[Linux线程]线程的同步--使用互斥锁完成线程同步

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>

pthread_mutex_t mutex;    //定义一个互斥量
int x;                    //定义一个全局变量
//这是线程1的入口函数
void threaddeal1(void)
{
while(x>0)              //如果X>0
{
pthread_mutex_lock(&mutex);        //对互斥量进行加锁操作
printf("线程1正在运行: x=%d \n",x); //输出当前的x值
x--;                                //将x的值-1
pthread_mutex_unlock(&mutex);       //对互斥两进行开锁操作
sleep(1);                           //休眠1秒
}
pthread_exit(NULL);                   //进程退出
}
//这是线程2的入口函数，线程2和线程1的操作完全相同
void threaddeal2(void)
{
while(x>0)
{
pthread_mutex_lock(&mutex);
printf("线程2正在运行: x=%d \n",x);
x--;
pthread_mutex_unlock(&mutex);
sleep(1);
}
pthread_exit(NULL);
}
//这是主函数
int main(int argc,char *argv[])
{
pthread_t threadid1,threadid2;
int ret;
ret = pthread_mutex_init(&mutex,NULL);   //初始化互斥锁
if(ret != 0)
{
printf ("初始化互斥锁失败.\n");
exit (1);
}
x = 10;     //给全局变量赋初始化值
ret = pthread_create(&threadid1, NULL, (void *)&threaddeal1, NULL);  //创建线程1
if(ret != 0)
{
printf ("创建线程1失败.\n");
exit (1);
}
ret = pthread_create(&threadid2, NULL, (void *)&threaddeal2, NULL);  //创建线程2
if(ret != 0)
{
printf ("创建线程2失败.\n");
exit (1);
}
pthread_join(threadid1, NULL);
pthread_join(threadid2, NULL);    //阻塞线程1和线程2
return (0);
}