linux 互斥锁之trylock的简单测试

/* ************************************************************************
 *       Filename:  n_trylock.c
 *    Description:  
 *        Version:  1.0
 *        Created:  2011骞?4鏈?2鏃?20鏃?9鍒?2绉?
 *       Revision:  none
 *       Compiler:  gcc
 *         Author:  wenhao (wh), hnrain1004@gmail.com
 *        Company:  sunplusapp
 * ************************************************************************/


#include <stdio.h>
#include <pthread.h>
#include <errno.h>
pthread_mutex_t mutex;

void *thread_a(void *arg)
{
    printf("thread a enter\n");
    pthread_mutex_lock(&mutex);
    printf("mutex a lock\n");
    sleep(6);
    pthread_mutex_unlock(&mutex);
    printf("mutex a unlock\n");
}

void *thread_b(void *arg)
{
    printf("thread b enter\n");
#if 1
    pthread_mutex_trylock(&mutex);
#else
    while(pthread_mutex_trylock(&mutex)==EBUSY)
    {
        printf("pthread b trylock\n");
        sleep(1);
    }
#endif
    printf("mutex b lock\n");
    pthread_mutex_unlock(&mutex);
    printf("mutex b unlock\n");
}

int main(int argc,char **argv)
{
    pthread_t tid_a,tid_b;
    int err;

    if(pthread_mutex_init(&mutex,NULL) != 0)
    {
        perror("pthread_mutex_init");

    }

    err = pthread_create(&tid_a,NULL,thread_a,NULL);
    if(err != 0)
    {
        perror("pthread_create thread_a");
    }

    sleep(1);
    err = pthread_create(&tid_b,NULL,thread_b,NULL);
    if(err < 0)
    {
        perror("pthread_create thread_b");
    }
    sleep(10);

    printf("the main close\n");

    return 0;
}