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From "Alexei Fedotov" <alexei.fedo...@gmail.com>
Subject Re: [DRLVM] contribution of alternative bytecode verifier
Date Wed, 14 Mar 2007 14:44:45 GMT
Hello Mikhail,

It's really nice to see that you are interested in bytecode
verification. I like an idea of your algorithm. BTW, is it possible to
make your verifier compatible with RI?

Have you taken a look at subroutine markup algortim suggested few
weeks ago (http://wiki.apache.org/harmony/Subroutine_Verification)? Do
you think it is correct and worth to be implemented?

Thank you in advance for review and feedback,
Alexei

On 3/14/07, Mikhail Loenko <mloenko@gmail.com> wrote:
> 2007/3/14, Petrashkova, Vera Y <vera.y.petrashkova@intel.com>:
> >
> > Here are the results of VTS tests running:
> > 4320 VTS tests were run
> > 4183 - passed on DRLVM
> > 4234 - passed on DRLVM with alternative bytecode verifier
>
> Thanks, Vera!
>
> So, some words about the contribution (H-3363)
>
> As you probably know classic implementation of verifier requires
> complex time and memory consuming dataflow analysis that generates a
> proof of type safety.
>
> Some alternative approaches, for example CLDC verifier, require the
> class file to be annotated with the proof of type safety. To make sure
> the byte code is valid, verifier just validates the proof. That
> validation is fast and does not require much memory.
>
> The contributed verifier is a new verification approach based on
> Constraint Propagation. It takes the original Java Class File
> containing no additional information. For that class file it neither
> generates a direct proof of its validness nor validates any existing
> proof.
>
> Instead it generates a proof that a proof of validness does exist :)
>
> The approach results in significant performance and memory footprint
> advantage over regular verification.
>
> I'm finishing a document describing new verification in more details
> and going to put it into the Harmony docs
>
> Thanks,
> Mikhail
>


-- 
With best regards,
Alexei,
ESSD, Intel

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