Looking for directions about compiling and tracing OpenJDK

[Jonathan Ben Avraham]

Hi Amos,
Pardon me, what does the class loader have to do with JMX?

  - yba


On Tue, 9 Oct 2012, Amos Shapira wrote:

> Date: Tue, 9 Oct 2012 22:06:16 +1100
> From: Amos Shapira <amos.shapira at gmail.com>
> To: Jonathan Ben Avraham <yba at tkos.co.il>
> Cc: linux-il <linux-il at cs.huji.ac.il>
> Subject: Re: Looking for directions about compiling and tracing OpenJDK
> 
> 
> Thanks to both of you.
> 
> 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.
> Can JMX do that? The code I'm looking at is written in pure C.
> 
> Amos
> 
> On Oct 9, 2012 10:00 PM, "Jonathan Ben Avraham" <yba at tkos.co.il> wrote:
>       Hi Amos,
>       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.
>       Regards,
>
>        - yba
> 
>
>       On Tue, 9 Oct 2012, Amos Shapira wrote:
>
>             Date: Tue, 9 Oct 2012 10:57:29 +1100
>             From: Amos Shapira <amos.shapira at gmail.com>
>             To: linux-il <linux-il at cs.huji.ac.il>
>             Subject: Looking for directions about compiling and tracing OpenJDK
>
>             Hi,
>
>             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).
>             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.
>
>             Does anyone here have experience in doing something like this and can give me some useful pointers on how to do this?
>
>             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.
>
>             Thanks,
>
>             --Amos
> 
> 
> 
>
>       --
>        EE 77 7F 30 4A 64 2E C5  83 5F E7 49 A6 82 29 BA    ~. .~   Tk Open Systems
>       =}------------------------------------------------ooO--U--Ooo------------{=
>            - yba at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
> 
> 
>

-- 
  EE 77 7F 30 4A 64 2E C5  83 5F E7 49 A6 82 29 BA    ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
      - yba at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -