Avoid using logging in signal handler

In some cases, logging can grab locks and thusly attempt to reschedule,
which will fail in signal handlers. this patch removes the actions
from the signal handers, just set a flat if it got a signal, then in
rpc_loop, check the flag and perform appropriate actions.

Change-Id: I7a477e1c95b63fa8070ec9d08656156571421bb6
Partial-Bug: #1029727

diff --git a/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py b/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py
index 4ca3423605e0f2899d7925e835454d940c108419..0c6668d3c8047b2506010d258fc2b25c0458e981 100644 (file)
--- a/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py
+++ b/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py
@@ -289,6 +289,9 @@ class OVSNeutronAgent(sg_rpc.SecurityGroupAgentRpcCallbackMixin,
         self.iter_num = 0
         self.run_daemon_loop = True
 
+        self.catch_sigterm = False
+        self.catch_sighup = False
+
         # The initialization is complete; we can start receiving messages
         self.connection.consume_in_threads()
 
@@ -1477,7 +1480,7 @@ class OVSNeutronAgent(sg_rpc.SecurityGroupAgentRpcCallbackMixin,
         ancillary_ports = set()
         tunnel_sync = True
         ovs_restarted = False
-        while self.run_daemon_loop:
+        while self._check_and_handle_signal():
             start = time.time()
             port_stats = {'regular': {'added': 0,
                                       'updated': 0,
@@ -1614,17 +1617,26 @@ class OVSNeutronAgent(sg_rpc.SecurityGroupAgentRpcCallbackMixin,
             self.rpc_loop(polling_manager=pm)
 
     def _handle_sigterm(self, signum, frame):
-        LOG.info(_LI("Agent caught SIGTERM, quitting daemon loop."))
-        self.run_daemon_loop = False
+        self.catch_sigterm = True
         if self.quitting_rpc_timeout:
             self.set_rpc_timeout(self.quitting_rpc_timeout)
 
     def _handle_sighup(self, signum, frame):
-        LOG.info(_LI("Agent caught SIGHUP, resetting."))
-        self.conf.reload_config_files()
-        config.setup_logging()
-        LOG.debug('Full set of CONF:')
-        self.conf.log_opt_values(LOG, std_logging.DEBUG)
+        self.catch_sighup = True
+
+    def _check_and_handle_signal(self):
+        if self.catch_sigterm:
+            LOG.info(_LI("Agent caught SIGTERM, quitting daemon loop."))
+            self.run_daemon_loop = False
+            self.catch_sigterm = False
+        if self.catch_sighup:
+            LOG.info(_LI("Agent caught SIGHUP, resetting."))
+            self.conf.reload_config_files()
+            config.setup_logging()
+            LOG.debug('Full set of CONF:')
+            self.conf.log_opt_values(LOG, std_logging.DEBUG)
+            self.catch_sighup = False
+        return self.run_daemon_loop
 
     def set_rpc_timeout(self, timeout):
         for rpc_api in (self.plugin_rpc, self.sg_plugin_rpc,