+typedef const s4u_Barrier* const_sg_bar_t;
+typedef s4u_ConditionVariable* sg_cond_t;
+typedef const s4u_ConditionVariable* const_sg_cond_t;
+typedef s4u_Mutex* sg_mutex_t;
+typedef const s4u_Mutex* const_sg_mutex_t;
+typedef s4u_Semaphore* sg_sem_t;
+typedef const s4u_Semaphore* const_sg_sem_t;