As anonymonk points out, XS code is meant to use New*() and Safefree(). In part, to avoid the predictable problems with multiple runtimes trying to manage heap memory. However, I find these PerlAPI functions inconvenient to use because of their non-standard calling syntax (a problem rife throughout the PerlAPI).

It means that you cannot initialise pointers in-line with their declarations. So, like many others, I've wrapped those APis in more convenient and intuative wrappers

void *Calloc( int n, int size ) {
    void *p;
    Newxz( p, n * size, char  );
    return p;
}

void Free( void *p ) {
    Safefree( p );
}
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Note the uppercase first chars. Done to avoid conflicts with the dozens of other definitions and re-definitions of calloc() and free() (along with malloc() et al.) spread throughout the Perl sources.