<p>Thanks to both of you.</p>
<p>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 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.</p>
<p>Amos</p>
<div class="gmail_quote">On Oct 9, 2012 10:00 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>
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 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>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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 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 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>
</blockquote>
<br>
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</blockquote></div>