[Ltrace-devel] multi-thread support for ltrace

[Manoj Kora]

Hi,

Thank you for your reply.

I took source and patch from the below link:

http://repository.maemo.org/pool/fremantle/free/l/ltrace/

I have gone through the patch and i have found the following observations:

* Here the support for multithreaded applications has been given by  controlling the order in which the events are processed.

* The main issue in this approach is that, it is necessary to restore the  original instruction whenever the threads trap on other thread’s  breakpoints. But this is not happening here.

* So workaround is made for is by disabling the library call tracing  using “-L” option.

* A good fix for this situation would require heavy changes to ltrace  process model.

So by disabling the "-L" option they are disabling the display of library calls, which degrades the functionality of ltrace.

So is there any workaround for this patch to overcome these problems and have a permanent solution?

Since it has been mentioned in the patch that, a good fix for this situation would require heavy changes for ltrace process model. So i thought of parallely going through the strace code to get an idea how to handle threads and implement the same for ltrace. 

Is this a good idea? Please give your inputs on this.

Thanks & Regards,
Manoj

--- On Mon, 1/11/10, Anderson Lizardo <anderson.lizardo at gmail.com> wrote:

From: Anderson Lizardo <anderson.lizardo at gmail.com>
Subject: Re: [Ltrace-devel] multi-thread support for ltrace
To: "Manoj Kora" <koramanoj at yahoo.com>
Cc: ltrace-devel at lists.alioth.debian.org
Date: Monday, January 11, 2010, 3:50 PM

Hi,

On Mon, Jan 11, 2010 at 5:45 AM, Manoj Kora <koramanoj at yahoo.com> wrote:
> So now i am trying to add the multi-threaded support for ltrace, but not able to find a proper approach for this, for example
>
> 1) Is there a workaround for the existing code?

For Maemo (Linux based OS running on Nokia tablets), there was some
work to implement multi-thread support:

http://repository.maemo.org/pool/fremantle/free/l/ltrace/

It has been a long time since I checked the code, but if you are on a
Debian based system, download and unpack the sources with:

dget -u http://repository.maemo.org/pool/fremantle/free/l/ltrace/ltrace_0.5+svn20070904-0.1maemo1.dsc

If you are not on Debian, you need to unpack the .orig.tar.gz and
manually apply the .diff.gz patch on it.

After this, you should find various patches on the debian/patches
directory, some of them related to thread support.

Hope that helps,
--
Anderson Lizardo
Instituto Nokia de Tecnologia (INdT)
Manaus - Brazil




      
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