int sched_get_priority_max(int policy);int sched_get_priority_min(int policy);

int pthread_attr_setschedparam(pthread_attr_t *attr, const struct sched_param *param);
int pthread_attr_getschedparam(const pthread_attr_t *attr, struct sched_param *param);param.sched_priority = 51; //设置优先级

int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy);

struct sched_param
{int __sched_priority; // 所要设定的线程优先级
};

#include <stdio.h>
#include <pthread.h>
#include <sched.h>
#include <assert.h>static int api_get_thread_policy (pthread_attr_t *attr)
{int policy;int rs = pthread_attr_getschedpolicy (attr, &policy);assert (rs == 0);switch (policy){case SCHED_FIFO:printf ("policy = SCHED_FIFO\n");break;case SCHED_RR:printf ("policy = SCHED_RR");break;case SCHED_OTHER:printf ("policy = SCHED_OTHER\n");break;default:printf ("policy = UNKNOWN\n");break; }return policy;
}static void api_show_thread_priority (pthread_attr_t *attr,int policy)
{int priority = sched_get_priority_max (policy);assert (priority != -1);printf ("max_priority = %d\n", priority);priority = sched_get_priority_min (policy);assert (priority != -1);printf ("min_priority = %d\n", priority);
}static int api_get_thread_priority (pthread_attr_t *attr)
{struct sched_param param;int rs = pthread_attr_getschedparam (attr, &param);assert (rs == 0);printf ("priority = %d\n", param.__sched_priority);return param.__sched_priority;
}static void api_set_thread_policy (pthread_attr_t *attr,int policy)
{int rs = pthread_attr_setschedpolicy (attr, policy);assert (rs == 0);api_get_thread_policy (attr);
}int main(void)
{pthread_attr_t attr;       // 线程属性struct sched_param sched;  // 调度策略int rs;/* * 对线程属性初始化* 初始化完成以后，pthread_attr_t 结构所包含的结构体* 就是操作系统实现支持的所有线程属性的默认值*/rs = pthread_attr_init (&attr);assert (rs == 0);     // 如果 rs 不等于 0，程序 abort() 退出/* 获得当前调度策略 */int policy = api_get_thread_policy (&attr);/* 显示当前调度策略的线程优先级范围 */printf ("Show current configuration of priority\n");api_show_thread_priority(&attr, policy);/* 获取 SCHED_FIFO 策略下的线程优先级范围 */printf ("show SCHED_FIFO of priority\n");api_show_thread_priority(&attr, SCHED_FIFO);/* 获取 SCHED_RR 策略下的线程优先级范围 */printf ("show SCHED_RR of priority\n");api_show_thread_priority(&attr, SCHED_RR);/* 显示当前线程的优先级 */printf ("show priority of current thread\n");int priority = api_get_thread_priority (&attr);/* 手动设置调度策略 */printf ("Set thread policy\n");printf ("set SCHED_FIFO policy\n");api_set_thread_policy(&attr, SCHED_FIFO);printf ("set SCHED_RR policy\n");api_set_thread_policy(&attr, SCHED_RR);/* 还原之前的策略 */printf ("Restore current policy\n");api_set_thread_policy (&attr, policy);/* * 反初始化 pthread_attr_t 结构* 如果 pthread_attr_init 的实现对属性对象的内存空间是动态分配的，* phread_attr_destory 就会释放该内存空间*/rs = pthread_attr_destroy (&attr);assert (rs == 0);return 0;
}

policy=SCHED_OTHER
Show current configuration of priority
max_priority=0
min_priority=0
show SCHED_FIFO of priority
max_priority=99
min_priority=1
show SCHED_RR of priority
max_priority=99
min_priority=1
show priority of current thread
priority=0Set thread policy
set SCHED_FIFO policy
policy= SCHED_FIFO
set SCHED_RR policy
policy= SCHED_RRRestore current policy
policy=SCHED_OTHER