> > That't not the reason. A Queue is built around a container, and it happens > to be a deque in the default implementation. But the important thing is > that a Queue is a synchronized object - it performs the necesary > synchronization to ensure proper operation even from multiple threads > attempting to use it at the same time. > So your comparison is meaningless, apart from telling that using mutexes > is not cheap. > > -- > Gabriel Genellina
Interesting, from the documentation for deque says; "Deques support thread-safe, ..." which would seem to imply a mutex of some sort would be used. But in looking at collectionsmodule.c for 2.5.1 I don't see any mutex which would seem to imply there is one place else, maybe the GIL, or the documentation is incorrect. On the other hand looking at the code in Queue.py there is a more code plus the not_full Condition variable plus the call to _put (which is a call to the deque.append) plus a notify on the not_empty conditional, so it's not surprising it's slower. If and when I think Queue is a performance impediment to an mproc I'll take another look at it, for now lots of things to learn. Thanks, Wink -- http://mail.python.org/mailman/listinfo/python-list
