File Pro And Bus Errors

[Nancy Palmquist]

J. Ryan Kelley wrote:
> 
> 
> Steve Wiltsie wrote:
> 
>> ----- Original Message ----- From: "J. Ryan Kelley" 
>> <ryan.kelley at trinitytransport.com>
>> To: "fplist3" <Filepro-list at lists.celestial.com>
>> Sent: Wednesday, July 06, 2005 7:07 AM
>> Subject: File Pro And Bus Errors
>>
>>
>>  
>>
>>> Good Morning,
>>>
>>> I've been working with Filepro for about 8 months now after recently
>>> graduating from college with a degree in Computer Science.  I've had
>>> experiences working with everything from C, and C++ to Fortran, to Lisp,
>>> and countless other languages, however never with FilePro until I
>>> started at my current position.  When I first started working with
>>> Filepro, I'll admit, I was impressed with how easy it was to step in and
>>> start working.  In fact, I was doing some programming in my first few
>>> hours on my first day.  The primary thing that I have found unsettling
>>> from day one, however, is the presence of the dreaded Bus Error.  I'm
>>> quite familiar with Bus Errors (aka Segmentation Faults) from my days
>>> working in C, where attempting to access a memory location you don't
>>> have permissions to access would cause this problem and dump you out.
>>> It was usually caused by an improperly indexed array, or an erroneous
>>> pointer.  This all made sense in C because of how low level it was,
>>> giving you direct access to the memory.
>>>
>>> Filepro, at least relative to C, is much more high level.  There is no
>>> point at which you are attempting to manipulate the system memory
>>> directly so these Bus Errors should cease to exist, unless being caused
>>> by a compiler/interpreter.  When I've questioned co-workers and other
>>> filepro developers in the past about what causes these errors, and how
>>> they can be avoided, I always get one reply, "Remove your comments."
>>> When I was first told this, I disputed it, and disputed it.  After all,
>>> in all (or at least i thought all) compilers/interpreters comments are
>>> completely disregarded and treated as if they were simply white space.
>>> Sadly, I have seen several instances in which removing some comments can
>>> remedy these errors.  In my opinion, comments are a very important part
>>> of the code itself, especially when working in a system with several
>>> developers who need to be able to easily digest what another programmer
>>> was attempting to do.  For a comment to attempt to access an
>>> unauthorized memory location is illogical, and I'm assuming that there
>>> is a better explanation for all of this.  As the days wear on, the bus
>>> errors seem to become more and more prevalent and are creating some
>>> serious issues that take me away from my daily duties.  Can anyone
>>> provide some helpful insight onto this problem, do comments really cause
>>> Bus Errors?  If So why and how?  Is there a patch in the works? and what
>>> else in FilePro can cause these nasty errors.
>>>
>>> Thank you,
>>>
>>>   
>>
>>
>> Ryan,
>>
>> Sorry you are getting "bus errors" in filePro.  However, you have 
>> failed to
>> provide anyone with enough information to help you.  For example:  what
>> version of filePro are you using?  is there an update available to a 
>> later
>> release of the same version you are using?  what operating system(s) are
>> involved?  do the systems get bus errors running anything else?
>>
>> I have been working in filePro doing development for my business 
>> customers
>> for over 20 years and I don't think this has been a problem I've seen 
>> for a
>> long, long time.  I think you have another problem that is showing itself
>> when filePro is running or you are running a very old version on a new
>> operating system.
>>
>> That's my 2 cents worth.
>>
>> Steve Wiltsie
>> microCONCEPTS Div. multi/user/inc.        Since 1981
>> (812) 474-0127                          Fax: (812) 474-0147
>>
>>
>>
>>
>>  
>>
> Steve,
> 
> Thanks for the quick reply.  I'm running on FP 5.0.13R4 on Solaris 9.  
> We see no bus errors outside of filepro, although this server runs only 
> a few other applications such as a fax server.  We see these bus errors 
> at different times, sometimes, before the processing even appears to 
> begin, and other times after certain fields are updated, the fields will 
> be updated, but some automatic indexes may need to be rebuilt to reflect 
> the change because of a bus error.
> 
> Thanks,

This error may be related to a corrupt file.  It could be the edits, 
screenss, automatic, input or output processing.  Since you say it seems 
to happen sometimes before you hit processing.  Do the following:

Remove or rename the processing both auto and input (make a safe copy of 
course),  Remove all indexes (each and every one - document the indexes 
before).  Then try the file and see if it functions correctly for access 
, update and add (without the programming it might hot be fully 
functional but you will be able to tell if it is giving you bus errors.

Then add back the indexes, create them from scratch.  and try the file 
again.  If it still works - add back the auto processing .  See if it 
still works.  (WRITE commands in the auto table could cause the problem 
you indicate.)

Finally, put back the input/output processing and try it again.  If it 
crashes, now it will indicate the processing is causing it.

Run the processing in debug mode and follow it till it crashes.  That 
will tell you where to look in the code.

I have had crashes in the past from stuff like ab(5,.0) which was typed 
by mistake ab(5,.o).  Or conflicts with labels, array names, lookup 
names, selection table names, long variables.

FilePro can check for syntax specific things but some errors can not be 
anticipated.  Those tend to cause the Bus Error type crashes.

I have seen bad edit tables (local or global) or exceeding the 200 limit 
can cause a crash.  (local + global edits can not exceed 200)

Good luck,

These are a real pain.  But there is a cause and if you persist you will 
track it down.

Nancy

-- 
Nancy Palmquist 		MOS & filePro Training Available
Virtual Software Systems	Web Based Training and Consulting	
PHONE: (412) 835-9417		   Web site:  http://www.vss3.com