rick.chan f498e91191 修正 SetThreadAffinity 接口,调整代码格式.
Signed-off-by: rick.chan <chenyang@autoai.com>
2021-06-07 16:50:29 +08:00

83 lines
1.8 KiB
C++

/**
* @file main.cpp
* @author Rick Chan
* @brief Android 系统下进程和线程的 CPU 亲和性设置参考程序.
* @version 0.1
* @date 2021-06-07
*
* @copyright Copyright (c) 2020
*
*/
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <pthread.h>
#include <sys/syscall.h>
int SetProcessAffinity(void) {
cpu_set_t set;
pid_t pid = getpid();
// 进程只在核 3 和核 7 上执行.
CPU_ZERO(&set);
CPU_SET(3, &set);
CPU_SET(7, &set);
int res, err;
(void)res;
(void)err;
res = sched_setaffinity(pid, sizeof(set), &set);
err = errno;
return res;
}
void SetThreadAffinity(size_t cpusetsize, cpu_set_t *cpuset) {
int err, syscallres;
pid_t pid = gettid();
// Linux 下可以直接使用 pthread_setaffinity_np() 函数将当前线程绑定在具体的 CPU 上, 而 Android 屏蔽了该 API, 需要通过 syscall(__NR_sched_setaffinity) 来实现.
syscallres = syscall(__NR_sched_setaffinity, pid, cpusetsize, cpuset);
if(syscallres)
err = errno;
}
void* DemoRoutine0(void* arg)
{
(void)arg;
cpu_set_t set;
CPU_ZERO(&set);
// DemoRoutine0 只运行在核 3 上.
CPU_SET(3, &set);
SetThreadAffinity(sizeof(set), &set);
while(1);
return nullptr;
}
void* DemoRoutine1(void* arg)
{
(void)arg;
cpu_set_t set;
CPU_ZERO(&set);
// DemoRoutine0 只运行在核 7 上.
CPU_SET(7, &set);
SetThreadAffinity(sizeof(set), &set);
while(1);
return nullptr;
}
int main(void)
{
pthread_t demoThrd0, demoThrd1;
cpu_set_t set;
SetProcessAffinity();
sched_getaffinity(getpid(), sizeof(set), &set);
printf("Current CPU Setbits=%lu.\r\n", set.__bits[0]);
pthread_create(&demoThrd0, nullptr, DemoRoutine0, nullptr);
pthread_create(&demoThrd1, nullptr, DemoRoutine1, nullptr);
pthread_join(demoThrd0, nullptr);
pthread_join(demoThrd1, nullptr);
return 0;
}