gh-128307: support eager_start kwarg in create_eager_task_factory, and pass kwargs from asyncio.create_task and TaskGroup.create_task

Doc/library/asyncio-eventloop.rst

@@ -361,7 +361,7 @@ Creating Futures and Tasks
 
  .. versionadded:: 3.5.2
 
-.. method:: loop.create_task(coro, *, name=None, context=None)
+.. method:: loop.create_task(coro, *, name=None, context=None, eager_start=None)
 
  Schedule the execution of :ref:`coroutine <coroutine>` *coro*.
  Return a :class:`Task` object.
@@ -377,12 +377,20 @@ Creating Futures and Tasks
  custom :class:`contextvars.Context` for the *coro* to run in.
  The current context copy is created when no *context* is provided.
 
+ An optional keyword-only *eager_start* argument allows specifying
+ if the task should execute eagerly during the call to create_task,
+ or be scheduled later. If *eager_start* is not passed the mode set
+ by :meth:`loop.set_task_factory` will be used.
+
  .. versionchanged:: 3.8
  Added the *name* parameter.
 
  .. versionchanged:: 3.11
  Added the *context* parameter.
 
+ .. versionchanged:: next
+ Added the *eager_start* parameter.
+
 .. method:: loop.set_task_factory(factory)
 
  Set a task factory that will be used by

Lib/asyncio/base_events.py

@@ -459,7 +459,7 @@ def create_future(self):
  return futures.Future(loop=self)
 
  def create_task(self, coro, **kwargs):
- """Schedule a coroutine object.
+ """Schedule or begin executing a coroutine object.
 
  Return a task object.
  """

Lib/asyncio/taskgroups.py

@@ -179,7 +179,7 @@ async def _aexit(self, et, exc):
  exc = None
 
 
- def create_task(self, coro, *, name=None, context=None):
+ def create_task(self, coro, **kwargs):
  """Create a new task in this group and return it.
 
  Similar to `asyncio.create_task`.
@@ -193,10 +193,7 @@ def create_task(self, coro, *, name=None, context=None):
  if self._aborting:
  coro.close()
  raise RuntimeError(f"TaskGroup{self!r} is shutting down")
- if context is None:
- task = self._loop.create_task(coro, name=name)
- else:
- task = self._loop.create_task(coro, name=name, context=context)
+ task = self._loop.create_task(coro, **kwargs)
 
  futures.future_add_to_awaited_by(task, self._parent_task)
 

Lib/asyncio/tasks.py

@@ -386,19 +386,13 @@ def __wakeup(self, future):
  Task = _CTask = _asyncio.Task
 
 
-def create_task(coro, *, name=None, context=None):
+def create_task(coro, **kwargs):
  """Schedule the execution of a coroutine object in a spawn task.
 
  Return a Task object.
  """
  loop = events.get_running_loop()
- if context is None:
- # Use legacy API if context is not needed
- task = loop.create_task(coro, name=name)
- else:
- task = loop.create_task(coro, name=name, context=context)
-
- return task
+ return loop.create_task(coro, **kwargs)
 
 
 # wait() and as_completed() similar to those in PEP 3148.
@@ -1030,9 +1024,9 @@ def create_eager_task_factory(custom_task_constructor):
  used. E.g. `loop.set_task_factory(asyncio.eager_task_factory)`.
  """
 
- def factory(loop, coro, *, name=None, context=None):
+ def factory(loop, coro, *, eager_start=True, **kwargs):
  return custom_task_constructor(
- coro, loop=loop, name=name, context=context, eager_start=True)
+ coro, loop=loop, eager_start=eager_start, **kwargs)
 
  return factory
 

Lib/test/test_asyncio/test_eager_task_factory.py

@@ -263,6 +263,24 @@ async def run():
 
  self.run_coro(run())
 
+ def test_eager_start_false(self):
+ name = None
+
+ async def asyncfn():
+ nonlocal name
+ name = asyncio.current_task().get_name()
+
+ async def main():
+ t = asyncio.get_running_loop().create_task(
+ asyncfn(), eager_start=False, name="example"
+ )
+ self.assertFalse(t.done())
+ self.assertIsNone(name)
+ await t
+ self.assertEqual(name, "example")
+
+ self.run_coro(main())
+
 
 class PyEagerTaskFactoryLoopTests(EagerTaskFactoryLoopTests, test_utils.TestCase):
  Task = tasks._PyTask
@@ -505,5 +523,24 @@ def tearDown(self):
  asyncio.current_task = asyncio.tasks.current_task = self._current_task
  return super().tearDown()
 
+
+class DefaultTaskFactoryEagerStart(test_utils.TestCase):
+ def test_eager_start_true_with_default_factory(self):
+ name = None
+
+ async def asyncfn():
+ nonlocal name
+ name = asyncio.current_task().get_name()
+
+ async def main():
+ t = asyncio.get_running_loop().create_task(
+ asyncfn(), eager_start=True, name="example"
+ )
+ self.assertTrue(t.done())
+ self.assertEqual(name, "example")
+ await t
+
+ asyncio.run(main(), loop_factory=asyncio.EventLoop)
+
 if __name__ == '__main__':
  unittest.main()

Lib/test/test_asyncio/test_tasks.py

@@ -89,8 +89,8 @@ class BaseTaskTests:
  Future = None
  all_tasks = None
 
- def new_task(self, loop, coro, name='TestTask', context=None):
- return self.__class__.Task(coro, loop=loop, name=name, context=context)
+ def new_task(self, loop, coro, name='TestTask', context=None, eager_start=None):
+ return self.__class__.Task(coro, loop=loop, name=name, context=context, eager_start=eager_start)
 
  def new_future(self, loop):
  return self.__class__.Future(loop=loop)
@@ -2686,6 +2686,35 @@ async def main():
 
  self.assertEqual([None, 1, 2], ret)
 
+ def test_eager_start_true(self):
+ name = None
+
+ async def asyncfn():
+ nonlocal name
+ name = self.current_task().get_name()
+
+ async def main():
+ t = self.new_task(coro=asyncfn(), loop=asyncio.get_running_loop(), eager_start=True, name="example")
+ self.assertTrue(t.done())
+ self.assertEqual(name, "example")
+ await t
+
+ def test_eager_start_false(self):
+ name = None
+
+ async def asyncfn():
+ nonlocal name
+ name = self.current_task().get_name()
+
+ async def main():
+ t = self.new_task(coro=asyncfn(), loop=asyncio.get_running_loop(), eager_start=False, name="example")
+ self.assertFalse(t.done())
+ self.assertIsNone(name)
+ await t
+ self.assertEqual(name, "example")
+
+ asyncio.run(main(), loop_factory=asyncio.EventLoop)
+
  def test_get_coro(self):
  loop = asyncio.new_event_loop()
  coro = coroutine_function()

Misc/NEWS.d/next/Library/2024-12-28-11-01-36.gh-issue-128307.BRCYTA.rst

@@ -0,0 +1 @@
+Add ``eager_start`` keyword argument to :meth:`asyncio.loop.create_task`