Two Coding Problems

[Ian Caddy]

Hi Sun Shine,

In answer to your second question, I would say it is because your init 
task is running off the end of the task and so the init task is deleted. 
  Then by the time your second task gets to run, it will find the first 
available ID and use it, and this would have been the one that the Init 
task was using.

To stop this effect, at the end of your init task, put an endless loop, 
such as:

while(1)
{
    rtems_task_wake_after(100);
}

or you could just suspend the task instead of deleting it (by running 
off the end, such as:

    rtems_task_suspend(0);

I hope this helps.

regards,

Ian Caddy


Sun Shine wrote:
> Hi,all
>   I have two questions here
> 
> 1. How can I get the TCB of a certain task? Is there any directive such 
> like "rtems_task_get_tcb"?
> 
> 2. I wrote an APP, In Init() I create a new task then start it.The 
> function of the new task is to create a new task, too.
>   Now the Init Task is named T0, the task created by T0 is named T1, and 
> the task created by T1 is named T2.
>   When running my app on SPARC leon2, the ID information is as follows:
>     T0    ID = a010001
>     T1    ID = a010002
>     T2    ID = a010001
>   I don't know why T2's ID is just the same as T0.
> 
>   The main functions are here:
>     
> rtems_task get_task_info(rtems_task_argument argument)
> {
>    rtems_id              tid;
>    rtems_task_priority   priority;
>    rtems_status_code     status;
>    status = rtems_task_ident(RTEMS_SELF, RTEMS_SEARCH_ALL_NODES, &tid);
>    status = rtems_task_set_priority(tid,RTEMS_CURRENT_PRIORITY,&priority);
>    printf("\tTask ID: %x\tpriority: %d\n",tid,priority);
>    status = rtems_task_delete(RTEMS_SELF);
> }
> 
> rtems_task create_task(rtems_task_argument argument)
> {
>    rtems_name            name = rtems_build_name('T','S','T',' ');
>    rtems_id              tid;
>    rtems_task_priority   priority;
>    rtems_status_code     status;
>    status = rtems_task_ident(RTEMS_SELF,RTEMS_SEARCH_ALL_NODES,&tid);
>    status = rtems_task_set_priority(tid,RTEMS_CURRENT_PRIORITY,&priority);
>    status = rtems_task_create(name,priority,RTEMS_MINIMUM_STACK_SIZE,
>                 RTEMS_PREEMPT,RTEMS_DEFAULT_ATTRIBUTES,&tid);
>    if(status!=RTEMS_SUCCESSFUL)
>      printf("Create task failed with status %d\n",status);
>    else
>      printf("Create Task %x with priority %d 
> successfully!\n",tid,priority);               status = 
> rtems_task_start(tid,get_task_info,argument);
>    if(status!=RTEMS_SUCCESSFUL)
>      printf("\tTask %x (%d) start failed with status 
> %d\n",tid,priority,status);
>    else
>      printf("\tTask %x (%d) start 
> successfully!\n",tid,priority);               status = 
> rtems_task_delete(RTEMS_SELF);
> }
> 
> rtems_task Init(rtems_task_argument argument)
> {
>  rtems_name            task_name;
>  rtems_status_code     status;
>  rtems_id              tid;
>  rtems_task_priority   priority;
> 
>  status = rtems_task_ident(RTEMS_SELF,RTEMS_SEARCH_ALL_NODES,&tid);
>  status = rtems_task_set_priority(tid,RTEMS_CURRENT_PRIORITY,&priority);
> 
>  printf("\nInit Task ID = %x\tprioirty = %d\n\n",tid,priority);
> 
>  task_name = rtems_build_name( 'T', 'A', '1', ' ' );
>  priority = 1;
>  status = rtems_task_create(task_name, 
> priority,RTEMS_MINIMUM_STACK_SIZE,         
> RTEMS_INTERRUPT_LEVEL(0),RTEMS_DEFAULT_ATTRIBUTES, &tid);
> 
>  if ( status != RTEMS_SUCCESSFUL )
>  {
>    printf("\tTask create failed with the status of %d\n",status);
>    exit(1);
>  }
>  else
>  {
>    printf("\tThe Task just created ID: %x\tpriority: %d\n",tid,priority);
>    status = rtems_task_set_priority(tid,RTEMS_CURRENT_PRIORITY,&priority);
>  }
>         status = rtems_task_start( tid, create_task, 0);
> 
>  if (status != RTEMS_SUCCESSFUL )
>  {
>     printf("\tTask %x start failed with the stauts of %d\n",tid,status);
>     exit(1);
>  }           status = rtems_task_delete( RTEMS_SELF );
> }
> 
> 
>  Thanks a lot !
>  SunPeng
> 
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-- 
Ian Caddy
Goanna Technologies Pty Ltd
+61 8 9221 1860