From c8a7b00d7f713054fb6a1ebef18fc1aeecaae2ab Mon Sep 17 00:00:00 2001
From: Richard Kojedzinszky <richard@kojedz.in>
Date: Wed, 30 Sep 2020 12:29:22 +0200
Subject: [PATCH 1/3] bpo-41891: ensure asyncio.wait_for waits for task
 completion

---
 Lib/asyncio/tasks.py                                         | 5 ++++-
 .../next/Library/2020-09-30-13-35-29.bpo-41891.pNAeYI.rst    | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Library/2020-09-30-13-35-29.bpo-41891.pNAeYI.rst

diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index 8b05434f273b52..45308bc5b74551 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -469,7 +469,10 @@ async def wait_for(fut, timeout, *, loop=None):
                 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/Misc/NEWS.d/next/Library/2020-09-30-13-35-29.bpo-41891.pNAeYI.rst b/Misc/NEWS.d/next/Library/2020-09-30-13-35-29.bpo-41891.pNAeYI.rst
new file mode 100644
index 00000000000000..75c25127803153
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-09-30-13-35-29.bpo-41891.pNAeYI.rst
@@ -0,0 +1 @@
+Ensure asyncio.wait_for waits for task completion

From 96564c65a1196e992b0a67f1c893a78b4afe8a38 Mon Sep 17 00:00:00 2001
From: Richard Kojedzinszky <richard@kojedz.in>
Date: Thu, 1 Oct 2020 09:39:18 +0200
Subject: [PATCH 2/3] bpo-41891: test cases for wait_for to behave
 consistently.

asyncio.wait_for should wait for the future to terminate in all cases.
---
 Lib/test/test_asyncio/test_asyncio_waitfor.py | 61 +++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 Lib/test/test_asyncio/test_asyncio_waitfor.py

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 00000000000000..eeb966f818891b
--- /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.time() + self.TASK_TIMEOUT
+
+        while True:
+            tosleep = exitat - time.time()
+            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()

From ffa0956e3a03494aca87ed2f077af77193bfd91a Mon Sep 17 00:00:00 2001
From: Richard Kojedzinszky <richard@kojedz.in>
Date: Fri, 2 Oct 2020 09:25:36 +0200
Subject: [PATCH 3/3] test_asyncio_waitfor: use monotonic time source

---
 Lib/test/test_asyncio/test_asyncio_waitfor.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Lib/test/test_asyncio/test_asyncio_waitfor.py b/Lib/test/test_asyncio/test_asyncio_waitfor.py
index eeb966f818891b..2ca64abbeb527c 100644
--- a/Lib/test/test_asyncio/test_asyncio_waitfor.py
+++ b/Lib/test/test_asyncio/test_asyncio_waitfor.py
@@ -14,10 +14,10 @@ def __init__(self):
         self.exited = False
 
     async def run(self):
-        exitat = time.time() + self.TASK_TIMEOUT
+        exitat = time.monotonic() + self.TASK_TIMEOUT
 
         while True:
-            tosleep = exitat - time.time()
+            tosleep = exitat - time.monotonic()
             if tosleep <= 0:
                 break