package com.jysemel.java.locks;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReentrantLock;


public class ReentrantLockDemo {

    /**
     * 默认创建非公平锁
     */
    private static final ReentrantLock lock = new ReentrantLock();

    public static void main(String[] args) {
        for (int i = 0; i < 10; i++) {
            new Thread(() -> {
                lock.lock();
                System.out.println(Thread.currentThread().getName() + "获取成功");
                try {
                    System.out.println(Thread.currentThread().getName() + "执行业务");
                    Thread.sleep(TimeUnit.SECONDS.toMillis(4));
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                } finally {
                    lock.unlock();
                    System.out.println(Thread.currentThread().getName() + "获取成功");
                }
            }).start();
        }
    }
}

package com.jysemel.java.locks;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;


public class ReentrantLockConditionDemo {

    private final Lock lock = new ReentrantLock();
    private final Condition condition = lock.newCondition();

    public void await() {
        if (lock.tryLock()) {
            try {
                System.out.println("await开始等待");
                condition.await();
                System.out.println("await结束等待");
            } catch (InterruptedException e) {
                System.out.println("--------------");
            } finally {
                lock.unlock();
            }
        }
    }


    public void signal() {
        if ( lock.tryLock()) {
            try {
                System.out.println("signal开始通知");
                try {
                    Thread.sleep(TimeUnit.SECONDS.toMillis(3));
                } catch (InterruptedException e) {
                    System.out.println("---------");
                }
                condition.signal();
                System.out.println("signal 唤醒通知完毕");
            } finally {
                lock.unlock();
            }
        }
    }


    public static void main(String[] args) throws InterruptedException {
        ReentrantLockConditionDemo counter= new ReentrantLockConditionDemo();
        // 先启动执行等待的线
        new Thread(counter::await).start();
        Thread.sleep(3000);
        // 过3秒，再启动执行通知的线程
        new Thread(counter::signal).start();
    }
}