Thread nonUiThread = new Thread(new Runnable()
                {

                    public void run()
                    {
                        try
                        {
                            for (int i = 0; i < N_STEPS; i++)
                            {
                                System.out.println(METHOD + " iteration " + i);
                                btnCreate.getDisplay().syncExec(new Runnable()
                                {

                                    public void run()
                                    {
                                        createAStep(composite_1);
                                    }
                                });
                                Thread.sleep(2000);
                                btnCreate.getDisplay().syncExec(new Runnable()
                                {

                                    public void run()
                                    {
                                        disposeAStep(composite_1);
                                    }
                                });
                            }

                        }
                        catch (Exception e)
                        {
                            // TODO: handle exception
                        }
                        finally
                        {
                            btnCreate.getDisplay().syncExec(new Runnable()
                            {
                                public void run()
                                {
                                    UICallBack.deactivate(someId);
                                }
                            });
                        }
                    }
                });
                nonUiThread.start();

 
 private void disposeAStep(Composite parent)
    {
        Control[] children = parent.getChildren();
        for (int i = 0; i < STEP && i < children.length; i++)
        {
            children[i].dispose();
        }
    }
private void createAStep(Composite parent)
    {
        for (int i = 0; i < STEP; i++)
        { 
            Button button = new Button(parent, SWT.None);
            button.setText("atext");
        }
        parent.layout();
    }