On Wed, May 26, 2004 at 01:35:30PM -0400, muppet wrote:
>
> Bill Moseley said:
> > I don't know how many values will be pushed onto the stack, so I can't
> > check. There may be no returned values on the stack, as well.
>
> then you need to do something like this:
>
> /* invoke perl sub */
> n = call_pv (name, G_ARRAY);
>
> /* refresh local copy of stack pointer */
> SPAGAIN;
>
> /* get any and all returned values off of the stack */
> while (n-- > 0) {
> SV * sv = POPs; /* pop last value off of the stack */
> /* do whatever with that value */
> }
No, I don't want to do anything with them there. I just want to return
them to perl.
> what's the "secondary routine"? the code you called with call_pv()? in that
> case they returned the values to your XS code, and you are now responsible for
> doing something with them. are you wanting simply to pass them straight back
> to your caller? or are you talking about using them in your xsub?
Pass them back to the caller.
So in Perl:
my @list = Foo->return_list( 'foo', 'bar' );
Where @list contains a list of Foo::Bla objects.
Then in XS:
MODULE = Foo PACKAGE = Foo
void
return_list( var_a, var_b )
char *var_a
char *var_b
PPCODE:
PUSHMARK(SP);
XPUSH( (SV *)var_a );
XPUSH( (SV *)var_b );
PUTBACK;
call_pv("Foo::secondary_function", G_ARRAY );
SPAGAIN;
void
secondary_function( var_a, var_b )
SV *var_a
SV *var_b
PPCODE:
LIST long_list = get_long_list( (char *)var_a, (char *)var_b )
while ( *long_list )
{
SV *object = sv_newmortal();
sv_setref_pv( object, "Foo::Bla", (void *)*long_list );
XPUSHs( object );
long_list++;
}
So "secondary_function" pushes any number of thingies onto the stack and
returns them to perl space. Like I said, the stack is a mystery to me,
so I'm not clear how perl knows how many Foo::Bla objects are on the
stack and how many to place in @list.
That is, I wonder if I need to check the return value from call_pv (the
number of items pushed on the stack, right?) and then in "return_list"
use that number to tell perl how many items I'm returning.
Sorry, that's not very clear, but hopefully the code makes it clear what
I'm attempting.
BTW -- I also was wondering how best to check for leaks in the Perl/XS
code -- make sure all my objects are destroyed like I expect.
Thanks,
--
Bill Moseley
[EMAIL PROTECTED]
