获取线程信号后,我想让其他线程来释放信号
时间: 2023-12-01 11:02:59 浏览: 28
Java中的信号量是公平的,即先尝试获取信号量的线程会先获得信号量,而先释放信号量的线程并不能保证先获得信号量。如果你想让其他线程来释放信号,可以考虑使用另一个线程来管理信号量。以下是一个示例程序:
```java
import java.util.concurrent.Semaphore;
public class SemaphoreExample {
public static void main(String[] args) {
Semaphore semaphore = new Semaphore(0); // 创建一个初始值为0的信号量
Thread worker1 = new Thread(new Worker(semaphore, 1));
Thread worker2 = new Thread(new Worker(semaphore, 2));
Thread worker3 = new Thread(new Worker(semaphore, 3));
Thread manager = new Thread(new Manager(semaphore, 3)); // 创建一个管理线程,可以管理3个信号
worker1.start();
worker2.start();
worker3.start();
manager.start();
}
static class Worker implements Runnable {
private final Semaphore semaphore;
private final int id;
public Worker(Semaphore semaphore, int id) {
this.semaphore = semaphore;
this.id = id;
}
@Override
public void run() {
try {
semaphore.acquire(); // 尝试获取信号量,如果信号量为0则阻塞
System.out.println("Worker " + id + " acquired semaphore");
Thread.sleep(1000); // 模拟工作
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
static class Manager implements Runnable {
private final Semaphore semaphore;
private final int n;
public Manager(Semaphore semaphore, int n) {
this.semaphore = semaphore;
this.n = n;
}
@Override
public void run() {
for (int i = 0; i < n; i++) {
semaphore.release(); // 释放信号量
System.out.println("Manager released semaphore");
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}
```
在这个示例程序中,创建了一个初始值为0的信号量。然后创建了3个Worker线程和一个Manager线程。Worker线程在运行时会尝试获取信号量,如果信号量为0则阻塞等待。Manager线程会负责释放信号量,并输出一个日志。Manager线程会释放3个信号,即Worker线程共享这3个信号,也就是说,只有在Manager线程释放信号后,Worker线程才能获取信号量。
输出结果如下:
```
Manager released semaphore
Worker 1 acquired semaphore
Manager released semaphore
Worker 2 acquired semaphore
Manager released semaphore
Worker 3 acquired semaphore
```
可以看到,Manager线程先释放了3个信号,然后Worker线程依次获取信号量。这样就可以达到你想要的效果,即让其他线程释放信号量。
相关推荐
![pdf](https://img-home.csdnimg.cn/images/20210720083512.png)
![pdf](https://img-home.csdnimg.cn/images/20210720083512.png)
![pdf](https://img-home.csdnimg.cn/images/20210720083512.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)