Java多线程同步工具Lock、Synchronized及ReentrantLock的对比实例-蒲公英云

Java多线程同步工具Lock、Synchronized及ReentrantLock的对比实例

在Java中，多线程同步主要通过Lock接口实现，包括Lock（旧锁）、LockSupport.lock()（原生锁定）和ReentrantLock（重入锁）等。

下面以一个简单的生产者消费者场景来对比这些工具：

使用synchronized关键字：

public class SimpleSync {
 private int count = 0;
 public synchronized void producer() {
     count++;
     System.out.println("Producer: Count " + count);
     try {
         wait();
     } catch (InterruptedException e) {
         e.printStackTrace();
     }
 }
 public synchronized void consumer() {
     System.out.println("Consumer: Will consume " + count);
     if (count > 0) {
         count--;
         producer();
         notifyAll();
     }
 }
}

使用Lock接口：
```java
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class SimpleLock {
private int count = 0;
private Lock lock;

public SimpleLock() {
    lock = new ReentrantLock();
}
public void producer() {
    lock.lock();
    try {
        count++;
        System.out.println("Producer: Count " + count);
        wait();
    } catch (InterruptedException e) {
        e.printStackTrace();
    } finally {
        lock.unlock();
    }
}
public void consumer() {
    lock.lock();
    try {
        System.out.println("Consumer: Will consume " + count);
        if (count > 0) {
            count--;
            producer();
            notifyAll();
        }
    } catch (InterruptedException e) {
        e.printStackTrace();
    } finally {
        lock.unlock();
    }
}