Zz Java对象头部的一些信息和Biased锁
void lock(Object obj, Thread currentTr){ if( obj biased to currentTr) return; if( obj biased to other thread) pause owner thread at safe point change mark word and lock record to pretend that obj is locked by other thread with general lock. else{ //fall to common lock }}void unlock(Object obj, Thread currentTr){ if( obj biased to currentTr) return . else fall to common lock}?? 这个ppt讲得很通俗：Lock Reservation: Java Locks Can Mostly Do Without Atomic Operations
