Java多线程并发编程中的死锁问题实例

原创今天药忘吃喽~ 2024-10-14 11:45 56阅读 0赞

死锁是多线程并发编程中的一种严重问题，当两个或更多的线程因争夺资源而造成的一种互相等待的现象时，就会出现死锁。

下面是一个简单的Java死锁示例：

```java
// 线程1拥有资源R1
class Thread1 extends Thread {
    private Resource R1;

Thread1(Resource r1) {
        R1 = r1;
    }

public void run() {
        try {
            acquire(R1); // 获取资源R1

System.out.println("Thread 1: Executing task");

executeTask();

release(R1); // 释放资源R1

System.out.println("Thread 1: Finished");

} catch (InterruptedException | RuntimeException e) {
            e.printStackTrace();
        }
    }

private void acquire(Resource r) {
        while (!r.isAvailable()) {
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        r.setAvailable(true);
    }

private void release(Resource r) {
        if (r.isAvailable()) {
            r.setAvailable(false);
            notifyAll();
        }
    }

private void executeTask() {
        // 这里是任务的执行代码，例如IO操作
        System.out.println("Thread 1: Running task");

try {
            Thread.sleep(5000); // 模拟耗时的任务
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

// 线程2拥有资源R2
class Thread2 extends Thread {
    private Resource R2;

Thread2(Resource r2) {
        R2 = r2;
    }

public void run() {
        try {
            acquire(R2);

System.out.println("Thread 2: Executing task");

executeTask();

release(R2);

System.out.println("Thread 2: Finished");

} catch (InterruptedException | RuntimeException e) {
            e.printStackTrace();
        }
    }

private void release(Resource r) {
        if (r.isAvailable()) {
            r.setAvailable(false);
            notifyAll();
        }
    }