java - 我应该调用 `executorService.shutdown` 和 `executorService.awaitTermination` 吗？

Question

/**
 * Blocks until all tasks have completed execution after a shutdown
 * request, or the timeout occurs, or the current thread is
 * interrupted, whichever happens first.
 *
 * @param timeout the maximum time to wait
 * @param unit the time unit of the timeout argument
 * @return {@code true} if this executor terminated and
 *         {@code false} if the timeout elapsed before termination
 * @throws InterruptedException if interrupted while waiting
 */
boolean awaitTermination(long timeout, TimeUnit unit)
    throws InterruptedException;

关闭后完成执行是什么意思？

这是否意味着我必须执行shutdown API？

我的代码应该是这样的:

@Test
public void setUserNamePropertyFromMultiThreadsUpdatesCorrectly() throws Exception {
        ..

        List<Callable<Void>> callables = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            callables.add(new Callable<Void>() {
                @Override
                public Void call() throws Exception {
                    ..
                    assertTrue(isSuccess);
                    return null;
                }
            });
        }
        ExecutorService executorService = Executors.newFixedThreadPool(10);
        try {
            executorService.invokeAll(callables);
            executorService.shutdown();
            executorService.awaitTermination(1, TimeUnit.MINUTES);
        } catch (InterruptedException e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }

   ..
}

或

 try {
                executorService.invokeAll(callables);
                executorService.awaitTermination(1, TimeUnit.MINUTES);
            } catch (InterruptedException e) {
                e.printStackTrace();
                throw new RuntimeException(e);
            }

什么这个方法不等待之前提交的任务 完整执行 是什么意思？即使任务没有完成也发送停止中断？

/**
 * Initiates an orderly shutdown in which previously submitted
 * tasks are executed, but no new tasks will be accepted.
 * Invocation has no additional effect if already shut down.
 *
 * <p>This method does not wait for previously submitted tasks to
 * complete execution.  Use {@link #awaitTermination awaitTermination}
 * to do that.
 */
void shutdown();

Answer 1

关闭:不再有传入任务。

awaitTermination:在关闭请求后调用。

What does this completed execution after a shutdown mean?

您应该首先调用shutdown。否则，您可能会等待很长时间，因为 awaitTermination 实际上并没有关闭您的执行程序。

Does it mean I have to execute a shutdown API?

是的，如上所述

What does This method does not wait for previously submitted tasks to complete execution mean?

这意味着，shutdown 不是阻塞调用...方法在调用后立即返回。被阻止直到一切完成..您调用awaitTermination。