itaps-parallel VisIt Linked with Parallel FMDB

[Tim Tautges]

Mark Miller wrote:

> For some reason, I cannot get to mesh machine right now.
> 
> Mark
> 

I just checked and was able to get there from ANL...

- tim

> 
> On Thu, 2008-11-13 at 17:40 -0500, Onkar Sahni wrote:
>> Thats good... keep us updated and in case if you need help in debugging
>> (and also if errors are coming from FMDB). I guess we would not be able to
>> resolve this before SC08 but if we do I will be happy to load a mesh in
>> VisIt and just project it and show that it loads.
>>
>> - Onkar
>>
>>> Hi Onkar,
>>>
>>> Some good news. I've managed to link VisIt with parallel FMDB vi iMeshP
>>> and open a multi-part sms file. However, when I go to plot it in VisIt,
>>> it is segv'ing somewhere in VisIt. So, I still have some work to do.
>>> However, up until now, it has been a major chore to get everything to
>>> link and operate correctly. VisIt's shared libraries have made it
>>> particularly difficult.
>>>
>>> Mark
>>>
>>> On Wed, 2008-11-12 at 16:33, Onkar Sahni wrote:
>>>> I think my point is being missed, here is my last attempt... if in case
>>>> of
>>>> MOAB "AC_CONFIG_HEADERS is called to produce MBCN_FCDefs.h" why not one
>>>> can produce "ITAPS_FCDefs.h" in a central place and one central
>>>> iMesh_protos.h includes ITAPS_FCDefs.h that is generated during as an
>>>> install/build process (all ITAPS header files can live in one location,
>>>> for example, /usr/local/itaps/headers).
>>>>
>>>> In summary, user/app. would do following basic steps:
>>>>
>>>> * Download itaps-headers (say in /<path-itaps-headers>/)
>>>> * Run configure to generate ITAPS_FCDefs.h in /<path-itaps-headers>/ (an
>>>> app./user would do this step with platform and compiler combination of
>>>> their choice)
>>>>
>>>> * Download any implementation/service (such as FMDB/MOAB/GRUMMP or
>>>> iZoltan)
>>>> * Run configure and compile it (point to /<path-itaps-headers>/ to get
>>>> header files from central place)
>>>>
>>>> * Write app. code like MHD solver
>>>> * Build it and link with appropriate libs. (ofcourse fortran name
>>>> mangling
>>>> has to be consistent while compling app. code with ITAPS_FCDefs.h
>>>> generated by app.)
>>>>
>>>> Is this not possible?
>>>>
>>>> - Onkar
>>>>
>>>>> On Wed, 2008-11-12 at 16:53 -0500, Onkar Sahni wrote:
>>>>>>> The FC_FUNC macro winds up getting defined by something; Autoconf's
>>>>>> configure script does some work to define it. Or, like Onkar
>>>> suggests,
>>>>>> you can define some logic ahead of time to set whatever FC_FUNC does
>>>>>> using logic like so...
>>>>>>> #ifdef AIX
>>>>>>> #define FC_FUNC(lowFunc,UPfunc) _lowFunc
>>>>>>> #elif GFORTRAN
>>>>>>> #define FC_FUNC(lowFunc,UPfunc) UPfunc
>>>>>>> #elif ...
>>>>>>> ..
>>>>>>> .
>>>>>>   So here is my question (basically what I was trying to ask in
>>>>>> tele-con)
>>>>>> which may or may not be possible:
>>>>>>
>>>>>>   Can "#define FC_FUNC............" be generated in a central place
>>>>>> during
>>>>>> the process to install and build itaps softwares (before building any
>>>>> I don't think it can because its definition depends on the name
>>>> mangling
>>>>> properties of the fortran compiler being used at time of
>>>> (configuration)
>>>>> compilation. Yes, the number of possible definitions for FC_FUNC is
>>>>> finite, but know which it should be set to for a given compiler (and
>>>>> what to use in the way of a detecting that) varies from compiler to
>>>>> compiler. The BEST you can achieve is to identify what FC_FUNC should
>>>> be
>>>>> identified for common cases or cases that you know of so that it
>>>> doesn't
>>>>> need to be re-computed with each configure/compile.
>>>>>
>>>>>> implementation/library or service). This would be an extra configure
>>>>>> step in say /usr/local/itaps/headers (central location where all
>>>> headers
>>>>>> sit along with probably configure stuff) and this step would just
>>>>>> generate a new header file say "itaps_fc_func.h".
>>>>>
>>>>>> Say if one uses gfortran then the header file generated in "central"
>>>>>> place
>>>>>> (as an extra step using configure in "central" place) will contain
>>>>>> following lines and every service and implementation simply use it.
>>>>>>
>>>>>>   #ifndef _ITAPS_FC_FUNC_H_
>>>>>>   #define _ITAPS_FC_FUNC_H_
>>>>>>
>>>>>>   /* following line is for specific platform, compiler... combination
>>>> */
>>>>>>   #define FC_FUNC(lowFunc,UPfunc) UPfunc
>>>>>>
>>>>>>   #endif
>>>>>>
>>>>>> - Onkar
>>>>>>
>>>>>>> The only issue I see with this approach is that you need to have
>>>>>> defined
>>>>>> ahead of time all the possible #ifdef #elif cases above and whenever
>>>> you
>>>>>> go to a new machine, then you'll have to re-visit this logic. So, I
>>>> like
>>>>>> the approach where Autconf's configure is used to set FC_FUNC.
>>>>>>> Finally, whatever FC_FUNC is set to, it MUST match the actual name
>>>>>> mangling used by whatever fortran compiler is being used to compile
>>>> the
>>>>>> code. So, it is not just a matter of everyone agreeing on an
>>>>>>> implementation for FC_FUNC. FC_FUNC must also address whatever name
>>>>>> mangling is being used by a given fortran compiler on a given
>>>> platform
>>>>>> when the code is getting compiled. For that reason, I think the best
>>>>>> approach is the Autoconf approach.
>>>>>>> Mark
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Mark C. Miller, Lawrence Livermore National Laboratory
>>>>>>> email: mailto:miller86 at llnl.gov
>>>>>>> (M/T/W) (925)-423-5901 (!!LLNL BUSINESS ONLY!!)
>>>>>>> (Th/F)  (530)-753-8511 (!!LLNL BUSINESS ONLY!!)
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>> --
>>>>> Mark C. Miller, Lawrence Livermore National Laboratory
>>>>> email: mailto:miller86 at llnl.gov
>>>>> (M/T/W) (925)-423-5901 (!!LLNL BUSINESS ONLY!!)
>>>>> (Th/F)  (530)-753-8511 (!!LLNL BUSINESS ONLY!!)
>>>>>
>>>>>
>>> --
>>> Mark C. Miller, Lawrence Livermore National Laboratory
>>> email: mailto:miller86 at llnl.gov
>>> (M/T/W) (925)-423-5901 (!!LLNL BUSINESS ONLY!!)
>>> (Th/F)  (530)-753-8511 (!!LLNL BUSINESS ONLY!!)
>>>
>>>
>>

-- 
================================================================
"You will keep in perfect peace him whose mind is
   steadfast, because he trusts in you."               Isaiah 26:3

              Tim Tautges            Argonne National Laboratory
          (tautges at mcs.anl.gov)      (telecommuting from UW-Madison)
          phone: (608) 263-8485      1500 Engineering Dr.
            fax: (608) 263-4499      Madison, WI 53706