timer: change to use time_mono (api break!)

[ccan] / ccan / timer / timer.h

diff --git a/ccan/timer/timer.h b/ccan/timer/timer.h
index 79399cc4e0e006fe7b455dc0cff20890130bea5f..5c40a3bbc1c9979251ad5c2b76ca6a0443c5926a 100644 (file)
--- a/ccan/timer/timer.h
+++ b/ccan/timer/timer.h
@@ -29,9 +29,9 @@ struct timer;
  * Example:
  *     struct timers timeouts;
  *
- *     timers_init(&timeouts, time_now());
+ *     timers_init(&timeouts, time_mono());
  */
-void timers_init(struct timers *timers, struct timeabs start);
+void timers_init(struct timers *timers, struct timemono start);
 
 /**
  * timers_cleanup - free allocations within timers struct.
@@ -45,28 +45,59 @@ void timers_init(struct timers *timers, struct timeabs start);
 void timers_cleanup(struct timers *timers);
 
 /**
- * timer_add - insert a timer.
+ * timer_init - initialize a timer.
+ * @timer: the timer to initialize
+ *
+ * Example:
+ *     struct timer t;
+ *
+ *     timer_init(&t);
+ */
+void timer_init(struct timer *t);
+
+/**
+ * timer_addrel - insert a relative timer.
  * @timers: the struct timers
- * @timer: the (uninitialized) timer to add
- * @when: when @timer expires.
+ * @timer: the (initialized or timer_del'd) timer to add
+ * @rel: when @timer expires (relative).
+ *
+ * This efficiently adds @timer to @timers, to expire @rel (rounded to
+ * TIMER_GRANULARITY nanoseconds) after the current time.  This
+ * is a convenient wrapper around timer_addmono().
+ *
+ * Example:
+ *     // Timeout in 100ms.
+ *     timer_addrel(&timeouts, &t, time_from_msec(100));
+ */
+void timer_addrel(struct timers *timers, struct timer *timer, struct timerel rel);
+
+/**
+ * timer_addmono - insert an absolute timer.
+ * @timers: the struct timers
+ * @timer: the (initialized or timer_del'd) timer to add
+ * @when: when @timer expires (absolute).
  *
  * This efficiently adds @timer to @timers, to expire @when (rounded to
  * TIMER_GRANULARITY nanoseconds).
  *
- * Example:
- *     struct timer t;
+ * Note that if @when is before time_mono(), then it will be set to expire
+ * immediately.
  *
+ * Example:
  *     // Timeout in 100ms.
- *     timer_add(&timeouts, &t, timeabs_add(time_now(), time_from_msec(100)));
+ *     timer_addmono(&timeouts, &t, timemono_add(time_mono(), time_from_msec(100)));
  */
-void timer_add(struct timers *timers, struct timer *timer, struct timeabs when);
+void timer_addmono(struct timers *timers, struct timer *timer,
+                  struct timemono when);
 
 /**
- * timer_del - remove an unexpired timer.
+ * timer_del - remove a timer.
  * @timers: the struct timers
- * @timer: the timer previously added with timer_add()
+ * @timer: the timer
  *
- * This efficiently removes @timer from @timers.
+ * This efficiently removes @timer from @timers, if timer_add() was
+ * called.  It can be called multiple times without bad effect, and
+ * can be called any time after timer_init().
  *
  * Example:
  *     timer_del(&timeouts, &t);
@@ -83,38 +114,35 @@ void timer_del(struct timers *timers, struct timer *timer);
  * timer (rounded to TIMER_GRANULARITY nanoseconds), and returns true.
  *
  * Example:
- *     struct timeabs next = { { (time_t)-1ULL, -1UL } };
+ *     struct timemono next = { { (time_t)-1ULL, -1UL } };
  *     timer_earliest(&timeouts, &next);
  */
-bool timer_earliest(struct timers *timers, struct timeabs *first);
+bool timer_earliest(struct timers *timers, struct timemono *first);
 
 /**
- * timers_expire - update timers structure and remove expired timers.
+ * timers_expire - update timers structure and remove one expire timer.
  * @timers: the struct timers
  * @expire: the current time
- * @list: the list for expired timers.
  *
- * @list will be initialized to the empty list, then all timers added
- * with a @when arg less than or equal to @expire will be added to it in
- * expiry order (within TIMER_GRANULARITY nanosecond precision).
+ * A timers added with a @when arg less than or equal to @expire will be
+ * returned (within TIMER_GRANULARITY nanosecond precision).  If
+ * there are no timers due to expire, NULL is returned.
  *
- * After this, @expire is considered the current time, and adding any
- * timers with @when before this value will be silently changed to
- * adding them with immediate expiration.
+ * After this returns NULL, @expire is considered the current time,
+ * and adding any timers with @when before this value will be silently
+ * changed to adding them with immediate expiration.
  *
  * You should not move @expire backwards, though it need not move
  * forwards.
  *
  * Example:
- *     struct list_head expired;
+ *     struct timer *expired;
  *
- *     timers_expire(&timeouts, time_now(), &expired);
- *     if (!list_empty(&expired))
+ *     while ((expired = timers_expire(&timeouts, time_mono())) != NULL)
  *             printf("Timer expired!\n");
+ *
  */
-void timers_expire(struct timers *timers,
-                  struct timeabs expire,
-                  struct list_head *list);
+struct timer *timers_expire(struct timers *timers, struct timemono expire);
 
 /**
  * timers_check - check timer structure for consistency
@@ -157,8 +185,12 @@ void timers_dump(const struct timers *timers, FILE *fp);
 struct timers {
        /* Far in the future. */
        struct list_head far;
+       /* Current time. */
        uint64_t base;
+       /* Overall first value. */
        uint64_t first;
+       /* First value in each level (plus 1 for far list) */
+       uint64_t firsts[(64 + TIMER_LEVEL_BITS-1) / TIMER_LEVEL_BITS + 1];
 
        struct timer_level *level[(64 + TIMER_LEVEL_BITS-1) / TIMER_LEVEL_BITS];
 };