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-rw-r--r--Lib/asyncio/tasks.py50
1 files changed, 33 insertions, 17 deletions
diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index 825e91f5594..fbd5c39a7c5 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -386,19 +386,13 @@ else:
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.
@@ -914,6 +908,25 @@ def gather(*coros_or_futures, return_exceptions=False):
return outer
+def _log_on_exception(fut):
+ if fut.cancelled():
+ return
+
+ exc = fut.exception()
+ if exc is None:
+ return
+
+ context = {
+ 'message':
+ f'{exc.__class__.__name__} exception in shielded future',
+ 'exception': exc,
+ 'future': fut,
+ }
+ if fut._source_traceback:
+ context['source_traceback'] = fut._source_traceback
+ fut._loop.call_exception_handler(context)
+
+
def shield(arg):
"""Wait for a future, shielding it from cancellation.
@@ -959,14 +972,11 @@ def shield(arg):
else:
cur_task = None
- def _inner_done_callback(inner, cur_task=cur_task):
- if cur_task is not None:
- futures.future_discard_from_awaited_by(inner, cur_task)
+ def _clear_awaited_by_callback(inner):
+ futures.future_discard_from_awaited_by(inner, cur_task)
+ def _inner_done_callback(inner):
if outer.cancelled():
- if not inner.cancelled():
- # Mark inner's result as retrieved.
- inner.exception()
return
if inner.cancelled():
@@ -978,10 +988,16 @@ def shield(arg):
else:
outer.set_result(inner.result())
-
def _outer_done_callback(outer):
if not inner.done():
inner.remove_done_callback(_inner_done_callback)
+ # Keep only one callback to log on cancel
+ inner.remove_done_callback(_log_on_exception)
+ inner.add_done_callback(_log_on_exception)
+
+ if cur_task is not None:
+ inner.add_done_callback(_clear_awaited_by_callback)
+
inner.add_done_callback(_inner_done_callback)
outer.add_done_callback(_outer_done_callback)
@@ -1030,9 +1046,9 @@ 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