allow for already dead horse on heroku worker termination

rq/worker.py

@@ -352,6 +352,19 @@ class Worker(object):
         signal.signal(signal.SIGINT, self.request_stop)
         signal.signal(signal.SIGTERM, self.request_stop)
 
+    def kill_horse(self):
+        """
+        Kill the horse but catch "No such process" error has the horse could already be dead.
+        """
+        try:
+            os.kill(self.horse_pid, signal.SIGKILL)
+        except OSError as e:
+            if e.errno == errno.ESRCH:
+                # "No such process" is fine with us
+                self.log.debug('Horse already dead')
+            else:
+                raise
+
     def request_force_stop(self, signum, frame):
         """Terminates the application (cold shutdown).
         """
@@ -361,13 +374,7 @@ class Worker(object):
         if self.horse_pid:
             msg = 'Taking down horse {0} with me'.format(self.horse_pid)
             self.log.debug(msg)
-            try:
-                os.kill(self.horse_pid, signal.SIGKILL)
-            except OSError as e:
-                # ESRCH ("No such process") is fine with us
-                if e.errno != errno.ESRCH:
-                    self.log.debug('Horse already down')
-                    raise
+            self.kill_horse()
         raise SystemExit()
 
     def request_stop(self, signum, frame):
@@ -834,7 +841,7 @@ class HerokuWorker(Worker):
         """If horse is alive send it SIGRTMIN"""
         if self.horse_pid != 0:
             self.log.warning('Warm shut down requested, sending horse SIGRTMIN signal')
-            os.kill(self.horse_pid, signal.SIGRTMIN)
+            self.kill_horse()
         else:
             self.log.warning('Warm shut down requested, no horse found')
 

tests/test_worker.py

@@ -833,7 +833,7 @@ class HerokuWorkerShutdownTestCase(TimeoutTestCase, RQTestCase):
         w._horse_pid = p.pid
         w.handle_warm_shutdown_request()
         p.join(2)
-        self.assertEqual(p.exitcode, -34)
+        self.assertEqual(p.exitcode, -9)
         self.assertFalse(os.path.exists(path))
 
     def test_handle_shutdown_request_no_horse(self):
@@ -842,5 +842,4 @@ class HerokuWorkerShutdownTestCase(TimeoutTestCase, RQTestCase):
         w = HerokuWorker('foo')
 
         w._horse_pid = 19999
-        with self.assertRaises(OSError):
         w.handle_warm_shutdown_request()