[Python-checkins] cpython (3.5): Issue #22970: asyncio: Fix inconsistency cancelling Condition.wait.
yury.selivanov
python-checkins at python.org
Sat Jun 11 12:01:28 EDT 2016
https://hg.python.org/cpython/rev/0bda9bc443ce
changeset: 101872:0bda9bc443ce
branch: 3.5
parent: 101870:9512cfd53903
user: Yury Selivanov <yury at magic.io>
date: Sat Jun 11 12:00:07 2016 -0400
summary:
Issue #22970: asyncio: Fix inconsistency cancelling Condition.wait.
Patch by David Coles.
files:
Lib/asyncio/locks.py | 8 ++++-
Lib/test/test_asyncio/test_locks.py | 25 +++++++++++++++++
Misc/NEWS | 3 ++
3 files changed, 35 insertions(+), 1 deletions(-)
diff --git a/Lib/asyncio/locks.py b/Lib/asyncio/locks.py
--- a/Lib/asyncio/locks.py
+++ b/Lib/asyncio/locks.py
@@ -329,7 +329,13 @@
self._waiters.remove(fut)
finally:
- yield from self.acquire()
+ # Must reacquire lock even if wait is cancelled
+ while True:
+ try:
+ yield from self.acquire()
+ break
+ except futures.CancelledError:
+ pass
@coroutine
def wait_for(self, predicate):
diff --git a/Lib/test/test_asyncio/test_locks.py b/Lib/test/test_asyncio/test_locks.py
--- a/Lib/test/test_asyncio/test_locks.py
+++ b/Lib/test/test_asyncio/test_locks.py
@@ -457,6 +457,31 @@
self.assertFalse(cond._waiters)
self.assertTrue(cond.locked())
+ def test_wait_cancel_contested(self):
+ cond = asyncio.Condition(loop=self.loop)
+
+ self.loop.run_until_complete(cond.acquire())
+ self.assertTrue(cond.locked())
+
+ wait_task = asyncio.Task(cond.wait(), loop=self.loop)
+ test_utils.run_briefly(self.loop)
+ self.assertFalse(cond.locked())
+
+ # Notify, but contest the lock before cancelling
+ self.loop.run_until_complete(cond.acquire())
+ self.assertTrue(cond.locked())
+ cond.notify()
+ self.loop.call_soon(wait_task.cancel)
+ self.loop.call_soon(cond.release)
+
+ try:
+ self.loop.run_until_complete(wait_task)
+ except asyncio.CancelledError:
+ # Should not happen, since no cancellation points
+ pass
+
+ self.assertTrue(cond.locked())
+
def test_wait_unacquired(self):
cond = asyncio.Condition(loop=self.loop)
self.assertRaises(
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -524,6 +524,9 @@
_conn_lost.
Patch by Łukasz Langa.
+- Issue #22970: asyncio: Fix inconsistency cancelling Condition.wait.
+ Patch by David Coles.
+
IDLE
----
--
Repository URL: https://hg.python.org/cpython
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