GH-90985: Revert "Deprecate passing a message into cancel()" (#97999)

Reason: we were too hasty in deprecating this.
We shouldn't deprecate it before we have a replacement.

Author: gvanrossum

Doc/library/asyncio-future.rst

@@ -197,11 +197,6 @@ Future Object
       .. versionchanged:: 3.9
          Added the *msg* parameter.
 
-      .. deprecated-removed:: 3.11 3.14
-         *msg* parameter is ambiguous when multiple :meth:`cancel`
-         are called with different cancellation messages.
-         The argument will be removed.
-
    .. method:: exception()
 
       Return the exception that was set on this Future.
@@ -282,8 +277,3 @@ the Future has a result::
 
    - :meth:`asyncio.Future.cancel` accepts an optional ``msg`` argument,
      but :func:`concurrent.futures.cancel` does not.
-
-     .. deprecated-removed:: 3.11 3.14
-        *msg* parameter is ambiguous when multiple :meth:`cancel`
-        are called with different cancellation messages.
-        The argument will be removed.

Doc/library/asyncio-task.rst

@@ -1144,10 +1144,8 @@ Task Object
       .. versionchanged:: 3.9
          Added the *msg* parameter.
 
-      .. deprecated-removed:: 3.11 3.14
-         *msg* parameter is ambiguous when multiple :meth:`cancel`
-         are called with different cancellation messages.
-         The argument will be removed.
+      .. versionchanged:: 3.11
+         The ``msg`` parameter is propagated from cancelled task to its awaiter.
 
       .. _asyncio_example_task_cancel:
 

Lib/asyncio/futures.py

@@ -8,7 +8,6 @@
 import contextvars
 import logging
 import sys
-import warnings
 from types import GenericAlias
 
 from . import base_futures
@@ -151,11 +150,6 @@ def cancel(self, msg=None):
         change the future's state to cancelled, schedule the callbacks and
         return True.
         """
-        if msg is not None:
-            warnings.warn("Passing 'msg' argument to Future.cancel() "
-                          "is deprecated since Python 3.11, and "
-                          "scheduled for removal in Python 3.14.",
-                          DeprecationWarning, stacklevel=2)
         self.__log_traceback = False
         if self._state != _PENDING:
             return False

Lib/asyncio/tasks.py

@@ -210,11 +210,6 @@ def cancel(self, msg=None):
 
         This also increases the task's count of cancellation requests.
         """
-        if msg is not None:
-            warnings.warn("Passing 'msg' argument to Task.cancel() "
-                          "is deprecated since Python 3.11, and "
-                          "scheduled for removal in Python 3.14.",
-                          DeprecationWarning, stacklevel=2)
         self._log_traceback = False
         if self.done():
             return False

Lib/test/test_asyncio/test_futures.py

@@ -229,22 +229,14 @@ def test_future_cancel_message_getter(self):
         self.assertTrue(hasattr(f, '_cancel_message'))
         self.assertEqual(f._cancel_message, None)
 
-        with self.assertWarnsRegex(
-            DeprecationWarning,
-            "Passing 'msg' argument"
-        ):
-            f.cancel('my message')
+        f.cancel('my message')
         with self.assertRaises(asyncio.CancelledError):
             self.loop.run_until_complete(f)
         self.assertEqual(f._cancel_message, 'my message')
 
     def test_future_cancel_message_setter(self):
         f = self._new_future(loop=self.loop)
-        with self.assertWarnsRegex(
-            DeprecationWarning,
-            "Passing 'msg' argument"
-        ):
-            f.cancel('my message')
+        f.cancel('my message')
         f._cancel_message = 'my new message'
         self.assertEqual(f._cancel_message, 'my new message')
 

Lib/test/test_asyncio/test_tasks.py

@@ -109,11 +109,7 @@ async def coro():
         self.assertTrue(hasattr(t, '_cancel_message'))
         self.assertEqual(t._cancel_message, None)
 
-        with self.assertWarnsRegex(
-            DeprecationWarning,
-            "Passing 'msg' argument"
-        ):
-            t.cancel('my message')
+        t.cancel('my message')
         self.assertEqual(t._cancel_message, 'my message')
 
         with self.assertRaises(asyncio.CancelledError) as cm:
@@ -125,11 +121,7 @@ def test_task_cancel_message_setter(self):
         async def coro():
             pass
         t = self.new_task(self.loop, coro())
-        with self.assertWarnsRegex(
-            DeprecationWarning,
-            "Passing 'msg' argument"
-        ):
-            t.cancel('my message')
+        t.cancel('my message')
         t._cancel_message = 'my new message'
         self.assertEqual(t._cancel_message, 'my new message')
 
