From 85f223e5b031eb8ab63fbca314a4fb296a3a2632 Mon Sep 17 00:00:00 2001 From: John Snow Date: Wed, 3 Sep 2025 01:06:30 -0400 Subject: python: backport 'avoid creating additional event loops per thread' MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This commit is two backports squashed into one to avoid regressions. python: *really* remove get_event_loop A prior commit, aa1ff990, switched away from using get_event_loop *by default*, but this is not good enough to avoid deprecation warnings as `asyncio.get_event_loop_policy().get_event_loop()` is *also* deprecated. Replace this mechanism with explicit calls to asyncio.get_new_loop() and revise the cleanup mechanisms in __del__ to match. python: avoid creating additional event loops per thread "Too hasty by far!", commit 21ce2ee4 attempted to avoid deprecated behavior altogether by calling new_event_loop() directly if there was no loop currently running, but this has the unfortunate side effect of potentially creating multiple event loops per thread if tests instantiate multiple QMP connections in a single thread. This behavior is apparently not well-defined and causes problems in some, but not all, combinations of Python interpreter version and platform environment. Partially revert to Daniel Berrange's original patch, which calls get_event_loop and simply suppresses the deprecation warning in Python<=3.13. This time, however, additionally register new loops created with new_event_loop() so that future calls to get_event_loop() will return the loop already created. Reported-by: Richard W.M. Jones Reported-by: Daniel P. Berrangé Signed-off-by: John Snow cherry picked from commit python-qemu-qmp@21ce2ee4f2df87efe84a27b9c5112487f4670622 cherry picked from commit python-qemu-qmp@c08fb82b38212956ccffc03fc6d015c3979f42fe Signed-off-by: John Snow Reviewed-by: Daniel P. Berrangé --- python/qemu/qmp/qmp_tui.py | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) (limited to 'python/qemu/qmp/qmp_tui.py') diff --git a/python/qemu/qmp/qmp_tui.py b/python/qemu/qmp/qmp_tui.py index 12bdc17c99..d946c20513 100644 --- a/python/qemu/qmp/qmp_tui.py +++ b/python/qemu/qmp/qmp_tui.py @@ -51,7 +51,7 @@ from .legacy import QEMUMonitorProtocol, QMPBadPortError from .message import DeserializationError, Message, UnexpectedTypeError from .protocol import ConnectError, Runstate from .qmp_client import ExecInterruptedError, QMPClient -from .util import pretty_traceback +from .util import get_or_create_event_loop, pretty_traceback # The name of the signal that is used to update the history list @@ -387,13 +387,7 @@ class App(QMPClient): """ screen = urwid.raw_display.Screen() screen.set_terminal_properties(256) - - try: - self.aloop = asyncio.get_running_loop() - except RuntimeError: - # No running asyncio event loop. Create one if necessary. - self.aloop = asyncio.get_event_loop_policy().get_event_loop() - + self.aloop = get_or_create_event_loop() self.aloop.set_debug(debug) # Gracefully handle SIGTERM and SIGINT signals -- cgit 1.4.1