[Xenomai-core] SWITCH TASK TO SECONDARY MODE DURING GDB SESSION DOESN'T WORK

[Roberto Bielli <roberto.bielli@domain.hid>]

Hi,

i try the next C code in a gdb session on a ARM target with brakpoints 
and i found a strange behaviour.
I expected that the task 'tsk1' never execute instead if i put a 
breakpoint on the instruction 'varInt += 1;' i see that it's executed.
I sospect that there is this behavior:

1. i start gdb with application. The application is not running.
2. i enable the breakpoint on the instruction 'err = 
rt_task_start(&tsk1, &test_tsk1, NULL );'
3. i enable the breakpoint on the instruction 'varInt += 1;' in tsk1
4. run the application that stop on the instruction 'err = 
rt_task_start(&tsk1, &test_tsk1, NULL );'
so the task is in secondary mode for the breakpoint hit if i understand 
correctly .
5. i make a single step and do the rt_task_start in main, so i see that 
i break in the task on the instruction 'varInt += 1;' in tsk1
this is strange because main has shadow and has a priority equal o 99, 
instead  tsk1 has a priority equal to 49.
6, the program execute the instruction  'varInt += 1;' and then return 
to main.
7 then the main has always the control.

The question is:
Why the priority is not respected ? I think this. Maybe the main is in 
secondary mode for the breakpoint and when make a rt_task_create the new 
task is in primary
mode for the initial instruction. Then receive the signal ( verified 
with rt_task_set_mode(0, T_WARNSW, NULL); ) and switch to secondary mode 
but initially the task tsk is in primary mode and execute before main.

Is a known problem ?

Best Regards



CODE---------------------------------


int varInt = 0;
RT_TASK tsk1, tskMain;

int main (int argc, char *argv[])
{
     int err;
     mlockall(MCL_CURRENT|MCL_FUTURE);

     rt_task_shadow(&tskMain, "main", 99, 0);

     err  = rt_task_create( &tsk1, "tsk1", 0, 49, T_FPU );
     err = rt_task_start(&tsk1, &test_tsk1, NULL );

     for (;;)
     {
         if( varInt > 1 )
             break;
     }


     printf("Task started\n");

     return 0;
}

void test_tsk1( void * args )
{

     for( ;;)
     {
         varInt += 1;
         rt_task_sleep( 100000000 );
     }
}

-- 
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Roberto Bielli
Sviluppo Software					
Axel S.r.l.					
							
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Varese - Italy					
							
Telefono: +39 0332 949600			
Fax:      +39 0332 969315			
							
E-mail:   roberto.bielli@domain.hid	
Web Site: www.axelsw.it

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