[ori_b]

Note that unless you are coding in Java, volatile is not a memory barrier, and both the CPU and compiler may reorder things around them.

[MaulingMonkey]

Yes - perhaps I should have written that as "volatile AND memory barriers". Either way, worth mentioning, as it's a common misunderstanding.

Further complicating matters is the fact that Microsoft's compilers will treat volatile as a memory barrier - for x86 code. But not for ARM! https://msdn.microsoft.com/en-us/library/jj204392.aspx

[jedmeyers]

Same thing might be with jvm. On x86 'concrete machine' volatile might be a memory barrier, but this behavior is not guaranteed by the definitions of Java 'abstract machine'.