JUC --- read-write lock

1. ReadWriteLock: The read operation and the write operation thread run together to improve the efficiency of the same operation.

2. Test code:

　　

public class T_ReadWriteLock {

    static Lock lock = new ReentrantLock();

    static ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
    static Lock readLock = readWriteLock.readLock();
    static Lock writeLock = readWriteLock.writeLock();


    public static void read(Lock lock){

        try {
            lock.lock();
            //读需要1秒
            Thread.sleep(1000);
            System.out.println("读完毕！");

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }

    }

    public static void write(Lock lock) {
        try {
            lock.lock();
            //写需要2秒
            Thread.sleep(2000);
            System.out.println("写完毕！");
        }catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }


    public static void main(String[] args) {

//        Runnable read = ()->read(lock);  //使用正常锁
//        Runnable write = ()->write(lock);

        Runnable read = ()->read(readLock);
        Runnable write = ()->write(writeLock);

        for (int i=0; i<18; i++) new Thread(read).start();
        for (int i=0; i<2; i++) new Thread(write).start();

    }

}