al_destroy_mutex - Allegro 5 API

       Free  the  resources used by the mutex.  The mutex should be unlocked.  Destroying a locked mutex results
       in undefined behaviour.

       Does nothing if mutex is NULL.

Allegro reference manual                                                               al_destroy_mutex(3alleg5)

       al_destroy_mutex - Allegro 5 API

              #include <allegro5/allegro.h>

              void al_destroy_mutex(ALLEGRO_MUTEX *mutex)