improve alarm framework based on suggestions from Max Duempel

7 files changed, 43 insertions, 29 deletions

diff --git a/ChangeLog b/ChangeLog
index 6d4759a..c090831 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -38,6 +38,7 @@ o rename class `buffer' to `queue' which is what it really implements
 o fix logfiles permissions, do not default to umask
 o wake up the daemon iff there are real events to handle instead of polling
 o add support for tagged vlan interfaces in the config file, e.g. eth0.1
+o improve alarm framework based on suggestions from Max Duempel
 
 version 0.9.5 (2007/07/29)
 ------------------------------
diff --git a/include/alarm.h b/include/alarm.h
index 82a1612..fbe34f6 100644
--- a/include/alarm.h
+++ b/include/alarm.h
@@ -10,4 +10,11 @@ struct alarm_list {
 	void			(*function)(struct alarm_list *a, void *data);
 };
 
+static inline void
+set_alarm_expiration(struct alarm_list *t, long tv_sec, long tv_usec)
+{
+	t->tv.tv_sec = tv_sec;
+	t->tv.tv_usec = tv_usec;
+}
+
 #endif
diff --git a/src/alarm.c b/src/alarm.c
index e1d2e24..eb2226b 100644
--- a/src/alarm.c
+++ b/src/alarm.c
@@ -28,16 +28,6 @@
 
 static LIST_HEAD(alarm_list);
 
-void set_alarm_expiration_secs(struct alarm_list *t, unsigned long expires)
-{
-	t->tv.tv_sec = expires;
-}
-
-void set_alarm_expiration_usecs(struct alarm_list *t, unsigned long expires)
-{
-	t->tv.tv_usec = expires;
-}
-
 void set_alarm_function(struct alarm_list *t,
 			void (*fcn)(struct alarm_list *a, void *data))
 {
@@ -51,8 +41,6 @@ void set_alarm_data(struct alarm_list *t, void *data)
 
 void init_alarm(struct alarm_list *t)
 {
-	INIT_LIST_HEAD(&t->head);
-
 	timerclear(&t->tv);
 	t->data 	= 0;
 	t->function 	= NULL;
@@ -77,14 +65,26 @@ void mod_alarm(struct alarm_list *alarm, unsigned long sc, unsigned long usc)
 	struct timeval tv;
 
 	list_del(&alarm->head);
-	INIT_LIST_HEAD(&alarm->head);
 	gettimeofday(&tv, NULL);
 	alarm->tv.tv_sec = tv.tv_sec + sc;
 	alarm->tv.tv_usec = tv.tv_usec + usc;
 	list_add_tail(&alarm->head, &alarm_list);
 }
 
-void do_alarm_run(struct timeval *next_alarm)
+int get_next_alarm(struct timeval *tv, struct timeval *next_alarm)
+{
+	struct list_head *i;
+	struct alarm_list *t;
+
+	list_for_each(i, &alarm_list) {
+		t = (struct alarm_list *) i;
+		timersub(&t->tv, tv, next_alarm);
+		return 1;
+	}
+	return 0;
+}
+
+int do_alarm_run(struct timeval *next_alarm)
 {
 	struct list_head *i, *tmp;
 	struct alarm_list *t;
@@ -97,10 +97,13 @@ void do_alarm_run(struct timeval *next_alarm)
 
 		if (timercmp(&t->tv, &tv, >)) {
 			timersub(&t->tv, &tv, next_alarm);
-			break;
+			return 1;
 		}
 
 		del_alarm(t);
 		t->function(t, t->data);
 	}
+
+	/* check for refreshed alarms to get the next one */
+	return get_next_alarm(&tv, next_alarm);
 }
diff --git a/src/cache_timer.c b/src/cache_timer.c
index c0075f5..02f3ae4 100644
--- a/src/cache_timer.c
+++ b/src/cache_timer.c
@@ -36,7 +36,7 @@ static void timer_add(struct us_conntrack *u, void *data)
 	struct alarm_list *alarm = data;
 
