JAVA併發程式設計實踐 79頁閉鎖

設定執行緒的集合點

import java.util.*;

import java.util.concurrent.*;

public class TestHarness{

    public long timeTasks(int nThreads,final Runnable task) throws Exception

    {

        final CountDownLatch startGate=new CountDownLatch(1);

        final CountDownLatch endGate=new CountDownLatch(nThreads);

        for(int i=0;i<nThreads;i++)

        {

            Thread t=new Thread(new Runnable(){

                public void run()

                {

                    try{

                        startGate.await();

                        task.run();

                    }

                    catch(Exception ex)

                    {}

                    finally{

                        endGate.countDown();

                    }

                }

            });

            t.start();

        }

        long start=System.nanoTime();

        startGate.countDown();

        endGate.await();

        long end=System.nanoTime();

        return end-start;

    }

    public static void main(String[] args) throws Exception

    {

        TestHarness t=new TestHarness();

        t.timeTasks(2,new Runnable(){

            public void run(){

                System.out.println(new Date());

            }

        });

    }

}

JAVA閉鎖

相關文章