????happens-before

??????JDK5?????java????μ?JSR -133?????????????????????????????JSR- 133?????????JSR-133?????happens-before?????????????????????????????????????????????????е????????????????????????????????????????????happens-before????????????????????????????????????????????????????????? ??????????????happens-before???????£?

?????? ?????????????????е??????????happens- before ???????е??????????????

?????? ????????????????????????????????happens- before ????????????????????????

?????? volatile?????????????volatile???д??happens- before ??????????????volatile??????

?????? ??????????A happens- before B????B happens- before C?????A happens- before C??

?????????????????????happens-before???????????ζ?????????????????????????????У?happens-before???????????????????е???????????????????????????????????????????????????the first is visible to and ordered before the second????happens- before????????????????????happens-before??????????塣

????happens-before??JMM??????????????

?????????????????happens-before????????????????????????????????????????????????java??????????happens-before??????????????????????????JMM?????????????????????????????????????Щ????????????