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gh-145587: fix busy loop in multiprocessing.connection.wait on Windows#145597

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Shrey-N wants to merge 3 commits intopython:mainfrom
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gh-145587: fix busy loop in multiprocessing.connection.wait on Windows#145597
Shrey-N wants to merge 3 commits intopython:mainfrom
Shrey-N:145587

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@Shrey-N Shrey-N commented Mar 6, 2026 •
edited by bedevere-app bot
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On Windows, multiprocessing.connection.wait returns immediately if the object_list is empty, regardless of the timeout.

This fix adds a check to make sure the function actually sleeps for the duration of the timeout, matching the Unix behavior and stopping the 100% CPU usage spike.

Verified locally:-

import time
from multiprocessing.connection import wait
start = time.time()
wait([], 1.0) # took 0s before, now takes 1
print(time.time() - start)

Fixes #145587

@Shrey-N
pythongh-145587: fix busy loop in multiprocessing.connection.wait on …
4ff9834 
…Windows

Ensure wait() blocks for the specified timeout when object_list is empty, preventing 100% CPU usage. This aligns the Windows behavior with the Unix implementation.
@Shrey-N Shrey-N requested a review from gpshead as a code owner March 6, 2026 16:11
@bedevere-app bedevere-app bot mentioned this pull request Mar 6, 2026
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multiprocessing.connection.wait high CPU load with empty object_list

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