Thanks for the feedback. Updated:
http://cr.openjdk.java.net/~psandoz/jdk9/JDK-8146458-checkIndex-exception-reporting/webrev/
http://cr.openjdk.java.net/~psandoz/jdk9/JDK-8146458-checkIndex-exception-reporting/specdiff/overview-summary.html
Changes:
- refer to “exception factory function”
- renamed rangeCheckExceptionMapper to outOfBoundsExceptionFactory. Tweaked the
documentation and added an api note for clarity.
- tests for String/ArrayIOOBE, and uniform checking of expected exception
message in all cases
> On 16 Jan 2016, at 08:36, John Rose <john.r.r...@oracle.com> wrote:
>
> On Jan 15, 2016, at 2:43 PM, Stuart Marks <stuart.ma...@oracle.com> wrote:
>>
>>
>> I think, in order to avoid introducing new functional interfaces, this
>> information is funneled into a single varargs call, which has to use Integer
>> boxes, because it then wraps its args into a List (thanks for using the new
>> List factory!), which then has to unpack the list and check its length
>> against the number of arguments for the particular message kind.
>
> And that's before String.format does a bunch more steps of the same kind,
> including boxing and varargs. And then the exception creation itself walks
> the entire thread stack. Micro-optimization is hopeless.
>
> But it doesn't matter because it's all on the slow path.
>
Yes. FWIW the implementation also avoids any varargs call for the main check
methods to keep the method size small (we could use @ForceInline instead, but i
would prefer to use that for cases where it is really needed).
>> I understand that this is the "slow" exception-throwing path, but my sense
>> is still that this ought to be made simpler. Perhaps the scope of what it's
>> trying to accomplished should be reduced, if that helps things.
>
> Simpler would be good but I don't see it any simpler, yet.
>
Me neither, any simpler and the generality is lost. Arguably there is actually
quite a simple rule underlying this: the arguments to the factory function take
on a form that is very similar to those required for a reflective look up and
invocation:
Objects.class.getMethod(checkKind, List.nCopies(args.size(),
int.class).toArray()).
invoke(null, args.toArray())
Paul.
> Do give it some thought!
>
