bpo-29703: asyncio: Fix creating new event loops in child processes. (#404)
diff --git a/Lib/asyncio/events.py b/Lib/asyncio/events.py
index 28a45fc..7b30b4c 100644
--- a/Lib/asyncio/events.py
+++ b/Lib/asyncio/events.py
@@ -11,6 +11,7 @@
import functools
import inspect
+import os
import reprlib
import socket
import subprocess
@@ -611,6 +612,9 @@
# A TLS for the running event loop, used by _get_running_loop.
class _RunningLoop(threading.local):
_loop = None
+ _pid = None
+
+
_running_loop = _RunningLoop()
@@ -620,7 +624,8 @@
This is a low-level function intended to be used by event loops.
This function is thread-specific.
"""
- return _running_loop._loop
+ if _running_loop._pid == os.getpid():
+ return _running_loop._loop
def _set_running_loop(loop):
@@ -629,6 +634,7 @@
This is a low-level function intended to be used by event loops.
This function is thread-specific.
"""
+ _running_loop._pid = os.getpid()
_running_loop._loop = loop
diff --git a/Lib/asyncio/test_utils.py b/Lib/asyncio/test_utils.py
index 99e3839..b12d5db 100644
--- a/Lib/asyncio/test_utils.py
+++ b/Lib/asyncio/test_utils.py
@@ -449,12 +449,15 @@
self.set_event_loop(loop)
return loop
+ def unpatch_get_running_loop(self):
+ events._get_running_loop = self._get_running_loop
+
def setUp(self):
self._get_running_loop = events._get_running_loop
events._get_running_loop = lambda: None
def tearDown(self):
- events._get_running_loop = self._get_running_loop
+ self.unpatch_get_running_loop()
events.set_event_loop(None)
diff --git a/Lib/test/test_asyncio/test_events.py b/Lib/test/test_asyncio/test_events.py
index 28d92a9..802763b 100644
--- a/Lib/test/test_asyncio/test_events.py
+++ b/Lib/test/test_asyncio/test_events.py
@@ -1,6 +1,7 @@
"""Tests for events.py."""
import collections.abc
+import concurrent.futures
import functools
import gc
import io
@@ -57,6 +58,15 @@
return version < (10, 5)
+def _test_get_event_loop_new_process__sub_proc():
+ async def doit():
+ return 'hello'
+
+ loop = asyncio.new_event_loop()
+ asyncio.set_event_loop(loop)
+ return loop.run_until_complete(doit())
+
+
ONLYCERT = data_file('ssl_cert.pem')
ONLYKEY = data_file('ssl_key.pem')
SIGNED_CERTFILE = data_file('keycert3.pem')
@@ -2181,6 +2191,18 @@
asyncio.set_child_watcher(None)
super().tearDown()
+ def test_get_event_loop_new_process(self):
+ async def main():
+ pool = concurrent.futures.ProcessPoolExecutor()
+ return await self.loop.run_in_executor(
+ pool, _test_get_event_loop_new_process__sub_proc)
+
+ self.unpatch_get_running_loop()
+
+ self.assertEqual(
+ self.loop.run_until_complete(main()),
+ 'hello')
+
if hasattr(selectors, 'KqueueSelector'):
class KqueueEventLoopTests(UnixEventLoopTestsMixin,
SubprocessTestsMixin,
diff --git a/Misc/NEWS b/Misc/NEWS
index 9da682b..68cb711 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -256,6 +256,9 @@
Library
-------
+- bpo-29703: Fix asyncio to support instantiation of new event loops
+ in child processes.
+
- bpo-29615: SimpleXMLRPCDispatcher no longer chains KeyError (or any other
exception) to exception(s) raised in the dispatched methods.
Patch by Petr Motejlek.