Re: [PATCH v5 0/6] MR1628: ntdll: Implement Low Fragmentation Heap.

[Jinoh Kang (＠iamahuman)]

Jinoh Kang (@iamahuman) commented about dlls/ntdll/heap.c:
> -
>    NtCurrentTeb()->HeapVirtualAffinity = affinity;
> - }
> - affinity %= ARRAY_SIZE(category->affinity_group);
> -
> - /* acquire a group, the thread will own it and no other thread can clear free bits.
> -
> * some other thread might still set the free bits if they are freeing blocks.
> -
> */
> - if (!(group = heap_acquire_category_group( heap, flags, block_size, category ))) return NULL;
> -
> - /* serialize with heap_free_block_lfh: atomically set GROUP_FLAG_FREE when the free bits are all 0. */
> - if (group_find_free_block( group, block_size, &block ))
> -
>    InterlockedAnd( &group->free_bits, ~GROUP_FLAG_FREE );
> - else
> -
>    InterlockedCompareExchange( &group->free_bits, GROUP_FLAG_FREE, 0 );
> -
> - /* if GROUP_FLAG_FREE was set, thread released its ownership. */

This comment is misleading since the current thread relinquishes ownership of the group in either case.  Note that, in the current design, a thread does not own its affinity group; the group slot can be shared with arbitrary number of threads.