Thread Subject:

Matalb crash after 'clear all' command

Hi all,

I work on 2 calculation servers with same Matalb : version R2011b (7.13.0.564), 64-bit
My bug is quite simple : after using mex-files function Matlab crash with the command : clear all

But I have 2 stranges things :
1 - one of two server doesn't crash (with the version and the same code)
2 - Matlab crash with "Segmentation fault" output message, but an empty backtrace (matlab_crash_dump)

For more information, I don't have any mexAtExit function which could cause this error.
I don't know if there is a special mechanism or anything else with the 'clear all' command ?

If someone have an idea ... Thanks for reply

is that a simple memory issue?

On Tuesday, June 26, 2012 7:29:07 AM UTC-4, SpongePatoche wrote:
> Hi all,
>
> I work on 2 calculation servers with same Matalb : version R2011b (7.13.0.564), 64-bit
> My bug is quite simple : after using mex-files function Matlab crash with the command : clear all
>
> But I have 2 stranges things :
> 1 - one of two server doesn't crash (with the version and the same code)
> 2 - Matlab crash with "Segmentation fault" output message, but an empty backtrace (matlab_crash_dump)
>
> For more information, I don't have any mexAtExit function which could cause this error.
> I don't know if there is a special mechanism or anything else with the 'clear all' command ?
>
> If someone have an idea ... Thanks for reply

"SpongePatoche" wrote in message <jsc6e3$blq$1@newscl01ah.mathworks.com>...

> I don't know if there is a special mechanism or anything else with the 'clear all' command ?

It has nothing with clear command. MEX bug can causes crashes randomly because it corrupts computer memory.

Bruno

"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <jsgu4g$l6g$1@newscl01ah.mathworks.com>...
> "SpongePatoche" wrote in message <jsc6e3$blq$1@newscl01ah.mathworks.com>...
>
> > I don't know if there is a special mechanism or anything else with the 'clear all' command ?
>
> It has nothing with clear command. MEX bug can causes crashes randomly because it corrupts computer memory.
=============

But that can be triggered partially by the CLEAR command, no? If the MEX function returns a mxArray pointer to memory that has already been de-allocated what would happen if you then tried to clear it again, through the CLEAR command?

"Matt J" wrote in message <jshdbv$jll$1@newscl01ah.mathworks.com>...
> "Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <jsgu4g$l6g$1@newscl01ah.mathworks.com>...
> > "SpongePatoche" wrote in message <jsc6e3$blq$1@newscl01ah.mathworks.com>...
> >
> > > I don't know if there is a special mechanism or anything else with the 'clear all' command ?
> >
> > It has nothing with clear command. MEX bug can causes crashes randomly because it corrupts computer memory.
> =============
>
> But that can be triggered partially by the CLEAR command, no? If the MEX function returns a mxArray pointer to memory that has already been de-allocated what would happen if you then tried to clear it again, through the CLEAR command?

Yes. The CLEAR command can easily trigger the crash because of this.

James Tursa