[Xenomai] Rescnt imbalance in rtdm_mutex_timedlock

[Erwin Pranz <erwin.pranz@sigmatek.at>]

Hello,

I am using rtdm_mutex_lock/rtdm_mutex_unlock in a rtdm driver and I get 
a signal SIGDEBUG_MIGRATE_PRIOINV when I call the driver from a 
priority-0 thread.The signal is sent in xnsynch_release_thread when 
rescnt is 0 on a XNOTHER thread, which means that rescnt is not balanced.

I think the reason why rescnt is not balanced is in 
rtdm_mutex_timedlock: when the owner of the mutex is NULL, the owner is 
changed to the calling thread, but rescnt is not increased.

I suggest the following fix in rtdm_mutex_timedlock:
-       else if (likely(xnsynch_owner(&mutex->synch_base) == NULL))
+       else if (likely(xnsynch_owner(&mutex->synch_base) == NULL)) {
                 xnsynch_set_owner(&mutex->synch_base, curr_thread);
+               if (xnthread_test_state(curr_thread, XNOTHER))
+                       xnthread_inc_rescnt(curr_thread);
+       }

Best regards,

-- 
Erwin Pranz
Software
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