From 5f1273fd18b89cdc59e580f5e2c9c2eef0df8049 Mon Sep 17 00:00:00 2001
From: Andrey Golovizin <ag@sologoc.com>
Date: Sat, 30 Aug 2014 20:51:17 +0200
Subject: [PATCH] Fix deadlocks in cached_property().

---
 pixelocr/utils.py | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/pixelocr/utils.py b/pixelocr/utils.py
index 4a6c98e..239f10e 100644
--- a/pixelocr/utils.py
+++ b/pixelocr/utils.py
@@ -16,20 +16,18 @@
 
 import functools
 import itertools
+from collections import defaultdict
 from threading import Lock
 
 
 def cached_property(fun):
     """A memoize decorator for class properties."""
     lock = Lock()
-    locks = {}
+    locks = defaultdict(Lock)
     @functools.wraps(fun)
     def get(self):
         with lock:
-            try:
-                obj_lock = self._lock
-            except AttributeError:
-                obj_lock = self._lock = Lock()
+            obj_lock = locks[self, fun]
         with obj_lock:
             try:
                 cache = self._cache