Clean up watchdog threads

This shouldn't impact real servers, as those processes were about to
wrap up anyway. It *can* cause some confusing behaviors in tests,
though.

Change-Id: Ifd8a64efcd3fc983596ba7cd9fe28eb9663c93d6

swift/common/utils/__init__.py

@@ -4853,6 +4853,14 @@ class Watchdog(object):
         if self._run_gth is None:
             self._run_gth = eventlet.spawn(self.run)
 
+    def kill(self):
+        """
+        Stop the watchdog greenthread.
+        """
+        if self._run_gth is not None:
+            self._run_gth.kill()
+            self._run_gth = None
+
     def run(self):
         while True:
             self._run()

swift/common/wsgi.py

@@ -460,7 +460,10 @@ def run_server(conf, logger, sock, global_conf=None, ready_callback=None,
     except socket.error as err:
         if err.errno != errno.EINVAL:
             raise
-    pool.waitall()
+    finally:
+        pool.waitall()
+        if hasattr(app._pipeline_final_app, 'watchdog'):
+            app._pipeline_final_app.watchdog.kill()
 
 
 class StrategyBase(object):

test/unit/common/test_wsgi.py

@@ -634,6 +634,7 @@ class TestWSGI(unittest.TestCase, ConfigAssertMixin):
         server_sock, server_app, server_logger = args
         self.assertEqual(sock, server_sock)
         self.assertIsInstance(server_app, swift.proxy.server.Application)
+        self.assertIsNone(server_app.watchdog._run_gth)
         self.assertEqual(20, server_app.client_timeout)
         self.assertIsInstance(server_logger, wsgi.NullLogger)
         self.assertTrue('custom_pool' in kwargs)

test/unit/helpers.py

@@ -335,6 +335,10 @@ def setup_servers(the_object_server=object_server, extra_conf=None):
 def teardown_servers(context):
     for server in context["test_coros"]:
         server.kill()
+    # We didn't start the proxy w/ run_server, so we have to kill the
+    # watchdog ourselves
+    context["test_servers"][0].watchdog.kill()
+    assert context["test_servers"][0].watchdog._run_gth is None
     rmtree(os.path.dirname(context["testdir"]))
     utils.logs.SysLogHandler = context["orig_SysLogHandler"]
     storage_policy._POLICIES = context["orig_POLICIES"]