On 19/12/2012 18:56, Aleksey Shipilev wrote:
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.
6476827
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.
I don't think we can make assumptions about the access to direct buffers
because it's it may not go through the Buffer API.
-Alan.