Merkwürdigkeit mit Sleep()

[hathor]

Mit folgendem Code kannst Du herausfinden, was Dein BS (WIN XP, WIN732, WIN764) auf der vorhandenen Hardware (Solo,Duo) bei Sleep() an Zeit "verbraucht":

Delphi-Quellcode:

procedure TForm1.Button1Click(Sender: TObject);
var a, b, c: Int64; r: real; i: Integer;
begin
For i:=0 to 20 do
BEGIN
  QueryPerformanceFrequency(a);
  QueryPerformanceCounter(b);
  Sleep(i);
  QueryPerformanceCounter(c);
  r:= (c - b) * 1000 / a;
  Memo1.lines.add('Sleep('+IntToStr(i)+') = '+ FloatToStrF(r, ffFixed, 12, 5)+' msec');
  Application.ProcessMessages;
END;
end;

Eine bessere SLEEP-Funktion:

Delphi-Quellcode:

procedure DelayQPC(t: cardinal);
var  a, b: Int64;
Begin
    QueryPerformanceFrequency(b);
    QueryPerformanceCounter(a);
    b := a + (b * t) div 1000;
    While a < b do QueryPerformanceCounter(a);
end;

Aufruf z.B:
DelayQPC(1000);

Test mit DelayQPC:

Delphi-Quellcode:

procedure DelayQPC(t: cardinal);
var a, b: Int64;
Begin
    QueryPerformanceFrequency(b);
    QueryPerformanceCounter(a);
    b := a + (b * t) div 1000; //10000 für 0.1 msec
    While a < b do QueryPerformanceCounter(a);
end;

procedure TForm1.Button1Click(Sender: TObject);
var a, b, c: Int64; r: real; i: Integer;
begin
For i:=1 to 20 do
BEGIN
  QueryPerformanceFrequency(a);
  QueryPerformanceCounter(b);
  DelayQPC(i*100);
  QueryPerformanceCounter(c);
  r:= (c - b) * 1000 / a;
  Memo1.lines.add('Sleep('+IntToStr(i*100)+') = '+ FloatToStrF(r, ffFixed, 12, 5)+' msec');
  Application.ProcessMessages;
END;
end;