[Xenomai-help] What returns rt_task_self in relation to rt_task_create

["M. Koehrer" <mathias_koehrer@domain.hid>]

Hi all,

I have a simple question concerning the Xenomai native API:
According to the API documentation, rt_task_self returns the 
address of the caller's task descriptor.
I have now written the following (simple application):
---------- START ----------
#include <stdio.h>
#include <sys/mman.h>
#include <native/task.h>

RT_TASK task_desc;

void mytask(void *cookie)
{
    RT_TASK *tsk = rt_task_self();
    printf("rt_task_self  %p\n"
           "task_desc     %p\n", tsk, &task_desc);
}

int main(void)
{
    mlockall(MCL_CURRENT|MCL_FUTURE);

    rt_task_create(&task_desc, "mytaskname", 0, 80, T_JOINABLE);
    rt_task_start(&task_desc, &mytask, NULL);

    rt_task_join(&task_desc);

    return 0;
}
------------ END -----------

I expect now that rt_task_self() returns exactly the address of the task_desc.
However, a different address is returned. 
The output of the application from above is:
rt_task_self  0x804a050
task_desc     0x8049878

How are those addresses related - how can I find out the descriptor address 
used for rt_task_create() at runtime?

Background of the question:
I want to write an application that uses a couple of similar tasks.
I have to store some task-specific information (internal states...).
Now I am looking for a simple way to get this information at runtime from my task
by calling rt_task_self() (or something similar) to use this address to reach my
additional information.

Thanks for any idea on this.

Regards

Mathias



-- 
Mathias Koehrer
mathias_koehrer@domain.hid


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