Function mi_page_fresh_alloc

3rd/mimalloc-2.0.9/src/page.c:262–284

allocate a fresh page from a segment

// allocate a fresh page from a segment
static mi_page_t* mi_page_fresh_alloc(mi_heap_t* heap, mi_page_queue_t* pq, size_t block_size, size_t page_alignment) {
  #if !MI_HUGE_PAGE_ABANDON
  mi_assert_internal(pq != NULL);
  mi_assert_internal(mi_heap_contains_queue(heap, pq));
  mi_assert_internal(page_alignment > 0 || block_size > MI_MEDIUM_OBJ_SIZE_MAX || block_size == pq->block_size);
  #endif
  mi_page_t* page = _mi_segment_page_alloc(heap, block_size, page_alignment, &heap->tld->segments, &heap->tld->os);
  if (page == NULL) {
    // this may be out-of-memory, or an abandoned page was reclaimed (and in our queue)
    return NULL;
  }
  mi_assert_internal(page_alignment >0 || block_size > MI_MEDIUM_OBJ_SIZE_MAX || _mi_page_segment(page)->kind != MI_SEGMENT_HUGE);
  mi_assert_internal(pq!=NULL || page->xblock_size != 0);
  mi_assert_internal(pq!=NULL || mi_page_block_size(page) >= block_size);
  // a fresh page was found, initialize it
  const size_t full_block_size = ((pq == NULL || mi_page_queue_is_huge(pq)) ? mi_page_block_size(page) : block_size); // see also: mi_segment_huge_page_alloc
  mi_assert_internal(full_block_size >= block_size);
  mi_page_init(heap, page, full_block_size, heap->tld);
  mi_heap_stat_increase(heap, pages, 1);
  if (pq != NULL) { mi_page_queue_push(heap, pq, page); }
  mi_assert_expensive(_mi_page_is_valid(page));
  return page;
}

// Get a fresh page to use
static mi_page_t* mi_page_fresh(mi_heap_t* heap, mi_page_queue_t* pq) {