/*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
*/
#include <folly/Baton.h>
+#include <folly/test/BatonTestHelpers.h>
#include <folly/test/DeterministicSchedule.h>
+#include <folly/portability/GTest.h>
+
#include <thread>
-#include <semaphore.h>
-#include <gflags/gflags.h>
-#include <gtest/gtest.h>
-#include <folly/Benchmark.h>
using namespace folly;
using namespace folly::test;
using folly::detail::EmulatedFutexAtomic;
-typedef DeterministicSchedule DSched;
-
TEST(Baton, basic) {
Baton<> b;
b.post();
b.wait();
}
-template <template<typename> class Atom>
-void run_pingpong_test(int numRounds) {
- Baton<Atom> batons[17];
- Baton<Atom>& a = batons[0];
- Baton<Atom>& b = batons[16]; // to get it on a different cache line
- auto thr = DSched::thread([&]{
- for (int i = 0; i < numRounds; ++i) {
- a.wait();
- a.reset();
- b.post();
- }
- });
- for (int i = 0; i < numRounds; ++i) {
- a.post();
- b.wait();
- b.reset();
- }
- DSched::join(thr);
-}
-
TEST(Baton, pingpong) {
DSched sched(DSched::uniform(0));
run_pingpong_test<DeterministicAtomic>(1000);
}
-BENCHMARK(baton_pingpong, iters) {
- run_pingpong_test<std::atomic>(iters);
-}
-
-BENCHMARK(baton_pingpong_emulated_futex, iters) {
- run_pingpong_test<EmulatedFutexAtomic>(iters);
-}
-
-BENCHMARK(posix_sem_pingpong, iters) {
- sem_t sems[3];
- sem_t* a = sems + 0;
- sem_t* b = sems + 2; // to get it on a different cache line
-
- sem_init(a, 0, 0);
- sem_init(b, 0, 0);
- auto thr = std::thread([=]{
- for (size_t i = 0; i < iters; ++i) {
- sem_wait(a);
- sem_post(b);
- }
- });
- for (size_t i = 0; i < iters; ++i) {
- sem_post(a);
- sem_wait(b);
- }
- thr.join();
-}
-
-template <template<typename> class Atom, typename Clock>
-void run_basic_timed_wait_tests() {
- Baton<Atom> b;
- b.post();
- // tests if early delivery works fine
- EXPECT_TRUE(b.timed_wait(Clock::now()));
-}
-
-template <template<typename> class Atom, typename Clock>
-void run_timed_wait_tmo_tests() {
- Baton<Atom> b;
-
- auto thr = DSched::thread([&]{
- bool rv = b.timed_wait(Clock::now() + std::chrono::milliseconds(1));
- // main thread is guaranteed to not post until timeout occurs
- EXPECT_FALSE(rv);
- });
- DSched::join(thr);
-}
-
-template <template<typename> class Atom, typename Clock>
-void run_timed_wait_regular_test() {
- Baton<Atom> b;
-
- auto thr = DSched::thread([&] {
- // To wait forever we'd like to use time_point<Clock>::max, but
- // std::condition_variable does math to convert the timeout to
- // system_clock without handling overflow.
- auto farFuture = Clock::now() + std::chrono::hours(1000);
- bool rv = b.timed_wait(farFuture);
- if (!std::is_same<Atom<int>, DeterministicAtomic<int>>::value) {
- // DeterministicAtomic ignores actual times, so doesn't guarantee
- // a lack of timeout
- EXPECT_TRUE(rv);
- }
- });
-
- if (!std::is_same<Atom<int>, DeterministicAtomic<int>>::value) {
- // If we are using std::atomic (or EmulatedFutexAtomic) then
- // a sleep here guarantees to a large extent that 'thr' will
- // execute wait before we post it, thus testing late delivery. For
- // DeterministicAtomic, we just rely on DeterministicSchedule to do
- // the scheduling. The test won't fail if we lose the race, we just
- // don't get coverage.
- std::this_thread::sleep_for(std::chrono::milliseconds(2));
- }
-
- b.post();
- DSched::join(thr);
-}
-
TEST(Baton, timed_wait_basic_system_clock) {
run_basic_timed_wait_tests<std::atomic, std::chrono::system_clock>();
run_basic_timed_wait_tests<EmulatedFutexAtomic, std::chrono::system_clock>();
run_timed_wait_regular_test<DeterministicAtomic, std::chrono::steady_clock>();
}
-template <template<typename> class Atom>
-void run_try_wait_tests() {
- Baton<Atom> b;
- EXPECT_FALSE(b.try_wait());
- b.post();
- EXPECT_TRUE(b.try_wait());
-}
-
TEST(Baton, try_wait) {
run_try_wait_tests<std::atomic>();
run_try_wait_tests<EmulatedFutexAtomic>();
run_try_wait_tests<DeterministicAtomic>();
}
-
-// I am omitting a benchmark result snapshot because these microbenchmarks
-// mainly illustrate that PreBlockAttempts is very effective for rapid
-// handoffs. The performance of Baton and sem_t is essentially identical
-// to the required futex calls for the blocking case
-
-int main(int argc, char** argv) {
- testing::InitGoogleTest(&argc, argv);
- gflags::ParseCommandLineFlags(&argc, &argv, true);
-
- auto rv = RUN_ALL_TESTS();
- if (!rv && FLAGS_benchmark) {
- folly::runBenchmarks();
- }
- return rv;
-}