Patch #1953

I implemented the function sys._compact_freelists() and C API functions PyInt_/PyFloat_CompactFreeList() to compact the pre-allocated blocks of ints and floats. They allow the user to reduce the memory usage of a Python process that deals with lots of numbers.
The patch also renames sys._cleartypecache to sys._clear_type_cache

2 files changed, 19 insertions, 1 deletions

diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index 72d103974a..b6aa96b327 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -710,7 +710,7 @@ def dash_R_cleanup(fs, ps, pic, abcs):
     sys.path_importer_cache.update(pic)
 
     # clear type cache
-    sys._cleartypecache()
+    sys._clear_type_cache()
 
     # Clear ABC registries, restoring previously saved ABC registries.
     for abc in [getattr(_abcoll, a) for a in _abcoll.__all__]:
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index aafbfa3756..a01ea3e9b4 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -363,6 +363,24 @@ class SysModuleTest(unittest.TestCase):
             self.assertEqual(type(getattr(sys.flags, attr)), int, attr)
         self.assert_(repr(sys.flags))
 
+    def test_clear_type_cache(self):
+        sys._clear_type_cache()
+
+    def test_compact_freelists(self):
+        sys._compact_freelists()
+        r = sys._compact_freelists()
+        # freed blocks shouldn't change
+        self.assertEqual(r[0][2], 0)
+        self.assertEqual(r[1][2], 0)
+        # fill freelists
+        ints = list(range(12000))
+        floats = [float(i) for i in ints]
+        del ints
+        del floats
+        # should free more than 200 blocks each
+        r = sys._compact_freelists()
+        self.assert_(r[0][2] > 200, r[0][2])
+        self.assert_(r[1][2] > 200, r[1][2])
 
 def test_main():
     test.test_support.run_unittest(SysModuleTest)