[gentoo-portage-dev] [PATCH v3] Use default asyncio event loop implementation in API consumer threads

[Zac Medico]

Make the _safe_loop function return an AsyncioEventLoop instance,
so that the default asyncio event loop implementation will be used
in API consumer threads. This is possible because the underlying
asyncio.get_event_loop() function returns a new event loop for
each thread. The AsyncioEventLoop _run_until_complete method will
now appropriately handle a ValueError from signal.set_wakeup_fd(-1)
if it is not called in the main thread.

Bug: https://bugs.gentoo.org/758755
Signed-off-by: Zac Medico <zmedico@g.o>
---
[PATCH v3] fixed AsyncioEventLoop _run_until_complete method to
handle ValueError from signal.set_wakeup_fd(-1)

 lib/portage/util/_eventloop/asyncio_event_loop.py | 6 +++++-
 lib/portage/util/futures/_asyncio/__init__.py     | 3 +--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/lib/portage/util/_eventloop/asyncio_event_loop.py b/lib/portage/util/_eventloop/asyncio_event_loop.py
index 836f1c30a..4d7047ae8 100644
--- a/lib/portage/util/_eventloop/asyncio_event_loop.py
+++ b/lib/portage/util/_eventloop/asyncio_event_loop.py
@@ -121,4 +121,8 @@ class AsyncioEventLoop(_AbstractEventLoop):
 		try:
 			return self._loop.run_until_complete(future)
 		finally:
-			self._wakeup_fd = signal.set_wakeup_fd(-1)
+			try:
+				self._wakeup_fd = signal.set_wakeup_fd(-1)
+			except ValueError:
+				# This is intended to fail when not called in the main thread.
+				pass
diff --git a/lib/portage/util/futures/_asyncio/__init__.py b/lib/portage/util/futures/_asyncio/__init__.py
index a902ad895..12013be00 100644
--- a/lib/portage/util/futures/_asyncio/__init__.py
+++ b/lib/portage/util/futures/_asyncio/__init__.py
@@ -34,7 +34,6 @@ import portage
 portage.proxy.lazyimport.lazyimport(globals(),
 	'portage.util.futures.unix_events:_PortageEventLoopPolicy',
 	'portage.util.futures:compat_coroutine@_compat_coroutine',
-	'portage.util._eventloop.EventLoop:EventLoop@_EventLoop',
 )
 from portage.util._eventloop.asyncio_event_loop import AsyncioEventLoop as _AsyncioEventLoop
 from portage.util._eventloop.global_event_loop import (
@@ -256,4 +255,4 @@ def _safe_loop():
 	"""
 	if portage._internal_caller:
 		return _global_event_loop()
-	return _EventLoop(main=False)
+	return _AsyncioEventLoop()
-- 
2.26.2