GH-93896: always set event loop in asyncio.run and IsolatedAsyncioTestCase

Lib/asyncio/runners.py

@@ -52,6 +52,7 @@ def __init__(self, *, debug=None, loop_factory=None):
  self._loop = None
  self._context = None
  self._interrupt_count = 0
+ self._set_event_loop = False
 
  def __enter__(self):
  self._lazy_init()
@@ -70,6 +71,8 @@ def close(self):
  loop.run_until_complete(loop.shutdown_asyncgens())
  loop.run_until_complete(loop.shutdown_default_executor())
  finally:
+ if self._set_event_loop:
+ events.set_event_loop(None)
  loop.close()
  self._loop = None
  self._state = _State.CLOSED
@@ -111,6 +114,8 @@ def run(self, coro, *, context=None):
 
  self._interrupt_count = 0
  try:
+ if self._set_event_loop:
+ events.set_event_loop(self._loop)
  return self._loop.run_until_complete(task)
  except exceptions.CancelledError:
  if self._interrupt_count > 0 and task.uncancel() == 0:
@@ -130,6 +135,7 @@ def _lazy_init(self):
  return
  if self._loop_factory is None:
  self._loop = events.new_event_loop()
+ self._set_event_loop = True
  else:
  self._loop = self._loop_factory()
  if self._debug is not None:

Misc/NEWS.d/next/Library/2022-07-06-06-02-02.gh-issue-93896.vIgWGr.rst

@@ -0,0 +1 @@
+Fix :func:`asyncio.run` and :class:`unittest.IsolatedAsyncioTestCase` to always the set event loop as it was done in Python 3.10 and earlier. Patch by Kumar Aditya.