Mailing List Archive

Update of /cvsroot/python/python/dist/src/Lib/test
In directory usw-pr-cvs1:/tmp/cvs-serv30082/221/Lib/test

Modified Files:
Tag: release22-maint
test_gc.py
Log Message:
Backport of a new test to check the interaction between cyclic GC
and the trashcan mechanism.


Index: test_gc.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/test/test_gc.py,v
retrieving revision 1.12
retrieving revision 1.12.10.1
diff -C2 -d -r1.12 -r1.12.10.1
*** test_gc.py 15 Oct 2001 22:49:27 -0000 1.12
--- test_gc.py 28 Mar 2002 23:18:08 -0000 1.12.10.1
***************
*** 172,175 ****
--- 172,203 ----
apply(gc.set_threshold, thresholds)

+ class Ouch:
+ n = 0
+ def __del__(self):
+ Ouch.n = Ouch.n + 1
+ if Ouch.n % 7 == 0:
+ gc.collect()
+
+ def test_trashcan():
+ # "trashcan" is a hack to prevent stack overflow when deallocating
+ # very deeply nested tuples etc. It works in part by abusing the
+ # type pointer and refcount fields, and that can yield horrible
+ # problems when gc tries to traverse the structures.
+ # If this test fails (as it does in 2.0, 2.1 and 2.2), it will
+ # most likely die via segfault.
+
+ gc.enable()
+ N = 200
+ for count in range(3):
+ t = []
+ for i in range(N):
+ t = [t, Ouch()]
+ u = []
+ for i in range(N):
+ u = [u, Ouch()]
+ v = {}
+ for i in range(N):
+ v = {1: v, 2: Ouch()}
+ gc.disable()

def test_all():
***************
*** 188,191 ****
--- 216,220 ----
run_test("__del__", test_del)
run_test("saveall", test_saveall)
+ run_test("trashcan", test_trashcan)

def test():