bpo-41891: ensure asyncio.wait_for waits for task completion (#22461)
diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index 0d3a24b..52f1e66 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -437,7 +437,10 @@ async def wait_for(fut, timeout):
return fut.result()
else:
fut.remove_done_callback(cb)
- fut.cancel()
+ # We must ensure that the task is not running
+ # after wait_for() returns.
+ # See https://bugs.python.org/issue32751
+ await _cancel_and_wait(fut, loop=loop)
raise
if fut.done():
diff --git a/Lib/test/test_asyncio/test_asyncio_waitfor.py b/Lib/test/test_asyncio/test_asyncio_waitfor.py
new file mode 100644
index 0000000..2ca64ab
--- /dev/null
+++ b/Lib/test/test_asyncio/test_asyncio_waitfor.py
@@ -0,0 +1,61 @@
+import asyncio
+import unittest
+import time
+
+def tearDownModule():
+ asyncio.set_event_loop_policy(None)
+
+
+class SlowTask:
+ """ Task will run for this defined time, ignoring cancel requests """
+ TASK_TIMEOUT = 0.2
+
+ def __init__(self):
+ self.exited = False
+
+ async def run(self):
+ exitat = time.monotonic() + self.TASK_TIMEOUT
+
+ while True:
+ tosleep = exitat - time.monotonic()
+ if tosleep <= 0:
+ break
+
+ try:
+ await asyncio.sleep(tosleep)
+ except asyncio.CancelledError:
+ pass
+
+ self.exited = True
+
+class AsyncioWaitForTest(unittest.TestCase):
+
+ async def atest_asyncio_wait_for_cancelled(self):
+ t = SlowTask()
+
+ waitfortask = asyncio.create_task(asyncio.wait_for(t.run(), t.TASK_TIMEOUT * 2))
+ await asyncio.sleep(0)
+ waitfortask.cancel()
+ await asyncio.wait({waitfortask})
+
+ self.assertTrue(t.exited)
+
+ def test_asyncio_wait_for_cancelled(self):
+ asyncio.run(self.atest_asyncio_wait_for_cancelled())
+
+ async def atest_asyncio_wait_for_timeout(self):
+ t = SlowTask()
+
+ try:
+ await asyncio.wait_for(t.run(), t.TASK_TIMEOUT / 2)
+ except asyncio.TimeoutError:
+ pass
+
+ self.assertTrue(t.exited)
+
+ def test_asyncio_wait_for_timeout(self):
+ asyncio.run(self.atest_asyncio_wait_for_timeout())
+
+
+if __name__ == '__main__':
+ unittest.main()