linux线程的优先级设置

linux并不是实时操作系统，把下面的代码运行一遍就能够理解了，代码有很详细的注释。

#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <pthread.h> #include <signal.h> #include <string.h> void * thr_fun(void *arg) { int policy, ret; struct sched_param param; //获取线程调度参数 ret = pthread_getschedparam(pthread_self(), &policy, &param); if(ret!=0) { printf("pthread_getschedparam %s/n", strerror(ret) ); exit(1); } if (policy == SCHED_FIFO) { printf("policy:SCHED_FIFO/n"); } else if (policy == SCHED_OTHER) { printf("policy:SCHED_OTHER/n"); } else if (policy == SCHED_RR) { printf("policy:SCHED_RR/n"); } printf("param:%d/n", param.sched_priority); long long i; while (1) { i++; i *= 2; } pthread_exit(NULL); } int main(void) { int ret; pthread_t tid; pthread_attr_t attr; int policy, inher; struct sched_param param; //初始化线程属性 pthread_attr_init(&attr); //获取继承的调度策略 ret = pthread_attr_getinheritsched(&attr, &inher); if (ret!=0) { printf("pthread_attr_getinheritsched/n%s/n", strerror(ret)); exit(1); } // if (inher == PTHREAD_EXPLICIT_SCHED) { printf("PTHREAD_EXPLICIT_SCHED/n"); } else if (inher == PTHREAD_INHERIT_SCHED) { printf("PTHREAD_INHERIT_SCHED/n"); inher = PTHREAD_EXPLICIT_SCHED; } //设置继承的调度策略 //必需设置inher的属性为 PTHREAD_EXPLICIT_SCHED，否则设置线程的优先级会被忽略 ret = pthread_attr_setinheritsched(&attr, inher); if (ret!=0) { printf("pthread_attr_setinheritsched/n%s/n", strerror(ret)); exit(1); } policy = SCHED_FIFO;//在Ubuntu9.10上需要root权限 //设置线程调度策略 ret = pthread_attr_setschedpolicy(&attr, policy); if (ret!=0) { printf(" pthread_attr_setschedpolicy/n%s/n", strerror(ret)); exit(1); } param.sched_priority = 3; //设置调度参数 ret = pthread_attr_setschedparam(&attr, &param); if (ret!=0) { printf(" pthread_attr_setschedparam/n%s/n", strerror(ret)); exit(1); } //创建线程 ret = pthread_create(&tid, &attr, thr_fun, NULL); if (ret!=0) { printf("pthread_create/n%s/n", strerror(ret)); exit(1); } while (1) { printf("hello world/n"); } pthread_join(tid, NULL); pthread_exit(NULL); }

线程中不要用perror，请使用strerror。