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NOQTIS

nqsetal(3)

nqsetal — set the allocator of the capsule and parser layers

libnoqtis, -lnoqtis

#include <noqtis.h>

typedef void *(*nqmalfn)(size_t size, void *user);
typedef void (*nqfreefn)(void *ptr, size_t size, void *user);

int
nqsetal(nqmalfn mal, nqfreefn fre, void *user);

The algorithm code of noqtis never allocates; the capsule layer (nqseal(3), nqchk(3)) and its parsers do, through one hook. () replaces it: mal is called with the size wanted and user, and returns the memory or NULL; fre is called with a pointer mal returned, the size that was asked for, and user. The library wipes memory before it gives it to fre, so a hook need not. The size makes pool and arena allocators and allocation accounting easy.

mal and fre both NULL restore the default, malloc(3) and free(3).

The hook is global and () is not thread safe: call it before any other function of the library, and never while another thread uses the library.

NQOK, or NQEARG when exactly one of mal and fre is NULL (the hook is then unchanged). A hook that returns NULL makes the calling function return NQEMEM.

Count the bytes in use:

static size_t used;

static void *mal(size_t n, void *u) {
  void *p = malloc(n);
  (void)u;
  if (p != NULL)
    used += n;
  return p;
}

static void fre(void *p, size_t n, void *u) {
  (void)u;
  used -= n;
  free(p);
}

/* at start-up */
nqsetal(mal, fre, NULL);

noqtis(3), nqchk(3), nqseal(3)