Message340464
So:
#1 we've a bug: the single-threaded ProcessPoolExecutor test program should work 100% reliably - it does not
#2 we've a cause: ProcessPoolExecutor is implemented internally using an unfortunate combination of fork and threads, this is causing the deadlock
#3 we've got a workaround - something like:
ProcessPoolExecutor(multiprocessing.get_context('spawn'))
but I'm guessing, the documentation is scant.
As for a fix, maybe:
- have ProcessPoolExecutor use 'spawn' by default; this way things always work
- have ProcessPoolExecutor properly synchronized its threads before "spawning"/"forking"/... so that "single-threaded" code works
- document that combining ProcessPoolExecutor's "fork" option and user threads isn't a good idea |
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Date |
User |
Action |
Args |
2019-04-18 02:34:06 | cagney | set | recipients:
+ cagney, gregory.p.smith, bquinlan, pitrou, vstinner, jwilk, josh.r, hroncok, pablogsal, hugh |
2019-04-18 02:34:06 | cagney | set | messageid: <1555554846.9.0.823559915095.issue35866@roundup.psfhosted.org> |
2019-04-18 02:34:06 | cagney | link | issue35866 messages |
2019-04-18 02:34:06 | cagney | create | |
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