/*
The following example shows how to use the LockList and
UnlockList methods to access a thread-safe version  of a
TList object:
*/
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)
{
}

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

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

TThreadList *threadList1;
bool mythreadRunning, youthreadRunning, listthreadRunning;
int globalCount;
TMyThread *secondProcess;
TYouThread *otherSecondProcess;
TListThread *listProcess; // thread arecustom descendants of TThread

void __fastcall TForm1::Button1Click(TObject *Sender)
{
  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 TMyThread::Execute()
{
  for (int I = 0; I <= 20; I++)
  {
    if (Terminated) break;
    TRadioButton *myRadio = new TRadioButton(Form1);
    globalCount = globalCount + 1;
    myRadio->Name = "RadioButton" + IntToStr(globalCount);
    threadList1->Add(myRadio);
    Sleep(1000);
  }
  mythreadRunning = FALSE;
}

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

void __fastcall TYouThread::Execute()
{
  for (int I = 0; I <= 10; I++)
  {
    if (Terminated) break;
    try
    {
      TList *list = threadList1->LockList();
      if (2*I < list->Count)
      {
        TControl *Temp = (TControl *)list->Items[2*I];
        threadList1->Remove(Temp);
      }
    }
    __finally
    {
      threadList1->UnlockList();
    }
    if (Terminated)
      MessageDlg("youThread has been asked to terminate, but is still running!",
        mtInformation, TMsgDlgButtons() << mbOK, 0);
    Sleep(3000);
  }
  youthreadRunning = FALSE;
}

void __fastcall TForm1::Button2Click(TObject *Sender)
{
  if (listthreadRunning == FALSE)
  {
    listthreadRunning = TRUE;
    listProcess = new TListThread(True); // create suspended – secondprocess does not run yet
    listProcess->FreeOnTerminate = True; // don't need to cleanup after terminate
    listProcess->Priority = tpLower;  // set the priority to lower than normal
    listProcess->Resume(); // now run the thread
  }
  else
    MessageDlg("This thread is still running.  You are going to hurt yourself!",
      mtInformation, TMsgDlgButtons() << mbOK, 0);
}

void __fastcall TListThread::Execute()
{
  while(True)
  {
    if (Terminated) break;
    Form1->ListBox1->Clear();
    TList *myList = threadList1->LockList();
    try
    {
      for (int I = 0; I < myList->Count; I++)
      {
        TControl *Temp = (TControl *)myList->Items[I];
        Form1->ListBox1->Items->Add(Temp->Name);
      }
    }
    __finally
    {
      threadList1->UnlockList();
    }
    Sleep(1000);
  }
}

void __fastcall TForm1::Button4Click(TObject *Sender)
{
  if (listProcess != NULL)
    listProcess->Terminate();
  if (secondProcess != NULL)
    secondProcess->Terminate();
  if (otherSecondProcess != NULL)
    otherSecondProcess->Terminate();
}

{
The following example shows how to use the LockList and
UnlockList methods to access a thread-safe version  of a
TList object:
}
type
  TForm1 = class(TForm)
    Button1: TButton;
    Button3: TButton;
    ListBox1: TListBox;
    Button2: TButton;
    Button4: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
  TListThread = class(TThread)
  protected
    procedure Execute; override;
  end;
  TMyThread = class(TThread)
  protected
    procedure Execute; override;
  end;
  TYouThread = class(TThread)
  protected
    procedure Execute; override;
  end;

var
  Form1: TForm1;
  threadList1: TThreadList;
  mythreadRunning, youthreadRunning, listThreadRunning: Boolean;
  globalCount: Integer;
  listProcess: TListThread; { TListThread is a custom descendant of TThread }
  secondProcess: TMyThread; { TMyThread is a custom descendant of TThread }
  otherSecondProcess: TYouThread; { TMyThread is a custom descendant of TThread }

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  if (mythreadRunning = FALSE) then
  begin
    mythreadRunning:= TRUE;
    secondProcess := TMyThread.Create(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 }
  end
  else
    MessageDlg('This thread is still running.  You are going to hurt yourself!',
      mtInformation, [mbOk], 0);
end;

procedure TMyThread.Execute;
var
  I: Integer;
  myRadio: TRadioButton;
begin
  for I := 0 to 20 do
  begin
    if (Terminated) then
    begin
      mythreadRunning:= FALSE;
      exit;
    end;
    myRadio:= TRadioButton.Create(Form1);
    globalCount:= globalCount + 1;
    myRadio.Name:= 'RadioButton' + IntToStr(globalCount);
    threadList1.Add(myRadio);
    Sleep(1000);
  end;
  mythreadRunning:= FALSE;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  if (listthreadRunning = FALSE) then
  begin
    listThreadRunning:= TRUE;
    listProcess := TListThread.Create(True); { create suspended – secondprocess does not run yet }
    listProcess.FreeOnTerminate := True; { don't need to cleanup after terminate }
    listProcess.Priority := tpLower;  // set the priority to lower than normal
    listProcess.Resume; { now run the thread }
  end;
end;

procedure TListThread.Execute;
var
  I: Integer;
  Temp: TControl;
  myList: TList;
begin
  while(True) do
  begin
    if (Terminated) then
    begin
      listthreadRunning:= FALSE;
      exit;
    end;
    Form1.ListBox1.Clear;
    myList:= threadList1.LockList;
    try
      for I := 0 to myList.Count-1 do
      begin
        Temp:= myList.Items[I];
        Form1.ListBox1.Items.Add(Temp.Name);
      end;
    finally
      threadList1.UnlockList;
    end;
    Sleep(1000);
  end;
  listthreadRunning:= FALSE;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  if (youthreadRunning = FALSE) then
  begin
    youthreadRunning:= TRUE;
    otherSecondProcess := TYouThread.Create(True); { create suspended – secondprocess does not run yet }
    otherSecondProcess.FreeOnTerminate := True; { don't need to cleanup after terminate }
    otherSecondProcess.Priority := tpLower;  // set the priority to lower than normal
    otherSecondProcess.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 (listProcess <> nil) then
    listProcess.Terminate;
  if (secondProcess <> nil) then
    secondProcess.Terminate;
  if (otherSecondProcess <> nil) then
    otherSecondProcess.Terminate;
end;

procedure TYouThread.Execute;
var
  I: Integer;
  Temp: TControl;
begin
  for I := 0 to 10 do
  begin
    if (Terminated) then
    begin
      youThreadRunning:= FALSE;
      exit;
    end;
    with threadList1.LockList do
    try
      if (2*I < Count) then
      begin
        Temp:= Items[2*I];
        threadList1.Remove(Temp);
      end;
    finally
      threadList1.UnlockList;
    end;
    if (Terminated) then
      MessageDlg('youThread has been asked to terminate, but is still running!',
        mtInformation, [mbOk], 0);
    Sleep(3000);
  end;
  youthreadRunning:= FALSE;
end;