Arg(1) - ->Arg(20) - ->Arg(50) - ->Arg(200); - -BENCHMARK_TEMPLATE(BM_Contended, std::mutex) - ->UseRealTime() - // ThreadPerCpu poorly handles non-power-of-two CPU counts. - ->Threads(1) - ->Threads(2) - ->Threads(4) - ->Threads(6) - ->Threads(8) - ->Threads(12) - ->Threads(16) - ->Threads(24) - ->Threads(32) - ->Threads(48) - ->Threads(64) - ->Threads(96) - ->Threads(128) - ->Threads(192) - ->Threads(256) - // Some empirically chosen amounts of work in critical section. - // 1 is low contention, 200 is high contention and few values in between. - ->Arg(1) - ->Arg(20) - ->Arg(50) - ->Arg(200); - -// Measure the overhead of conditions on mutex release (when they must be -// evaluated). Mutex has (some) support for equivalence classes allowing -// Conditions with the same function/argument to potentially not be multiply -// evaluated. -// -// num_classes==0 is used for the special case of every waiter being distinct. -void BM_ConditionWaiters(benchmark::State& state) { - int num_classes = state.range(0); - int num_waiters = state.range(1); - - struct Helper { - static void Waiter(absl::BlockingCounter* init, absl::Mutex* m, int* p) { - init->DecrementCount(); - m->LockWhen(absl::Condition( - static_cast([](int* v) { return *v == 0; }), p)); - m->Unlock(); - } - }; - - if (num_classes == 0) { - // No equivalence classes. - num_classes = num_waiters; - } - - absl::BlockingCounter init(num_waiters); - absl::Mutex mu; - std::vector equivalence_classes(num_classes, 1); - - // Must be declared last to be destroyed first. - absl::synchronization_internal::ThreadPool pool(num_waiters); - - for (int i = 0; i < num_waiters; i++) { - // Mutex considers Conditions with the same function and argument - // to be equivalent. - pool.Schedule([&, i] { - Helper::Waiter(&init, &mu, &equivalence_classes[i % num_classes]); - }); - } - init.Wait(); - - for (auto _ : state) { - mu.Lock(); - mu.Unlock(); // Each unlock requires Condition evaluation for our waiters. - } - - mu.Lock(); - for (int i = 0; i < num_classes; i++) { - equivalence_classes[i] = 0; - } - mu.Unlock(); -} - -// Some configurations have higher thread limits than others. -#if defined(__linux__) && !defined(ABSL_HAVE_THREAD_SANITIZER) -constexpr int kMaxConditionWaiters = 8192; -#else -constexpr int kMaxConditionWaiters = 1024; -#endif -BENCHMARK(BM_ConditionWaiters)->RangePair(0, 2, 1, kMaxConditionWaiters); - -} // namespace -- cgit 1.4.1