perlembed: reference counts

semuel has asked for the wisdom of the Perl Monks concerning the following question:

Hello.

I am writing a program in C that embeds Perl. one of my functions does this:

void my_load_module(pTHX_ const char *module_name) {
    SV *sv_name = newSVpv(module_name, 0);
    load_module(PERL_LOADMOD_NOIMPORT, sv_name, Nullsv);
//    SvREFCNT_dec(sv_name);
}
[download]

The problem is, if I uncomment the last line, I get en error saying the I try to decresed a ref_count of zero.
or, in Perl's own words:

Attempt to free unreferenced scalar: SV 0x0....
[download]

why?
Shmuel.

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Re: perlembed: reference counts by Joost (Canon) on Sep 19, 2007 at 22:08 UTC
I don't know why, but it seems that load_module decreases the refcount of the sv_name argument (at least it does for me with perl 5.8.8/linux). `SV sv_name = newSVpv("Carp", 0); warn("refbefore %d",SvREFCNT(sv_name)); load_module(PERL_LOADMOD_NOIMPORT, sv_name, Nullsv); warn("refafter %d",SvREFCNT(sv_name));` [download] output: `refbefore 1 at .... refafter 0 at ....` [download] "What should it profit a man, if he should win a flame war, yet lose his cool?"*	[reply] [d/l] [select]
Re^2: perlembed: reference counts by semuel (Novice) on Sep 20, 2007 at 19:09 UTC
The question is, of course, why. I am looking for documentation, comment or even a pointer to the source code will be enough. (I looked for that function in the source code, and for some reason could not find it...)	[reply]
Re^3: perlembed: reference counts by Joost (Canon) on Sep 20, 2007 at 19:13 UTC
Perl_load_module is in op.c and calls Perl_vload_module (also in op.c) I can't spot anything obvious. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply]
Re^4: perlembed: reference counts (bug) by tye (Sage) on Sep 20, 2007 at 19:56 UTC