[Python-checkins] bpo-32610: Fix asyncio.all_tasks() to return only pending tasks. (GH-7174)

Mon May 28 20:16:47 EDT 2018

https://github.com/python/cpython/commit/ddc613f20394eba25f2420f6d2fa62b277c95058
commit: ddc613f20394eba25f2420f6d2fa62b277c95058
branch: 3.7
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: GitHub <noreply at github.com>
date: 2018年05月28日T17:16:43-07:00
summary:
bpo-32610: Fix asyncio.all_tasks() to return only pending tasks. (GH-7174)
(cherry picked from commit 416c1ebd9896b394790dcb4f9f035b1a44ebe9ff)
Co-authored-by: Yury Selivanov <yury at magic.io>
files:
A Misc/NEWS.d/next/Library/2018-05-28-16-40-32.bpo-32610.KvUAsL.rst
M Doc/library/asyncio-task.rst
M Lib/asyncio/__init__.py
M Lib/asyncio/runners.py
M Lib/asyncio/tasks.py
M Lib/test/test_asyncio/test_tasks.py
M Modules/_asynciomodule.c

diff --git a/Doc/library/asyncio-task.rst b/Doc/library/asyncio-task.rst
index 4892333d8cee..233cc9454967 100644
--- a/Doc/library/asyncio-task.rst
+++ b/Doc/library/asyncio-task.rst
@@ -443,6 +443,8 @@ Task
 Return a set of all tasks for an event loop.
 
 By default all tasks for the current event loop are returned.
+ If *loop* is ``None``, :func:`get_event_loop` function
+ is used to get the current loop.
 
 .. classmethod:: current_task(loop=None)
 
@@ -567,8 +569,9 @@ Task functions
 
 Return a set of :class:`Task` objects created for the loop.
 
- If *loop* is ``None`` :func:`get_event_loop` is used for getting
- current loop.
+ If *loop* is ``None``, :func:`get_running_loop` is used for getting
+ current loop (contrary to the deprecated :meth:`Task.all_tasks` method
+ that uses :func:`get_event_loop`.)
 
 .. versionadded:: 3.7
 
diff --git a/Lib/asyncio/__init__.py b/Lib/asyncio/__init__.py
index 23ea055912ea..26859024300e 100644
--- a/Lib/asyncio/__init__.py
+++ b/Lib/asyncio/__init__.py
@@ -18,6 +18,10 @@
 from .tasks import *
 from .transports import *
 
+# Exposed for _asynciomodule.c to implement now deprecated
+# Task.all_tasks() method. This function will be removed in 3.9.
+from .tasks import _all_tasks_compat # NoQA
+
 __all__ = (base_events.__all__ +
 coroutines.__all__ +
 events.__all__ +
diff --git a/Lib/asyncio/runners.py b/Lib/asyncio/runners.py
index bb54b7252786..5fbab03dd001 100644
--- a/Lib/asyncio/runners.py
+++ b/Lib/asyncio/runners.py
@@ -51,8 +51,7 @@ def run(main, *, debug=False):
 
 
 def _cancel_all_tasks(loop):
- to_cancel = [task for task in tasks.all_tasks(loop)
- if not task.done()]
+ to_cancel = tasks.all_tasks(loop)
 if not to_cancel:
 return
 
diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index 4a9db2a3a05c..67fb57c6a781 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -33,6 +33,16 @@ def current_task(loop=None):
 
 def all_tasks(loop=None):
 """Return a set of all tasks for the loop."""
+ if loop is None:
+ loop = events.get_running_loop()
+ return {t for t in _all_tasks
+ if futures._get_loop(t) is loop and not t.done()}
+
+
+def _all_tasks_compat(loop=None):
+ # Different from "all_task()" by returning *all* Tasks, including
+ # the completed ones. Used to implement deprecated "Tasks.all_task()"
+ # method.
 if loop is None:
 loop = events.get_event_loop()
 return {t for t in _all_tasks if futures._get_loop(t) is loop}
@@ -82,7 +92,7 @@ def all_tasks(cls, loop=None):
 "use asyncio.all_tasks() instead",
 PendingDeprecationWarning,
 stacklevel=2)
- return all_tasks(loop)
+ return _all_tasks_compat(loop)
 
