Interview was hopeless, I was asked answer a question , how main thread terminates child thread gracefully. I answered that with some mechanism you communicate to child thread that you should stop executing by informing throw request in queue or any other way, then he asked tell me easiest way , i did not answer any thing for that because i felt i have told in a generic way ("i.e. u have to communicate to child thread in some way ) But he was expecting like a global variable which is shared between the parent and child thread. SO i felt he does not deserve to be interviewer.