easiest way to force a write membar in jdk7 and 8

[Andy Nuss]

Hi,
I tried posting a related question on the concurrency-interest mailing list but for some reason my messages are bouncing there but not here.
Basically, the idea is that some thread has been working with an int[] and filling it with values.  From some range such as [0,8) of the array, that thread is sure never again to change those values.  Now it wishes to publish the int[] range in a threadsafe way in some new wrapper object.
It cannot construct simply this (I believe), especially if somehow another thread has seen the "ar":
class IntArray {    final int[] ar;    final int from;    final int to;    IntArray (int[] ar, int from, int to) {        this.ar = ar; this.from = from; this.to = to;
    }
}
Would it work to use this:
class IntArrayVolatile {    volatile int[] ar;    final int from;    final int to;    IntArrayVolatile (int[] ar, int from, int to) {        this.ar = ar; this.from = from; this.to = to;
    }
    IntArray publish () {        return new IntArray(ar, from, to);
    }}
and then in the thread do this:   int[] ar = new int[100];   ... fill values from [0, 8) never again to change
   IntArray publishar = new IntArrayVolatile(ar, from, to).publish();   ... give publishar to other threads   ... keep filling values from position 8 and higher in "ar" and publishing further ranges in a similar way

Obviously, this is alot about the internal workings of hotspot with the membars for volatile variables.
Andy
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