线程通信

condition精准唤醒

public class ConditionDemo {
    private int curThread = 1;
    private Lock lock = new ReentrantLock();
    private Condition cond1 = lock.newCondition();
    private Condition cond2 = lock.newCondition();
    private Condition cond3 = lock.newCondition();
    public void printOnce() {
        lock.lock();
        try {
            while (1 != curThread) {
                cond1.await();
            }
            System.out.println(Thread.currentThread().getName() + ": AAA");
            curThread = 2;
            cond2.signalAll();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
    public void printTriple() {
        lock.lock();
        try {
            while (2 != curThread) {
                cond2.await();
            }
            for (int i = 0; i < 3; i++) {
                System.out.println(Thread.currentThread().getName() + ": BBB");
            }
            curThread = 3;
            cond3.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
    public void printFifth() {
        lock.lock();
        try {
            while (3 != curThread) {
                cond3.await();
            }
            for (int i = 0; i < 5; i++) {
                System.out.println(Thread.currentThread().getName() + ": CCC");
            }
            curThread = 1;
            cond1.signal();
            System.out.println("=======================");
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public static void main(String[] args) {
        ConditionDemo an = new ConditionDemo();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                an.printOnce();
            }
        }, "线程A").start();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                an.printTriple();
            }
        }, "线程B").start();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                an.printFifth();
            }
        }, "线程C").start();
    }
}