Function mi_segment_reclaim_or_alloc

3rd/mimalloc-2.0.9/src/segment.c:1463–1482

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static mi_segment_t* mi_segment_reclaim_or_alloc(mi_heap_t* heap, size_t needed_slices, size_t block_size, mi_segments_tld_t* tld, mi_os_tld_t* os_tld)
{
  mi_assert_internal(block_size < MI_HUGE_BLOCK_SIZE);
  mi_assert_internal(block_size <= MI_LARGE_OBJ_SIZE_MAX);
  
  // 1. try to reclaim an abandoned segment
  bool reclaimed;
  mi_segment_t* segment = mi_segment_try_reclaim(heap, needed_slices, block_size, &reclaimed, tld);
  if (reclaimed) {
    // reclaimed the right page right into the heap
    mi_assert_internal(segment != NULL);
    return NULL; // pretend out-of-memory as the page will be in the page queue of the heap with available blocks
  }
  else if (segment != NULL) {
    // reclaimed a segment with a large enough empty span in it
    return segment;
  }
  // 2. otherwise allocate a fresh segment
  return mi_segment_alloc(0, 0, heap->arena_id, tld, os_tld, NULL);  
}


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