条件量练习
<pre><code>/**********************************************************************************
* 设计程序，创建三个线程，任务1条件满足时解除任务二的挂起状态，任务3用于控制x的值
* author：jindouliu2024@163.com
* date：2025.5.12
*
*
* Copyright (c)2024-2025 jindouliu2024@163.com All right Reserved
********************************************************************************/
</code></pre>
<pre><code>#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
pthread_t task1_id;
pthread_t task2_id;
pthread_t task3_id;
pthread_t main_id;
int x = 10,y = 20;
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_tcond = PTHREAD_COND_INITIALIZER;
void * task1(void *arg)
{
while(1){
//上锁
pthread_mutex_lock(&mutex);
//如果不满足，则一直阻塞等待
while(x <= y){
printf("running1\n");
pthread_cond_wait(&cond,&mutex);
}
//如果满足，则通知唤醒
pthread_cond_broadcast(&cond);
//解锁
pthread_mutex_unlock(&mutex);
}
pthread_exit(NULL);
}
void * task2(void *arg)
{
while(1){
//上锁
pthread_mutex_lock(&mutex);
printf("running2\n");
//如果不满足，则一直阻塞等待
if(x > y){
printf("条件满足\n");
pthread_cond_broadcast(&cond);
}
//解锁
pthread_mutex_unlock(&mutex);
sleep(1);
}
pthread_exit(NULL);
}
void * task3(void *arg)
{
while(1){
//上锁
pthread_mutex_lock(&mutex);
if(x > y){
y += 10;
}
x += 2;
printf("running3\n");
//解锁
pthread_mutex_unlock(&mutex);
sleep(1);
}
pthread_exit(NULL);
}
int main()
{
//初始化条件变量
pthread_cond_init(&cond,NULL);
//初始化互斥锁
pthread_mutex_init(&mutex,NULL);
//设置主线程为可分离属性
pthread_detach(pthread_self());
//pthread_t task1_id,task2_id，main_id;
//定义线程属性对象
pthread_attr_t thread_arr;
//初始化线程属性对象
pthread_attr_init(&thread_arr);
//设置线程属性
pthread_attr_setdetachstate(&thread_arr,PTHREAD_CREATE_DETACHED);
//使用线程属性创建线程
pthread_create(&task1_id,&thread_arr,task1,NULL);
pthread_create(&task2_id,&thread_arr,task2,NULL);
pthread_create(&task3_id,&thread_arr,task3,NULL);
//主线程退出
pthread_exit(NULL);
return 0;
}
</code></pre><br><br>
来源：https://www.cnblogs.com/lradian/p/18872285
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