Linux编程之互斥锁线程控制

/*互斥锁线程控制*/
#include<stdio.h>
#include<stdlib.h>
#include<pthread.h>

#define THREAD_NUMBER 3/*线程数*/ 
#define REPEAT_NUMBER 5 /*每个线程中的小任务数*/
#define DELAY_TIME_LEVELS 10.0 /*小任务之间的最大时间间隔*/
pthread_mutex_t mutex;


void *thrd_func(void *arg)
{
    /*线程函数历程*/
    printf("in thrd_func function\n");

    int thrd_num=(int)arg;
    int delay_time=0;
    int count=0;
    int res;

    res=pthread_mutex_lock(&mutex);

    if(res<0)
    {
        printf("thread %d lock failed\n",thrd_num);
        pthread_exit(NULL);
    }


    printf("thread %d is starting\n",thrd_num);

    for(count=0;count<REPEAT_NUMBER;count++)
    {
        delay_time=(int)(rand() * DELAY_TIME_LEVELS / (RAND_MAX))+1;
        sleep(delay_time);
        printf("\t thread %d :job %d delay=%d\n",thrd_num,count,delay_time);
    }

    printf("thread %d finished\n",thrd_num);

    pthread_exit(NULL); 


}



int main()
{
    int no=0,res;
    void *thrd_ret;
    pthread_t thread[THREAD_NUMBER];  /*线程表示符*/

    srand(time(NULL));

    /*互斥锁初始化*/
    pthread_mutex_init(&mutex,NULL);

    for(no=0;no<THREAD_NUMBER;no++)
    {
        /*创建多线程*/
        res=pthread_create(&thread[no],NULL,thrd_func,(void *)no);
        /*if(res != 0); { // printf("file\n"); printf("creat thread %d failed\n",no); printf("filure ID is %d\n",res); exit(res); } */
    }  //end for

    printf("creat treads success\n Waitting for thread to finish...\n");

    for(no=0;no<THREAD_NUMBER;no++)
    {
        /*等待线程的结束*/
        res=pthread_join(thread[no],&thrd_ret);

        if(!res)
        {
            printf("Thread %d jioned\n",no);

        }
        else
        {
            printf("Thread %d jioned filed\n"); 

        }
        /*互斥解锁*/
        pthread_mutex_unlock(&mutex);
    }

    pthread_mutex_destroy(&mutex);

    return 0;   
}

程序运行结果：

参考图书《从实践中学嵌入式Linux应用编程程序开发》
华清远见嵌入式学院 冯利美 编著
电子工业出版社