public class Test {
public static void main(String[] args) {
System.out.println("interrupting..");
Thread.currentThread().interrupt();
try {
Thread.sleep(100);
System.out.println("done.");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
Granted, this is an over-simplified test, and won't test for JVM bugs.
Calvin
On 6/1/07, Doug Cutting <[EMAIL PROTECTED]> wrote:
Are you certain that interrupt() is called before sleep()? If
interrupt() is called during the sleep() then it should clearly throw
the InterruptedException. The question is whether it is thrown if the
call to interrupt() precedes the call to sleep(). Please feel free to
post your test program. And, yes, the thread dump would be most welcome.
Cheers,
Doug
Calvin Yu wrote:
> You're right Doug, I ran a simple test to verify that interrupt() will
> result in a InterruptedException on a call to sleep(), so my hang up
> problem is something else. I'm going to rerun my job and post a
> thread dump of the hang up.
>
> Calvin
>
>
> On 6/1/07, Doug Cutting <[EMAIL PROTECTED]> wrote:
>> Calvin Yu wrote:
>> > The problem seems to be with the MapTask's (MapTask.java) sort
>> > progress thread (line #196) not stopping after the sort is completed,
>> > and hence the call to join() (line# 190) never returns. This is
>> > because that thread is only catching the InterruptedException, and not
>> > checking the thread's interrupted flag as well. According to the
>> > Javadocs, an InterruptedException is thrown only if the Thread is in
>> > the middle of the sleep(), wait(), join(), etc. calls, and during
>> > normal operations only the interrupted flag is set.
>>
>> I think that, if a thread is interrupted, and its interrupt flag is set,
>> and sleep() is called, then sleep() should immediately throw an
>> InterruptedException. That's what the javadoc implies to me:
>>
>> Throws: InterruptedException - if another thread has interrupted
>> the current thread.
>>
>> So this could be a JVM bug, or perhaps that's not the contract.
>>
>> I think we should fix this as a part of HADOOP-1431. We should change
>> that to use the mechanism we use elsewhere. We should have a 'running'
>> flag that's checked in the thread's main loop, and method to stop the
>> thread that sets this flag to false and interrupts it. That works
>> reliably in many places.
>>
>> Perhaps for the 0.14 release this logic should be abstracted into a base
>> class for Daemon threads, so that we don't re-invent it everywhere.
>>
>> Doug
>>
