2 * Copyright 2016 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #include <folly/CallOnce.h>
23 #include <folly/Benchmark.h>
25 #include <glog/logging.h>
27 DEFINE_int32(threads, 16, "benchmark concurrency");
29 template <typename CallOnceFunc>
30 void bm_impl(CallOnceFunc&& fn, int64_t iters) {
31 std::deque<std::thread> threads;
32 for (int i = 0; i < FLAGS_threads; ++i) {
33 threads.emplace_back([&fn, iters] {
34 for (int64_t j = 0; j < iters; ++j) {
39 for (std::thread& t : threads) {
44 BENCHMARK(StdCallOnceBench, iters) {
47 bm_impl([&] { std::call_once(flag, [&] { ++out; }); }, iters);
51 BENCHMARK(FollyCallOnceBench, iters) {
52 folly::once_flag flag;
54 bm_impl([&] { folly::call_once(flag, [&] { ++out; }); }, iters);
58 int main(int argc, char** argv) {
59 gflags::ParseCommandLineFlags(&argc, &argv, true);
60 folly::runBenchmarks();