Merge "Avoid using logging in signal handler"

1 files changed, 35 insertions, 16 deletions

diff --git a/nova/service.py b/nova/service.py
index bb2964b95..71d26257a 100644
--- a/nova/service.py
+++ b/nova/service.py
@@ -103,6 +103,12 @@ FLAGS = flags.FLAGS
 FLAGS.register_opts(service_opts)
 
 
+class SignalExit(SystemExit):
+    def __init__(self, signo, exccode=1):
+        super(SignalExit, self).__init__(exccode)
+        self.signo = signo
+
+
 class Launcher(object):
     """Launch one or more services and wait for them to complete."""
 
@@ -160,14 +166,11 @@ class Launcher(object):
 
 class ServiceLauncher(Launcher):
     def _handle_signal(self, signo, frame):
-        signame = {signal.SIGTERM: 'SIGTERM', signal.SIGINT: 'SIGINT'}[signo]
-        LOG.info(_('Caught %s, exiting'), signame)
-
         # Allow the process to be killed again and die from natural causes
         signal.signal(signal.SIGTERM, signal.SIG_DFL)
         signal.signal(signal.SIGINT, signal.SIG_DFL)
 
-        sys.exit(1)
+        raise SignalExit(signo)
 
     def wait(self):
         signal.signal(signal.SIGTERM, self._handle_signal)
@@ -187,8 +190,14 @@ class ServiceLauncher(Launcher):
         status = None
         try:
             super(ServiceLauncher, self).wait()
+        except SignalExit as exc:
+            signame = {signal.SIGTERM: 'SIGTERM',
+                       signal.SIGINT: 'SIGINT'}[exc.signo]
+            LOG.info(_('Caught %s, exiting'), signame)
+            status = exc.code
         except SystemExit as exc:
             status = exc.code
+        finally:
             self.stop()
         rpc.cleanup()
 
@@ -207,6 +216,7 @@ class ServerWrapper(object):
 class ProcessLauncher(object):
     def __init__(self):
         self.children = {}
+        self.sigcaught = None
         self.running = True
         rfd, self.writepipe = os.pipe()
         self.readpipe = eventlet.greenio.GreenPipe(rfd, 'r')
@@ -215,16 +225,8 @@ class ProcessLauncher(object):
         signal.signal(signal.SIGINT, self._handle_signal)
 
     def _handle_signal(self, signo, frame):
-        signame = {signal.SIGTERM: 'SIGTERM', signal.SIGINT: 'SIGINT'}[signo]
-        LOG.info(_('Caught %s, stopping children'), signame)
-
+        self.sigcaught = signo
         self.running = False
-        for pid in self.children:
-            try:
-                os.kill(pid, signal.SIGTERM)
-            except OSError as exc:
-                if exc.errno != errno.ESRCH:
-                    raise
 
         # Allow the process to be killed again and die from natural causes
         signal.signal(signal.SIGTERM, signal.SIG_DFL)
@@ -242,9 +244,8 @@ class ProcessLauncher(object):
     def _child_process(self, server):
         # Setup child signal handlers differently
         def _sigterm(*args):
-            LOG.info(_('Received SIGTERM, stopping'))
             signal.signal(signal.SIGTERM, signal.SIG_DFL)
-            server.stop()
+            raise SignalExit(signal.SIGTERM)
 
         signal.signal(signal.SIGTERM, _sigterm)
         # Block SIGINT and let the parent send us a SIGTERM
@@ -287,11 +288,18 @@ class ProcessLauncher(object):
             status = 0
             try:
                 self._child_process(wrap.server)
+            except SignalExit as exc:
+                signame = {signal.SIGTERM: 'SIGTERM',
+                           signal.SIGINT: 'SIGINT'}[exc.signo]
+                LOG.info(_('Caught %s, exiting'), signame)
+                status = exc.code
             except SystemExit as exc:
                 status = exc.code
             except BaseException:
                 LOG.exception(_('Unhandled exception'))
                 status = 2
+            finally:
+                wrap.server.stop()
 
             os._exit(status)
 
@@ -334,7 +342,6 @@ class ProcessLauncher(object):
 
     def wait(self):
         """Loop waiting on children to die and respawning as necessary"""
-        # Loop calling wait and respawning as necessary
         while self.running:
             wrap = self._wait_child()
             if not wrap:
@@ -343,6 +350,18 @@ class ProcessLauncher(object):
             while self.running and len(wrap.children) < wrap.workers:
                 self._start_child(wrap)
 
+        if self.sigcaught:
+            signame = {signal.SIGTERM: 'SIGTERM',
+                       signal.SIGINT: 'SIGINT'}[self.sigcaught]
+            LOG.info(_('Caught %s, stopping children'), signame)
+
+        for pid in self.children:
+            try:
+                os.kill(pid, signal.SIGTERM)
+            except OSError as exc:
+                if exc.errno != errno.ESRCH:
+                    raise
+
         # Wait for children to die
         if self.children:
             LOG.info(_('Waiting on %d children to exit'), len(self.children))