Question

我将Long类型的LinkedBlockingQueue列表提交给ThreadPoolExecutor，条件应为每个线程选择long类型的LinkedBlockingQueue并并行执行

这是我的方法逻辑

public void doParallelProcess() {

    List<LinkedBlockingQueue<Long>> linkedBlockingQueueList = splitListtoBlockingQueues();
    ThreadPoolExecutor executor = new ThreadPoolExecutor(1, linkedBlockingQueueList.size(), 0L,
            TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>(), Executors.defaultThreadFactory());
    Long initial = System.currentTimeMillis();
    try {

        System.out.println("linkedBlockingQueueList begin size is " + linkedBlockingQueueList.size() + "is empty"
                + linkedBlockingQueueList.isEmpty());

        while (true) {
            linkedBlockingQueueList.parallelStream().parallel().filter(q -> !q.isEmpty()).forEach(queue -> {
                Long id = queue.poll();
                MyTestRunnable runnab = new MyTestRunnable(id);
                executor.execute(runnab);
                System.out.println("Task Count: " + executor.getTaskCount() + ", Completed Task Count: "
                        + executor.getCompletedTaskCount() + ", Active Task Count: " + executor.getActiveCount());
            });

            System.out.println("linkedBlockingQueueList end size is " + linkedBlockingQueueList.size() + "is empty"
                    + linkedBlockingQueueList.isEmpty());

            System.out.println("executor service " + executor);

            if (executor.getCompletedTaskCount() == (long) mainList.size()) {
                break;
            }

            while (executor.getActiveCount() != 0) {
                System.out.println("Task Count: " + executor.getTaskCount() + ", Completed Task Count: "
                        + executor.getCompletedTaskCount() + ", Active Task Count: " + executor.getActiveCount());
                Thread.sleep(1000L);
            }

        }
    } catch (Exception e) {
    } finally {
        executor.shutdown();
        while (!executor.isTerminated()) {
        }
    }
} `

如何将LinkedBlockingQueue列表提交到单个线程例子：

List<LinkedBlockingQueue<Long>>每个LinkedBlockingQueue 包含50个队列数据
List<LinkedBlockingQueue<Long>>的大小是50
每个线程应选择一个LinkedBlockingQueue<Long>并执行50个队列任务。

Answer 1

ExecutorService的输入是Runnable或Callable。您提交的任何任务都需要实现这两个接口之一。如果要向线程池提交一堆任务并等待它们全部完成，则可以使用invokeAll方法并遍历生成的Future s，调用get关于每个问题：请参见有关类似问题的信息丰富的answer。

不过，您不需要将输入任务分批处理。您永远不希望执行程序服务在仍有要做的工作时具有空闲线程！您希望它能够在资源释放后立即抓住下一个任务，并且以这种方式进行批处理与此相反。您的代码正在执行此操作：

while non-empty input lists exist {
    for each non-empty input list L {
        t = new Runnable(L.pop())
        executor.submit(t)
    }
    while (executor.hasTasks()) {
        wait
    }
}

一旦这些任务之一完成，该线程就应该可以自由地进行其他工作。但这不是因为您要等到所有N个任务都完成后再提交。使用invokeAll一次提交所有内容，然后让执行者服务执行其构建的工作。

Answer 2

Executors类是线程池的主要条目：

    ExecutorService executor = Executors.newCachedThreadPool();
    linkedBlockingQueueList.forEach(queue -> executor.submit(() -> { /* process queue */ }));

如果您确实想自己创建ThreadPoolExecutor（它确实使您可以更好地控制配置），则可以使用至少两种方法指定默认线程工厂：

忽略线程工厂参数：

    ThreadPoolExecutor executor = new ThreadPoolExecutor(1, linkedBlockingQueueList.size(),
            0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>());

再次使用Executors类来获取默认线程工厂：

    ThreadPoolExecutor executor = new ThreadPoolExecutor(1, linkedBlockingQueueList.size(),
            0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>(),
            Executors.defaultThreadFactory());

如何将List <linkedblockingqueue <long >>提交给ThreadPoolExecutor，每个线程将选择一个LinkedBlockingQueue并并行执行

2 个答案: