Comments for @Blog("Baptiste Wicht")

Comment on Java Concurrency – Part 6 : Atomic Variables by Andrew

Andrew — Sat, 04 Feb 2012 23:26:00 +0000

Clear and Nice aritcle, now i have understood the difference and impact between / of the atomic variables and synchronization.
Thank you!!

Comment on File copy in Java – Benchmark by Anonymous

Anonymous — Thu, 02 Feb 2012 15:27:00 +0000

Hi Vicne,

Yes, none of my disk were a SSD. You’re right that working on the same is slower than with two disks, but based on my benchmark results, it doesn’t look much slower as we should think.

You’re absolutely right about the native method. For very little files, it’s only slower because of the overhead from Java invocation of a command.
If you run this kind of benchmarks on your own, I’m very interested of the results.

Thanks

Best Regards

Baptiste

Comment on Boost intrusive_ptr : faster shared pointer by Anonymous

Anonymous — Thu, 02 Feb 2012 15:15:00 +0000

No, I didn’t run any benchmark on my own. I shall try to do one in the future.

In most of the cases, the difference won’t be noticeable. In my case, it improved the time of creating an Abstract Syntax Tree with Boost Spirit.

Comment on Boost intrusive_ptr : faster shared pointer by Anonymous

Anonymous — Thu, 02 Feb 2012 00:06:00 +0000

Nice article. Have you measured the performance of an intrusive_ptr vs. a make_shared allocated shared_ptr?

Comment on File copy in Java – Benchmark by Vicne

Vicne — Wed, 01 Feb 2012 09:16:00 +0000

Very interesting posts, and thanks for sharing the source

A few thoughts :

You were asking for comments regarding same disk vs different disk difference. I guess your disks are not SSD, so when working on the same disk, the heads have to physically move back and forth between the areas to read from and write to, which is much slower than linear read on one disk and linear write on another. Same disk copying benefits highly from big memory buffers of course.
I also noticed that native method seems to be slower than any java method for small files, which is a nonsense of course. I guess the reason is that the overhead due to creating an environment to run a native process from java (Runtime.getRuntime().exec()) is predominant in this case. This influence could be reduced by performing a “cp src/* dst/” on a folder containing a thousand of small files.
Anyway, I’m more interested in large files (20GB+) across network shares so I’ll try to adapt your source to this case.

Best regards,

Vicne

Comment on JTheque Core 2.1.0 released ! by Modern Dining Tables

Modern Dining Tables — Fri, 27 Jan 2012 15:29:00 +0000

He was released on bail of 100000 euros ($131600), banned from
leaving the country and from meeting former executives of his now
defunct company Poly …

Comment on Do not use relative path with LogBack by Anonymous

Anonymous — Thu, 26 Jan 2012 18:19:00 +0000

Interesting, thank you

That’s certainly here that all my logs were hidden.

Comment on Do not use relative path with LogBack by Adam

Adam — Thu, 26 Jan 2012 16:17:00 +0000

I am using a similar relative path running in Tomcat and my logs are showing up in %CATALINA_HOME%/logs

Comment on Compilers : Principles, Techniques & Tools – Book Review by Anonymous

Anonymous — Mon, 23 Jan 2012 18:18:00 +0000

Hi Andreas,

Thank you for your opinion. As you said, there is a huge difference between just reading a book and using it.

Thanks also for the reference. I didn’t know this book, Engineering a compiler. Looks interesting.

My next book about compilers will certainly be Advanced compiler design and implementation, by S. Muchnik, as this is the only one available (to my knowledge) in Kindle store for now. But I’ll put yours on my wish list

Comment on Compilers : Principles, Techniques & Tools – Book Review by Andreas Haufler

Andreas Haufler — Mon, 23 Jan 2012 10:28:00 +0000

Thanks for this in-depth review of the dragon book. I think everyone working with compilers or even “just” parsers and lexers needs a book to explain the underlying algorithms and concepts. The dragon book is probably both, the most prominent and the most discussed book for this topic. A review like yours is worth a lot, since one knows, that you really care about the topics. I think there’s always a difference between really using a book for a problem at hand in contrast to “just” read it to pass an exam.

I recently also gained interest in compiler construction and checked out the available books. I ended up with “Enginnering a Compiler” by Keith Cooper, since it also is a profound and well written book AND it is way cheaper in germany