multiprocessing, what am I doing wrong?

MRAB python at
Thu Feb 23 21:42:05 CET 2012

On 23/02/2012 17:59, Eric Frederich wrote:
> Below is some pretty simple code and the resulting output.
> Sometimes the code runs through but sometimes it just freezes for no
> apparent reason.
> The output pasted is where it just got frozen on me.
> It called start() on the 2nd worker but the 2nd worker never seemed to
> enter the run method.

The 2nd worker did enter the run method; there are 2 lines of "2".

Maybe there's an uncaught exception in the run method for some reason.
Try doing something like this:

     args = self.inbox.get_nowait()
except Queue.Empty:
     import traceback
     print "*** Exception in worker"
     print >> sys.stderr, traceback.print_exc()
     print "***"

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