深入解析Java中的并发工具：Lock和Condition示例-蒲公英云

深入解析Java中的并发工具：Lock和Condition示例

原创红太狼 2024-10-13 14:03 165阅读 0赞

在Java中，Lock和Condition是两个重要的并发工具，分别用于管理共享资源的访问权限以及线程之间的通信。

Lock（锁）：

ReentrantLock：这是最常用的锁实现，它提供了可重入、公平竞争等特性。
使用示例：
```java
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class LockExample {
private final Lock lock = new ReentrantLock();

public void lockResource() {
    try {
        lock.lock();
        System.out.println("Resource locked.");
    } catch (InterruptedException e) {
        // Handle interruption
        e.printStackTrace();
    } finally {
        // Always unlock
        try {
            lock.unlock();
            System.out.println("Resource unlocked.");
        } catch (Exception e) {
            // Handle any exception while unlocking
            e.printStackTrace();
        }
    }
}
public static void main(String[] args) {
    LockExample example = new LockExample();
    example.lockResource();  // Acquire the lock
    Thread.sleep(500);  // Let other threads execute
    example.lockResource();  // Try to acquire again, should fail due to lock held
}

}


2. Condition（条件）：
- `Condition`：它是`Lock`的一部分，用于在锁定共享资源的同时进行线程间的通信。
- 使用示例：
```java
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class ConditionExample {
    private final Lock lock = new ReentrantLock();
    private final Condition condition = lock.newCondition();
    public void signal() {
        lock.lock();
        try {
            condition.signalAll();  // Notify all waiting threads
            System.out.println("Signaled.");
        } finally {
            lock.unlock();
        }
    }
    public void await() throws InterruptedException {
        lock.lock();
        try {
            condition.await();  // Wait until notified or timeout occurs
            System.out.println("Awoken.");
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
    public static void main(String[] args) {
        ConditionExample example = new ConditionExample();
        example.signal();  // Notify all waiting threads
        Thread.sleep(500);  // Let other threads execute
        example.await();  // Wait until notified or timeout occurs
    }
}