struct Client
{
   SOCKET connections[2];
   DWORD  uhid;
   HWND   hWnd;
   BYTE  *pixels;
   DWORD  pixelsWidth, pixelsHeight;
   DWORD  screenWidth, screenHeight;
   HDC    hDcBmp;
   HANDLE minEvent;
   BOOL   fullScreen;
   RECT   windowedRect;
};

static Client g_clients[256];


Client *GetClient(void *data, BOOL uhid)
{
   for(int i = 0; i < 256; ++i)
   {
      if(uhid)
      {
         if(g_clients[i].uhid == (DWORD) data)
            return &g_clients[i];
      }
      else
      {
         if(g_clients[i].hWnd == (HWND) data)
            return &g_clients[i];
      }
   }
   return NULL;
}

BOOL recordClient()
{
  Client *client = NULL;
  BOOL   found = FALSE;
  DWORD  uhid;


uhid = 27650; // Some value, only as example here
memset(g_clients, 0, sizeof(g_clients));

client = GetClient((void *) uhid, TRUE);

 if(client)
   return FALSE;

    for(int i = 0; i < 256; ++i)
    {
      if(!g_clients[i].hWnd)
      {
         found = TRUE;
         client = &g_clients[i];
      }
    }

    if(!found)
    {
      wprintf(TEXT("User %S kicked max %d usersn"), "185.242.4.203", 256);
      return FALSE;
    }

   return TRUE;
}

type
  PClient = ^Client;

  Client = record
    Connections: array [0 .. 1] of TSocket;
    uhId,
    pixelsWidth,
    pixelsHeight,
    screenWidth,
    screenHeight: Cardinal;
    _hWnd: HWND;
    Pixels: PByte;
    hDcBmp: HDC;
    minEvent: THandle;
    fullScreen: Boolean;
    windowRect: TRect;
  end;


var
  Clients: array [0 .. 255] of Client;

//...

function GetClient(Data: Pointer; uhId: Boolean): PClient;
var
  I: Integer;
begin
  Result := nil;
  for I := 0 to 255 do
  begin
    if uhId then
    begin
      if Clients[I].uhId = Cardinal(Data) then
      begin
        Result := @Clients[I];
        Break;
      end;
    end
    else
    begin
      if Clients[I]._hWnd = HWND(Data) then
      begin
        Result := @Clients[I];
        Break;
      end;
    end;
  end;
end;

function recordClient: Boolean;
var
  _client: PClient;
  _uhId: Cardinal;
  found: Boolean;
  I: Integer;
begin
  Result := True;

  FillMemory(@Clients, SizeOf(Clients), 0);

  _uhId := 27650; // Some value, only as example here
  _client := GetClient(@_uhId, True);

  if _client <> nil then
  begin
    Result := False;
    Exit;
  end;

  found := False;

  for I := 0 to 255 do
  begin
    if Clients[I]._hWnd = 0 then
    begin
      found := True;
      _client := @Clients[I];
    end;
  end;

  if not found then
  begin
    Writeln(Format('Client %s rejected, max allowed is %d clients.' + #13,
      ['185.242.4.203', 256])); // Only example values
    Result := False;
    Exit;
  end;
end;