Mailing List Archive

Update of /cvsroot/python/python/dist/src/Modules
In directory usw-pr-cvs1:/tmp/cvs-serv864/python/Modules

Modified Files:
gcmodule.c
Log Message:
visit_decref(): Two optimizations.

1. You're not supposed to call this with a NULL argument, although the
docs could be clearer about that. The other visit_XYZ() functions
don't bother to check. This doesn't either now, although it does
assert non-NULL-ness now.

2. It doesn't matter whether the object is currently tracked, so don't
bother checking that either (if it isn't currently tracked, it may
have some nonsense value in gc_refs, but it doesn't hurt to
decrement gibberish, and it's cheaper to do so than to make everyone
test for trackedness).

It would be nice to get rid of the other tests on IS_TRACKED. Perhaps
trackedness should not be a matter of not being in any gc list, but
should be a matter of being in a new "untracked" gc list. This list
simply wouldn't be involved in the collection mechanism. A newly
created object would be put in the untracked list. Tracking would
simply unlink it and move it into the gen0 list. Untracking would do
the reverse. No test+branch needed then. visit_move() may be vulnerable
then, though, and I don't know how this would work with the trashcan.


Index: gcmodule.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Modules/gcmodule.c,v
retrieving revision 2.46
retrieving revision 2.47
diff -C2 -d -r2.46 -r2.47
*** gcmodule.c 30 Jun 2002 17:56:40 -0000 2.46
--- gcmodule.c 30 Jun 2002 21:31:03 -0000 2.47
***************
*** 197,205 ****
* cause an error.
*/
! if (op && PyObject_IS_GC(op)) {
! if (IS_TRACKED(op)) {
! AS_GC(op)->gc.gc_refs--;
! }
! }
return 0;
}
--- 197,203 ----
* cause an error.
*/
! assert(op != NULL);
! if (PyObject_IS_GC(op))
! AS_GC(op)->gc.gc_refs--;
return 0;
}