I know that AWT has a EventQueue,which we can use to post events into
the JVM not the OS.
But it seems that SWT doesn't has such an EventQueue. The only way to
post event is the Display.post(), which will post event into OS.

The reason I want to post event into JVM not OS is that I want to run
serveral instances of GUI application test on the same box. Is there
any other choices?

Thanks.
Tony.