Issue #22185: Fix an occasional RuntimeError in threading.Condition.wait() caused by mutation of the waiters queue without holding the lock.
Patch by Doug Zongker.
diff --git a/Lib/threading.py b/Lib/threading.py
index 3407083..dfe9d41 100644
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -284,6 +284,7 @@
waiter.acquire()
self._waiters.append(waiter)
saved_state = self._release_save()
+ gotit = False
try: # restore state no matter what (e.g., KeyboardInterrupt)
if timeout is None:
waiter.acquire()
@@ -293,14 +294,14 @@
gotit = waiter.acquire(True, timeout)
else:
gotit = waiter.acquire(False)
- if not gotit:
- try:
- self._waiters.remove(waiter)
- except ValueError:
- pass
return gotit
finally:
self._acquire_restore(saved_state)
+ if not gotit:
+ try:
+ self._waiters.remove(waiter)
+ except ValueError:
+ pass
def wait_for(self, predicate, timeout=None):
"""Wait until a condition evaluates to True.