[Python-Dev] bpo-34837: Multiprocessing.Pool API Extension (original) (raw)

[Python-Dev] bpo-34837: Multiprocessing.Pool API Extension - Pass Data to Workers w/o Globals

Chris Jerdonek chris.jerdonek at gmail.com
Thu Oct 18 16:16:57 EDT 2018

On Thu, Oct 18, 2018 at 9:11 AM Michael Selik <michael.selik at gmail.com> wrote:

On Thu, Oct 18, 2018 at 8:35 AM Sean Harrington <seanharr11 at gmail.com> wrote:

Further, let me pivot on my idea of qualname...we can use the id of func as the cache key to address your concern, and store this id on the task tuple (i.e. an integer in-lieu of the func previously stored there).

Possible. Does the Pool keep a reference to the passed function in the main process? If not, couldn't the garbage collector free that memory location and a new function could replace it? Then it could have the same qualname and id in CPython. Edge case, for sure. Worse, it'd be hard to reproduce as it'd be dependent on the vagaries of memory allocation.

I'm not following this thread closely, but I just wanted to point out that qualname won't necessarily be an attribute of the object if the API accepts any callable. (I happen to be following an issue on the tracker where this came up.)

--Chris

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