RFR: [MVT] MethodHandlesTest fails with assertions enabled

[Maurizio Cimadamore]

Thanks for the review. Here's an updated webrev:

http://cr.openjdk.java.net/~mcimadamore/8185142-jdk_v2/

Maurizio


On 24/07/17 17:28, Vladimir Ivanov wrote:
> Thanks for taking care of it, Maurizio!
>
> ========================================
> +    static final class Carrier_Q {
> +        @Stable
> +        final Object boxedValue;
> +        @Stable
> +        final MethodHandle unboxHandle;
>
> @Stable isn't needed. Final fields in java.lang.invoke are trusted by 
> JIT-compilers.
>
> ========================================
> +        static final MethodHandle BOX_VALUE_GETTER;
> +        static final MethodHandle UNBOX_HANDLE_GETTER;
>
> +                NamedFunction unboxGetter = new 
> NamedFunction(Carrier_Q.UNBOX_HANDLE_GETTER);
>
> +                NamedFunction boxedValue = new 
> NamedFunction(Carrier_Q.BOX_VALUE_GETTER);
>
> Maybe cache NamedFunctions right away?
>
> ========================================
> -        return mh.copyWithExtendL(type2, form2, value)
> -                 .copyWithExtendL(type2, form2, unbox);
> +        try {
> +            return mh.copyWithExtendL(type2, form2, new 
> Carrier_Q(value, unbox));
> +        } catch (Throwable ex) {
> +            throw new IllegalStateException(ex);
> +        }
>
> Why do you need a try-catch block here?
>
> Otherwise, looks good.
>
> Best regards,
> Vladimir Ivanov
>
> On 7/24/17 7:14 PM, Maurizio Cimadamore wrote:
>> Hi,
>> this is a fix for a problem when running MethodHandlesTest with 
>> assertions enabled (-esa). Currently, bound method handles with value 
>> types are handled by encoding a bound value as a boxed value + unbox 
>> MH pair - but doing so breaks some arity invariants for BMHs. This 
>> makes the pair encoding explicit, by adding a small carrier class for 
>> the box/MH pair, which is then used to encode the bound value.
>>
>> http://cr.openjdk.java.net/~mcimadamore/8185142-jdk/
>>
>> Maurizio
>>