Author: Armin Rigo <[email protected]> Branch: miniscan Changeset: r52977:c5c715bfac2b Date: 2012-02-28 14:09 +0100 http://bitbucket.org/pypy/pypy/changeset/c5c715bfac2b/
Log: Comment. diff --git a/pypy/rpython/memory/gc/minimark.py b/pypy/rpython/memory/gc/minimark.py --- a/pypy/rpython/memory/gc/minimark.py +++ b/pypy/rpython/memory/gc/minimark.py @@ -116,6 +116,10 @@ TID_MASK = (first_gcflag << 7) - 1 +# The remaining unused bits (GCFLAG_HIGH_MASK) are set to a known pattern +# in all objects (GCFLAG_HIGH). From a random address in the nursery, it +# let us know if it points to a valid object: either "definitely not", or +# "very likely". We can't be sure, though, so be careful. GCFLAG_HIGH_MASK = intmask(~TID_MASK) assert GCFLAG_HIGH_MASK < 0 and not (GCFLAG_HIGH_MASK & GCFLAG_CARDS_SET) GCFLAG_HIGH = intmask(0x5555555555555555 & GCFLAG_HIGH_MASK) _______________________________________________ pypy-commit mailing list [email protected] http://mail.python.org/mailman/listinfo/pypy-commit
