in reply to memory leak in eval_pv?

eval_*(...) take the same flags as their cousins call_*(...) in that you must specify G_DISCARD to discard the return value of the eval or you'll leak SV's with refcount one.

Update: After speaking with ysth I learned that eval_pv(...) doesn't care about G_DISCARD. While my initial diagnosis was correct, you're not freeing the SV returned by eval_*(...), a solution that works is:

SvREFCNT_dec(eval_pv(...));

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Re^2: memory leak in eval_pv?
by lightspeed (Initiate) on May 16, 2007 at 11:13 UTC
    Hi Trizor, Many thanks for your reply - alas this did not seem to fix the leak. The code I have now is: 
       #include <EXTERN.h>
   #include <perl.h>
   static PerlInterpreter *my_perl;
   main (int argc, char **argv, char **env)
   {
       STRLEN n_a;
       int i;
       char *embedding[] = { "", "-e", "sub fred {1;};" };
       my_perl = perl_alloc();
       perl_construct( my_perl );
       perl_parse(my_perl, NULL, 3, embedding, NULL);
       perl_run(my_perl);
       for(i=0; i < 10000000; i++) {
         SvREFCNT_dec(eval_pv("1;", TRUE));
       }
       perl_destruct(my_perl);
       perl_free(my_perl);
   }

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    and compiled with perl 5.8.3 still leaks. In a previous attempt (before I posted) I tried assigning the eval_pv() to an SV* and explicitly calling SV_free on it (and also setting it mortal with sv_2motral) but neither of these helped. I was coming to the conclusion that the leak may be inside eval_pv/sv iteself so I thought I'd post here to see if anyone else had seen similar issues. I guess the thing to try next is to build the latest 5.8.8 perl and try it with that. Many thanks, Shaun.
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      Just to wrap this one up.... It appears that eval_pv (and eval_sv) return a mortal SV* that must be cleaned up by "topping and tailing" the call to eval_pv with: 
               ENTER;
         SAVETMPS;
         value = (eval_pv("1;", TRUE));
         FREETMPS;
         LEAVE;

      [download]
      The assignment SV* value is required, else errors about freeing unreferenced value are generated. Shaun.
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