gh-125541: Make Ctrl-C interrupt threading.Lock.acquire() on Windows

[colesbury]

• Issue: Make ctrl-c interrupt threading.Lock.acquire() on Windows #125541

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📚 Documentation preview 📚:
https://cpython-previews--125546.org.readthedocs.build/en/125546/library/threading.html
https://cpython-previews--125546.org.readthedocs.build/en/125546/library/_thread.html

[colesbury]

Lockbench results are within the noise margin:

Tools\lockbench\lockbench.py

Before:

C:\Users\Administrator\cpython>PCBuild\amd64\python.exe Tools\lockbench\lockbench.py
Lock Type           Threads           Acquisitions (kHz)   Fairness
PyMutex             1                 67954                1.00
PyMutex             2                 36700                1.00
PyMutex             3                 14673                0.99
PyMutex             4                 24245                1.00
PyMutex             5                 12929                1.00
PyMutex             6                  7775                1.00
PyMutex             7                  5316                1.00
PyMutex             8                  3868                1.00
PyMutex             9                  2791                1.00
PyMutex             10                 1947                1.00
PyThread_type_lock  1                 28604                1.00
PyThread_type_lock  2                 19378                1.00
PyThread_type_lock  3                  6893                0.99
PyThread_type_lock  4                  3620                1.00
PyThread_type_lock  5                  2222                1.00
PyThread_type_lock  6                  1464                1.00
PyThread_type_lock  7                  1391                1.00
PyThread_type_lock  8                  1339                1.00
PyThread_type_lock  9                  1092                1.00
PyThread_type_lock  10                 1141                1.00

After:

C:\Users\Administrator\cpython>PCBuild\amd64\python.exe Tools\lockbench\lockbench.py
Lock Type           Threads           Acquisitions (kHz)   Fairness
PyMutex             1                 67936                1.00
PyMutex             2                 38318                0.98
PyMutex             3                 14288                0.99
PyMutex             4                 22348                1.00
PyMutex             5                 13601                1.00
PyMutex             6                  8422                1.00
PyMutex             7                  5346                1.00
PyMutex             8                  4194                1.00
PyMutex             9                  2776                1.00
PyMutex             10                 1937                1.00
PyThread_type_lock  1                 28766                1.00
PyThread_type_lock  2                 14875                0.96
PyThread_type_lock  3                  5971                0.95
PyThread_type_lock  4                  3149                1.00
PyThread_type_lock  5                  2008                1.00
PyThread_type_lock  6                  1473                1.00
PyThread_type_lock  7                  1378                1.00
PyThread_type_lock  8                  1425                1.00
PyThread_type_lock  9                  1252                1.00
PyThread_type_lock  10                 1168                1.00

[pitrou]

LGTM, but I'm not a Windows developer. Did you manually check that this works @colesbury ?
(I suspect it's not really possible to write an automated test for this?)

[colesbury]

Yes, I manually tested on Windows with variations of the following script:

import threading
import time

l1 = threading.Lock()
l2 = threading.Lock()

def thread_run():
    l2.acquire()
    l1.acquire()

t = threading.Thread(target=thread_run)
t.start()

time.sleep(0.1)
l1.acquire()
l2.acquire()

t.join()