<p>I was responding to Ira's suggestion to try to use JMX for that.</p>
<div class="gmail_quote">On Oct 9, 2012 10:22 PM, "Jonathan Ben Avraham" <<a href="mailto:yba@tkos.co.il">yba@tkos.co.il</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi Amos,<br>
Pardon me, what does the class loader have to do with JMX?<br>
<br>
- yba<br>
<br>
<br>
On Tue, 9 Oct 2012, Amos Shapira wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Date: Tue, 9 Oct 2012 22:06:16 +1100<br>
From: Amos Shapira <<a href="mailto:amos.shapira@gmail.com" target="_blank">amos.shapira@gmail.com</a>><br>
To: Jonathan Ben Avraham <<a href="mailto:yba@tkos.co.il" target="_blank">yba@tkos.co.il</a>><br>
Cc: linux-il <<a href="mailto:linux-il@cs.huji.ac.il" target="_blank">linux-il@cs.huji.ac.il</a>><br>
Subject: Re: Looking for directions about compiling and tracing OpenJDK<br>
<br>
<br>
Thanks to both of you.<br>
<br>
To give more details of what I'm after - I want to know whether the class bytecode address points into the mmap(2)'ed jar file or into malloc(3)'ed memory. I think I<br>
found part of the code path inside the jdk source which does this and now I'm trying to determine what are the situations in which each option is taken.<br>
Can JMX do that? The code I'm looking at is written in pure C.<br>
<br>
Amos<br>
<br>
On Oct 9, 2012 10:00 PM, "Jonathan Ben Avraham" <<a href="mailto:yba@tkos.co.il" target="_blank">yba@tkos.co.il</a>> wrote:<br>
Hi Amos,<br>
I did something like this with the JarSigner code in order to reverse engineer it in C, which in the end I was able to do. IMHO, gdb is too high a<br>
granularity to get anything usable out of the JVM execution. I suspect that there is no alternative to sowing System.out.print's throughout the code.<br>
Regards,<br>
<br>
- yba<br>
<br>
<br>
On Tue, 9 Oct 2012, Amos Shapira wrote:<br>
<br>
Date: Tue, 9 Oct 2012 10:57:29 +1100<br>
From: Amos Shapira <<a href="mailto:amos.shapira@gmail.com" target="_blank">amos.shapira@gmail.com</a>><br>
To: linux-il <<a href="mailto:linux-il@cs.huji.ac.il" target="_blank">linux-il@cs.huji.ac.il</a>><br>
Subject: Looking for directions about compiling and tracing OpenJDK<br>
<br>
Hi,<br>
<br>
I have an idea which involves going somewhat deep into the bowls of the Java Jar class loader when using the official Oracle JDK 6 (and soon<br>
7).<br>
To verify this I started looking at the JDK source code but it's not small and I'd like to try to trace through it while it executes Java<br>
programs.<br>
<br>
Does anyone here have experience in doing something like this and can give me some useful pointers on how to do this?<br>
<br>
I'd like to be able to do "gdb java -jar HelloWorld.jar" and single-step through the class loader while it loads HelloWorld.jar.<br>
<br>
Thanks,<br>
<br>
--Amos<br>
<br>
<br>
<br>
<br>
--<br>
EE 77 7F 30 4A 64 2E C5 83 5F E7 49 A6 82 29 BA ~. .~ Tk Open Systems<br>
=}----------------------------<u></u>--------------------ooO--U--<u></u>Ooo------------{=<br>
- <a href="mailto:yba@tkos.co.il" target="_blank">yba@tkos.co.il</a> - tel: <a href="tel:%2B972.2.679.5364" value="+97226795364" target="_blank">+972.2.679.5364</a>, <a href="http://www.tkos.co.il" target="_blank">http://www.tkos.co.il</a> -<br>
<br>
<br>
<br>
</blockquote>
<br>
-- <br>
EE 77 7F 30 4A 64 2E C5 83 5F E7 49 A6 82 29 BA ~. .~ Tk Open Systems<br>
=}----------------------------<u></u>--------------------ooO--U--<u></u>Ooo------------{=<br>
- <a href="mailto:yba@tkos.co.il" target="_blank">yba@tkos.co.il</a> - tel: <a href="tel:%2B972.2.679.5364" value="+97226795364" target="_blank">+972.2.679.5364</a>, <a href="http://www.tkos.co.il" target="_blank">http://www.tkos.co.il</a> -<br>
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