From 1fa2f614d44986ced299f999d611cf2d2706b84a Mon Sep 17 00:00:00 2001
From: Richard Fuchs <rfuchs@sipwise.com>
Date: Wed, 25 Jul 2012 16:40:07 +0000
Subject: [PATCH] it's inefficient to walk the entire list of poller items
 every second just to look for times which we don't really use. so instead,
 use the linked timers list for this purpose. this is also inefficient for
 timer remove, but since we don't use those times anyway, we don't care.

---
 daemon/poller.c | 50 ++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 37 insertions(+), 13 deletions(-)

diff --git a/daemon/poller.c b/daemon/poller.c
index ab51c26c7..66425dbeb 100644
--- a/daemon/poller.c
+++ b/daemon/poller.c
@@ -44,6 +44,14 @@ static int epoll_events(struct poller_item *i) {
 }
 
 
+static void poller_fd_timer(void *p) {
+	struct poller_item *it = p;
+
+	if (it->timer)
+		it->timer(it->fd, it->ptr);
+}
+
+
 int poller_add_item(struct poller *p, struct poller_item *i) {
 	struct poller_item *ip;
 	unsigned int u;
@@ -77,22 +85,46 @@ int poller_add_item(struct poller *p, struct poller_item *i) {
 	memcpy(ip, i, sizeof(*ip));
 	p->items[i->fd] = ip;
 
+	if (i->timer)
+		poller_timer(p, poller_fd_timer, ip);
+
 	return 0;
 }
 
 
+int poller_find_timer(gconstpointer a, gconstpointer b) {
+	const struct timer_item *it = a;
+	const struct poller_item *x = b;
+
+	if (it->ptr == x)
+		return 0;
+	return 1;
+}
+
+
 int poller_del_item(struct poller *p, int fd) {
+	struct poller_item *it;
+	GList *l;
+
 	if (!p || fd < 0)
 		return -1;
 	if (fd >= p->items_size)
 		return -1;
-	if (!p->items || !p->items[fd])
+	if (!p->items || !(it = p->items[fd]))
 		return -1;
 
 	if (epoll_ctl(p->fd, EPOLL_CTL_DEL, fd, NULL))
 		abort();
 
-	g_slice_free1(sizeof(**p->items), p->items[fd]);
+	if (it->timer) {
+		l = g_list_find_custom(p->timers, it, poller_find_timer);
+		if (l) {
+			g_slice_free1(sizeof(struct timer_item), l->data);
+			p->timers = g_list_delete_link(p->timers, l);
+		}
+	}
+
+	g_slice_free1(sizeof(*it), it);
 	p->items[fd] = NULL;
 
 	return 0;
@@ -128,7 +160,7 @@ int poller_poll(struct poller *p, int timeout) {
 	int ret, i;
 	struct poller_item *it;
 	time_t last;
-	GList *li;
+	GList *li, *ne;
 	struct timer_item *ti;
 	struct epoll_event evs[128], *ev, e;
 
@@ -140,19 +172,11 @@ int poller_poll(struct poller *p, int timeout) {
 	last = p->now;
 	p->now = time(NULL);
 	if (last != p->now) {
-		for (li = p->timers; li; li = li->next) {
+		for (li = p->timers; li; li = ne) {
+			ne = li->next;
 			ti = li->data;
 			ti->func(ti->ptr);
 		}
-
-		for (i = 0; i < p->items_size; i++) {
-			it = p->items[i];
-			if (!it)
-				continue;
-			if (!it->timer)
-				continue;
-			it->timer(it->fd, it->ptr);
-		}
 		return p->items_size;
 	}