Latch模式--多线程同步

旧城等待， 2023-07-25 05:28 16阅读 0赞

1，相关文章推荐

[Java多线程---CountDownLatch用法实例][Java_---CountDownLatch]

[POI结合线程池批量处理导入减少导入时间][POI]

2，直接源码

package com.wayne.latchPattern;
    
    import java.sql.Time;
    import java.util.concurrent.TimeUnit;
    
    public abstract class Latch {
    
        protected int limit;
    
        public Latch(int limit){
            this.limit = limit;
        }
    
        public abstract void await() throws InterruptedException;
    
        public abstract void await(TimeUnit timeUnit,long time) throws InterruptedException, WaitTimeoutException;
    
        public abstract void countdown();
    
        public abstract int getUnArrived();
    }

package com.wayne.latchPattern;
    
    import java.util.concurrent.TimeUnit;
    
    public class CountDownLatch extends Latch {
    
        public CountDownLatch(int limit){
            super(limit);
        }
    
        @Override
        public void await() throws InterruptedException {
            synchronized (this){
                while (limit >0) {
                    this.wait();
                }
            }
        }
    
        @Override
        public void await(TimeUnit timeUnit, long time) throws InterruptedException,WaitTimeoutException {
            if(time <= 0 ){
                throw new IllegalArgumentException("time is invaild.");
            }
    
            long remainingNanos = timeUnit.toNanos(time);
            final long endNanos = System.nanoTime() + remainingNanos;
            synchronized (this){
                while (limit > 0){
                    if(TimeUnit.NANOSECONDS.toMillis(remainingNanos)<= 0){
                        throw new WaitTimeoutException("The wait time over specify time.");
                    }
    
                    this.wait(TimeUnit.NANOSECONDS.toMillis(remainingNanos));
                    remainingNanos = endNanos - System.nanoTime();
                }
            }
        }
    
        @Override
        public void countdown() {
            synchronized (this){
                if(limit <= 0){
                    throw new IllegalStateException(" all arrived");
                }
    
                limit--;
                this.notifyAll();
            }
        }
    
        @Override
        public int getUnArrived() {
            synchronized (this){
                return limit;
            }
        }
    }

package com.wayne.latchPattern;
    
    import org.omg.CORBA.TIMEOUT;
    
    import java.util.Random;
    import java.util.concurrent.TimeUnit;
    
    public class ProgrammerTravel extends Thread {
    
        private final Latch latch;
    
        private final String programmer;
    
        private final String transport;
    
        public ProgrammerTravel(Latch latch,String programmer,String transport){
            this.latch = latch;
            this.programmer = programmer;
            this.transport = transport;
        }
    
        @Override
        public void run() {
            try{
                System.out.println(programmer+" start to move with "+ transport);
                TimeUnit.SECONDS.sleep(new Random(System.currentTimeMillis()).nextInt(10));
            } catch (Exception e){
                e.printStackTrace();
            }
    
            System.out.println(programmer+" with "+transport+ " has arrived!");
            latch.countdown();
        }
    }

package com.wayne.latchPattern;
    
    public class WaitTimeoutException extends Exception {
    
        public WaitTimeoutException(String message){
            super(message);
        }
    }

package com.wayne.latchPattern;
    
    import java.util.concurrent.TimeUnit;
    
    public class LatchPatternTest {
    
        public static void main(String[] args) throws InterruptedException, WaitTimeoutException {
            Latch latch = new CountDownLatch(4);
            new ProgrammerTravel(latch,"Wayne","Bicycle").start();
            new ProgrammerTravel(latch,"Bruce","Bus").start();
            new ProgrammerTravel(latch,"Batman","Car").start();
            new ProgrammerTravel(latch,"IronMan","Flight").start();
            latch.await(TimeUnit.SECONDS,5);
    
            System.out.println("All arrived,let's start!");
        }
    }

[Java_---CountDownLatch]: https://blog.csdn.net/a80C51/article/details/78884901
[POI]: https://blog.csdn.net/a80C51/article/details/78920448