Re: [PATCH v2 0/1] MR2153: win32u: invalidate all cached keys after input

[Rémi Bernon (＠rbernon)]

Rémi Bernon (@rbernon) commented about dlls/win32u/message.c:
> +#define BTN_MASK (MOUSEEVENTF_LEFTDOWN|MOUSEEVENTF_LEFTUP|MOUSEEVENTF_RIGHTDOWN|MOUSEEVENTF_RIGHTUP| \
> -
>              MOUSEEVENTF_MIDDLEDOWN|MOUSEEVENTF_MIDDLEUP|MOUSEEVENTF_XDOWN|MOUSEEVENTF_XUP)
> -
>    if (input->type == INPUT_KEYBOARD ||
> -
>        (input->type == INPUT_MOUSE && 0 != (input->mi.dwFlags & BTN_MASK)))
> -
>    {
> -
>        /* always invalidate cross-thread key caches after sending key-related input;
> -
>           cache data from reply is only fresh if no other threads also incremented */
> -
>        if ((ULONG)InterlockedIncrement(&global_key_state_counter) == counter+1)
> -
>            ++counter;
> -
>    }
>
> +#undef BTN_MASK
>          if (key_state_info)
>          {
>              key_state_info->time    = NtGetTickCount();
>              key_state_info->counter = counter;
>          }

IIUC the problem is coming from one thread having a more up to date key state cache than the other because it received the X input and called `send_hardware_message`? And I understand this is caused by this part here, so what about instead:

1) Remove this optimization (as well as the key state buffer returned from `send_hardware_message` request),

2) Always invalidate the keystate for all threads by incrementing `global_key_state_counter` unconditionally in `case INPUT_KEYBOARD:` and `if (input->mi.dwFlags & ~(MOUSEEVENTF_ABSOLUTE | MOUSEEVENTF_MOVE))` in `case INPUT_MOUSE:`?