Is an “atomic” interrupt check possible in java?

问题

If using following "idiom" with interruption in Java, for example from this answer.

while (!Thread.currentThread().isInterrupted()) {
    try {
        Object value = queue.take();
        handle(value);
    } catch (InterruptedException e) {
        Thread.currentThread().interrupt();
    }
}

Where take is a blocking operation, can an interrupt not be ignored for the time being if an interrupt "arrives" between the check of Thread.currentThread().isInterrupted() and the call queue.take()? Is this not a "check-than-act" operation? If so, can it somehow be guaranteed that the loop is left in any case if the thread is interrupted?

It is possible to use poll with a timeout so that the loop is left after the timeout, but is it possible to check the interrupted status and act on it atomically?

回答1:

I would swap the try/catch and while loop:

try {
  while (true) {
    Object value = queue.take();
    handle(value);
  }
} catch (InterruptedException e) {
  Thread.currentThread().interrupt();
}

The take() operation will throw an InterruptedException immediately if the thread is interrupted, and at the same time break out of the while loop.

回答2:

Only a call could clear then interrupted flag so nothing could happend between isInterrupted and queue.take().

回答3:

but is it possible to check the interrupted status and act on it atomically

Well - I don't know what you mean "atomically" here. May we assume you want something like onInterrupt(...)?

Interrupts are meant to "interrupt" the thread, so all default I/O operations throw an InterruptedException you can catch or check. It give the threads opportunity to stop gracefully closing / releasing any locked resources.

As event handling you may want to implement a Cancellable task, where you could handle your own cancel events (well, not the default JRE interrupts).

来源：https://stackoverflow.com/questions/37742304/is-an-atomic-interrupt-check-possible-in-java