@foo

interface

    type
      TProcRef = reference to procedure;
      TWorkerThread = class(TThread)
      public
        proc: TProcRef;
        procedure Execute; override;
        class procedure RunInThread(AProc: TProcRef);
      end;

implementation

procedure TWorkerThread.Execute;
begin
  inherited;
  proc;
end;

class procedure TWorkerThread.RunInThread(AProc: TProcRef);
begin
  with TWorkerThread.Create(true) do
  begin
    FreeOnTerminate := true;
    proc := AProc;
    Resume;
  end;
end;

procedure P;
begin
  while true do
  begin
    sleep(1000);
    beep;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  TWorkerThread.RunInThread(P);
end;

TWorkerThread.RunInThread(procedure begin while true do begin sleep(1000); beep; end; end);