Fix bug #133 - Kqueue backend crash (BSD/OSX)

src/network/kqueue.c

@@ -32,19 +32,29 @@ struct net_connection_kqueue
 	NET_CON_STRUCT_COMMON
 	struct kevent ev_r;
 	struct kevent ev_w;
+	int change;
 };
 
 struct net_backend_kqueue
 {
 	int kqfd;
 	struct net_connection_kqueue** conns;
-	struct kevent** changes;
+	struct kevent* changes;
-	size_t nchanges;
+	int* change_list;
+	size_t change_list_len;
 	struct kevent events[KQUEUE_EVBUFFER];
 	struct net_backend_common* common;
 };
 
+#define CHANGE_ACTION_ADD       0x0001
+#define CHANGE_ACTION_MOD       0x0002
+#define CHANGE_ACTION_DEL       0x0004
+#define CHANGE_OP_WANT_READ     0x0100
+#define CHANGE_OP_WANT_WRITE    0x0200
+
 static void net_backend_set_handlers(struct net_backend_handler* handler);
+static void add_change(struct net_backend_kqueue* backend, struct net_connection_kqueue* con, int actions);
+static size_t create_change_list(struct net_backend_kqueue* backend);
 
 const char* net_backend_name_kqueue()
 {
@@ -56,12 +66,13 @@ int net_backend_poll_kqueue(struct net_backend* data, int ms)
 	int res;
 	struct timespec tspec = { 0, };
 	struct net_backend_kqueue* backend = (struct net_backend_kqueue*) data;
+	size_t changes;
 
 	tspec.tv_sec = (ms / 1000);
 	tspec.tv_nsec = ((ms % 1000) * 1000000);
 
-	res = kevent(backend->kqfd, *backend->changes, backend->nchanges, backend->events, KQUEUE_EVBUFFER, &tspec);
+	changes = create_change_list(backend);
-	backend->nchanges = 0;
+	res = kevent(backend->kqfd, backend->changes, changes, backend->events, KQUEUE_EVBUFFER, &tspec);
 
 	if (res == -1 && errno == EINTR)
 		return 0;
@@ -76,12 +87,14 @@ void net_backend_process_kqueue(struct net_backend* data, int res)
 	for (n = 0; n < res; n++)
 	{
 		struct net_connection_kqueue* con = (struct net_connection_kqueue*) backend->events[n].udata;
-		int ev = -1;
+		if (con && con->sd >= 0 && backend->conns[con->sd])
+		{
+			int ev = 0;
 			if (backend->events[n].filter == EVFILT_READ) ev = NET_EVENT_READ;
 			else if (backend->events[n].filter == EVFILT_WRITE) ev = NET_EVENT_WRITE;
-		if (con)
 			net_con_callback((struct net_connection*) con, ev);
 		}
+	}
 }
 
 struct net_connection* net_con_create_kqueue(struct net_backend* data)
@@ -102,58 +115,37 @@ void net_con_initialize_kqueue(struct net_backend* data, struct net_connection*
 
 void net_con_backend_add_kqueue(struct net_backend* data, struct net_connection* con_, int events)
 {
-	unsigned short flags_r = EV_ADD;
-	unsigned short flags_w = EV_ADD;
 	struct net_backend_kqueue* backend = (struct net_backend_kqueue*) data;
 	struct net_connection_kqueue* con = (struct net_connection_kqueue*) con_;
+	int operation;
 
 	backend->conns[con->sd] = con;
 
-	if (events & NET_EVENT_READ)
+	operation = CHANGE_ACTION_ADD;
-	    flags_r |= EV_ENABLE;
-	else
-	    flags_r |= EV_DISABLE;
 
-	EV_SET(&con->ev_r, con->sd, EVFILT_READ, flags_r, 0, 0, con);
+	if (events & NET_EVENT_READ)
-	backend->changes[backend->nchanges++] = &con->ev_r;
+	  operation |= CHANGE_OP_WANT_READ;
 
 	if (events & NET_EVENT_WRITE)
-	    flags_w |= EV_ENABLE;
+	  operation |= CHANGE_OP_WANT_WRITE;
-	else
-	    flags_w |= EV_DISABLE;
 
-	EV_SET(&con->ev_w, con->sd, EVFILT_WRITE, flags_w, 0, 0, con);
+	add_change(backend, con, operation);
-	backend->changes[backend->nchanges++] = &con->ev_w;
 }
 
 void net_con_backend_mod_kqueue(struct net_backend* data, struct net_connection* con_, int events)
 {
-	unsigned short flags_r = 0;
-	unsigned short flags_w = 0;
 	struct net_backend_kqueue* backend = (struct net_backend_kqueue*) data;
 	struct net_connection_kqueue* con = (struct net_connection_kqueue*) con_;
 
-	if (events & NET_EVENT_READ)
+	int operation = CHANGE_ACTION_ADD;
-	    flags_r |= EV_ENABLE;
-	else
-	    flags_r |= EV_DISABLE;
 
