Fix poll_until exception type

This patch adds catching loopingcall.LoopingCallTimeOut and raising
PollTimeOut exceptions.

Without this change we didn't know which exception would be thrown in
case of task timeout in function poll_until. As in the rest of the
trove code we catch only PollTimeOut exception it was possible to miss
loopingcall.LoopingCallTimeOut.

Change-Id: Ic3f8bdf99e82ac5c438354a4f3af7c6856d14f34

1 files changed, 11 insertions, 7 deletions

diff --git a/trove/common/utils.py b/trove/common/utils.py
index 7710923c..91ed1698 100644
--- a/trove/common/utils.py
+++ b/trove/common/utils.py
@@ -18,7 +18,6 @@ import collections
 import inspect
 import os
 import shutil
-import time
 import uuid
 
 from eventlet.timeout import Timeout
@@ -186,14 +185,11 @@ class MethodInspector(object):
 
 def build_polling_task(retriever, condition=lambda value: value,
                        sleep_time=1, time_out=0):
-    start_time = time.time()
 
     def poll_and_check():
         obj = retriever()
         if condition(obj):
             raise loopingcall.LoopingCallDone(retvalue=obj)
-        if time_out > 0 and time.time() - start_time > time_out:
-            raise exception.PollTimeOut
 
     return loopingcall.BackOffLoopingCall(
         f=poll_and_check).start(initial_delay=False,
@@ -201,6 +197,14 @@ def build_polling_task(retriever, condition=lambda value: value,
                                 max_interval=30, timeout=time_out)
 
 
+def wait_for_task(polling_task):
+    """Waits for the task until it is finished"""
+    try:
+        return polling_task.wait()
+    except loopingcall.LoopingCallTimeOut:
+        raise exception.PollTimeOut
+
+
 def poll_until(retriever, condition=lambda value: value,
                sleep_time=1, time_out=0):
     """Retrieves object until it passes condition, then returns it.
@@ -209,9 +213,9 @@ def poll_until(retriever, condition=lambda value: value,
     amount of time is eclipsed.
 
     """
-
-    return build_polling_task(retriever, condition=condition,
-                              sleep_time=sleep_time, time_out=time_out).wait()
+    task = build_polling_task(retriever, condition=condition,
+                              sleep_time=sleep_time, time_out=time_out)
+    return wait_for_task(task)
 
 
 # Copied from nova.api.openstack.common in the old code.