PYTHON-6074 Fix pool deadlock when a greenlet is killed during checkin - #23
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blink1073 wants to merge 10 commits into
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PYTHON-6074 Fix pool deadlock when a greenlet is killed during checkin#23blink1073 wants to merge 10 commits into
blink1073 wants to merge 10 commits into
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# Conflicts: # doc/changelog.rst
Under gevent, notify() is a yield point, so a kill delivered inside it left accounted False and the fallback decremented the accounting a second time. Set the flag before notify() so only interruption during condition acquisition triggers the fallback.
Adds a test interrupting the error handler while it waits to acquire size_cond, covering the fallback that re-applies the checkout accounting.
When AMPLIFY_RACE is enabled the test reassigns gevent.thread.sleep globally; register a cleanup so the widened sleep window doesn't leak into later tests.
blink1073
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Sep 8, 2026
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PYTHON-6074
Changes in this PR
Under gevent, killing a greenlet that is checking a connection back into the pool can leave the pool's
requestsandactive_socketscounters permanently inflated atmaxPoolSize. Every later checkout then blocks forever on the size-gate wait, freezing all database operations for the process. This change makes the pool's checkin accounting uninterruptible by aGreenletExit, so the counters and the connection are always restored.Pool.checkinapply its counter decrement and connection return in one critical section, re-applying them if aGreenletExitinterrupts before they complete.test_gevent_kill_churn_deadlock, which runs workers and a killing reaper under gevent and fails if operations stall.Test Plan
waitQueueTimeoutMS); the same script runs clean for 5 minutes with the fix.test_gevent_task,test_gevent_timeout,test_gevent_timeout_when_creating_connection) still pass.just lintandjust typingare clean.