ScheduledExecutorService and ThreadPoolTaskExecutor that interrupts tasks after a timeout

问题

I Used ExecutorService that interrupts tasks after a timeout.I use a ScheduledExecutorService for this. First I submitted the thread and it once to begin immediately and retain the future that is created. After that i use ScheduledExecutorService as a new task that would cancel the retained future after some period of time.

//Start Spring executor to submit tasks
ThreadPoolTaskExecutor taskExecutor = (ThreadPoolTaskExecutor) ApplicationContextProvider.getApplicationContext().getBean("taskExecutor"); 

CompletionService completionService = new ExecutorCompletionService(taskExecutor);
//End Spring executor to submit tasks

// Start ScheduledExecutorService  to submit returned future object to timeout

ScheduledExecutorService executor = Executors.newScheduledThreadPool(Integer.parseInt(config.getProperty("DBPOLLER_COREPOOLSIZE")));

final Future<String> future = completionService.submit(batchJob); // Submit actual task and get future

// submit future

executor.schedule(new Runnable() {
      public void run() {
                         future.cancel(true);
      }
   }, dbPollerTimeOut, TimeUnit.MINUTES);

int count = taskExecutor.getActiveCount();

 if (count == 0) {

                taskExecutor.shutdown();
                executor.shutdown();
                finalExitStatus = 0;                    
                break;

            }

I have implemented the solution which is in below url: ExecutorService that interrupts tasks after a timeout, it was working fine, until timeout, but once timeout happens, it cancels all theenter code here tasks i ThreadPool which is not acceptable. I need to cancel only tasks that are long running and reach timeout.

Any idea how to achieve this?

回答1:

It is not clear what your CompletionService is, and you are submitting your batchJob on it, so it is hard to tell exact root cause of your problem. But ideal scenario of submitting few tasks and cancelling them after some time, is to use ScheduledExecutorService for both purposes.

So, can try submitting the batchJobon instance of ScheduledExecutorService i.e. executor.

final Future<String> future = executor.submit(batchJob); // Submit actual task and get future

EDIT UPDATE: Important change you SHOULD do in your code
I see that you are never stopping your ScheduledExecutorService which is wrong because resources it occupies will never be released until you stop it. So, your updated code should be as below:

ScheduledExecutorService executor = Executors.newScheduledThreadPool(Integer.parseInt(config.getProperty("DBPOLLER_COREPOOLSIZE")));
final Future<String> future = executor.submit(batchJob); // Submit actual task and get future
executor.schedule(new Runnable() {
      public void run() {
        future.cancel(true);
        executor.shutdownNow();
      }
   }, dbPollerTimeOut, TimeUnit.MINUTES);

来源：https://stackoverflow.com/questions/30649643/scheduledexecutorservice-and-threadpooltaskexecutor-that-interrupts-tasks-after

标签

java

multithreading

concurrency

threadpool

executorservice