Regarding while (!executor.isTerminated())

Question

Can anyone tell me how
while (!executor.isTerminated())
works.
According to the implementation of isTerminated() method in ThreadPoolExecutor class , it only returns runState.
But the doubt is how is the while condition checked for all the threads.There should be some check inside isTerminated method which takes all the threads and one by one check the state of each thread and then return.
Can anyone explain?..
Or i am missing some big thing here.

Answer 1

Here in above code !executor.isTerminated() checks if all threads were terminated or not.
but if we check isterminated() method it has only
public boolean isTerminated() {
return runState == TERMINATED;
how does this check applied on all the threads.runState will be set to TERMINATED when the last (working) thread has finished running its task. Which makes it clear that there is no more thread is in running state. Therefore there is no meed to check each and every individual thread for completion of its task.
As mentioned by one of the early poster, please refer tryTerminate().
Here is the JavaDoc
private void tryTerminate()
Transitions to TERMINATED state if either (SHUTDOWN and pool and queue empty) or (STOP and pool empty), otherwise unless stopped, ensuring that there is at least one live thread to handle queued tasks. This method is called from the three places in which termination can occur: in workerDone on exit of the last thread after pool has been shut down, or directly within calls to shutdown or shutdownNow, if there are no live threads.