Java并发编程：Lock和Condition使用示例-蒲公英云

Java并发编程：Lock和Condition使用示例

在Java并发编程中，Lock和Condition是两个重要的同步工具。下面分别给出它们的使用示例。

Lock（锁）：

ReentrantLock 是最常用的锁实现，它具有公平性和可重入性。

示例代码：

import java.util.concurrent.locks.ReentrantLock;
public class LockExample {
    private final ReentrantLock lock = new ReentrantLock();
    public void criticalSection() {
        try {
            // 获取锁
            lock.lock();
            // 执行临界区操作
            System.out.println("Critical section is executing.");
            // 释放锁
            lock.unlock();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
    public static void main(String[] args) {
        LockExample example = new LockExample();
        example.criticalSection();
    }
}

Condition（条件）：

Variable 类是与条件相关的变量。
ConditionalVariable 和 Semaphore 是实现条件的两种方式。

示例代码：

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 criticalSection() throws InterruptedException {
        lock.lock();
        try {
            // 设置条件
            condition.signalAll();
            System.out.println("Signalling all threads.");
            // 等待条件
            while (!condition.await(1, TimeUnit.SECONDS)))) {
                System.out.println("Waiting for condition signal.");
            }
            System.out.println("Condition has been signalled and thread is waiting.");
        } finally {
            lock.unlock();
        }
    }
    public static void main(String[] args) {
        ConditionExample example = new ConditionExample();
        example.criticalSection();
    }
}