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

(cherry picked from commit 416c1ebd9896b394790dcb4f9f035b1a44ebe9ff)

Co-authored-by: Yury Selivanov <yury@magic.io>

3 files changed, 16 insertions, 3 deletions

diff --git a/Lib/asyncio/__init__.py b/Lib/asyncio/__init__.py
index 23ea055912..2685902430 100644
--- a/Lib/asyncio/__init__.py
+++ b/Lib/asyncio/__init__.py
@@ -18,6 +18,10 @@ from .subprocess import *
 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 bb54b72527..5fbab03dd0 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 4a9db2a3a0..67fb57c6a7 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -34,6 +34,16 @@ 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 @@ class Task(futures._PyFuture):  # Inherit Python Task implementation
                       "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)