[Boost-users] thread group

Hi, I am creating "n" number of thread in a loop like this. for(int i=0;i<n;++i) { boost::shared_ptr<boost::thread> th(new boost::thread(boost::bind(&Enum::Execute,shared_from_this(),i,x))); } How can I join all these threads? The approach I used is given below... Before the loop I have created a thread_group object boost::thread_group tg; for(int i=0;i<n;++i) { boost::shared_ptr<boost::thread> th(new boost::thread(boost::bind(&Enum::Execute,shared_from_this(),i,x))); tg.add_thread(th.get()); } tg.join_all(); But the threads are not joined, it is exiting without completion. What could be the mistake I am doing? Thanks, Lloyd