From bbb668bbec2e2fa6b7f64b9af9504b973016058c Mon Sep 17 00:00:00 2001
From: Matt Riedemann <mriedem.os@gmail.com>
Date: Mon, 19 Mar 2018 19:24:32 -0400
Subject: [PATCH] Fix message for unexpected external event

During live migration, we get vif plugged events
that we're not waiting for, and if InstanceEvents._events
is empty, pop_instance_event() will log a message about
shutting down, but the compute service isn't actually
shutting down. When it is, ComputeManager.cleanup_host()
calls cancel_all_events() which sets _events to None, so
we should only mention shutting down when _events is None.

Change-Id: Ie868273c4b9629f9b35645df5785304ebba5d64c
Closes-Bug: #1756994
---
 nova/compute/manager.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index ea1b93cf7174..6b251f988560 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -342,7 +342,7 @@ class InstanceEvents(object):
 
         @utils.synchronized(self._lock_name(instance))
         def _pop_event():
-            if not self._events:
+            if self._events is None:
                 LOG.debug('Unexpected attempt to pop events during shutdown',
                           instance=instance)
                 return no_events_sentinel