java.nio.*Buffer read/write atomicity

Aleksey Shipilev aleksey.shipilev at
Wed Dec 19 18:56:34 UTC 2012

On 12/19/2012 10:45 PM, Alan Bateman wrote:
> On memory model rules then there is is an outstanding bug to update the
> buffer spec with at least minimal properties. Doug might remember the
> discussion with Dave Dice about this a few years ago. I've always meant
> to do it but it never got to the top of the list.

Aha, thanks, Alan. Does anyone has the CR number handy? Searching
through bugtrack has a lots of false hits.

> That aside, I'm not aware of any discussion about the atomicity issue
> that you are concerned about now. As buffers are accessed directly in
> native code and by system calls then I think you would be limited to
> only specifying the put and get methods.

I don't think there are problems with full-width ops in non-BB
implementations. The problematic area seems to be ByteBuffer allocated
on heap. Direct ByteBuffer seems to be atomic.


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