// 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 <gtest/gtest.h> #include <pthread.h> #include <sched.h> #include <unistd.h> #include <stdio.h> #include <bthread/processor.h> namespace { volatile bool stop = false; void* spinner(void*) { long counter = 0; for (; !stop; ++counter) { cpu_relax(); } printf("spinned %ld\n", counter); return NULL; } void* yielder(void*) { int counter = 0; for (; !stop; ++counter) { sched_yield(); } printf("sched_yield %d\n", counter); return NULL; } TEST(SchedYieldTest, sched_yield_when_all_core_busy) { stop = false; const int kNumCores = sysconf(_SC_NPROCESSORS_ONLN); ASSERT_TRUE(kNumCores > 0); pthread_t th0; pthread_create(&th0, NULL, yielder, NULL); pthread_t th[kNumCores]; for (int i = 0; i < kNumCores; ++i) { pthread_create(&th[i], NULL, spinner, NULL); } sleep(1); stop = true; for (int i = 0; i < kNumCores; ++i) { pthread_join(th[i], NULL); } pthread_join(th0, NULL); } } // namespace