foo.c

    /* assign heap_page body (contains heap_page_header and RVALUEs) */
    page_body = (struct heap_page_body *)rb_aligned_malloc(HEAP_PAGE_ALIGN, HEAP_PAGE_SIZE);
    if (page_body == 0) {
	rb_memerror();
    }

    /* assign heap_page entry */
    page = calloc1(sizeof(struct heap_page));
    if (page == 0) {
        rb_aligned_free(page_body);
	rb_memerror();
    }