Re: [Xenomai-help] rt_task_join() call hangs in shared lib destructor

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Gilles Chanteperdrix wrote:
> Mauro Salvini wrote:
>>> It looks like a typical pthread_join deadlock. The thread you are 
>>> joining is locked on a pthread mutex, that some other thread (I
>>> would say, the one calling pthread_join) has. It can not work. You
>>> should not call pthread_join while holding a mutex.
>> Yes, it looks like this, but I don't use any mutex in my task. It
>> looks like dlclose() locks a mutex used also by pthread_join() (that
>> was called into shared object destructor), and here is deadlock. But
>> executing realtime task as normal thread does not raise this issue.
> 
> The trace you sent clearly shows that the problem happens because
> rt_task_trampoline calls pthread_exit. In your tests with
> rt_task_shadow/pthread_create, did you try to use pthread_exit? Or could
> you try replacing the call to pthread_exit in rt_task_trampoline with a
> return?

Answering to myself: no, in your examples you did not use pthread_exit,
that is the difference with the rt_task_create case.

So, could you try the following patch?

diff --git a/src/skins/native/task.c b/src/skins/native/task.c
index be4ea2c..70ba6f7 100644
--- a/src/skins/native/task.c
+++ b/src/skins/native/task.c
@@ -113,7 +113,7 @@ static void *rt_task_trampoline(void *cookie)

       fail:

-	pthread_exit((void *)err);
+	return (void *)err;
 }

 int rt_task_create(RT_TASK *task,


-- 
                                                                Gilles.