unl_mtx
ER unl_mtx (ID mtxid);
If a task has been queued to the target mutex wait queue when this service call is issued, mutex lock processing is performed by the task (the first task in the wait queue) immediately after mutex unlock processing.
As a result, the task is unlinked from the wait queue and moves from the WAITING state (mutex wait state) to the READY state, or from the WAITING-SUSPENDED state to the SUSPENDED state. And this service call changes the current priority of the task to the ceiling priority of the target mutex. However, this service call does not change the current priority when the task has locked other mutexes and the ceiling priority of the target mutex is lower than or equal to the ceiling priority of the locked mutexes.
Note 1 A locked mutex can be unlocked only by the task that locked the mutex.
If this service call is issued for a mutex that was not locked by the invoking task, "E_ILUSE" is returned.
If this service call is issued for a mutex that was not locked by the invoking task, "E_ILUSE" is returned.