unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ExtCtrls, Vcl.StdCtrls;

const
  ttmSecond : Double = 1/(24*60*60*1000);

type
  TCycleThread = class(TThread)
  protected
    procedure Execute; override;
  private
    StartZyklus : TDateTime;

    Procedure Zyklus;
  public
    SollZykluszeit : Integer;
    IstZyklusZeit : Double;

    MinCycle,
    AktCycle,
    MaxCycle: Double;

    ChgEvent: TNotifyEvent;

    Constructor Create (CreateSuspended : Boolean);
    Destructor Destroy; override;
  end;

type
  TForm1 = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Timer1: TTimer;
    Label3: TLabel;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private
    { Private-Deklarationen }
    MyThread : TCycleThread;

    procedure ChangeEvent(Sender: TObject);
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

function Elapsedms(LastTime: TDateTime): Double;
begin
  Result := (Now - LastTime) / ttmSecond;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  H : THandle;
begin
  H := GetCurrentProcess();
  SetPriorityClass(H, HIGH_PRIORITY_CLASS);

  MyThread := TCycleThread.Create(True);
  MyThread.SollZykluszeit := 6;
  MyThread.ChgEvent := ChangeEvent;
  MyThread.Start;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  if Assigned(MyThread) then
    FreeAndNil(MyThread);
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  Timer1.Enabled := False;
  if Assigned(MyThread) then
  begin
    Label2.Caption := 'kürzeste Zykluszeit: ' + MyThread.MinCycle.ToString;
    Label1.Caption := 'Aktuelle Zykluszeit: ' + MyThread.AktCycle.ToString;
    Label3.Caption := 'längste Zykluszeit: ' + MyThread.MaxCycle.ToString;
  end;
end;

procedure TForm1.ChangeEvent(Sender: TObject);
begin
  Timer1.Enabled := True;
end;

{ TCycleThread }

constructor TCycleThread.Create(CreateSuspended: Boolean);
begin
  Inherited Create (CreateSuspended);

  Priority := tpHighest;

  MinCycle := -1;
  AktCycle := -1;
  MaxCycle := -1;
end;

destructor TCycleThread.Destroy;
begin

  Inherited Destroy;
end;

procedure TCycleThread.Execute;
var
  Return : LongWord;
  ThreadHandle : THandle;
begin
  FreeOnTerminate := False;

  StartZyklus := Now;
  try
    while not Terminated do
    begin
      ThreadHandle := Self.ThreadID;
      Return := MsgWaitForMultipleObjects (0, ThreadHandle, False, SollZykluszeit, QS_ALLINPUT);
      if Return = WAIT_OBJECT_0 then
      begin

      end
      else
      begin
        if not Terminated then
        begin
          Zyklus;
        end;
      end;
    end;
  finally
  end;
end;

procedure TCycleThread.Zyklus;
begin
  if Terminated then Exit;

  //Tue irgendwas
  IstZyklusZeit := (Elapsedms (StartZyklus));
  StartZyklus := Now;

  if (IstZyklusZeit < MinCycle) or (MinCycle = -1) then
    MinCycle := IstZyklusZeit;

  AktCycle := IstZyklusZeit;

  if (IstZyklusZeit > MaxCycle) or (MaxCycle = -1) then
    MaxCycle := IstZyklusZeit;

  if Assigned(ChgEvent) then
    ChgEvent(Self);
end;

end.