Switch out custom wakeup system for timerfd.

adsbus/outgoing.c

@@ -111,7 +111,7 @@ static void outgoing_connect_result(struct outgoing *outgoing, int result) {
 
 		default:
 			LOG(outgoing->id, "Can't connect to %s/%s: %s", hbuf, sbuf, strerror(result));
-			peer_close(&outgoing->peer);
+			assert(!close(outgoing->peer.fd));
 			outgoing->addr = outgoing->addr->ai_next;
 			// Tail recursion :/
 			outgoing_connect_next(outgoing);

adsbus/peer.c

@@ -10,7 +10,6 @@
 
 #include "log.h"
 #include "server.h"
-#include "wakeup.h"
 
 #include "peer.h"
 
@@ -118,7 +117,7 @@ void peer_loop() {
 		}
 #define MAX_EVENTS 10
 		struct epoll_event events[MAX_EVENTS];
-		int delay = list_is_empty(&peer_always_trigger_head) ? wakeup_get_delay() : 0;
+		int delay = list_is_empty(&peer_always_trigger_head) ? -1 : 0;
 		int nfds = epoll_wait(peer_epoll_fd, events, MAX_EVENTS, delay);
 		if (nfds == -1 && errno == EINTR) {
 			continue;
@@ -136,7 +135,5 @@ void peer_loop() {
 				peer_call(iter);
 			}
 		}
-
-		wakeup_dispatch();
 	}
 }

adsbus/wakeup.c

@@ -1,83 +1,69 @@
 #include <assert.h>
 #include <limits.h>
 #include <stdlib.h>
-#include <time.h>
+#include <sys/timerfd.h>
+#include <unistd.h>
 
 #include "peer.h"
 #include "rand.h"
 
 #include "wakeup.h"
 
-struct wakeup_entry {
-	int fd;
-	uint64_t absolute_time_ms;
-	struct peer *peer;
+struct wakeup {
+	struct peer peer;
+	struct peer *inner_peer;
 	struct list_head wakeup_list;
 };
 
 static struct list_head wakeup_head = LIST_HEAD_INIT(wakeup_head);
 
-static uint64_t wakeup_get_time_ms() {
-	struct timespec tp;
-	assert(!clock_gettime(CLOCK_MONOTONIC_COARSE, &tp));
-#define MS_PER_S UINT64_C(1000)
-#define NS_PER_MS UINT64_C(1000000)
-	assert(tp.tv_sec >= 0);
-	assert(tp.tv_nsec >= 0);
-	return ((uint64_t) tp.tv_sec * MS_PER_S) + ((uint64_t) tp.tv_nsec / NS_PER_MS);
+static void wakeup_handler(struct peer *peer) {
+	struct wakeup *wakeup = container_of(peer, struct wakeup, peer);
+
+	uint64_t events;
+	assert(read(wakeup->peer.fd, &events, sizeof(events)) == sizeof(events));
+	assert(events == 1);
+
+	peer_close(&wakeup->peer);
+	peer_call(wakeup->inner_peer);
+	list_del(&wakeup->wakeup_list);
+	free(wakeup);
 }
 
 void wakeup_init() {
 }
 
 void wakeup_cleanup() {
-	struct wakeup_entry *iter, *next;
+	struct wakeup *iter, *next;
 	list_for_each_entry_safe(iter, next, &wakeup_head, wakeup_list) {
 		free(iter);
 	}
 }
 
-int wakeup_get_delay() {
-	if (list_is_empty(&wakeup_head)) {
-		return -1;
-	}
-	uint64_t now = wakeup_get_time_ms();
-	struct wakeup_entry *next_to_fire = list_entry(wakeup_head.next, struct wakeup_entry, wakeup_list);
-	if (next_to_fire->absolute_time_ms > now) {
-		uint64_t delta = next_to_fire->absolute_time_ms - now;
-		assert(delta < INT_MAX);
-		return (int) delta;
-	} else {
-		return 0;
-	}
-}
-
-void wakeup_dispatch() {
-	uint64_t now = wakeup_get_time_ms();
-	struct wakeup_entry *iter, *next;
-	list_for_each_entry_safe(iter, next, &wakeup_head, wakeup_list) {
-		if (iter->absolute_time_ms > now) {
-			break;
-		}
-		peer_call(iter->peer);
-		list_del(&iter->wakeup_list);
-		free(iter);
-	}
-}
-
 void wakeup_add(struct peer *peer, uint32_t delay_ms) {
-	struct wakeup_entry *entry = malloc(sizeof(*entry));
-	entry->absolute_time_ms = wakeup_get_time_ms() + delay_ms;
-	entry->peer = peer;
+	struct wakeup *wakeup = malloc(sizeof(*wakeup));
+	wakeup->inner_peer = peer;
+	list_add(&wakeup->wakeup_list, &wakeup_head);
 
-	struct wakeup_entry *iter, *next;
-	list_for_each_entry_safe(iter, next, &wakeup_head, wakeup_list) {
-		if (iter->absolute_time_ms > entry->absolute_time_ms) {
-			list_add(&entry->wakeup_list, &iter->wakeup_list);
-			return;
-		}
-	}
-	list_add(&entry->wakeup_list, &wakeup_head);
+	wakeup->peer.fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
+	assert(wakeup->peer.fd >= 0);
+
+#define MS_PER_S UINT64_C(1000)
+#define NS_PER_MS UINT64_C(1000000)
+	const struct itimerspec ts = {
+		.it_interval = {
+			.tv_sec = 0,
+			.tv_nsec = 0,
+		},
+		.it_value = {
+			.tv_sec = delay_ms / MS_PER_S,
+			.tv_nsec = (delay_ms % MS_PER_S) * NS_PER_MS,
+		},
+	};
+	assert(!timerfd_settime(wakeup->peer.fd, 0, &ts, NULL));
+
+	wakeup->peer.event_handler = wakeup_handler;
+	peer_epoll_add(&wakeup->peer, EPOLLIN);
 }
 
 #define RETRY_MIN_MS 2000

adsbus/wakeup.h

@@ -6,7 +6,5 @@ struct peer;
 
 void wakeup_init(void);
 void wakeup_cleanup(void);
-int wakeup_get_delay(void);
-void wakeup_dispatch(void);
 void wakeup_add(struct peer *, uint32_t);
 uint32_t wakeup_get_retry_delay_ms(uint32_t);