Display.getDefault().syncExec

Display.getDefault().asyncExec

showProgress.addSelectionListener(new SelectionAdapter() {
      public void widgetSelected(SelectionEvent event) {
        try {
      
            new ProgressMonitorDialog(shell).run(true, true, new IRunnableWithProgress() {
				
	       public void run(IProgressMonitor monitor) throws InvocationTargetException, InterruptedException {
		  monitor.beginTask("Running long running operation", IProgressMonitor.UNKNOWN);
		  Display.getDefault().syncExec(new Runnable() {
		  public void run() {
		     for (int i = 0; i < 0100; i += 1) {
			try {
			    Thread.sleep(1000);								
			    readDataFromGUI();
			} catch (InterruptedException e) {								
			     e.printStackTrace();
			}

     		     }
		   }
          	});
		monitor.done();
	      }
	 });
        } catch (InvocationTargetException e) {
          MessageDialog.openError(shell, "Error", e.getMessage());
        } catch (InterruptedException e) {
          MessageDialog.openInformation(shell, "Cancelled", e.getMessage());
        }
      }
    });