revert change to call kevent immediately.

tcpbench (at a minimum) relies on the old behavior of changes all happening
after all event handlers run. in particular, it resets the event for the
listening socket *before* calling accept(), when it is still readable.
kevent then (correctly) says it is readable on the next go through the loop.
silly, subtle, and stupid.
problem reported by kettenis

1 files changed, 65 insertions, 6 deletions

diff --git a/lib/libevent/kqueue.c b/lib/libevent/kqueue.c
index 04ba3289af3..82a0c7e6f17 100644
--- a/lib/libevent/kqueue.c
+++ b/lib/libevent/kqueue.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kqueue.c,v 1.37 2015/12/16 20:12:31 tedu Exp $	*/
+/*	$OpenBSD: kqueue.c,v 1.38 2015/12/25 17:10:05 tedu Exp $	*/
 
 /*
  * Copyright 2000-2002 Niels Provos <provos@citi.umich.edu>
@@ -51,6 +51,8 @@
 #define NEVENT		64
 
 struct kqop {
+	struct kevent *changes;
+	int nchanges;
 	struct kevent *events;
 	struct event_list evsigevents[NSIG];
 	int nevents;
@@ -62,6 +64,7 @@ static void *kq_init	(struct event_base *);
 static int kq_add	(void *, struct event *);
 static int kq_del	(void *, struct event *);
 static int kq_dispatch	(struct event_base *, void *, struct timeval *);
+static int kq_insert	(struct kqop *, struct kevent *);
 static void kq_dealloc (struct event_base *, void *);
 
 const struct eventop kqops = {
@@ -100,8 +103,14 @@ kq_init(struct event_base *base)
 	kqueueop->pid = getpid();
 
 	/* Initalize fields */
+	kqueueop->changes = calloc(NEVENT, sizeof(struct kevent));
+	if (kqueueop->changes == NULL) {
+		free (kqueueop);
+		return (NULL);
+	}
 	kqueueop->events = calloc(NEVENT, sizeof(struct kevent));
 	if (kqueueop->events == NULL) {
+		free (kqueueop->changes);
 		free (kqueueop);
 		return (NULL);
 	}
@@ -115,6 +124,51 @@ kq_init(struct event_base *base)
 	return (kqueueop);
 }
 
+static int
+kq_insert(struct kqop *kqop, struct kevent *kev)
+{
+	int nevents = kqop->nevents;
+
+	if (kqop->nchanges == nevents) {
+		struct kevent *newchange;
+		struct kevent *newresult;
+
+		nevents *= 2;
+
+		newchange = reallocarray(kqop->changes,
+		    nevents, sizeof(struct kevent));
+		if (newchange == NULL) {
+			event_warn("%s: malloc", __func__);
+			return (-1);
+		}
+		kqop->changes = newchange;
+
+		newresult = reallocarray(kqop->events,
+		    nevents, sizeof(struct kevent));
+
+		/*
+		 * If we fail, we don't have to worry about freeing,
+		 * the next realloc will pick it up.
+		 */
+		if (newresult == NULL) {
+			event_warn("%s: malloc", __func__);
+			return (-1);
+		}
+		kqop->events = newresult;
+
+		kqop->nevents = nevents;
+	}
+
+	memcpy(&kqop->changes[kqop->nchanges++], kev, sizeof(struct kevent));
+
+	event_debug(("%s: fd %d %s%s",
+		__func__, (int)kev->ident,
+		kev->filter == EVFILT_READ ? "EVFILT_READ" : "EVFILT_WRITE",
+		kev->flags == EV_DELETE ? " (del)" : ""));
+
+	return (0);
+}
+
 static void
 kq_sighandler(int sig)
 {
@@ -125,6 +179,7 @@ static int
 kq_dispatch(struct event_base *base, void *arg, struct timeval *tv)
 {
 	struct kqop *kqop = arg;
+	struct kevent *changes = kqop->changes;
 	struct kevent *events = kqop->events;
 	struct event *ev;
 	struct timespec ts, *ts_p = NULL;
@@ -135,7 +190,9 @@ kq_dispatch(struct event_base *base, void *arg, struct timeval *tv)
 		ts_p = &ts;
 	}
 
-	res = kevent(kqop->kq, NULL, 0, events, kqop->nevents, ts_p);
+	res = kevent(kqop->kq, changes, kqop->nchanges,
+	    events, kqop->nevents, ts_p);
+	kqop->nchanges = 0;
 	if (res == -1) {
 		if (errno != EINTR) {
 			event_warn("kevent");
@@ -269,7 +326,7 @@ kq_add(void *arg, struct event *ev)
 			kev.flags |= EV_ONESHOT;
 		kev.udata = ev;
 
-		if (kevent(kqop->kq, &kev, 1, NULL, 0, NULL) == -1)
+		if (kq_insert(kqop, &kev) == -1)
 			return (-1);
 
 		ev->ev_flags |= EVLIST_X_KQINKERNEL;
@@ -284,7 +341,7 @@ kq_add(void *arg, struct event *ev)
 			kev.flags |= EV_ONESHOT;
 		kev.udata = ev;
 
-		if (kevent(kqop->kq, &kev, 1, NULL, 0, NULL) == -1)
+		if (kq_insert(kqop, &kev) == -1)
 			return (-1);
 
 		ev->ev_flags |= EVLIST_X_KQINKERNEL;
@@ -335,7 +392,7 @@ kq_del(void *arg, struct event *ev)
 		kev.filter = EVFILT_READ;
 		kev.flags = EV_DELETE;
 
-		if (kevent(kqop->kq, &kev, 1, NULL, 0, NULL) == -1)
+		if (kq_insert(kqop, &kev) == -1)
 			return (-1);
 
 		ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
@@ -347,7 +404,7 @@ kq_del(void *arg, struct event *ev)
 		kev.filter = EVFILT_WRITE;
 		kev.flags = EV_DELETE;
 
-		if (kevent(kqop->kq, &kev, 1, NULL, 0, NULL) == -1)
+		if (kq_insert(kqop, &kev) == -1)
 			return (-1);
 
 		ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
@@ -363,6 +420,8 @@ kq_dealloc(struct event_base *base, void *arg)
 
 	evsignal_dealloc(base);
 
+	if (kqop->changes)
+		free(kqop->changes);
 	if (kqop->events)
 		free(kqop->events);
 	if (kqop->kq >= 0 && kqop->pid == getpid())