Bug with pthreads

[Joel Sherrill]

Peter Pointner wrote:
> 
> Ok, now i reply to my own mail with a fix. The patch at the end of this
> message changes the POSIX thread name thing so that it looks like that in
> the ITRON api. Seem to work.

I am building this now and will trace in but if you can look at it also
I would appreciate it.

When you get to _Thread_Initialize, does the name point to "psx\0" or to
the address of default_name on the stack.  My reading of this code makes
me believe the latter.

Regardless, my first impression is that the name stuff needs to be
eliminated from
both pthread.c and pthreadcreate.c.

I also suspect that other POSIX managers may suffer from having
unecessary names.

Comments appreciated.
 
> Peter
> 
> On Tue, 22 Feb 2000, Peter Pointner wrote:
> 
> > Hello,
> >
> > I think there is a bug somewhere in the posix api:
> >
> > a) exec/posix/src/pthread.c, _POSIX_Threads_Manager_initialization() calls
> >    _Objects_Initialize_information with parameter 'is_string' set to TRUE.
> >
> > b) exec/posix/src/pthreadcreate.c, pthread_create() defines
> >       char * default_name = "psx";
> >    on the stack, then calls
> >       _Thread_Initialize( ..., &default_name);
> >
> > c) exec/score/src/threadinitialize.c, _Thread_Initialize() gives this
> >    parameter to the macro _Objects_Open
> >
> > d) exec/score/macros/rtems/score/object.inl, _Objects_Open() decides
> >    (based on the information from a) ), to pass this parameter to
> >    _Objects_Copy_name_string
> >
> > e) exec/score/src/objectcopynamestring.c, _Objects_Copy_name_string treats
> >    the value as pointer to a null terminated string and copies it.
> >
> > If I didn't get something wrong, this might lead to unpredictable results,
> > if this '&default_name' doesn't contain a null byte.
> >
> > I'm a bit too confused now to fix that. Any takers?
> >
> > Peter
> >
> 
> Index: pthread.c
> ===================================================================
> RCS file: /m/e2k/rtems-4.5/rtems/c/src/exec/posix/src/pthread.c,v
> retrieving revision 1.1.1.1
> diff -u -r1.1.1.1 pthread.c
> --- pthread.c   2000/02/09 13:23:13     1.1.1.1
> +++ pthread.c   2000/02/23 10:27:50
> @@ -356,8 +356,8 @@
>      FALSE,                               /* does not support global */
>      maximum_pthreads,
>      sizeof( Thread_Control ),
> -    TRUE,
> -    5,                                   /* length is arbitrary for now */
> +    FALSE,
> +    0,                                   /* posix threads don't have a name */
>      TRUE                                 /* this class is threads */
>    );
> 

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
   Support Available             (256) 722-9985