From f8d6aa9c9ad676a29ff0874b5bf5b9fb898259c7 Mon Sep 17 00:00:00 2001
From: Miguel Angel Ajo <mangelajo@redhat.com>
Date: Tue, 24 Mar 2015 13:07:37 +0000
Subject: [PATCH] Stop any spawned ProcessMonitor at test cleanup

Base test class adds a cleanup fixture to stop any
spawned process monitor via unit or functional tests,
which otherwise would keep running after the tests already
finished, and execution functions go unpatched.

Without this patch unit tests will randomly fail
when we enable process monitor by default at change:
I85fe31bee30714148168a293eea29fa0a37f9701

Co-Authored-By: Maru Newby <marun@redhat.com>

Change-Id: Ide799a52391b14ff921de25788e8b0f0463fb8f8
---
 neutron/agent/linux/external_process.py       |  6 ++++-
 neutron/tests/base.py                         | 25 +++++++++++++++++++
 .../functional/agent/linux/test_keepalived.py |  1 -
 .../agent/linux/test_process_monitor.py       |  1 -
 4 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/neutron/agent/linux/external_process.py b/neutron/agent/linux/external_process.py
index 95beddd99..0dff4efa8 100644
--- a/neutron/agent/linux/external_process.py
+++ b/neutron/agent/linux/external_process.py
@@ -199,7 +199,11 @@ class ProcessMonitor(object):
         self._monitored_processes.pop(service_id, None)
 
     def stop(self):
-        """Stop the process monitoring. """
+        """Stop the process monitoring.
+
+        This method will stop the monitoring thread, but no monitored
+        process will be stopped.
+        """
         self._monitor_processes = False
 
     def _spawn_checking_thread(self):
diff --git a/neutron/tests/base.py b/neutron/tests/base.py
index 6886af9e3..d9e61f061 100644
--- a/neutron/tests/base.py
+++ b/neutron/tests/base.py
@@ -27,10 +27,12 @@ import logging as std_logging
 import os.path
 
 import fixtures
+import mock
 from oslo_concurrency.fixture import lockutils
 from oslo_config import cfg
 from oslo_messaging import conffixture as messaging_conffixture
 
+from neutron.agent.linux import external_process
 from neutron.common import config
 from neutron.common import rpc as n_rpc
 from neutron import policy
@@ -61,6 +63,28 @@ def fake_consume_in_threads(self):
 bool_from_env = sub_base.bool_from_env
 
 
+class ProcessMonitorFixture(fixtures.Fixture):
+    """Test fixture to capture and cleanup any spawn process monitor."""
+    def setUp(self):
+        super(ProcessMonitorFixture, self).setUp()
+        self.old_callable = (
+            external_process.ProcessMonitor._spawn_checking_thread)
+        p = mock.patch("neutron.agent.linux.external_process.ProcessMonitor."
+                       "_spawn_checking_thread",
+                       new=lambda x: self.record_calls(x))
+        p.start()
+        self.instances = []
+        self.addCleanup(self.stop)
+
+    def stop(self):
+        for instance in self.instances:
+            instance.stop()
+
+    def record_calls(self, instance):
+        self.old_callable(instance)
+        self.instances.append(instance)
+
+
 class BaseTestCase(sub_base.SubBaseTestCase):
 
     @staticmethod
@@ -97,6 +121,7 @@ class BaseTestCase(sub_base.SubBaseTestCase):
         cfg.CONF.set_override('state_path', self.get_default_temp_dir().path)
 
         self.addCleanup(CONF.reset)
+        self.useFixture(ProcessMonitorFixture())
 
         self.useFixture(fixtures.MonkeyPatch(
             'neutron.common.exceptions.NeutronException.use_fatal_exceptions',
diff --git a/neutron/tests/functional/agent/linux/test_keepalived.py b/neutron/tests/functional/agent/linux/test_keepalived.py
index 9e1060ea0..f0fe113e6 100644
--- a/neutron/tests/functional/agent/linux/test_keepalived.py
+++ b/neutron/tests/functional/agent/linux/test_keepalived.py
@@ -36,7 +36,6 @@ class KeepalivedManagerTestCase(base.BaseTestCase,
             'router1', self.expected_config, conf_path=cfg.CONF.state_path,
             process_monitor=self.process_monitor)
         self.addCleanup(self.manager.get_process().disable)
-        self.addCleanup(self.process_monitor.stop)
 
     def test_keepalived_spawn(self):
         self.manager.spawn()
diff --git a/neutron/tests/functional/agent/linux/test_process_monitor.py b/neutron/tests/functional/agent/linux/test_process_monitor.py
index d202d2e0e..1bf50803f 100644
--- a/neutron/tests/functional/agent/linux/test_process_monitor.py
+++ b/neutron/tests/functional/agent/linux/test_process_monitor.py
@@ -34,7 +34,6 @@ class BaseTestProcessMonitor(base.BaseTestCase):
         self._process_monitor = None
         self.create_child_processes_manager('respawn')
         self.addCleanup(self.cleanup_spawned_children)
-        self.addCleanup(self._process_monitor.stop)
 
     def create_child_processes_manager(self, action):
         cfg.CONF.set_override('check_child_processes_action', action, 'AGENT')
-- 
2.45.2