K 10 svn:author V 7 davidxu K 8 svn:date V 27 2010-11-16T01:56:19.592668Z K 7 svn:log V 300 Because umtx_thread_cleanup() no longer is called with process lock held, There is a race that a thread is exiting while another thread tries to add an entry into its mutex contention list, add uq_exiting flag to indicating that a thread is exiting, and a PI entry should not be added to the thread. END