Re: Which tool would you use to track down a signal 10 (SIGBUS)?

FROM : Brooke Callahan
DATE : Sun May 01 23:26:40 2005

> Message: 4
> Date: Sat, 30 Apr 2005 10:56:02 -0700
> From: "Frederick C. Lee" <<email_removed>>
> Subject: Which tool would you use to track down a signal 10 (SIGBUS)?
> To: Cocoa Developers <<email_removed>>
> Message-ID: <<email_removed>>
> Content-Type: text/plain; charset=WINDOWS-1252; format=flowed
>
> Greetings:
>    I've been encountering a 'signal 10 (SIGBUS)' error off/on when I
> launch my program.  I could recompile and wait a few moments and
> relaunch and all is okay ...for awhile...  Then I get the signal 10
> again after another relaunch.  It's like a loose wire that's 
> driving me
> nuts!
>
>    I'm in Development mode running from XCode 1.5 on Panther.  I've
> trace it down to a C routine used to read an old DBF file.  At 
> least I
> think that's the culprit.  I only get this problem during RUN, not
> DEBUG and Exception Handlers that I have place in don't appear to 
> catch
> it.
>
>    1) What would cause a signal 10 crash?    <-- a memory 
> crash...similar
> to other signals like 11, etc.?


Improper memory access, like the following:

int *address;
int value;

address = 1;
value = *address;

"It can also occur if you access mmap(2)'d memory beyond the end of 
the file but within the region of the mmap(2)."
http://www.wlug.org.nz/SIGBUS

>            2) What tool do you recommend to find the culpret?   
> Shark?
> Others?  Any docs?


This is a good place to start:
http://developer.apple.com/technotes/tn2004/tn2124.html

One of the most useful things (for me) is the CrashReporter.  You can 
find the crash log for any apps here:
/Users/{$USER}/Library/Logs/CrashReporter/{$APP}.crash.log

> Thanks for the tip in advance.
>
> Ric.
>
> The following is what I get:
> Executable “eGIS” has exited due to signal 10 (SIGBUS).