catching exceptions in _queue_consumer meta task

This commit is contained in:
Daniil Fajnberg 2022-03-16 16:57:03 +01:00
parent 689a74c678
commit 44c03cc493
3 changed files with 25 additions and 12 deletions

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@ -1,6 +1,6 @@
[metadata]
name = asyncio-taskpool
version = 0.7.0
version = 0.7.1
author = Daniil Fajnberg
author_email = mail@daniil.fajnberg.de
description = Dynamically manage pools of asyncio tasks
@ -9,7 +9,7 @@ long_description_content_type = text/markdown
keywords = asyncio, concurrency, tasks, coroutines, asynchronous, server
url = https://git.fajnberg.de/daniil/asyncio-taskpool
project_urls =
Bug Tracker = https://git.fajnberg.de/daniil/asyncio-taskpool/issues
Bug Tracker = https://github.com/daniil-berg/asyncio-taskpool/issues
classifiers =
Development Status :: 3 - Alpha
Programming Language :: Python :: 3

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@ -775,8 +775,15 @@ class TaskPool(BaseTaskPool):
if next_arg is self._QUEUE_END_SENTINEL:
# The `_queue_producer()` either reached the last argument or was cancelled.
return
await self._start_task(star_function(func, next_arg, arg_stars=arg_stars), group_name=group_name,
ignore_lock=True, end_callback=release_cb, cancel_callback=cancel_callback)
try:
await self._start_task(star_function(func, next_arg, arg_stars=arg_stars), group_name=group_name,
ignore_lock=True, end_callback=release_cb, cancel_callback=cancel_callback)
except Exception as e:
# This means an exception occurred during task **creation**, meaning no task has been created.
# It does not imply an error within the task itself.
log.exception("%s occurred while trying to create task: %s(%s%s)",
str(e.__class__.__name__), func.__name__, '*' * arg_stars, str(next_arg))
map_semaphore.release()
async def _map(self, group_name: str, group_size: int, func: CoroutineFunc, arg_iter: ArgsT, arg_stars: int,
end_callback: EndCB = None, cancel_callback: CancelCB = None) -> None:

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@ -603,28 +603,34 @@ class TaskPoolTestCase(CommonTestCase):
@patch.object(pool, 'star_function')
@patch.object(pool.TaskPool, '_start_task')
@patch.object(pool, 'Semaphore')
@patch.object(pool.TaskPool, '_get_map_end_callback')
async def test__queue_consumer(self, mock__get_map_end_callback: MagicMock, mock_semaphore_cls: MagicMock,
@patch.object(pool, 'Semaphore')
async def test__queue_consumer(self, mock_semaphore_cls: MagicMock, mock__get_map_end_callback: MagicMock,
mock__start_task: AsyncMock, mock_star_function: MagicMock):
mock__get_map_end_callback.return_value = map_cb = MagicMock()
mock_semaphore_cls.return_value = semaphore = Semaphore(3)
mock_star_function.return_value = awaitable = 'totally an awaitable'
arg1, arg2 = 123456789, 'function argument'
mock__get_map_end_callback.return_value = map_cb = MagicMock()
awaitable = 'totally an awaitable'
mock_star_function.side_effect = [awaitable, awaitable, Exception()]
arg1, arg2, bad = 123456789, 'function argument', None
mock_q_maxsize = 3
mock_q = MagicMock(__aenter__=AsyncMock(side_effect=[arg1, arg2, pool.TaskPool._QUEUE_END_SENTINEL]),
mock_q = MagicMock(__aenter__=AsyncMock(side_effect=[arg1, arg2, bad, pool.TaskPool._QUEUE_END_SENTINEL]),
__aexit__=AsyncMock(), maxsize=mock_q_maxsize)
group_name, mock_func, stars = 'whatever', MagicMock(), 3
group_name, mock_func, stars = 'whatever', MagicMock(__name__="mock"), 3
end_cb, cancel_cb = MagicMock(), MagicMock()
self.assertIsNone(await self.task_pool._queue_consumer(mock_q, group_name, mock_func, stars, end_cb, cancel_cb))
# We expect the semaphore to be acquired 3 times, then be released once after the exception occurs, then
# acquired once more when the `_QUEUE_END_SENTINEL` is reached. Since we initialized it with a value of 3,
# at the end of the loop, we expect it be locked.
self.assertTrue(semaphore.locked())
mock_semaphore_cls.assert_called_once_with(mock_q_maxsize)
mock__get_map_end_callback.assert_called_once_with(semaphore, actual_end_callback=end_cb)
mock__start_task.assert_has_awaits(2 * [
call(awaitable, group_name=group_name, ignore_lock=True, end_callback=map_cb, cancel_callback=cancel_cb)
])
mock_star_function.assert_has_calls([
call(mock_func, arg1, arg_stars=stars),
call(mock_func, arg2, arg_stars=stars)
call(mock_func, arg2, arg_stars=stars),
call(mock_func, bad, arg_stars=stars)
])
@patch.object(pool, 'create_task')