ReentrantReadWriteLock 可重入读写锁例子-优快云博客

本文通过使用ReentrantReadWriteLock实现读写锁的并发控制，详细介绍了如何在多线程环境中进行资源的读写操作，确保数据的一致性和线程安全。通过示例代码展示了读线程和写线程的执行过程，以及如何利用线程池来管理这些线程。

示例：

import lombok.extern.slf4j.Slf4j;

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantReadWriteLock;


@Slf4j
public class ReadAndWriteMain {

    private static final ReentrantReadWriteLock LOCK = new ReentrantReadWriteLock();

    private static int num = 0;

    private static void op(Lock lock, boolean read) {
        try {
            lock.lock();
            Thread.sleep(1000L);
            if (read) {
                log.info("thread-id:{}\t读操作\tnum:{}", Thread.currentThread().getId(), num);
            } else {
                log.info("thread-id:{}\t写操作\tnum:{}", Thread.currentThread().getId(), ++num);
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public static class ReadThread implements Runnable {

        @Override
        public void run() {
            op(LOCK.readLock(), true);
        }

    }

    public static class WriteThread implements Runnable {

        @Override
        public void run() {
            op(LOCK.writeLock(), false);
        }

    }

    private static ThreadFactory factory = Thread::new;

    private static ThreadPoolExecutor exec =
            new ThreadPoolExecutor(10, 10, 5L, TimeUnit.SECONDS,
                    new ArrayBlockingQueue<>(10),
                    factory);


    public static void main(String[] args) {
        long st = System.currentTimeMillis();
        int n = 5;
        for (int i = 0; i < n; i++) {
            exec.execute(new ReadThread());
            exec.execute(new ReadThread());
//            exec.execute(new WriteThread());
        }
        quit(st);
    }

    private static void quit(long st) {
        exec.shutdown();
        while (true) {
            if (exec.isTerminated()) {
                log.info("执行耗时: {}ms", (System.currentTimeMillis() - st));
                return;
            }
        }
    }

}

转载于:https://my.oschina.net/pipimao/blog/3068055