 def __init__(self, coro, *, loop=None):
 super().__init__(loop=loop)
diff --git a/Lib/test/test_asyncio/test_tasks.py b/Lib/test/test_asyncio/test_tasks.py
index e5334c6ff914..33300c91a367 100644
--- a/Lib/test/test_asyncio/test_tasks.py
+++ b/Lib/test/test_asyncio/test_tasks.py
@@ -1897,8 +1897,10 @@ def kill_me(loop):
 # See http://bugs.python.org/issue29271 for details:
 asyncio.set_event_loop(self.loop)
 try:
- self.assertEqual(asyncio.all_tasks(), {task})
- self.assertEqual(asyncio.all_tasks(None), {task})
+ with self.assertWarns(PendingDeprecationWarning):
+ self.assertEqual(Task.all_tasks(), {task})
+ with self.assertWarns(PendingDeprecationWarning):
+ self.assertEqual(Task.all_tasks(None), {task})
 finally:
 asyncio.set_event_loop(None)
 
@@ -2483,6 +2485,9 @@ class TaskLike:
 def _loop(self):
 return loop
 
+ def done(self):
+ return False
+
 task = TaskLike()
 loop = mock.Mock()
 
@@ -2496,6 +2501,9 @@ class TaskLike:
 def get_loop(self):
 return loop
 
+ def done(self):
+ return False
+
 task = TaskLike()
 loop = mock.Mock()
 
@@ -2504,6 +2512,23 @@ def get_loop(self):
 self.assertEqual(asyncio.all_tasks(loop), {task})
 self._unregister_task(task)
 
+ def test__register_task_3(self):
+ class TaskLike:
+ def get_loop(self):
+ return loop
+
+ def done(self):
+ return True
+
+ task = TaskLike()
+ loop = mock.Mock()
+
+ self.assertEqual(asyncio.all_tasks(loop), set())
+ self._register_task(task)
+ self.assertEqual(asyncio.all_tasks(loop), set())
+ self.assertEqual(asyncio.Task.all_tasks(loop), {task})
+ self._unregister_task(task)
+
 def test__enter_task(self):
 task = mock.Mock()
 loop = mock.Mock()
diff --git a/Misc/NEWS.d/next/Library/2018-05-28-16-40-32.bpo-32610.KvUAsL.rst b/Misc/NEWS.d/next/Library/2018-05-28-16-40-32.bpo-32610.KvUAsL.rst
new file mode 100644
index 000000000000..372908063247
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-05-28-16-40-32.bpo-32610.KvUAsL.rst
@@ -0,0 +1 @@
+Make asyncio.all_tasks() return only pending tasks.
diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c
index c4d19034ce45..e3537cc81c4c 100644
--- a/Modules/_asynciomodule.c
+++ b/Modules/_asynciomodule.c
@@ -11,7 +11,7 @@ module _asyncio
 /* identifiers used from some functions */
 _Py_IDENTIFIER(__asyncio_running_event_loop__);
 _Py_IDENTIFIER(add_done_callback);
-_Py_IDENTIFIER(all_tasks);
+_Py_IDENTIFIER(_all_tasks_compat);
 _Py_IDENTIFIER(call_soon);
 _Py_IDENTIFIER(cancel);
 _Py_IDENTIFIER(current_task);
@@ -2125,7 +2125,7 @@ _asyncio_Task_all_tasks_impl(PyTypeObject *type, PyObject *loop)
 return NULL;
 }
 
- all_tasks_func = _PyObject_GetAttrId(asyncio_mod, &PyId_all_tasks);
+ all_tasks_func = _PyObject_GetAttrId(asyncio_mod, &PyId__all_tasks_compat);
 if (all_tasks_func == NULL) {
 return NULL;
 }
