没有发生的安全发布 - 之前？(Safe Publication without happens-before? Anyhow besides final?)

 根据JCP（16.2.2。安全公告）： 
 
 
 
 发生这种情况 - 在担保实际上比可靠的出版物更具有可见性和有序性的承诺之前。 当X从A安全地发布到B时，安全发布可保证X的状态可见性，但不保证其他变量A可能已触及的状态的可见性。 但是，如果将X放入队列中 - 在B从该队列中提取X之前，B不仅看到X处于A离开它的状态（假设X未被A或其他任何人修改），而且B看到所有A在切换前都做过了（同样需要注意） 
 
 
 我想知道什么时候安全发布可以没有发生 - 之前，即不使用volatile / atomics或同步（或通过框架，如使用任何列在里面的AQS）？ 
 
 一种情况是不可变对象中的最终字段，您可以在其中发布它，而不需要执行任何其他步骤。 
 
 还有其他情况吗？ 
 
 UPD：重读3.5.3。 安全出版惯用语，另一种情况 - “从静态初始化器初始化对象引用”。 现在看来这些都是选项。 

According to JCP (16.2.2. Safe Publication): 
 
 
 
This happens-before guarantee is actually a stronger promise of visibility and ordering than made by safe publication. When X is safely published from A to B, the safe publication guarantees visibility of the state of X, but not of the state of other variables A may have touched. But if A putting X on a queue happens-before B fetches X from that queue, not only does B see X in the state that A left it (assuming that X has not been subsequently modified by A or anyone else), but B sees everything A did before the handoff (again, subject to the same caveat)
 
 
I'm wondering when safe publication can be without happens-before, i.e. w/o using volatile/atomics or synchronization (or via frameworks such as AQS which use any of listed inside)?
 
One case is final fields in immutable object, where you can publish it as is w/o any additional steps.
 
Are there any other cases?
 
UPD: re-read 3.5.3. Safe Publication Idioms, another case - "Initializing an object reference from a static initializer". Seems now these are all options.

原文：https://stackoverflow.com/questions/5458848