[Jython-checkins] SF.net SVN: jython:[7104] trunk/jython/Lib/test/test_defaultdict_jy.py

[<zy...@us...>]

Revision: 7104
          http://jython.svn.sourceforge.net/jython/?rev=7104&view=rev
Author:   zyasoft
Date:     2010-08-25 01:40:46 +0000 (Wed, 25 Aug 2010)

Log Message:
-----------
Now test that defaultdict's __missing__/default_factory is computed
atomically.

Modified Paths:
--------------
    trunk/jython/Lib/test/test_defaultdict_jy.py

Modified: trunk/jython/Lib/test/test_defaultdict_jy.py
===================================================================
--- trunk/jython/Lib/test/test_defaultdict_jy.py	2010-08-25 01:38:26 UTC (rev 7103)
+++ trunk/jython/Lib/test/test_defaultdict_jy.py	2010-08-25 01:40:46 UTC (rev 7104)
@@ -3,10 +3,15 @@
 Made for Jython.
 """
 import pickle
+import time
+import threading
 import unittest
 from collections import defaultdict
 from test import test_support
+from random import randint
 
+from java.util.concurrent.atomic import AtomicInteger
+
 class PickleTestCase(unittest.TestCase):
 
     def test_pickle(self):
@@ -15,8 +20,63 @@
             self.assertEqual(pickle.loads(pickle.dumps(d, proto)), d)
 
 
+# TODO push into test_support or some other common module - run_threads
+# is originally from test_list_jy.py
+
+class ThreadSafetyTestCase(unittest.TestCase):
+
+    def run_threads(self, f, num=10):
+        threads = []
+        for i in xrange(num):
+            t = threading.Thread(target=f)
+            t.start()
+            threads.append(t)
+        timeout = 10. # be especially generous
+        for t in threads:
+            t.join(timeout)
+            timeout = 0.
+        for t in threads:
+            self.assertFalse(t.isAlive())
+
+    def test_inc_dec(self):
+
+        class Counter(object):
+            def __init__(self):
+                self.atomic = AtomicInteger()
+                 # waiting is important here to ensure that
+                 # defaultdict factories can step on each other
+                time.sleep(0.001)
+
+            def decrementAndGet(self):
+                return self.atomic.decrementAndGet()
+
+            def incrementAndGet(self):
+                return self.atomic.incrementAndGet()
+
+            def get(self):
+                return self.atomic.get()
+
+            def __repr__(self):
+                return "Counter<%s>" % (self.atomic.get())
+
+        counters = defaultdict(Counter)
+        size = 17
+        
+        def tester():
+            for i in xrange(1000):
+                j = (i + randint(0, size)) % size
+                counters[j].decrementAndGet()
+                time.sleep(0.0001)
+                counters[j].incrementAndGet()
+
+        self.run_threads(tester, 20)
+        
+        for i in xrange(size):
+            self.assertEqual(counters[i].get(), 0, counters)
+
+
 def test_main():
-    test_support.run_unittest(PickleTestCase)
+    test_support.run_unittest(PickleTestCase, ThreadSafetyTestCase)
 
 
 if __name__ == '__main__':


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