Add acuire_with_timeout().

tests/helpers/threading.py

@@ -1,9 +1,25 @@
 from __future__ import absolute_import
 
+import sys
 import threading
+import time
 import warnings
 
 
+if sys.version_info < (3,):
+    def acquire_with_timeout(lock, timeout):
+        segments = int(timeout * 10) + 1
+        for _ in range(segments):
+            if lock.acquire(False):
+                return True
+            time.sleep(0.1)
+        else:
+            return False
+else:
+    def acquire_with_timeout(lock, timeout):
+        return lock.acquire(timeout=timeout)
+
+
 def get_locked_and_waiter(timeout=1.0):
     _timeout = timeout
     lock = threading.Lock()
@@ -12,7 +28,7 @@ def get_locked_and_waiter(timeout=1.0):
     def wait(timeout=_timeout, reason=None):
         if timeout is None:
             timeout = _timeout
-        if lock.acquire(timeout=timeout):
+        if acquire_with_timeout(lock, timeout):
             lock.release()
         else:
             msg = 'timed out waiting'