Merge "redis: make sure we don't release and heartbeat a lock at the same time"

tooz/drivers/redis.py

@@ -20,6 +20,7 @@ import contextlib
 from distutils import version
 import logging
 import string
+import threading
 
 from concurrent import futures
 from oslo_utils import encodeutils
@@ -58,6 +59,9 @@ class RedisLock(locking.Lock):
     def __init__(self, coord, client, name, timeout):
         name = "%s_%s_lock" % (coord.namespace, six.text_type(name))
         super(RedisLock, self).__init__(name)
+        # NOTE(jd) Make sure we don't release and heartbeat at the same time by
+        # using a exclusive access lock (LP#1557593)
+        self._exclusive_access = threading.Lock()
         self._lock = client.lock(name,
                                  timeout=timeout,
                                  thread_local=False)
@@ -86,20 +90,22 @@ class RedisLock(locking.Lock):
             return acquired
 
     def release(self):
-        if not self.acquired:
+        with self._exclusive_access:
-            return False
+            if not self.acquired:
-        with _translate_failures():
-            try:
-                self._lock.release()
-            except exceptions.LockError:
                 return False
-            self._coord._acquired_locks.discard(self)
+            with _translate_failures():
-            return True
+                try:
+                    self._lock.release()
+                except exceptions.LockError:
+                    return False
+                self._coord._acquired_locks.discard(self)
+                return True
 
     def heartbeat(self):
-        if self.acquired:
+        with self._exclusive_access:
-            with _translate_failures():
+            if self.acquired:
-                self._lock.extend(self._lock.timeout)
+                with _translate_failures():
+                    self._lock.extend(self._lock.timeout)
 
     @property
     def acquired(self):