说明：对多线程与相互排斥锁不熟悉的请參考其他

#include <pthread.h>

#include <stdio.h>

#include <stdlib.h>

pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;/*初始化相互排斥锁*/

pthread_cond_t cond = PTHREAD_COND_INITIALIZER;/*初始化条件变量*/

void *thread1(void *);

void *thread2(void *);

int i=1;

int main(void)

{

    pthread_t t_a;

    pthread_t t_b;

    pthread_create(&t_a,NULL,thread1,(void *)NULL);/*创建进程t_a*/

    pthread_create(&t_b,NULL,thread2,(void *)NULL); /*创建进程t_b*/

    pthread_join(t_a, NULL);/*等待进程t_a结束 和windows的waitForSingleObject 相似*/

    pthread_join(t_b, NULL);/*等待进程t_b结束 和windows的waitForSingleObject 相似*/

    /* 释放资源*/

    pthread_mutex_destroy(&mutex);

    pthread_cond_destroy(&cond);

    exit(0);

}

void *thread1(void *junk)

{

    for(i=1;i<=6;i++)

    {

	printf("now i = %d\n", i);

        pthread_mutex_lock(&mutex);/*锁住相互排斥量*/

		printf("thread1: lock %d\n", __LINE__);

        if(i%3==0){

			printf("thread1:signal 1  %d\n", __LINE__);

            pthread_cond_signal(&cond);/*条件改变，发送信号，通知t_b进程*/

			printf("thread1:signal 2  %d\n", __LINE__);

			sleep(1);

		}

        pthread_mutex_unlock(&mutex);/*解锁相互排斥量*/

		printf("thread1: unlock %d\n\n", __LINE__);

		sleep(1);

	}

}

void *thread2(void *junk)

{

    while(i<6)

    {

        pthread_mutex_lock(&mutex);

		printf("thread2: lock %d\n", __LINE__);

		if(i%3!=0){

			printf("thread2: wait 1  %d\n", __LINE__);

	    /*pthread_cond_wait 函数将解锁mutex。并使当前线程堵塞在cond指向的条件变量上*/

            pthread_cond_wait(&cond,&mutex);/*解锁mutex，并等待cond改变*/

			printf("thread2: wait 2  %d\n", __LINE__);;

		}

        pthread_mutex_unlock(&mutex);

		printf("thread2: unlock %d\n\n", __LINE__);

		sleep(1);

	}

}

root@ubuntu:/usr/syw/linux/Thread# gcc -g threadDemo3_arg.c -o thread3
-lpthread

root@ubuntu:/usr/syw/linux/Thread# ./thread3

now i = 1

thread2: lock 44

thread2: wait 1  46

thread1: lock 27

thread1: unlock 35

now i = 2

thread1: lock 27

thread1: unlock 35

now i = 3

thread1: lock 27

thread1:signal 1  29

thread1:signal 2  31

thread1: unlock 35

thread2: wait 2  49

thread2: unlock 52

now i = 4

thread2: lock 44

thread2: wait 1  46

thread1: lock 27

thread1: unlock 35

now i = 5

thread1: lock 27

thread1: unlock 35

now i = 6

thread1: lock 27

thread1:signal 1  29

thread1:signal 2  31

thread1: unlock 35

thread2: wait 2  49

thread2: unlock 52