GH-126491: Lower heap size limit with faster marking (GH-127519)

* Faster marking of reachable objects

* Changes calculation of work to do and work done.

* Merges transitive closure calculations

1 files changed, 3 insertions, 11 deletions

diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py
index b514005..baf8e95 100644
--- a/Lib/test/test_gc.py
+++ b/Lib/test/test_gc.py
@@ -1161,27 +1161,19 @@ class IncrementalGCTests(unittest.TestCase):
             return head
 
         head = make_ll(1000)
-        count = 1000
-
-        # There will be some objects we aren't counting,
-        # e.g. the gc stats dicts. This test checks
-        # that the counts don't grow, so we try to
-        # correct for the uncounted objects
-        # This is just an estimate.
-        CORRECTION = 20
 
         enabled = gc.isenabled()
         gc.enable()
         olds = []
         initial_heap_size = _testinternalcapi.get_tracked_heap_size()
-        for i in range(20_000):
+        iterations = max(20_000, initial_heap_size)
+        for i in range(iterations):
             newhead = make_ll(20)
-            count += 20
             newhead.surprise = head
             olds.append(newhead)
             if len(olds) == 20:
                 new_objects = _testinternalcapi.get_tracked_heap_size() - initial_heap_size
-                self.assertLess(new_objects, 27_000, f"Heap growing. Reached limit after {i} iterations")
+                self.assertLess(new_objects, initial_heap_size/2, f"Heap growing. Reached limit after {i} iterations")
                 del olds[:]
         if not enabled:
             gc.disable()