Function slab_map_indices

src/foundation/slab_alloc.c:136–145

}

static bool slab_map_indices(uintptr_t base, size_t *i1, size_t *i2, size_t *i3) {
    uintptr_t pnum = base >> SLAB_PAGE_SHIFT;
    if ((pnum >> SLAB_MAP_TOTAL_BITS) != 0) {
        return false; /* address beyond coverage — never produced by malloc here */
    }
    *i1 = (size_t)((pnum >> (SLAB_MAP_L2_BITS + SLAB_MAP_L3_BITS)) & (SLAB_MAP_L1_SIZE - 1));
    *i2 = (size_t)((pnum >> SLAB_MAP_L3_BITS) & (SLAB_MAP_L2_SIZE - 1));
    *i3 = (size_t)(pnum & (SLAB_MAP_L3_SIZE - 1));
    return true;
}

/* Lock-free. Returns the slab page whose base == (ptr & mask), or NULL if the
 * masked base is not a registered slab page (i.e. ptr is a plain heap block). */