Re: [Boost-users] [Thread] Timed join returning true before thread terminated

Subject: Re: [Boost-users] [Thread] Timed join returning true before thread terminated
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2012-03-09 02:02:13

Le 09/03/12 04:32, John Rocha a écrit :
> Hello,
>
> I'm working on a multi-threaded application that uses boost threads. 
> The threads are deployed in a cascading mechanism such as:
>
> Main thread creates thread1
>
> thread 1 creates threads 2, 3 and 4
>
> thread 2 creates threads 5-14
>
>
> The shutdown mechanism is to send a thread interrupt and then do a 
> timed join to wait for the child thread[s] to finish their shutdown.
>
> So Main sends a thread interrupt to thread1, and then waits for X seconds
>
> thread 1 sends a thread interrupt to thread 2, and does a timed wait, 
> then thread 3 and wait then thread 4 and wait
>
> thread 2 does the same for each of its children: send a thread 
> interrupt and then wait.
>
How and when thread1 starts the shutdown processing?
> The problem is, that on rare occasions (1 out of 474 attempts in my 
> last test cycle), thread 1 will return early from the timed_join, and 
> it returns true, indicating the child thread is dead -- but it's not.
>
> I have timed logging that shows when a specific threads, shutdown 
> activities start and stop, and I can see that thread 1 isn't waiting 
> 10 seconds for the child to exit, and I can see the child is still 
> running.
>
>
> Any suggestions for this? The only thing I can think of right now is 
> that maybe thread1 is getting an interrupt for something that is 
> causing it to leave it's timed_join early? I haven't looked into the 
> boost code for this yet. I'm hoping that this is something others have 
> encountered and already solved?
>
> Or maybe other debugging tips could be provided?
Could you post a simple example? This would help to better analyze the 
issue.

Best,
Vicente