harmony-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Alexei Fedotov <alexei.fedo...@gmail.com>
Subject Re: Doubting exception priority compatibility
Date Wed, 18 Nov 2009 09:19:53 GMT
Hello Jesse,

Your link points to Google code which I cannot probably browse due to
ACQ restrictions. Anyway, I guess from your message that Google for
the sake of user friendliness added messages to NPE exceptions, thus
changing the exception order. I accept usability motivation for
proposed wiki change. The motivation still have to be compared with
performance motivation when NPE are quickly thrown by means of
hardware interrupt without any message.

Generally I find usability more important than performance. As for
exception messages, I like them only when they add some vital
information for a programmer, otherwise they just make information
retrieval more challenging. From the other side, there likely exist
people who benefit from exception messages if they are localized.

As for dropping tests, I'm stil not convinced. Why not to fix tests
instead? We have to be continuously improving.

P.S. Concerning your question, I faced a problem with
SecurityException testing getCertificates() behavior when worked with
[1]. I added many non- specification asserts to the tests to
understand when SecurityException should be thrown and be somehow
compatible. My JIRA does not reference this problem, though extra
asserts can be located in the patch to the unit test. Later we got a
related bug report [2] concerning the implementation.

P.P.S. I was looking for a JIRA issue which references a user
applciation fail due to exception order and failed. I have found the
author of the automatic tool instead [3]. I think it worth listen to
him.

[1] https://issues.apache.org/jira/browse/HARMONY-4569
[2] http://markmail.org/thread/ckfp3wy6dhrzjwh7
[3] https://issues.apache.org/jira/browse/HARMONY-325



On Tue, Nov 17, 2009 at 8:20 PM, Jesse Wilson <jessewilson@google.com> wrote:
> For better or for worse, Dalvik was changed long ago to ignore exception
> priorities. We get exception messages for NPEs and save branches. The full
> set of deltas are here:
>
> http://www.google.com/codesearch?q=multiple+errors+lang:java+package:git://android.git.kernel.org/platform/dalvik.git
>
> 2009/11/17 Alexei Fedotov <alexei.fedotov@gmail.com>
>>
>> I don't argue changing exception order for a particular case if the
>> change improves code simplicity and gives performance benefit on
>> important real load, e.g. the change improved Eclipse startup time by
>> 4%.
>>
>
> I think the primary difference in our thinking is how much we value
> exception priority consistency. I don't believe it has any value and
> therefore we're imposing an unnecessary constraint on our code. Does anyone
> have a real world example, (perhaps a bugreport) demonstrating where
> exception priority incompatibility has caused grief?
>



-- 
With best regards / с наилучшими пожеланиями,
Alexei Fedotov / Алексей Федотов,
http://www.telecom-express.ru/
http://harmony.apache.org/
http://www.expressaas.com/
http://openmeetings.googlecode.com/

Mime
View raw message