RFR: 8166651: OrderAccess::load_acquire &etc should have const parameters

[Kim Barrett]

> On May 26, 2017, at 8:04 AM, Erik Österlund <erik.osterlund at oracle.com> wrote:
> 
> Hi Kim,
> 
> Thanks for doing this. It looks good to me.

Thanks.

> 
> /Erik
> 
> On 2017-05-25 01:42, Kim Barrett wrote:
>> Please review this change to Atomic::load and OrderAccess::load_acquire
>> overloads to make their source const qualified, e.g. instead of
>> "volatile T*" make them "const volatile T*".  This eliminates the need
>> for casting away const when, for example, applying one of these
>> operations to a member variable when in a const-qualified method.
>> 
>> There are probably places that previously required casting away const
>> but now do not. Similarly, there are probably places where values
>> couldn't be const or member functions couldn't be const qualified, but
>> now can be. I did a little searching and found a few candidates, but
>> none that were otherwise trivial to add to this change, so haven't
>> included any.
>> 
>> This change touches platform-specific code for non-Oracle supported
>> platforms that I can't test, so I'd like reviews from the respective
>> platform owners.
>> 
>> Aside regarding aarch64: I don't know why gcc's __atomic_load doesn't
>> const-qualify the source argument; that seems like a bug.  Or maybe
>> they are, but not documented that way.  And I wonder why the aarch64
>> port uses __atomic_load rather than __atomic_load_n.
>> 
>> CR:
>> https://bugs.openjdk.java.net/browse/JDK-8166651
>> 
>> Webrev:
>> http://cr.openjdk.java.net/~kbarrett/8166651/hotspot.00
>> 
>> Testing:
>> JPRT