/* * THREADING_OSX.H * http://yyshen.github.io/2015/01/18/binding_threads_to_cores_osx.html */ #pragma once #include #include #include #define SYSCTL_CORE_COUNT "machdep.cpu.core_count" struct cpu_set_t { uint32_t count; } ; static inline void CPU_ZERO(cpu_set_t *cs) { cs->count = 0; } static inline void CPU_SET(int num, cpu_set_t *cs) { cs->count |= (1 << num); } [[nodiscard]] static inline int CPU_ISSET(int num, cpu_set_t *cs) { return (cs->count & (1 << num)); } [[nodiscard]] int sched_getaffinity(pid_t pid, size_t cpu_size, cpu_set_t *cpu_set) { int32_t core_count = 0; size_t len = sizeof(core_count); int ret = sysctlbyname(SYSCTL_CORE_COUNT, &core_count, &len, 0, 0); if (ret) { // printf("error while get core count %d\n", ret); return -1; } cpu_set->count = 0; for (int i = 0; i < core_count; i++) { cpu_set->count |= (1 << i); } return 0; } [[nodiscard]] int pthread_setaffinity_np(pthread_t thread, size_t cpu_size, cpu_set_t *cpu_set) { thread_port_t mach_thread; int core = 0; for (core = 0; core < 8 * cpu_size; core++) { if (CPU_ISSET(core, cpu_set)) break; } // printf("binding to core %d\n", core); thread_affinity_policy_data_t policy = { core }; mach_thread = pthread_mach_thread_np(thread); thread_policy_set(mach_thread, THREAD_AFFINITY_POLICY, (thread_policy_t)&policy, 1); return 0; }