ReentrantLock读写锁

Z时代
2024-01-10
分类：综合

写写共享读写互斥写写互斥

适合读多的业务提高效率

import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock.ReadLock;
import java.util.concurrent.locks.ReentrantReadWriteLock.WriteLock;
public class UseReentrantReadWriteLock {
	private ReentrantReadWriteLock rwLock = new ReentrantReadWriteLock();
	private ReadLock readLock = rwLock.readLock();
	private WriteLock writeLock = rwLock.writeLock();
	public void read(){
		try {
			readLock.lock();
			System.out.println("当前线程:" + Thread.currentThread().getName() + "进入...");
			Thread.sleep(3000);
			System.out.println("当前线程:" + Thread.currentThread().getName() + "退出...");
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			readLock.unlock();
		}
	}
	public void write(){
		try {
			writeLock.lock();
			System.out.println("当前线程:" + Thread.currentThread().getName() + "进入...");
			Thread.sleep(3000);
			System.out.println("当前线程:" + Thread.currentThread().getName() + "退出...");
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			writeLock.unlock();
		}
	}
	public static void main(String[] args) {
		final UseReentrantReadWriteLock urrw = new UseReentrantReadWriteLock();
		Thread t1 = new Thread(new Runnable() {
			public void run() {
				urrw.read();
			}
		}, "t1");
		Thread t2 = new Thread(new Runnable() {
			public void run() {
				urrw.read();
			}
		}, "t2");
		Thread t3 = new Thread(new Runnable() {
			public void run() {
				urrw.write();
			}
		}, "t3");
		Thread t4 = new Thread(new Runnable() {
			public void run() {
				urrw.write();
			}
		}, "t4");		
		//读读共享
		t1.start();
		t2.start();
		//读写互斥
//		t1.start(); // R 
//		t3.start(); // W
		//写写互斥
		t3.start();
		t4.start();
	}}