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Re: [GCJ] Performance of GUI applications on embedded systems
- From: Andrew Haley <aph at redhat dot com>
- To: ffileppo <ffileppo at libero dot it>
- Cc: java <java at gcc dot gnu dot org>, classpath <classpath at gnu dot org>
- Date: Thu, 06 Nov 2008 16:40:06 +0000
- Subject: Re: [GCJ] Performance of GUI applications on embedded systems
- References: <K9WZ9Y$0DBCD008EE6ABA1BF31318A9F51108EC@libero.it>
ffileppo wrote:
>> Here's one improvement. If you can get rid of the places in the GTK peers
>> where class and method lookups are performed at runtime you'll probably
>> have a fix. This shouldn't be a massive amount of work, just rather
>> boring.
>>
>> In gcj,
>>
>> * Compiled java code is quite fast.
>> * Class lookup by name is slow.
>> * Calling JNI code from compiled java code is quite fast.
>> * Calling compiled java code from JNI code is slow.
>> * Exceptions are slow.
> I'm testing your patch on my embedded system and now I can see that GUI performance are very much better (particularly during application startup).
>
> Thank you so much!
>
> However running my test case (please see my first post) I see that CPU usage is always at 100% (after the application is running),
> so the responsiveness is still not very good.
What do you expect? You're setting up a Timer with a delay of
0 milliseconds between events, and it's running continuously.
Andrew.