/*
This example shows how to create a thread and start it
running at a lower priority than the main execution thread.
Set the thread’s FreeOnTerminate property is True, so that
there is no need to free the thread when it finishes. To
create the extension choose the
File | New | Other | Thread Object menu.
*/
bool mythreadRunning;
bool youthreadRunning;

class TMyThread : public TThread
{
__published:    // IDE-managed Components
private:    // User declarations
protected:  // User declarations
    void __fastcall Execute();
public:     // User declarations
    __fastcall TMyThread(bool suspended);
};

__fastcall TMyThread::TMyThread(bool suspended)
    : TThread(suspended)
{
}

class TYouThread : public TThread
{
__published:    // IDE-managed Components
private:    // User declarations
protected:  // User declarations
    void __fastcall Execute();
public:     // User declarations
    __fastcall TYouThread(bool suspended);
};

__fastcall TYouThread::TYouThread(bool suspended)
    : TThread(suspended)
{
}

void __fastcall TMyThread::Execute()
{
  Form1->Memo1->Lines->Add("Process has been running for this many seconds:");
  for (int I = 0; I <= 10; I++)
  {
    Form1->Memo1->Lines->Add("Low priority process " + IntToStr(I));
    Sleep(1000);
  }
  mythreadRunning = FALSE;
}

void __fastcall TYouThread::Execute()
{
  Form1->Memo3->Lines->Add("Second low priority process has been running for this many seconds:");
  for (int I = 0; I <= 10; I++)
  {
    Form1->Memo3->Lines->Add("Second low priority process " + IntToStr(I));
    Sleep(1000);
  }
  youthreadRunning = FALSE;
}

void __fastcall TForm1::Button1Click(TObject *Sender)
{
  TMyThread *SecondProcess; // TMyThread is a custom descendant of TThread
  if (mythreadRunning == FALSE)
  {
    mythreadRunning = TRUE;
    SecondProcess = new TMyThread(True); // create suspended – secondprocess does not run yet
    SecondProcess->FreeOnTerminate = True; // don't need to cleanup after terminate
    SecondProcess->Priority = tpLower;  // set the priority to lower than normal
    SecondProcess->Resume(); // now run the thread
  }
  else
    MessageDlg("This thread is still running.  You are going to hurt yourself!",
      mtInformation, TMsgDlgButtons() << mbOK, 0);
}

void __fastcall TForm1::Button2Click(TObject *Sender)
{
  Form1->Memo2->Lines->Add("Do some work in the main process for 10 seconds:");
  for (int I = 0; I <= 10; I++)
  {
    Form1->Memo2->Lines->Add("Main process " + IntToStr(I));
    Sleep(1000);
  }
}

void __fastcall TForm1::Button3Click(TObject *Sender)
{
  TYouThread *SecondProcess; // TMyThread is a custom descendant of TThread
  if (youthreadRunning == FALSE)
  {
    youthreadRunning = TRUE;
    SecondProcess = new TYouThread(True); // create suspended – secondprocess does not run yet
    SecondProcess->FreeOnTerminate = True; // don't need to cleanup after terminate
    SecondProcess->Priority = tpLower;  // set the priority to lower than normal
    SecondProcess->Resume(); // now run the thread
  }
  else
    MessageDlg("This thread is still running.  You are going to hurt yourself!",
      mtInformation, TMsgDlgButtons() << mbOK, 0);
}

void __fastcall TForm1::FormCreate(TObject *Sender)
{
  mythreadRunning = FALSE;
  youthreadRunning = FALSE;
}

{
This example shows how to create a thread and start it
running at a lower priority than the main execution thread.
Set the thread’s FreeOnTerminate property is True, so that
there is no need to free the thread when it finishes.  The
Execute procedure must be overridden in the extension class
of TThread or an "Abstract Error" will result. To create the
extension choose the File | New | Other | Thread Object menu.
}
procedure TForm1.Button1Click(Sender: TObject);
begin
  if (mythreadRunning = FALSE) then
  begin
    mythreadRunning:= TRUE;
    MyProcess := TMyThread.Create(True); { create suspended - secondprocess does not run yet }
    MyProcess.FreeOnTerminate := True; { don't need to cleanup after terminate }
    MyProcess.Priority := tpLower;  // set the priority to lower than normal
    MyProcess.Resume; { now run the thread }
  end
  else
    MessageDlg('This thread is still running.  You are going to hurt yourself!',
      mtInformation, [mbOk], 0);
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
  if mythreadRunning then MyProcess.Terminate();
end;

procedure TMyThread.Execute;
var I: Integer;
begin
  Form1.Memo1.Lines.Add('Process has been running for this many seconds:');
  for I := 0 to 10 do
  begin
    if Terminated then break;
    Form1.Memo1.Lines.Add('Low priority process ' + InttoStr(I));
    Sleep(1000);
  end;
  mythreadRunning:= FALSE;
end;

procedure TYouThread.Execute;
var I: Integer;
begin
  Form1.Memo3.Lines.Add('Second low priority process has been running for this many seconds:');
  for I := 0 to 10 do
  begin
    if Terminated then break;
    Form1.Memo3.Lines.Add('Second low priority process ' + InttoStr(I));
    Sleep(1000);
  end;
    youthreadRunning:= FALSE;
end;

procedure TForm1.Button2Click(Sender: TObject);
var   I: Integer;
begin
  Form1.Memo2.Lines.Add('Do some work in the main process for 10 seconds:');
  for I := 0 to 10 do
  begin
    Form1.Memo2.Lines.Add('Main process ' + InttoStr(I));
    Sleep(1000);
  end;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  if (youthreadRunning = FALSE) then
  begin
    youthreadRunning:= TRUE;
    YouProcess := TYouThread.Create(True); { create suspended – secondprocess does not run yet }
    YouProcess.FreeOnTerminate := True; { don't need to cleanup after terminate }
    YouProcess.Priority := tpLower;  // set the priority to lower than normal
    YouProcess.Resume; { now run the thread }
  end
  else
    MessageDlg('This thread is still running.  You are going to hurt yourself!',
      mtInformation, [mbOk], 0);
end;

procedure TForm1.Button5Click(Sender: TObject);
begin
  if youthreadRunning then YouProcess.Terminate();
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  mythreadRunning:= FALSE;
  youthreadRunning:= FALSE;
end;