Function dlrealloc

lib/dlmalloc/malloc.c:5180–5223

#if !ONLY_MSPACES

void* dlrealloc(void* oldmem, size_t bytes) {
  void* mem = 0;
  if (oldmem == 0) {
    mem = dlmalloc(bytes);
  }
  else if (bytes >= MAX_REQUEST) {
    MALLOC_FAILURE_ACTION;
  }
#ifdef REALLOC_ZERO_BYTES_FREES
  else if (bytes == 0) {
    dlfree(oldmem);
  }
#endif /* REALLOC_ZERO_BYTES_FREES */
  else {
    size_t nb = request2size(bytes);
    mchunkptr oldp = mem2chunk(oldmem);
#if ! FOOTERS
    mstate m = gm;
#else /* FOOTERS */
    mstate m = get_mstate_for(oldp);
    if (!ok_magic(m)) {
      USAGE_ERROR_ACTION(m, oldmem);
      return 0;
    }
#endif /* FOOTERS */
    if (!PREACTION(m)) {
      mchunkptr newp = try_realloc_chunk(m, oldp, nb, 1);
      POSTACTION(m);
      if (newp != 0) {
        check_inuse_chunk(m, newp);
        mem = chunk2mem(newp);
      }
      else {
        mem = internal_malloc(m, bytes);
        if (mem != 0) {
          size_t oc = chunksize(oldp) - overhead_for(oldp);
          memcpy(mem, oldmem, (oc < bytes)? oc : bytes);
          internal_free(m, oldmem);
        }
      }
    }
  }
  return mem;
}

void* dlrealloc_in_place(void* oldmem, size_t bytes) {
  void* mem = 0;