Creando un Delay en delphi (o Sleep o Pause)

Desde Torry's Delphi Pages, podemos encontrar una buena implementación de la mano de Simon Grossenbacher. Estas funciones nos permiten crear retardos y pausas sin que la CPU llegue hasta el 100%. Están probadas y testadas y yo las utilizo en mis aplicaciones. Aquí os dejo el código fuente:

// 1. Delay

procedure Delay(dwMilliseconds: Longint);
var
  iStart, iStop: DWORD;
begin
  iStart := GetTickCount;
  repeat
    iStop := GetTickCount;
    Application.ProcessMessages;
    Sleep(1);
  until (iStop - iStart) >= dwMilliseconds;
end;

// 2. Delay con API

procedure Delay(msecs: Longint);
var
  targettime: Longint;
  Msg: TMsg;
begin
  targettime := GetTickCount + msecs;
  while targettime > GetTickCount do
    if PeekMessage(Msg, 0, 0, 0, PM_REMOVE) then
    begin
      if Msg.message = WM_QUIT then
      begin
        PostQuitMessage(Msg.wParam);
        Break;
      end;
      TranslateMessage(Msg);
      DispatchMessage(Msg);
    end;
end;

// 3. Sleep

{
The Sleep function suspends the execution of the current
thread for a specified interval.
}

Sleep(dwMilliseconds: Word);


// 4. Combined Delay

{
Including the Sleep in the loop prevents the app from hogging
100% of the CPU for doing practically nothing but running around the loop.
}

procedure PauseFunc(delay: DWORD);
var
  lTicks: DWORD;
begin
  lTicks := GetTickCount + delay;
  repeat
    Sleep(100);
    Application.ProcessMessages;
  until (lTicks <= GetTickCount) or Application.Terminated;
end;

// 5. more resource sparing:

procedure Delay(Milliseconds: Integer);
var
  Tick: DWORD;
  Event: THandle;
begin
  Event := CreateEvent(nil, False, False, nil);
  try
    Tick := GetTickCount + DWORD(Milliseconds);
    while (Milliseconds > 0) and
      (MsgWaitForMultipleObjects(1, Event, False, Milliseconds,
      QS_ALLINPUT) <> WAIT_TIMEOUT) do
    begin
      Application.ProcessMessages;
      Milliseconds := Tick - GetTickCount;
    end;
  finally
    CloseHandle(Event);
  end;
end;