Function mi_segment_is_valid

3rd/mimalloc-2.0.9/src/segment.c:255–303

}

static bool mi_segment_is_valid(mi_segment_t* segment, mi_segments_tld_t* tld) {
  mi_assert_internal(segment != NULL);
  mi_assert_internal(_mi_ptr_cookie(segment) == segment->cookie);
  mi_assert_internal(segment->abandoned <= segment->used);
  mi_assert_internal(segment->thread_id == 0 || segment->thread_id == _mi_thread_id());
  mi_assert_internal(mi_commit_mask_all_set(&segment->commit_mask, &segment->decommit_mask)); // can only decommit committed blocks
  //mi_assert_internal(segment->segment_info_size % MI_SEGMENT_SLICE_SIZE == 0);
  mi_slice_t* slice = &segment->slices[0];
  const mi_slice_t* end = mi_segment_slices_end(segment);
  size_t used_count = 0;
  mi_span_queue_t* sq;
  while(slice < end) {
    mi_assert_internal(slice->slice_count > 0);
    mi_assert_internal(slice->slice_offset == 0);
    size_t index = mi_slice_index(slice);
    size_t maxindex = (index + slice->slice_count >= segment->slice_entries ? segment->slice_entries : index + slice->slice_count) - 1;
    if (mi_slice_is_used(slice)) { // a page in use, we need at least MAX_SLICE_OFFSET valid back offsets
      used_count++;
      for (size_t i = 0; i <= MI_MAX_SLICE_OFFSET && index + i <= maxindex; i++) {
        mi_assert_internal(segment->slices[index + i].slice_offset == i*sizeof(mi_slice_t));
        mi_assert_internal(i==0 || segment->slices[index + i].slice_count == 0);
        mi_assert_internal(i==0 || segment->slices[index + i].xblock_size == 1);
      }
      // and the last entry as well (for coalescing)
      const mi_slice_t* last = slice + slice->slice_count - 1;
      if (last > slice && last < mi_segment_slices_end(segment)) {
        mi_assert_internal(last->slice_offset == (slice->slice_count-1)*sizeof(mi_slice_t));
        mi_assert_internal(last->slice_count == 0);
        mi_assert_internal(last->xblock_size == 1);
      }
    }
    else {  // free range of slices; only last slice needs a valid back offset
      mi_slice_t* last = &segment->slices[maxindex];
      if (segment->kind != MI_SEGMENT_HUGE || slice->slice_count <= (segment->slice_entries - segment->segment_info_slices)) {
        mi_assert_internal((uint8_t*)slice == (uint8_t*)last - last->slice_offset);
      }
      mi_assert_internal(slice == last || last->slice_count == 0 );
      mi_assert_internal(last->xblock_size == 0 || (segment->kind==MI_SEGMENT_HUGE && last->xblock_size==1));
      if (segment->kind != MI_SEGMENT_HUGE && segment->thread_id != 0) { // segment is not huge or abandoned
        sq = mi_span_queue_for(slice->slice_count,tld);
        mi_assert_internal(mi_span_queue_contains(sq,slice));
      }
    }
    slice = &segment->slices[maxindex+1];
  }
  mi_assert_internal(slice == end);
  mi_assert_internal(used_count == segment->used + 1);
  return true;
}
#endif

/* -----------------------------------------------------------