New submission from Max:
It seems both me and many other people (judging from SO questions) are confused
about whether it's ok to write this:
from multiprocessing import Process, Queue
q = Queue()
def f():
q.put([42, None, 'hello'])
def main():
p = Process(target=f)
p.start()
print(q.get()) # prints "[42, None, 'hello']"
p.join()
if __name__ == '__main__':
main()
It's not ok (doesn't work on Windows presumably because somehow when it's
pickled, the connection between global queues in the two processes is lost;
works on Linux, because I guess fork keeps more information than pickle, so the
connection is maintained).
I thought it would be good to clarify in the docs that all the Queue() and
Manager().* and other similar objects should be passed as parameters not just
defined as globals.
----------
assignee: docs@python
components: Documentation
messages: 289454
nosy: docs@python, max
priority: normal
severity: normal
status: open
title: Clarify how to share multiprocessing primitives
type: behavior
versions: Python 3.6
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Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue29795>
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