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From: Alexander Terekhov <terekhov@web.de>
Newsgroups: comp.programming.threads
Subject: Re: usage of vyukov's mpsc queue
Date: Wed, 21 Sep 2011 17:06:34 +0200
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Ephi Sinowitz wrote:
[...]
> Producers set event after the push(). Event only transitions from
> unset to set when producer is inside the while loop.
> Now when Consumer goes back to Wait he should see the set event. The
> only issue is that he may still see a NULL next pointer because there
> are no memory barriers in the push(). In that case the consumer will
> go back to wait and the event will stay unset forever. But the 30
> second time limit should take care of that.
> for(;;)
>        WaitForSingleObject(m_queueEvent, 30000);
>         while (void* item = vyukov_queue.pop())
>         {
>             // do work
>         }
> }

With *timed* wait on <whatever> in consumer, push() and pop() need the
same barriers as without <whatever> blocking synchronization object.

Think of it as sleep(30) instead of WaitForSingleObject(m_queueEvent,
30000).

regards,
alexander.