diff --git a/oauth2client/appengine.py b/oauth2client/appengine.py
index 2811069..68d5066 100644
--- a/oauth2client/appengine.py
+++ b/oauth2client/appengine.py
@@ -229,7 +229,7 @@
     self._property_name = property_name
     self._cache = cache
 
-  def get(self):
+  def locked_get(self):
     """Retrieve Credential from datastore.
 
     Returns:
@@ -248,7 +248,7 @@
 
     return credential
 
-  def put(self, credentials):
+  def locked_put(self, credentials):
     """Write a Credentials to the datastore.
 
     Args:
diff --git a/oauth2client/django_orm.py b/oauth2client/django_orm.py
index 581fe8e..5e511db 100644
--- a/oauth2client/django_orm.py
+++ b/oauth2client/django_orm.py
@@ -86,7 +86,7 @@
     self.key_value = key_value
     self.property_name = property_name
 
-  def get(self):
+  def locked_get(self):
     """Retrieve Credential from datastore.
 
     Returns:
@@ -102,7 +102,7 @@
         credential.set_store(self)
     return credential
 
-  def put(self, credentials):
+  def locked_put(self, credentials):
     """Write a Credentials to the datastore.
 
     Args:
diff --git a/oauth2client/file.py b/oauth2client/file.py
index 89140b8..60a6385 100644
--- a/oauth2client/file.py
+++ b/oauth2client/file.py
@@ -46,20 +46,32 @@
     self._filename = filename
     self._lock = threading.Lock()
 
-  def get(self):
+  def acquire_lock(self):
+    """Acquires any lock necessary to access this Storage.
+
+    This lock is not reentrant."""
+    self._lock.acquire()
+
+  def release_lock(self):
+    """Release the Storage lock.
+
+    Trying to release a lock that isn't held will result in a
+    RuntimeError.
+    """
+    self._lock.release()
+
+  def locked_get(self):
     """Retrieve Credential from file.
 
     Returns:
       oauth2client.client.Credentials
     """
-    self._lock.acquire()
     credentials = None
     try:
       f = open(self._filename, 'r')
       content = f.read()
       f.close()
     except IOError:
-      self._lock.release()
       return credentials
 
     # First try reading as JSON, and if that fails fall back to pickle.
@@ -74,19 +86,15 @@
         credentials.set_store(self)
       except:
         pass
-    finally:
-      self._lock.release()
 
     return credentials
 
-  def put(self, credentials):
+  def locked_put(self, credentials):
     """Write Credentials to file.
 
     Args:
       credentials: Credentials, the credentials to store.
     """
-    self._lock.acquire()
     f = open(self._filename, 'w')
     f.write(credentials.to_json())
     f.close()
-    self._lock.release()