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.
diff --git a/Misc/ACKS b/Misc/ACKS
index 4986dc6..5a388ff 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1500,4 +1500,5 @@
Kai Zhu
Tarek Ziadé
Gennadiy Zlobin
+Doug Zongker
Peter Åstrand
diff --git a/Misc/NEWS b/Misc/NEWS
index 854fc73..ab5eee6 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -27,6 +27,10 @@
Library
-------
+- 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.
+
- Issue #22182: Use e.args to unpack exceptions correctly in
distutils.file_util.move_file. Patch by Claudiu Popa.