X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=sched.h;h=303877a4435d0b31fc779ac03d68e20326af17b2;hp=7681567be31534e3ef98af3dc19f16f0958290d7;hb=0b38d56fdd56cc51ee4286a49a4aa91d83618fc1;hpb=ffb2eaa90429f6d5c3d369509efcdf91c5463dad

diff --git a/sched.h b/sched.h
index 7681567b..303877a4 100644
--- a/sched.h
+++ b/sched.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2006-2010 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2014 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -10,25 +10,27 @@
 /**
  * Paraslash's scheduler.
  *
- * Designed with KISS in mind. It manages two lists of tasks.  The pre_select
- * list contains pointers to functions that are called before calling select()
- * from the main loop. Similarly, \a post_select_list is a list of function
- * pointers each of which is called after the select call. Tasks add hooks to
- * these lists by registering themselves to the scheduler.
+ * Designed with KISS in mind. It maintains a list of task structures which is
+ * extended when a new task is registered. Each task may define a pre_select
+ * function which is called from the scheduler main loop before it calls
+ * select(). Similarly, each task must define a post_select function which is
+ * called after the select call.
  */
 struct sched {
 	/** Initial value before any pre_select call. */
 	struct timeval default_timeout;
 	/** The current timeout for the upcoming select call. */
-	struct timeval timeout;
+	struct timeval select_timeout;
 	/** fds that should be watched for readability. */
 	fd_set rfds;
 	/** fds that should be watched for writability. */
 	fd_set wfds;
 	/** Highest numbered file descriptor in any of the above fd sets. */
 	int max_fileno;
-	/** In non-NULL, use this function instead of para_select. */
+	/** If non-NULL, use this function instead of para_select. */
 	int (*select_function)(int, fd_set *, fd_set *, struct timeval *);
+	/** Tasks which have been registered to the scheduler. */
+	struct list_head task_list;
 };
 
 /**
@@ -37,50 +39,50 @@ struct sched {
  * Before registering a task to the scheduler, the task structure must be
  * filled in properly by the caller.
  *
- * If one of these functions sets \a t->error to a negative value, the
- * task gets unregistered automatically.
- *
- * \sa struct sched.
+ * \sa \ref sched.
  */
 struct task {
 	/**
-	 * The pre select hook of \a t.
+	 * The optional pre select hook of \a t.
 	 *
 	 * Its purpose is to add file descriptors to the fd sets of the
 	 * scheduler and to decrease the select timeout if necessary.
 	 */
 	void (*pre_select)(struct sched *s, struct task *t);
 	/**
-	 * The postselect hook of \a t.
+	 * The mandatory post select hook of \a t.
 	 *
-	 * Evaluate and act upon the results of the previous select call.
+	 * Its purpose is to evaluate and act upon the results of the previous
+	 * select call. If this function returns a negative value, the
+	 * scheduler unregisters the task.
 	 */
-	void (*post_select)(struct sched *s, struct task *t);
-	/** Whether this task is in error state. */
+	int (*post_select)(struct sched *s, struct task *t);
+	/** Whether this task is active (>=0) or in error state (<0). */
 	int error;
-	/** Position of the task in the pre_select list of the scheduler. */
-	struct list_head pre_select_node;
-	/** Position of the task in the post_select list of the scheduler. */
-	struct list_head post_select_node;
+	/** Position of the task in the task list of the scheduler. */
+	struct list_head node;
 	/** Descriptive text and current status of the task. */
 	char status[255];
+	/** If less than zero, the task was notified by another task. */
+	int notification;
 };
 
 /**
  * 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.
+ * there is no need to call clock_gettime() directly.
  */
 extern struct timeval *now;
 
-void register_task(struct task *t);
+void register_task(struct sched *s, struct task *t);
 int schedule(struct sched *s);
-char *get_task_list(void);
-int kill_task(char *id);
-void sched_shutdown(void);
+char *get_task_list(struct sched *s);
+void task_notify(struct task *t, int err);
+void task_notify_all(struct sched *s, int err);
+int task_get_notification(const struct task *t);
 void sched_min_delay(struct sched *s);
-void sched_request_timeout(struct timeval *timeout, struct sched *s);
+void sched_request_timeout(struct timeval *to, struct sched *s);
 void sched_request_timeout_ms(long unsigned ms, struct sched *s);
-void sched_request_barrier(struct timeval *barrier, struct sched *s);
-void sched_request_barrier_or_min_delay(struct timeval *barrier, 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);