I'm trying to find a Perl embedding solution without getting all memory grabbed by the process itself; in this process, I've isolated the very few code lines that really make me go nuts.
Consider the following bare-bones program, which actually doesn't try to do nothing really interesting but setting the same Perl variable one million times. 
#include <EXTERN.h>
#include <perl.h>
#include <unistd.h>
#include <stdio.h>

void do_something () {
    dSP;
    ENTER;
    SAVETMPS;
    PUSHMARK(SP);
    eval_pv("$a = 1", 1);
    SPAGAIN;
    FREETMPS;
    LEAVE;
}

int main (int argc, char* argv[]) {
    PerlInterpreter *my_perl = perl_alloc();
    char *embedding[] = {"", "-e", "0"};
    I32 i;
    char c;

    perl_construct(my_perl);
    perl_parse(my_perl, NULL, 3, embedding, NULL);
    PL_exit_flags |= PERL_EXIT_DESTRUCT_END;

    printf("Press a key to start\n");
    read(0, &c, 1);
    for (i = 0; i < 1000000; ++i)
        do_something();
    
    printf("Press a key to continue\n");
    read(0, &c, 1);
    PL_perl_destruct_level = 1;
    perl_destruct(my_perl);
    perl_free(my_perl);
    
    printf("Press a key to exit\n");
    read(0, &c, 1);

    return 0;
}

[download]
What I really don't understand is why the process keeps growing demanding more memory as the index variable i increases.

After a suggestion from Joost (see below his response), I ended up finding that the following version of do_something shows less leakage (but not zero): 

void do_something () {
    dSP;
    ENTER;
    SAVETMPS;
    eval_pv("$a = 1", 1);
    FREETMPS;
    LEAVE;
}

[download]
The only thing that has popped to my mind is that maybe the return value from eval_pv, which is actually an SV*, could be the source of my problems, but I tried to either mark it as mortal or decrease its reference count with the only result of getting an error message about disposing of a variable without references.

What am I missing (apart from memory)?

Thank you in advance,

-- Flavio

In reply to Bare-bones embedding and memory leakage by polettix

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