@@ -706,14 +698,7 @@ async def sleep():
                 async def coro():
                     task = self.new_task(loop, sleep())
                     await asyncio.sleep(0)
-                    if cancel_args not in ((), (None,)):
-                        with self.assertWarnsRegex(
-                                DeprecationWarning,
-                                "Passing 'msg' argument"
-                        ):
-                            task.cancel(*cancel_args)
-                    else:
-                        task.cancel(*cancel_args)
+                    task.cancel(*cancel_args)
                     done, pending = await asyncio.wait([task])
                     task.result()
 
@@ -747,14 +732,7 @@ async def sleep():
                 async def coro():
                     task = self.new_task(loop, sleep())
                     await asyncio.sleep(0)
-                    if cancel_args not in ((), (None,)):
-                        with self.assertWarnsRegex(
-                                DeprecationWarning,
-                                "Passing 'msg' argument"
-                        ):
-                            task.cancel(*cancel_args)
-                    else:
-                        task.cancel(*cancel_args)
+                    task.cancel(*cancel_args)
                     done, pending = await asyncio.wait([task])
                     task.exception()
 
@@ -777,17 +755,10 @@ async def sleep():
             fut.set_result(None)
             await asyncio.sleep(10)
 
-        def cancel(task, msg):
-            with self.assertWarnsRegex(
-                    DeprecationWarning,
-                    "Passing 'msg' argument"
-            ):
-                task.cancel(msg)
-
         async def coro():
             inner_task = self.new_task(loop, sleep())
             await fut
-            loop.call_soon(cancel, inner_task, 'msg')
+            loop.call_soon(inner_task.cancel, 'msg')
             try:
                 await inner_task
             except asyncio.CancelledError as ex:
@@ -813,11 +784,7 @@ async def sleep():
         async def coro():
             task = self.new_task(loop, sleep())
             # We deliberately leave out the sleep here.
-            with self.assertWarnsRegex(
-                    DeprecationWarning,
-                    "Passing 'msg' argument"
-            ):
-                task.cancel('my message')
+            task.cancel('my message')
             done, pending = await asyncio.wait([task])
             task.exception()
 
@@ -2179,14 +2146,7 @@ async def test():
                 async def main():
                     qwe = self.new_task(loop, test())
                     await asyncio.sleep(0.2)
-                    if cancel_args not in ((), (None,)):
-                        with self.assertWarnsRegex(
-                                DeprecationWarning,
-                                "Passing 'msg' argument"
-                        ):
-                            qwe.cancel(*cancel_args)
-                    else:
-                        qwe.cancel(*cancel_args)
+                    qwe.cancel(*cancel_args)
                     await qwe
 
                 try:

Misc/NEWS.d/next/Library/2022-10-06-23-42-00.gh-issue-90985.s280JY.rst

@@ -0,0 +1 @@
+Earlier in 3.11 we deprecated ``asyncio.Task.cancel("message")``. We realized we were too harsh, and have undeprecated it.

Modules/_asynciomodule.c

@@ -1116,16 +1116,6 @@ static PyObject *
 _asyncio_Future_cancel_impl(FutureObj *self, PyObject *msg)
 /*[clinic end generated code: output=3edebbc668e5aba3 input=925eb545251f2c5a]*/
 {
-    if (msg != Py_None) {
-        if (PyErr_WarnEx(PyExc_DeprecationWarning,
-                         "Passing 'msg' argument to Future.cancel() "
-                         "is deprecated since Python 3.11, and "
-                         "scheduled for removal in Python 3.14.",
-                         2))
-        {
-            return NULL;
-        }
-    }
     ENSURE_FUTURE_ALIVE(self)
     return future_cancel(self, msg);
 }
@@ -2214,16 +2204,6 @@ static PyObject *
 _asyncio_Task_cancel_impl(TaskObj *self, PyObject *msg)
 /*[clinic end generated code: output=c66b60d41c74f9f1 input=7bb51bf25974c783]*/
 {
-    if (msg != Py_None) {
-        if (PyErr_WarnEx(PyExc_DeprecationWarning,
-                         "Passing 'msg' argument to Task.cancel() "
-                         "is deprecated since Python 3.11, and "
-                         "scheduled for removal in Python 3.14.",
-                         2))
-        {
-            return NULL;
-        }
-    }
     self->task_log_tb = 0;
 
     if (self->task_state != STATE_PENDING) {