pthread创建RR线程

#define _GNU_SOURCE 

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sched.h>  
#include <pthread.h>
#include <unistd.h> 
#include <errno.h>
#include <string.h>

typedef void* (*threadfunc)(void *data);
int thread_stop = 0;

void *pt_fn(void * data)
{
    while(!thread_stop)
    {
        printf("pt_fn.\n");
    }
    return ((void *)0)
}

int pcreate_rr_thread(pthread_t *tid, int priority, threadfunc func, void *data)
{
    pthread_attr_t  attr;
    struct sched_param  params;
    int ret = 0;
    pthread_attr_init(&attr);
    //不继承父线程的调度策略
    if((ret = pthread_attr_setinheritsched(&attr,PTHREAD_EXPLICIT_SCHED)))
    {
        printf("pthread_attr_setinheritsched failed.\n");
    }
    //设置子线程为RR调度策略         
    if((ret = pthread_attr_setschedpolicy(&attr,SCHED_RR)))
    {
        printf("pthread_attr_setschedpolicy failed.\n");
    }
    //设置优先级
    params.sched_priority = priority;
    if((ret = pthread_attr_setschedparam(&attr, ¶ms)))
    {
        printf("pthread_attr_setschedparam failed.\n");
    }
    //创建线程
    if((ret = pthread_create(tid, &attr, func, (void *)data)))
    {
        printf("pthread_create failed with error.\n");
    }
    
    return ret;
    
}

int main(void)
{

    char exit;
    pthread_t thread;
    int max_prio;

    max_prio = sched_get_priority_max(SCHED_RR);
    if((ret = pcreate_rr_thread(&thread, max_prio, pt_fn, NULL)))
    {
        printf("pcreate_rr_thread thread failed.\n");
        goto err_pthread_tx;
    }
    while(exit != 'q')
    {
        scanf("%c", &exit);
    }
    thread_stop = 1;   
    pthread_join(thread, NULL);
    printf("exit successed.\n");
    return ret;
err_pthread_tx:
    return ret;    
}

//编译 gcc -o thread thread.c -pthread