Java并发编程之常用的辅助类详解

public class CountDownLatchDemo {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		for(int i=1;i<=6;i++){
			new Thread(()->{
				System.out.println(Thread.currentThread().getName()+"\t离开教室");
			},String.valueOf(i)).start();
		}
		System.out.println(Thread.currentThread().getName()+"\t班长关门走人");
	}
}

public CountDownLatch(int count) {
 if (count < 0) throw new IllegalArgumentException("count < 0");
 this.sync = new Sync(count);
 }

public static void main(String[] args) throws InterruptedException {
		//6个同学正在上自习，每个人就有一个1计数器，走1个数字减1，main线程启动，必须要等计时器从6变成0，才能开始。
		CountDownLatch countDownLatch=new CountDownLatch(6);
		for(int i=1;i<=6;i++){
			new Thread(()->{
				System.out.println(Thread.currentThread().getName()+"\t离开教室");
				countDownLatch.countDown();		//计算减少一个
			},String.valueOf(i)).start();
		}
		countDownLatch.await();	//班长前面需要被阻塞
		System.out.println(Thread.currentThread().getName()+"\t班长关门走人");
	}

public CyclicBarrier(int parties)
public CyclicBarrier(int parties, Runnable barrierAction)

public static void main(String[] args) {
		// TODO Auto-generated method stub
		CyclicBarrier cyclicBarrier=new CyclicBarrier(7,()->{System.out.println("召唤神龙");});
		for(int i=1;i<=7;i++){
			final int tempInt=i;
			new Thread(()->{
				System.out.println(Thread.currentThread().getName()+"\t收集到第"+tempInt+"颗龙珠");
				try {
					//某个线程收集到了龙珠只能先等着，等龙珠收齐了才能召唤神龙
					cyclicBarrier.await();
				} catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			},String.valueOf(i)).start();;
		}
	}

public static void main(String[] args) {
		//模拟6部车抢3个空车位
		Semaphore semaphore=new Semaphore(3);//模拟资源类，有3个空车位
		for(int i=1;i<=6;i++){
			new Thread(()->{
				try {
					//谁先抢到了，谁就占一个车位，并且要把semaphore中的资源数减1
					semaphore.acquire();
					System.out.println(Thread.currentThread().getName()+"\t抢占到了车位");
					TimeUnit.SECONDS.sleep(3);
					System.out.println(Thread.currentThread().getName()+"\t离开了车位");
					
				} catch (Exception e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}finally{
					//释放车位
					semaphore.release();
				}
				
			},String.valueOf(i)).start();
		}
	}