bpo-34075: Deprecate non-ThreadPoolExecutor in loop.set_default_execu… · python/cpython@22d2508 (original) (raw)

5 files changed

lines changed

Original file line number	Diff line number	Diff line change
@@ -906,7 +906,14 @@ pool of processes). By default, an event loop uses a thread pool executor
906	906
907	907	.. method:: AbstractEventLoop.set_default_executor(executor)
908	908
909		- Set the default executor used by :meth:`run_in_executor`.
	909	+ Set executor as the default executor used by :meth:`run_in_executor`.
	910	+ executor should be an instance of
	911	+:class:`~concurrent.futures.ThreadPoolExecutor`.
	912	+
	913	+ .. deprecated:: 3.8
	914	+ Using an executor that is not an instance of
	915	+:class:`~concurrent.futures.ThreadPoolExecutor` is deprecated and
	916	+ will trigger an error in Python 3.9.
910	917
911	918
912	919	Error Handling API

Original file line number	Diff line number	Diff line change
@@ -164,6 +164,12 @@ Deprecated
164	164	They will be removed in Python 3.9.
165	165	(Contributed by Serhiy Storchaka in :issue:`29209`.)
166	166
	167	+* Passing an object that is not an instance of
	168	+:class:`concurrent.futures.ThreadPoolExecutor` to
	169	+:meth:`asyncio.AbstractEventLoop.set_default_executor()` is
	170	+ deprecated and will be prohibited in Python 3.9.
	171	+ (Contributed by Elvis Pranskevichus in :issue:`34075`.)
	172	+
167	173
168	174	Removed
169	175	=======

Original file line number	Diff line number	Diff line change
@@ -741,6 +741,12 @@ def run_in_executor(self, executor, func, *args):
741	741	executor.submit(func, *args), loop=self)
742	742
743	743	def set_default_executor(self, executor):
	744	+if not isinstance(executor, concurrent.futures.ThreadPoolExecutor):
	745	+warnings.warn(
	746	+'Using the default executor that is not an instance of '
	747	+'ThreadPoolExecutor is deprecated and will be prohibited '
	748	+'in Python 3.9',
	749	+DeprecationWarning, 2)
744	750	self._default_executor = executor
745	751
746	752	def _getaddrinfo_debug(self, host, port, family, type, proto, flags):

Original file line number	Diff line number	Diff line change
@@ -1,5 +1,6 @@
1	1	"""Tests for base_events.py"""
2	2
	3	+import concurrent.futures
3	4	import errno
4	5	import logging
5	6	import math
@@ -211,10 +212,21 @@ def test__add_callback_cancelled_handle(self):
211	212	self.assertFalse(self.loop._ready)
212	213
213	214	def test_set_default_executor(self):
214		-executor = mock.Mock()
	215	+class DummyExecutor(concurrent.futures.ThreadPoolExecutor):
	216	+def submit(self, fn, args, *kwargs):
	217	+raise NotImplementedError(
	218	+'cannot submit into a dummy executor')
	219	+
	220	+executor = DummyExecutor()
215	221	self.loop.set_default_executor(executor)
216	222	self.assertIs(executor, self.loop._default_executor)
217	223
	224	+def test_set_default_executor_deprecation_warnings(self):
	225	+executor = mock.Mock()
	226	+
	227	+with self.assertWarns(DeprecationWarning):
	228	+self.loop.set_default_executor(executor)
	229	+
218	230	def test_call_soon(self):
219	231	def cb():
220	232	pass

Original file line number	Diff line number	Diff line change
@@ -0,0 +1,2 @@
	1	+Deprecate passing non-ThreadPoolExecutor instances to
	2	+:meth:`AbstractEventLoop.set_default_executor`.