pthread support in ppc405 gdb

pthread support in ppc405 gdb

[Bryan Rittmeyer]

Hi,

The company I work for is porting a large, threaded C++ program to
proprietary ppc405-based hardware. We are using a custom in-house
toolchain I developed based on gcc 3.0.1 and the Montavista HHL 2.0
release--the gcc 2.95.3 release in HHL 2.0 lacks sufficient C++
support to build our codebase, which is primarily developed in
M$ Visual C++.

We have a mission-critical need for a ppc405 source level debugger
(gdb) which can handle complex, threaded C++ applications. However,
the HHL 2.0 release notes say the following:

* gdb 5.0
   gdb 5.0 included with HHL 2.0 does not support
   debugging multi-threaded (pthread) applications.

What are the problem areas that prevent gdb 5.0 from debugging
threaded applications on the ppc405? Is anyone on the
list or within MontaVista willing to work with me to fix
threading support in gdb?

We are willing to do whatever it takes to get x86-workstation-quality
gdb on the embedded ppc405 (and, tangentially, the sh4).

Thanks!

-Bryan

--
Bryan Rittmeyer
mailto:bryan@ixiacom.com


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Re: pthread support in ppc405 gdb

[Mark Hatle]

Bryan Rittmeyer wrote:
>
> Hi,
>
> * gdb 5.0
>    gdb 5.0 included with HHL 2.0 does not support
>    debugging multi-threaded (pthread) applications.
>
> What are the problem areas that prevent gdb 5.0 from debugging
> threaded applications on the ppc405? Is anyone on the
> list or within MontaVista willing to work with me to fix
> threading support in gdb?
>
> We are willing to do whatever it takes to get x86-workstation-quality
> gdb on the embedded ppc405 (and, tangentially, the sh4).

The problem is that gdb 5.0 does not have thread support.  This is not
something that is "easily" added to 5.0.  The gdb 5.1 coming out (from
my understanding, I'm not working specifically on gdb, so if I am wrong
I appologize in advance) does have thread support.  From my
understanding it is a pretty significant change.  We have gdb 5.1
testing in house on a few platforms, but I'm not sure about 405.

AFAIK "real" gdb 5.0 on x86 also does not have thread support.  RedHat
or another distro vendor may have grafted x86 thread support in, or it
may partially work... but gdb 5.1 will be the first gdb version to be
released with thread support.

If you have a MontaVista support contract, contact us.  Otherwise, I
don't believe we are planning on releasing the gdb 5.1 work we have done
so far until our next release.

--Mark Hatle
MontaVista Software, Inc.

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Re: pthread support in ppc405 gdb

[Marius Groeger]

In linux.ppc.embedded, Bryan Rittmeyer wrote:

> We have a mission-critical need for a ppc405 source level debugger
> (gdb) which can handle complex, threaded C++ applications. However,
> the HHL 2.0 release notes say the following:
>
> * gdb 5.0
>    gdb 5.0 included with HHL 2.0 does not support
>    debugging multi-threaded (pthread) applications.

The current gdb snapshots have fairly decent support for pthreads. I'd be
careful though with "complex, threaded C++ applications". That has always
beed a problem with gdb (at least on other platforms where threads were
supported). This is - at least partially - due to the inherent, er,
weirdness of C++.

Elinos does support pthread debugging btw.

Regards
Marius.

----------------------------------------------------------------------
Marius Groeger        SYSGO Real-Time Solutions GmbH    www.sysgo.de
Software Engineering  Embedded and Real-Time Software   www.osek.de
mgroeger @ sysgo de   Germany                           www.elinos.com

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