| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you 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 |
| // |
| // http://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 <stdlib.h> |
| #include <unistd.h> |
| #include <stdio.h> |
| #include <signal.h> |
| #include <gtest/gtest.h> |
| #include "butil/time.h" |
| #include "butil/macros.h" |
| #include "butil/errno.h" |
| #include <limits.h> // INT_MAX |
| #include "butil/atomicops.h" |
| #include "bthread/bthread.h" |
| #include <bthread/sys_futex.h> |
| #include <bthread/processor.h> |
| |
| namespace { |
| volatile bool stop = false; |
| |
| butil::atomic<int> nthread(0); |
| |
| void* read_thread(void* arg) { |
| butil::atomic<int>* m = (butil::atomic<int>*)arg; |
| int njob = 0; |
| while (!stop) { |
| int x; |
| while (!stop && (x = *m) != 0) { |
| if (x > 0) { |
| while ((x = m->fetch_sub(1)) > 0) { |
| ++njob; |
| const long start = butil::cpuwide_time_ns(); |
| while (butil::cpuwide_time_ns() < start + 10000) { |
| } |
| if (stop) { |
| return new int(njob); |
| } |
| } |
| m->fetch_add(1); |
| } else { |
| cpu_relax(); |
| } |
| } |
| |
| ++nthread; |
| bthread::futex_wait_private(m/*lock1*/, 0/*consumed_njob*/, NULL); |
| --nthread; |
| } |
| return new int(njob); |
| } |
| |
| TEST(FutexTest, rdlock_performance) { |
| const size_t N = 100000; |
| butil::atomic<int> lock1(0); |
| pthread_t rth[8]; |
| for (size_t i = 0; i < ARRAY_SIZE(rth); ++i) { |
| ASSERT_EQ(0, pthread_create(&rth[i], NULL, read_thread, &lock1)); |
| } |
| |
| const int64_t t1 = butil::cpuwide_time_ns(); |
| for (size_t i = 0; i < N; ++i) { |
| if (nthread) { |
| lock1.fetch_add(1); |
| bthread::futex_wake_private(&lock1, 1); |
| } else { |
| lock1.fetch_add(1); |
| if (nthread) { |
| bthread::futex_wake_private(&lock1, 1); |
| } |
| } |
| } |
| const int64_t t2 = butil::cpuwide_time_ns(); |
| |
| bthread_usleep(3000000); |
| stop = true; |
| for (int i = 0; i < 10; ++i) { |
| bthread::futex_wake_private(&lock1, INT_MAX); |
| sched_yield(); |
| } |
| |
| int njob = 0; |
| int* res; |
| for (size_t i = 0; i < ARRAY_SIZE(rth); ++i) { |
| pthread_join(rth[i], (void**)&res); |
| njob += *res; |
| delete res; |
| } |
| printf("wake %lu times, %" PRId64 "ns each, lock1=%d njob=%d\n", |
| N, (t2-t1)/N, lock1.load(), njob); |
| ASSERT_EQ(N, (size_t)(lock1.load() + njob)); |
| } |
| |
| TEST(FutexTest, futex_wake_before_wait) { |
| int lock1 = 0; |
| timespec timeout = { 1, 0 }; |
| ASSERT_EQ(0, bthread::futex_wake_private(&lock1, INT_MAX)); |
| ASSERT_EQ(-1, bthread::futex_wait_private(&lock1, 0, &timeout)); |
| ASSERT_EQ(ETIMEDOUT, errno); |
| } |
| |
| void* dummy_waiter(void* lock) { |
| bthread::futex_wait_private(lock, 0, NULL); |
| return NULL; |
| } |
| |
| TEST(FutexTest, futex_wake_many_waiters_perf) { |
| |
| int lock1 = 0; |
| size_t N = 0; |
| pthread_t th; |
| for (; N < 1000 && !pthread_create(&th, NULL, dummy_waiter, &lock1); ++N) {} |
| |
| sleep(1); |
| int nwakeup = 0; |
| butil::Timer tm; |
| tm.start(); |
| for (size_t i = 0; i < N; ++i) { |
| nwakeup += bthread::futex_wake_private(&lock1, 1); |
| } |
| tm.stop(); |
| printf("N=%lu, futex_wake a thread = %" PRId64 "ns\n", N, tm.n_elapsed() / N); |
| ASSERT_EQ(N, (size_t)nwakeup); |
| |
| sleep(2); |
| const size_t REP = 10000; |
| nwakeup = 0; |
| tm.start(); |
| for (size_t i = 0; i < REP; ++i) { |
| nwakeup += bthread::futex_wake_private(&lock1, 1); |
| } |
| tm.stop(); |
| ASSERT_EQ(0, nwakeup); |
| printf("futex_wake nop = %" PRId64 "ns\n", tm.n_elapsed() / REP); |
| } |
| |
| butil::atomic<int> nevent(0); |
| |
| void* waker(void* lock) { |
| bthread_usleep(10000); |
| const size_t REP = 100000; |
| int nwakeup = 0; |
| butil::Timer tm; |
| tm.start(); |
| for (size_t i = 0; i < REP; ++i) { |
| nwakeup += bthread::futex_wake_private(lock, 1); |
| } |
| tm.stop(); |
| EXPECT_EQ(0, nwakeup); |
| printf("futex_wake nop = %" PRId64 "ns\n", tm.n_elapsed() / REP); |
| return NULL; |
| } |
| |
| void* batch_waker(void* lock) { |
| bthread_usleep(10000); |
| const size_t REP = 100000; |
| int nwakeup = 0; |
| butil::Timer tm; |
| tm.start(); |
| for (size_t i = 0; i < REP; ++i) { |
| if (nevent.fetch_add(1, butil::memory_order_relaxed) == 0) { |
| nwakeup += bthread::futex_wake_private(lock, 1); |
| int expected = 1; |
| while (1) { |
| int last_expected = expected; |
| if (nevent.compare_exchange_strong(expected, 0, butil::memory_order_relaxed)) { |
| break; |
| } |
| nwakeup += bthread::futex_wake_private(lock, expected - last_expected); |
| } |
| } |
| } |
| tm.stop(); |
| EXPECT_EQ(0, nwakeup); |
| printf("futex_wake nop = %" PRId64 "ns\n", tm.n_elapsed() / REP); |
| return NULL; |
| } |
| |
| TEST(FutexTest, many_futex_wake_nop_perf) { |
| pthread_t th[8]; |
| int lock1; |
| std::cout << "[Direct wake]" << std::endl; |
| for (size_t i = 0; i < ARRAY_SIZE(th); ++i) { |
| ASSERT_EQ(0, pthread_create(&th[i], NULL, waker, &lock1)); |
| } |
| for (size_t i = 0; i < ARRAY_SIZE(th); ++i) { |
| ASSERT_EQ(0, pthread_join(th[i], NULL)); |
| } |
| std::cout << "[Batch wake]" << std::endl; |
| for (size_t i = 0; i < ARRAY_SIZE(th); ++i) { |
| ASSERT_EQ(0, pthread_create(&th[i], NULL, batch_waker, &lock1)); |
| } |
| for (size_t i = 0; i < ARRAY_SIZE(th); ++i) { |
| ASSERT_EQ(0, pthread_join(th[i], NULL)); |
| } |
| } |
| } // namespace |