Use functools.wraps to make sure wrapped method's metadata (docstring and name) doesn't get mangled.

2 files changed, 14 insertions, 4 deletions

diff --git a/nova/tests/test_misc.py b/nova/tests/test_misc.py
index 154b6fae6..9f572b58e 100644
--- a/nova/tests/test_misc.py
+++ b/nova/tests/test_misc.py
@@ -14,11 +14,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from datetime import datetime
 import errno
 import os
 import select
-import time
 
 from nova import test
 from nova.utils import parse_mailmap, str_dict_replace, synchronized
@@ -62,6 +60,16 @@ class ProjectTestCase(test.TestCase):
 
 
 class LockTestCase(test.TestCase):
+    def test_synchronized_wrapped_function_metadata(self):
+        @synchronized('whatever')
+        def foo():
+            """Bar"""
+            pass
+        self.assertEquals(foo.__doc__, 'Bar', "Wrapped function's docstring "
+                                              "got lost")
+        self.assertEquals(foo.__name__, 'foo', "Wrapped function's name "
+                                               "got mangled")
+
     def test_synchronized(self):
         rpipe, wpipe = os.pipe()
         pid = os.fork()
diff --git a/nova/utils.py b/nova/utils.py
index 48f12350f..9929e6fef 100644
--- a/nova/utils.py
+++ b/nova/utils.py
@@ -23,11 +23,14 @@ System-level utilities and helper functions.
 
 import base64
 import datetime
+import functools
 import inspect
 import json
 import lockfile
+import netaddr
 import os
 import random
+import re
 import socket
 import string
 import struct
@@ -35,8 +38,6 @@ import sys
 import time
 import types
 from xml.sax import saxutils
-import re
-import netaddr
 
 from eventlet import event
 from eventlet import greenthread
@@ -496,6 +497,7 @@ def loads(s):
 
 def synchronized(name):
     def wrap(f):
+        @functools.wraps(f)
         def inner(*args, **kwargs):
             lock = lockfile.FileLock(os.path.join(FLAGS.lock_path,
                                                   'nova-%s.lock' % name))