-	if (!(con->ev_r.flags & flags_r))
+	if (events & NET_EVENT_READ)
-	{
+	  operation |= CHANGE_OP_WANT_READ;
-	    EV_SET(&con->ev_r, con->sd, EVFILT_READ, flags_r, 0, 0, con);
-	    backend->changes[backend->nchanges++] = &con->ev_r;
-	}
 
 	if (events & NET_EVENT_WRITE)
-	    flags_r |= EV_ENABLE;
+	  operation |= CHANGE_OP_WANT_WRITE;
-	else
-	    flags_r |= EV_DISABLE;
 
-	if (!(con->ev_w.flags & flags_w))
+	add_change(backend, con, operation);
-	{
-	    EV_SET(&con->ev_w, con->sd, EVFILT_WRITE, flags_w, 0, 0, con);
-	    backend->changes[backend->nchanges++] = &con->ev_w;
-	}
 }
 
 void net_con_backend_del_kqueue(struct net_backend* data, struct net_connection* con_)
@@ -162,11 +154,8 @@ void net_con_backend_del_kqueue(struct net_backend* data, struct net_connection*
 	struct net_connection_kqueue* con = (struct net_connection_kqueue*) con_;
 
 	/* No need to remove it from the kqueue filter, the kqueue man page says
-	   it is automatically removed when the descriptor is closed. */
+	   it is automatically removed when the descriptor is closed... */
-	EV_SET(&con->ev_r, con->sd, EVFILT_READ,  EV_DELETE, 0, 0, 0);
+	add_change(backend, con, CHANGE_ACTION_DEL);
-	backend->changes[backend->nchanges++] = &con->ev_r;
-	EV_SET(&con->ev_w, con->sd, EVFILT_WRITE, EV_DELETE, 0, 0, 0);
-	backend->changes[backend->nchanges++] = &con->ev_w;
 
 	// Unmap the socket descriptor.
 	backend->conns[con->sd] = 0;
@@ -178,6 +167,7 @@ void net_backend_shutdown_kqueue(struct net_backend* data)
 	close(backend->kqfd);
 	hub_free(backend->conns);
 	hub_free(backend->changes);
+	hub_free(backend->change_list);
 	hub_free(backend);
 }
 
@@ -197,8 +187,8 @@ struct net_backend* net_backend_init_kqueue(struct net_backend_handler* handler,
 	}
 
 	backend->conns = hub_malloc_zero(sizeof(struct net_connection_kqueue*) * common->max);
-	backend->conns = hub_malloc_zero(sizeof(struct net_connection_kqueue*) * common->max);
+	backend->changes = hub_malloc_zero(sizeof(struct kevent) * common->max * 2);
-	backend->changes = hub_malloc_zero(sizeof(struct kevent*) * common->max * 2);
+	backend->change_list = hub_malloc_zero(sizeof(int) * common->max);
 	backend->common = common;
 
 	net_backend_set_handlers(handler);
@@ -218,4 +208,71 @@ static void net_backend_set_handlers(struct net_backend_handler* handler)
 	handler->con_del = net_con_backend_del_kqueue;
 }
 
+static void add_change(struct net_backend_kqueue* backend, struct net_connection_kqueue* con, int actions)
+{
+	if (actions && !con->change)
+	{
+		backend->change_list[backend->change_list_len++] = con->sd;
+		con->change = actions;
+	}
+}
+
+static size_t create_change_list(struct net_backend_kqueue* backend)
+{
+	size_t n = 0;
+	size_t changes = 0;
+	int sd;
+	struct net_connection_kqueue* con;
+	unsigned short flags_r = 0;
+	unsigned short flags_w = 0;
+
+	for (; n < backend->change_list_len; n++)
+	{
+		sd = backend->change_list[n];
+		con = backend->conns[sd];
+		if (con)
+		{
+			flags_r = 0;
+			flags_w = 0;
+
+			if (con->change & CHANGE_ACTION_ADD)
+			{
+				flags_r |= EV_ADD;
+				flags_w |= EV_ADD;
+			}
+
+			if (con->change & CHANGE_OP_WANT_READ)
+				flags_r |= EV_ENABLE;
+			else
+				flags_r |= EV_DISABLE;
+
+			if (con->change & CHANGE_OP_WANT_WRITE)
+				flags_w |= EV_ENABLE;
+			else
+				flags_w |= EV_DISABLE;
+
+			if (con->ev_r.flags != flags_r)
+			{
+				EV_SET(&con->ev_r, sd, EVFILT_READ, flags_r, 0, 0, con);
+				memcpy(&backend->changes[changes++], &con->ev_r, sizeof(struct kevent));
+			}
+
+			if (con->ev_w.flags != flags_w)
+			{
+				EV_SET(&con->ev_w, sd, EVFILT_WRITE, flags_w, 0, 0, con);
+				memcpy(&backend->changes[changes++], &con->ev_w, sizeof(struct kevent));
+			}
+
+			con->change = 0;
+		}
+		else
+		{
+			EV_SET(&backend->changes[changes++], sd, EVFILT_READ, EV_DELETE, 0, 0, 0);
+			EV_SET(&backend->changes[changes++], sd, EVFILT_READ, EV_DELETE, 0, 0, 0);
+		}
+	}
+	backend->change_list_len = 0;
+	return changes;
+}
+
 #endif /* USE_KQUEUE */