参考

1. wine 8.14
2. https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-waitforinputidle
   作用：等待特定进程完成它的初始化输入，等待用户输入(且没有挂起的输入)直到等待时间超时。

DWORD WINAPI NtUserWaitForInputIdle(HANDLE process, DWORD timeout, BOOL wow)
{
    ......
  
  SERVER_START_REQ(get_process_idle_event)
  {
      ...
      handles[1] = wine_server_ptr_handle(reply->event);
  }
  ...
  if(!handles[1]) return WAIT_FAILED;  //no event to wait on

  start_time = NtGetTickCount();
  ...
  for(;;)
  {
      ret = NtUserMsgWaitForMultipleObjectsEx(2,handles, timeout-elapsed, QS_SENDMESSAGE, 0);
      switch(ret)
      {
        case WAIT_OBJECT_0:
                return 0;
        case WAIT_OBJECT_0+2:
                process_sent_messages();
                break;
        case WAIT_TIMEOUT:
        case WAIT_FAILED:
                return ret;
        default:
                return 0;

      }
      
      if(timeout != INFINITE)
       {
          elapsed = NtGetTickCount() - start_time;
          if(elapsed > timeout)
                break;
        }
   }

  return WAIT_TIMEOUT;
}

调用get_process_idle_event查看是否有需要等待的输入事件，如果存在，则调用函数NtUserMsgWaitForMultipleObjectsEx根据输入事件的不同状态进行处理。