RE: Free memory after newSVpv

________________________________
> From: [email protected] 
> Date: Fri, 2 Nov 2012 22:40:31 -0700 
> Subject: Free memory after newSVpv 
> To: [email protected] 
> 
> Very quick question I hope someone can answer. 
> 
> I'm calling sendTask() in a C++ library where I pass a char* that is 
> supposedly malloced and returned so I need to free() it. 
> 
> The problem is when I call Safefree() below the code fails (in odd 
> ways), but if I don't call Safefree() /free() then it works ok. 
> 
> 
> Looking at the code below, if "buffer" is malloc'd and returned and 
> newSVpv copies the buffer into the SV then is it correct to call 
> Safefree() or free() as I'm doing below? 
> 
> 
> void 
> sendTask( MyClient * THIS, unsigned int id, char * message_payload, 
> unsigned int message_length ) 
> PPCODE: 
> char * buffer = NULL; 
> int buffer_length; 
> int status; 
> 
> THIS->sendTask( id, message_payload, message_length, buffer, 
> &buffer_length, &status ); 
> XPUSHs( sv_2mortal( newSVpv( buffer, buffer_length ) ) ); 
> Safefree( buffer ); 
> XPUSHs( sv_2mortal( newSViv( status ) ) ); 
> 


Do not confuse Perl's memory allocator as described in perlclib with your C compiler's or OS's clib's malloc. They are 2 different allocators and the mem blocks come from 2 different pools (not 100% true, but let us keep this simple and sane). Read the docs for whatever the sendTask C++ method is and figure out what the C++ lib's docs tell you to use to free var buffer.