def _shutdown_tasks(loop: asyncio.AbstractEventLoop) -> None:
"""Завершение в случае ошибки.
После ошибки происходит отмена всех заданий, чтобы не захламлять сообщение об ошибке множеством
сообщений, о том, что результат выполнения задания не был awaited.
Идея кода позаимствована из реализации asyncio.app.
"""
to_cancel = asyncio.all_tasks(loop)
if not to_cancel:
return
for task in to_cancel:
task.cancel()
loop.run_until_complete(asyncio.gather(*to_cancel, loop=loop, return_exceptions=True))
for canceled_task in to_cancel:
if canceled_task.cancelled():
continue
if canceled_task.exception() is not None:
loop.call_exception_handler(
{
"message": "unhandled EventBus exception",
"exception": canceled_task.exception(),
"task": canceled_task,
},
)
loop.run_until_complete(loop.shutdown_asyncgens())
loop.run_until_complete(loop.shutdown_default_executor())
def _destroy_loop(loop: asyncio.AbstractEventLoop) -> None:
async def murder(future: asyncio.Future[typing.Any]) -> None:
# These include _GatheringFuture which must be awaited if the children
# throw an asyncio.CancelledError, otherwise it will spam logs with warnings
# about exceptions not being retrieved before GC.
try:
_LOGGER.log(ux.TRACE, "killing %s", future)
future.cancel()
await future
except asyncio.CancelledError:
pass
except Exception as ex:
loop.call_exception_handler({
"message":
"Future raised unexpected exception after requesting cancellation",
"exception": ex,
"future": future,
})
remaining_tasks = [
t for t in asyncio.all_tasks(loop)
if not t.cancelled() and not t.done()
]
if remaining_tasks:
_LOGGER.debug("terminating %s remaining tasks forcefully",
len(remaining_tasks))
loop.run_until_complete(
asyncio.gather(*(murder(task) for task in remaining_tasks)))
else:
_LOGGER.debug("No remaining tasks exist, good job!")
if sys.version_info >= (3, 9):
_LOGGER.debug("shutting down default executor")
with contextlib.suppress(NotImplementedError):
# This seems to raise a NotImplementedError when running with uvloop.
loop.run_until_complete(loop.shutdown_default_executor())
_LOGGER.debug("shutting down asyncgens")
loop.run_until_complete(loop.shutdown_asyncgens())
_LOGGER.debug("closing event loop")
loop.close()
