Merged revisions 70546 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r70546 | antoine.pitrou | 2009-03-23 19:41:45 +0100 (lun., 23 mars 2009) | 9 lines

  Issue #4688: Add a heuristic so that tuples and dicts containing only
  untrackable objects are not tracked by the garbage collector. This can
  reduce the size of collections and therefore the garbage collection overhead
  on long-running programs, depending on their particular use of datatypes.

  (trivia: this makes the "binary_trees" benchmark from the Computer Language
  Shootout 40% faster)
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1 files changed, 27 insertions, 0 deletions

diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py
index 414e17aa8f..2262b367fa 100644
--- a/Lib/test/test_gc.py
+++ b/Lib/test/test_gc.py
@@ -415,6 +415,33 @@ class GCTests(unittest.TestCase):
 
         self.assertEqual(gc.get_referents(1, 'a', 4j), [])
 
+    def test_is_tracked(self):
+        # Atomic built-in types are not tracked, user-defined objects and
+        # mutable containers are.
+        # NOTE: types with special optimizations (e.g. tuple) have tests
+        # in their own test files instead.
+        self.assertFalse(gc.is_tracked(None))
+        self.assertFalse(gc.is_tracked(1))
+        self.assertFalse(gc.is_tracked(1.0))
+        self.assertFalse(gc.is_tracked(1.0 + 5.0j))
+        self.assertFalse(gc.is_tracked(True))
+        self.assertFalse(gc.is_tracked(False))
+        self.assertFalse(gc.is_tracked(b"a"))
+        self.assertFalse(gc.is_tracked("a"))
+        self.assertFalse(gc.is_tracked(bytearray(b"a")))
+        self.assertFalse(gc.is_tracked(type))
+        self.assertFalse(gc.is_tracked(int))
+        self.assertFalse(gc.is_tracked(object))
+        self.assertFalse(gc.is_tracked(object()))
+
+        class UserClass:
+            pass
+        self.assertTrue(gc.is_tracked(gc))
+        self.assertTrue(gc.is_tracked(UserClass))
+        self.assertTrue(gc.is_tracked(UserClass()))
+        self.assertTrue(gc.is_tracked([]))
+        self.assertTrue(gc.is_tracked(set()))
+
     def test_bug1055820b(self):
         # Corresponds to temp2b.py in the bug report.