 	init_alarm(alarm);
-	set_alarm_expiration_secs(alarm, CONFIG(cache_timeout));
+	set_alarm_expiration(alarm, CONFIG(cache_timeout), 0);
 	set_alarm_data(alarm, u);
 	set_alarm_function(alarm, timeout);
 	add_alarm(alarm);
diff --git a/src/run.c b/src/run.c
index eab3ad2..3481193 100644
--- a/src/run.c
+++ b/src/run.c
@@ -224,19 +224,20 @@ static int __run(struct timeval *next_alarm)
 
 void run(void)
 {
-	struct timeval next_alarm = {
-		.tv_sec 	= 1,
-		.tv_usec 	= 0
-	};
+	struct timeval next_alarm;
 	struct timeval *next = &next_alarm;
+	struct timeval tv;
 
-	if (CONFIG(flags) & CTD_STATS_MODE)
-		next = NULL;
+	/* initialization: get the first alarm available */
+	gettimeofday(&tv, NULL);
+	get_next_alarm(&tv, next);
 
 	while(1) {
 		if (__run(next)) {
 			sigprocmask(SIG_BLOCK, &STATE(block), NULL);
-			do_alarm_run(next);
+			next = &next_alarm;
+			if (!do_alarm_run(next))
+				next = NULL; /* no next alarms */
 			sigprocmask(SIG_UNBLOCK, &STATE(block), NULL);
 		}
 	}
diff --git a/src/sync-alarm.c b/src/sync-alarm.c
index 632eff2..3d20867 100644
--- a/src/sync-alarm.c
+++ b/src/sync-alarm.c
@@ -31,8 +31,9 @@ static void refresher(struct alarm_list *a, void *data)
 	debug_ct(u->ct, "persistence update");
 
 	init_alarm(a);
-	set_alarm_expiration_secs(a, random() % CONFIG(refresh) + 1);
-	set_alarm_expiration_usecs(a, random() % 999999 + 1);
+	set_alarm_expiration(a, 
+			     random() % CONFIG(refresh) + 1,
+			     random() % 999999 + 1);
 
 	set_alarm_data(a, u);
 	set_alarm_function(a, refresher);
@@ -48,8 +49,9 @@ static void cache_alarm_add(struct us_conntrack *u, void *data)
 	struct alarm_list *alarm = data;
 
 	init_alarm(alarm);
-	set_alarm_expiration_secs(alarm, random() % CONFIG(refresh) + 1);
-	set_alarm_expiration_usecs(alarm, random() % 999999 + 1);
+	set_alarm_expiration(alarm, 
+			     random() % CONFIG(refresh) + 1,
+			     random() % 999999 + 1);
 	set_alarm_data(alarm, u);
 	set_alarm_function(alarm, refresher);
 	add_alarm(alarm);
diff --git a/src/sync-ftfw.c b/src/sync-ftfw.c
index ac1b8b6..125e82e 100644
--- a/src/sync-ftfw.c
+++ b/src/sync-ftfw.c
@@ -88,7 +88,7 @@ static void do_alive_alarm(struct alarm_list *a, void *data)
 	tx_queue_add_ctlmsg(NET_F_ALIVE, 0, 0);
 
 	init_alarm(&alive_alarm);
-	set_alarm_expiration_secs(&alive_alarm, 1);
+	set_alarm_expiration(&alive_alarm, 1, 0);
 	set_alarm_function(&alive_alarm, do_alive_alarm);
 	add_alarm(&alive_alarm);
 }
@@ -112,7 +112,7 @@ static int ftfw_init()
 
 	/* XXX: alive message expiration configurable */
 	init_alarm(&alive_alarm);
-	set_alarm_expiration_secs(&alive_alarm, 1);
+	set_alarm_expiration(&alive_alarm, 1, 0);
 	set_alarm_function(&alive_alarm, do_alive_alarm);
 	add_alarm(&alive_alarm);