CountDownLatch和CyclicBarrier的简单应用1

爱被打了一巴掌 2022-04-05 10:44 159阅读 0赞

import java.util.Random;
    import java.util.concurrent.CountDownLatch;
    public class Test11 {
    	public static void main(String[] args) throws InterruptedException {
    		Runnable task = new Runnable(){
    			@Override
    			public void run() {
    				try {
    					int rand = new Random().nextInt(1000);
    					Thread.sleep(rand);
    					System.out.println(Thread.currentThread().getName()+"##"+rand);
    				} catch (InterruptedException e) {e.printStackTrace();}
    			}
    		};
    		Test11 t = new Test11();
    		System.out.println("共执行时间："+t.timeTask(3, task));
    	}
    	public long timeTask(int ThreadNum,final Runnable task) throws InterruptedException{
    		final CountDownLatch startGete = new CountDownLatch(1);
    		final CountDownLatch endGete = new CountDownLatch(ThreadNum);
    		for(int i=0; i<ThreadNum; i++){
    			new Thread(){
    				public void run(){
    					try {
    						startGete.await();
    						task.run();
    					} catch (InterruptedException e) {
    						e.printStackTrace();
    					}finally{						
    						endGete.countDown();
    					}
    				}
    			}.start();
    		}
    		long start = System.currentTimeMillis();
    		startGete.countDown();
    		endGete.await();
    		long end = System.currentTimeMillis();
    		return end - start;
    	}
    	/**
    	 * 运行结果：因为三个线程并行执行所以不会比最大的执行时间多很多
    	 *  Thread-1##108
    		Thread-2##125
    		Thread-0##662
    		共执行时间：672
    	 */
    }

import java.util.Random;
    import java.util.concurrent.CyclicBarrier;
    import java.util.concurrent.atomic.AtomicInteger;
    public class Test12 {
    	public static void main(String[] args) throws InterruptedException {
    		Runnable task = new Runnable(){
    			@Override
    			public void run() {
    				try {
    					int rand = new Random().nextInt(1000);
    					Thread.sleep(rand);
    					System.out.println(Thread.currentThread().getName()+"##"+rand);
    				} catch (InterruptedException e) {e.printStackTrace();}
    			}
    		};
    		Test12 t = new Test12();
    		System.out.println("共执行时间："+t.timeTask(3, task));
    	}
    	public long timeTask(int ThreadNum,final Runnable task) throws InterruptedException{
    		final CyclicBarrier endGete = new CyclicBarrier(ThreadNum);
    		long start = System.currentTimeMillis();
    		final AtomicInteger count = new AtomicInteger(3);
    		for(int i=0; i<ThreadNum; i++){
    			new Thread(){
    				public void run(){
    					try {
    						endGete.await();
    						task.run();
    					} catch (Exception e) {
    						e.printStackTrace();
    					}finally{
    						count.decrementAndGet() ;
    					}
    				}
    			}.start();
    		}
    		while(count.get() > 0){
    //			System.out.println("等待.......");
    		}
    		long end = System.currentTimeMillis();
    		return end - start;
    	}
    	/**
    	 * 运行结果：因为三个线程并行执行所以不会比最大的执行时间多很多
    		Thread-1##86
    		Thread-2##331
    		Thread-0##663
    		共执行时间：672
    	 */
    }