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Subject: Re: Exception in thread QueueFeederThread (most likely raised during interpreter shutdown)
From: Ziliang Chen <zlchen.ken@gmail.com>
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Xref: csiph.com comp.lang.python:39515

On Thursday, February 21, 2013 2:20:41 AM UTC+8, MRAB wrote:
> On 2013-02-20 08:26, Ziliang Chen wrote: > Hi Guys, > I am using the mult=
iprocessing module. The following code snippet occasionally throws the "Exc=
eption in thread QueueFeederThread (most likely raised during interpreter s=
hutdown)" exception. > > I searched google for the cause, someone says ther=
e are some issues with the multiprocessing.Queue (need do some sleep at whe=
re the queue is used). > > Could you please shed your light here, what is w=
rong, how can I use the multiprocess correctly ? > > Thanks very much ! > >=
 The python version is 2.6 and on Win7 x64 OS. > > ------------------ > fro=
m multiprocessing import Process,Queue > > def listTest(q): > print q.get()=
 > > def queueTest(): > q =3D Queue() > q.put([1,2,3,4,5,6]) > p =3D Proces=
s(target=3DlistTest,args=3D(q,)) > p.start() > p.join() > > if __name__=3D=
=3D'__main__': > queueTest() > > Exception in thread QueueFeederThread (mos=
t likely raised during interpreter shutdown): > I think it may be a race co=
ndition. When I tried it, sometimes it failed, sometimes it didn't. It seem=
ed to be better behaved when I put a small sleep at the end to delay the ma=
in process exiting.

Thanks, MRAB!
Yeah, I saw such kind of workaround after googling.
But seriously, why is there a race condition here ? Is there any misuse of =
queue here ?