After reading Leopold Toetsch's post, I'm going to simplify part of my
proposal slightly.
Benjamin Goldberg wrote:
[snip]
> To avoid premature cleanup, any time that the contents of a
> refcounted variable is assigned to a non-refcounted variable, an
> opcode to set a "reachable by non-refcounted variable" flag on the
> value precedes the assignment.
Actually, as Leopold suggested, we could merely set a global
interpreter->needs_lazy_dod flag to true.
[snip]
> [*] How does this flag get cleared, you might ask?
>
> Simplest would be to not clear it at all. This would be mostly
> harmless in terms of when objects get destructed, but would probably
> result in more DoD runs than we really need -- blech. [**]
>
> A more "proper" solution would be to clear it during/after each DoD
> run.
>
> During the course of a DoD run, when we look for what PMCs are
> reachable, we keep track of what each thing was reachable *from*.
This needs a bit of clarification, I think.
IIRC, DoD normally happens something vaguely like this:
for my $p (@all_pmcs) {
clear_is_live_flag($p);
}
our $traverse;
sub set_is_live_flag($p) {
if( !test_is_live_flag($p) and test_is_agregate($p) ) {
$traverse = [$p, $traverse];
}
really_set_is_live_flag($p);
}
set_is_live_flag($_) for @rootset;
while( $traverse ) {
((my $p), $traverse) = splice @$traverse;
$p->set_live_flag_on_contained_objects();
}
for my $p (@all_pmcs) {
next if test_is_live_flag($p);
free_pmc($p);
}
My proposal would change the set_is_live_flag to something like:
sub set_is_live_flag($p, $contained_in) {
if( test_uses_refcounting($p) and
not test_has_refcount_trait($contained_in) ) {
$needs_lazy_dod = 1;
}
if( !test_is_live_flag($p) and test_is_agregate($p) ) {
$traverse = [$p, $traverse];
}
really_set_is_live_flag($p);
}
Where $contained_in would be the variable (or agregate object) which the
object $p is contained in.
--
$a=24;split//,240513;s/\B/ => /for@@=qw(ac ab bc ba cb ca
);{push(@b,$a),($a-=6)^=1 for 2..$a/6x--$|;print "[EMAIL PROTECTED]
]\n";((6<=($a-=6))?$a+=$_[$a%6]-$a%6:($a=pop @b))&&redo;}
