1 files changed, 43 insertions, 1 deletions
diff --git a/Lib/test/test_threading_local.py b/Lib/test/test_threading_local.py
index 0aaedbc93b..b7dd538f8e 100644
--- a/Lib/test/test_threading_local.py
+++ b/Lib/test/test_threading_local.py
@@ -1,9 +1,51 @@
 import unittest
 from doctest import DocTestSuite
 from test import test_support
+import threading
+import weakref
+import gc
+
+class Weak(object):
+    pass
+
+def target(local, weaklist):
+    weak = Weak()
+    local.weak = weak
+    weaklist.append(weakref.ref(weak))
+
+class ThreadingLocalTest(unittest.TestCase):
+
+    def test_local_refs(self):
+        self._local_refs(20)
+        self._local_refs(50)
+        self._local_refs(100)
+
+    def _local_refs(self, n):
+        local = threading.local()
+        weaklist = []
+        for i in range(n):
+            t = threading.Thread(target=target, args=(local, weaklist))
+            t.start()
+            t.join()
+        del t
+
+        gc.collect()
+        self.assertEqual(len(weaklist), n)
+
+        # XXX threading.local keeps the local of the last stopped thread alive.
+        deadlist = [weak for weak in weaklist if weak() is None]
+        self.assertEqual(len(deadlist), n-1)
+
+        # Assignment to the same thread local frees it sometimes (!)
+        local.someothervar = None
+        gc.collect()
+        deadlist = [weak for weak in weaklist if weak() is None]
+        self.assert_(len(deadlist) in (n-1, n), (n, len(deadlist)))
 
 def test_main():
-    suite = DocTestSuite('_threading_local')
+    suite = unittest.TestSuite()
+    suite.addTest(DocTestSuite('_threading_local'))
+    suite.addTest(unittest.makeSuite(ThreadingLocalTest))
 
     try:
         from thread import _local