imported from https://holmeshe.me/understanding-memcached-source-code-II/

slabs_init@slabs.c

static int do_slabs_newslab(const unsigned int id) {
    slabclass_t *p = &slabclass[id]; // scr: ----------------------------> 1)
    slabclass_t *g = &slabclass[SLAB_GLOBAL_PAGE_POOL]; // scr: ---------> *)
    int len = settings.slab_reassign ? settings.item_size_max // scr: ---> 2)
        : p->size * p->perslab;
    char *ptr;

    if ((mem_limit && mem_malloced + len > mem_limit && p->slabs > 0 // -> 3)
         && g->slabs == 0)) {
        mem_limit_reached = true;
        MEMCACHED_SLABS_SLABCLASS_ALLOCATE_FAILED(id);
        return 0;
    }

    if ((grow_slab_list(id) == 0) || // scr: ----------------------------> 4)
        (((ptr = get_page_from_global_pool()) == NULL) && // scr: -------> *)
        ((ptr = memory_allocate((size_t)len)) == 0))) { // scr: ---------> 5)

        MEMCACHED_SLABS_SLABCLASS_ALLOCATE_FAILED(id);
        return 0;
    }

    memset(ptr, 0, (size_t)len);
    split_slab_page_into_freelist(ptr, id); // scr: ---------------------> 6)

    p->slab_list[p->slabs++] = ptr; // scr: -----------------------------> 7)
    MEMCACHED_SLABS_SLABCLASS_ALLOCATE(id);

    return 1;
}