Warten, bis mehrere Threads beendet sind

[HeikoAdams]

Hallo,
ich habe folgendes Problem: In meinder Synchronisations-Software nutze ich einen Thread zum Erstellen von Dateilisten mehrmals.
Wie kann ich es am besten bewerkstelligen, das meine Software solange wartet, bis alle Instanzen des Threads beendet sind?

Mein Thread ist wie folgt deklariert:

Delphi-Quellcode:

  TFileListTh = class(TThread)
  private
    FSource: TStringList;
    FDest: TStringList;
    FSourceDir: string;
    FDestDir: string;
    FMode: Word;
    procedure CreateSourceFileList;
    procedure CreateDestFileList;
  public
    property Source: TStringList read FSource write FSource;
    property Dest: TStringList read FDest write FDest;
    property sSourceDir: string read FSourceDir write FSourceDir;
    property sDestDir: string read FDestDir write FDestDir;
    property nMode: Word read FMode write FMode;

    destructor Destroy; override;
  protected
    procedure Execute; override;
    constructor Create(CreateSuspended: Boolean);
  end;

...

constructor TFileListTh.Create(CreateSuspended: Boolean);
begin
  inherited Create(CreateSuspended);
  FSource := TStringList.Create;
  FDest := TStringList.Create;
end;

procedure TFileListTh.Execute;
begin
  case FMode of
    0: CreateSourceFileList;
    1: CreateDestFileList;
  end;
end;

procedure TFileListTh.CreateSourceFileList;
var
  nCount: Integer;
begin
  if (FSourceDir <> '') then
    if AdvBuildFileList(IncludeTrailingPathDelimiter(FSourceDir) + '*.*',
      faAnyFile or faDirectory, FSource, amAny, [flFullNames, flRecursive]) then
    begin
      for nCount := FSource.Count - 1 downto 0 do
        if (Pos('\.', FSource.Strings[nCount]) > 0) then
          FSource.Delete(nCount);
    end;

  FSource.Sort;
end;

procedure TFileListTh.CreateDestFileList;
var
  nCount: Integer;
begin
  if (FDestDir <> '') then
    if AdvBuildFileList(IncludeTrailingPathDelimiter(FDestDir) + '*.*',
      faAnyFile or faDirectory, FDest, amAny, [flFullNames, flRecursive]) then
    begin
      for nCount := FDest.Count - 1 downto 0 do
        if (Pos('\.', FDest.Strings[nCount]) > 0) then
          FDest.Delete(nCount);
    end;

  FDest.Sort;
end;

destructor TFileListTh.Destroy;
begin
  FSource.Free;
  FDest.Free;
  inherited;
end;