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

[Jinoh Kang (＠iamahuman)]

Jinoh Kang (@iamahuman) commented about dlls/ntdll/heap.c:
> -
>    group = group_allocate( heap, flags, block_size, category );
> - else
> -
>    group = CONTAINING_RECORD( entry, struct group, entry );
> -
> - return group;
>
> +}
> -
>
> +/* release a thread owned and fully freed group to the category shared group, or free its memory */
> +static NTSTATUS heap_release_category_group( struct heap *heap, ULONG flags, struct category *category,
> -
>                                         struct group *group )
>
> +{
> - DWORD affinity = NtCurrentTeb()->HeapVirtualAffinity % ARRAY_SIZE(category->affinity_group);
> - NTSTATUS status = STATUS_SUCCESS;
> -
> - /* we cannot use InterlockedExchangePointer here because to the contrary to our current group,
> -
> * the current affinity_group might be only partially free.

This explanation is not exactly right, since there is a way to use `InterlockedExchangePointer` here without a problem: we can simply move the old group into the `category->groups` list, just like `find_free_block_lfh`.  A more useful comment would explain _why_ we choose not to replace the affinity group in some cases.