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)
........
diff --git a/Lib/test/test_dict.py b/Lib/test/test_dict.py
index 308143d..1c9bca8 100644
--- a/Lib/test/test_dict.py
+++ b/Lib/test/test_dict.py
@@ -665,6 +665,104 @@
gc.collect()
self.assert_(ref() is None, "Cycle was not collected")
+ def _not_tracked(self, t):
+ # Nested containers can take several collections to untrack
+ gc.collect()
+ gc.collect()
+ self.assertFalse(gc.is_tracked(t), t)
+
+ def _tracked(self, t):
+ self.assertTrue(gc.is_tracked(t), t)
+ gc.collect()
+ gc.collect()
+ self.assertTrue(gc.is_tracked(t), t)
+
+ def test_track_literals(self):
+ # Test GC-optimization of dict literals
+ x, y, z, w = 1.5, "a", (1, None), []
+
+ self._not_tracked({})
+ self._not_tracked({x:(), y:x, z:1})
+ self._not_tracked({1: "a", "b": 2})
+ self._not_tracked({1: 2, (None, True, False, ()): int})
+ self._not_tracked({1: object()})
+
+ # Dicts with mutable elements are always tracked, even if those
+ # elements are not tracked right now.
+ self._tracked({1: []})
+ self._tracked({1: ([],)})
+ self._tracked({1: {}})
+ self._tracked({1: set()})
+
+ def test_track_dynamic(self):
+ # Test GC-optimization of dynamically-created dicts
+ class MyObject(object):
+ pass
+ x, y, z, w, o = 1.5, "a", (1, object()), [], MyObject()
+
+ d = dict()
+ self._not_tracked(d)
+ d[1] = "a"
+ self._not_tracked(d)
+ d[y] = 2
+ self._not_tracked(d)
+ d[z] = 3
+ self._not_tracked(d)
+ self._not_tracked(d.copy())
+ d[4] = w
+ self._tracked(d)
+ self._tracked(d.copy())
+ d[4] = None
+ self._not_tracked(d)
+ self._not_tracked(d.copy())
+
+ # dd isn't tracked right now, but it may mutate and therefore d
+ # which contains it must be tracked.
+ d = dict()
+ dd = dict()
+ d[1] = dd
+ self._not_tracked(dd)
+ self._tracked(d)
+ dd[1] = d
+ self._tracked(dd)
+
+ d = dict.fromkeys([x, y, z])
+ self._not_tracked(d)
+ dd = dict()
+ dd.update(d)
+ self._not_tracked(dd)
+ d = dict.fromkeys([x, y, z, o])
+ self._tracked(d)
+ dd = dict()
+ dd.update(d)
+ self._tracked(dd)
+
+ d = dict(x=x, y=y, z=z)
+ self._not_tracked(d)
+ d = dict(x=x, y=y, z=z, w=w)
+ self._tracked(d)
+ d = dict()
+ d.update(x=x, y=y, z=z)
+ self._not_tracked(d)
+ d.update(w=w)
+ self._tracked(d)
+
+ d = dict([(x, y), (z, 1)])
+ self._not_tracked(d)
+ d = dict([(x, y), (z, w)])
+ self._tracked(d)
+ d = dict()
+ d.update([(x, y), (z, 1)])
+ self._not_tracked(d)
+ d.update([(x, y), (z, w)])
+ self._tracked(d)
+
+ def test_track_subtypes(self):
+ # Dict subtypes are always tracked
+ class MyDict(dict):
+ pass
+ self._tracked(MyDict())
+
from test import mapping_tests