RFR: 8043275 Interface initialization for default methods

[Keith McGuigan]

Thanks for the explanation -- that makes sense.  Sure, you can put me down
as a reviewer for this.



On Tue, Oct 21, 2014 at 10:26 AM, Karen Kinnear <karen.kinnear at oracle.com>
wrote:

> Keith,
>
> Thank you so much for looking at this.
>
> Let me see if I can explain this clearly.
>
> In the "before" code has_default_methods only counted public non-abstract
> instance methods - i.e. the methods
> that could be inherited from an interface. The has_default_methods flag,
> as you know, is used in reducing the default method
> inheritance calculations.
>
> In the updated specification, it was determined that we should initialize
> superinterfaces that contain non-abstract instance methods,
> regardless of their access. Invocation of static methods triggers
> initialization, so that case is already covered. The concern with
> only initializing superinterfaces containing public non-abstract instance
> methods was that there might be a way to do an invokespecial
> on a private interface method and if there were a bug, possibly circumvent
> the access check (I was not able to create a test case for
> that despite bytecode patching). Should we ever extend interface methods
> to allow additional access flags, this would naturally extend
> with the minimum of surprise for folks.
>
> So the initialization loop follows the has_default_methods (which I could
> rename could_inherit_default_methods but that got a little long and
> complicated) and explicitly initializes any interface that
> declares_default_methods.
>
> hope that makes sense,
> thanks,
> Karen
>
> p.s. does that mean I can count you as a reviewer :-) ?
>
>
> On Oct 16, 2014, at 9:13 AM, Keith McGuigan wrote:
>
> Hi Karen,
>
> Why in classFileParser.cpp does the check for 'has_default_methods' check
> for a method not being private, but the 'declares_default_methods' check
> omits that check?
>
> On Thu, Oct 16, 2014 at 2:01 AM, Karen Kinnear <karen.kinnear at oracle.com>
> wrote:
>
>>
>> Please review for 9 (8u40 back port will follow):
>>
>> webrev: http://cr.openjdk.java.net/~acorn/8043275/webrev/
>> bug: https://bugs.openjdk.java.net/browse/JDK-8043275
>>
>> Summary:
>>   Fix superinterface initialization to be based on declaring a non-static
>> instance method rather than on declaring or inheriting one
>>
>> Tested (linux-x64):
>> defmeth - enhanced
>> jtreg TestInterfaceInit and TestInterfaceOrder
>> jtreg hotspot, jdk.lambda, java.util, java.lang
>> jck vm, lang
>> nsk: vm.defmeth (added 2 tests), vm.mlvm, vm.fast.quick
>>
>> Thanks to Dan Smith, Alex Buckley, John Rose for specification
>> clarification.
>>
>> thanks,
>> Karen
>>
>>
>
>
> --
> [image: twitter-icon-large.png]
> Keith McGuigan
> @kamggg
> kmcguigan at twitter.com
>
>
>


-- 

[image: twitter-icon-large.png]

Keith McGuigan

@kamggg

kmcguigan at twitter.com