X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=sched.h;h=ada1cc106c068706fc175cc883450c17a237f4b7;hp=021474a21a5303d405d91b985a0a70de1d198801;hb=6ba4caacaeb4ac2d8e5fc15699bf89f496d59901;hpb=24758c5f17064273786e704b84ceff56c234e347

diff --git a/sched.h b/sched.h
index 021474a2..ada1cc10 100644
--- a/sched.h
+++ b/sched.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2006-2013 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -10,11 +10,11 @@
 /**
  * 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. */
@@ -29,47 +29,37 @@ struct sched {
 	int max_fileno;
 	/** If non-NULL, use this function instead of para_select. */
 	int (*select_function)(int, fd_set *, fd_set *, struct timeval *);
-	/** Currently active pre_select functions. */
-	struct list_head pre_select_list;
-	/** Currently active post_select functions. */
-	struct list_head post_select_list;
+	/** Tasks which have been registered to the scheduler. */
+	struct list_head task_list;
 };
 
-/**
- * Paraslash's task structure.
- *
- * 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.
- */
-struct task {
+struct task;
+
+/** Information that must be supplied by callers of \ref task_register(). */
+struct task_info {
+	/** Used for log messages and by \ref get_task_list(). */
+	const char *name;
 	/**
-	 * The pre select hook of \a t.
+	 * The optional pre select method.
 	 *
 	 * 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);
+	void (*pre_select)(struct sched *s, void *context);
 	/**
-	 * The postselect hook of \a t.
+	 * The mandatory post select method.
 	 *
-	 * 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.
+	 */
+	int (*post_select)(struct sched *s, void *context);
+	/**
+	 * This pointer is saved when the task is registered. It is passed to
+	 * ->pre_select() and ->post_select(). Usually this is a pointer to the
+	 * struct owned by the caller which contains the task pointer.
 	 */
-	void (*post_select)(struct sched *s, struct task *t);
-	/** Whether this task is in error state. */
-	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;
-	/** Descriptive text and current status of the task. */
-	char status[255];
-	/** If less than zero, the task was notified by another task. */
-	int notification;
+	void *context;
 };
 
 /**
@@ -78,14 +68,17 @@ struct task {
  * scheduler are allowed to block, this value should be accurate enough so that
  * there is no need to call clock_gettime() directly.
  */
-extern struct timeval *now;
+extern const struct timeval *now;
 
-void register_task(struct sched *s, struct task *t);
+struct task *task_register(struct task_info *info, struct sched *s);
 int schedule(struct sched *s);
+void sched_shutdown(struct sched *s);
 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(struct task *t);
+int task_get_notification(const struct task *t);
+int task_status(const struct task *t);
+int task_reap(struct task **tptr);
 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);