Question

执行下面的代码后，我得到时间为0，因为主线程中存在时间计算，它正在计算durationTime值然后执行threadPool。

我想找到执行线程所花费的总时间。

public static void main(String[] args) {
        long startTime = System.nanoTime(); 
        int numberThread=10;
        String apiToBeCall="abcApi";

        Runnable r1=new SFSrmMainClass(apiToBeCall);

        ExecutorService threadPool=Executors.newFixedThreadPool(numberThread);
        for (int i=0;i<numberThread;i++)
        {

            threadPool.execute(r1);
        }
        threadPool.shutdown();

        long endTime = System.nanoTime();
         long durationTime = (endTime - startTime); 
        System.out.println("time for "+apiToBeCall +" is having thread="+numberThread +" is "+durationTime/1000000000);
    }

Answer 1

在调用shutdown（）之后使用awaitTermination，这会阻塞主线程直到所有线程都完成。

示例：

static long measureTasks(final int nThreads, final Runnable... tasks) 
    throws InterruptedException
{
    final ExecutorService pool = Executors.newFixedThreadPool(nThreads);
    final long startTime = System.nanoTime();

    for (Runnable task : tasks)
        pool.execute(task);

    pool.shutdown();
    pool.awaitTermination(10, TimeUnit.SECONDS);

    return System.nanoTime() - startTime;
}

如何找到多线程应用程序的执行时间

1 个答案: