How to reference running tasks in ThreadPoolExecutor?

Question

Hi all!
So this is a scenario: Thread pool size is 10 and there were 100 submitted callables)
threadPoolExecutor.submit(callable); // times 100Assuming that the tasks are still running, how do I find out which callables are currently being executed?
Thanks,
Andre

Answer 1

You're never going to get that because it's implementation-specific. It could be that the implementation doesn't even have it on a java thread but is using native threads to handle the execution. I'm not certain of all the rules of the specs but I'm sure there's enough leeway that a method which tells you which ones are on separate threads would eliminate optimization techniques.
What you CAN do is make your callable class have method which tell you if it's executing or not.
public class MyCallable implements Callable
     private volatile boolean isRunning = false;
     public void call() throws Exception
         try
                    ...open a lock...
                    isRunning = true;
                    ...close lock...
          finally
                    ...open a lock...
                    isRunning = false;
                    ...close lock...
     public boolean isRunning()
          boolean isRunningTmp = false;
               ...open a lock...
                   isRunningTmp = isRunning;
               ...close lock...
          return isRunningTmp;
}