-void *register_task(struct task *t);
-void unregister_task(struct task *t);
-int sched(struct sched *s);
-void init_sched(void);
-char *get_task_list(void);
-int kill_task(char *id);
+/**
+ * This is set by the scheduler at the beginning of its main loop. It may be
+ * used (read-only) from everywhere. As none of the functions called by the
+ * scheduler are allowed to block, this value should be accurate enough so that
+ * there is no need to call gettimeofday() directly.
+ */
+extern struct timeval *now;
+
+void register_task(struct sched *s, struct task *t);
+int schedule(struct sched *s);
+char *get_task_list(struct sched *s);
+void sched_shutdown(struct sched *s);
+void sched_min_delay(struct sched *s);
+void sched_request_timeout(struct timeval *to, struct sched *s);
+void sched_request_timeout_ms(long unsigned ms, struct sched *s);
+int sched_request_barrier(struct timeval *barrier, struct sched *s);
+int sched_request_barrier_or_min_delay(struct timeval *barrier, struct sched *s);