I think to be very near to the solution of this problem.
Thanks to Gilles for his patience.
Now I will retry to make a summary of the problem.
********************
**** MY PROBLEM ****
********************
I have an user space xenomai application.
It works fine. If I try to debug it with gdb, sometimes, in some points,
xenomai stops to works. All xenomai threads are like stopped.
In my case they are stopped in rt_task_sleep() or other wait operations.
Linux instead continues to work normally.
To make xenomai usable and working I have to reset the processor.
I have no other way.
**************************
**** SOLUTION / PATCH ****
**************************
file : xenomai-2.5.6/ksrc/skins/native/task.c
function : int rt_task_delete(RT_TASK *task)
See my code signed with =======>
int rt_task_delete(RT_TASK *task)
{
int err = 0;
spl_t s;
if (!task) {
if (!xnpod_primary_p())
return -EPERM;
task = xeno_current_task();
} else if (xnpod_asynch_p())
return -EPERM;
xnlock_get_irqsave(&nklock, s);
task = xeno_h2obj_validate(task, XENO_TASK_MAGIC, RT_TASK);
if (!task) {
err = xeno_handle_error(task, XENO_TASK_MAGIC, RT_TASK);
goto unlock_and_exit;
}
/* Make sure the target task is out of any safe section. */
err = __native_task_safewait(task);
if (err)
goto unlock_and_exit;
=========> if (xnthread_test_state(&task->thread_base, XNDEBUG))
=========> {
=========> unlock_timers();
=========> }
/* Does not return if task is current. */
xnpod_delete_thread(&task->thread_base);
unlock_and_exit:
xnlock_put_irqrestore(&nklock, s);
return err;
}
As you can see, my patch unlock timers if the xenomai thread is killed.
***************************
**** DETAILS OF MY BUG ****
***************************
I have a xenomai application with 70 real-time threads.
Suppose that thread 1 deletes thread 70 with rt_task_delete().
This is my case.
I put a breakpoint and run my xenomai application.
When my breakpoint is reached gdb stops all my xenomai threads.
If I press "c" to continue, gdb restarts my application,
that is every thread, one by one (thread 1, thread 2, thread 3,
.... , thread 70).
If I press "c" on gdb, the following scenario could happens :
1) gdb start thread 1
2) thread 1 starts immediately
3) thread 1 delete thread 70 by rt_task_delete()
...
4) gdb start thread 2
5) gdb start thread 3
6) gdb start thread 4
7) gdb start thread 5
8) gdb start thread 6
...
.) gdb start thread 68
.) gdb start thread 69
.) gdb start thread 70
The thread 1 finds thread 70 in debug mode !
My patch adjust this problem.
I realize that it is a very special case, but it is my case.
I'd like to know if the patch is valid or can be written in a different way.
For example, I could insert my patch directly in xnpod_delete_thread().
The function unlock_timers() cannot be called from
xenomai-2.5.6/ksrc/skins/native/task.c
because it is defined static. This is a detail. There are simple ways to
solve this.
Thanks in advance,
Paolo Minazzi
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