Convert the window pane (pty master side) fd over to use a bufferevent.

The evbuffer API is very similar to the existing tmux buffer API so this was
remarkably painless. Not many possible ways to do it, I suppose.

cmd-paste-buffer.c

@@ -27,7 +27,7 @@
  */
 
 int	cmd_paste_buffer_exec(struct cmd *, struct cmd_ctx *);
-void	cmd_paste_buffer_lf2cr(struct buffer *, const char *, size_t);
+void	cmd_paste_buffer_lf2cr(struct window_pane *, const char *, size_t);
 
 const struct cmd_entry cmd_paste_buffer_entry = {
 	"paste-buffer", "pasteb",
@@ -65,9 +65,9 @@ cmd_paste_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 	if (pb != NULL && *pb->data != '\0') {
 		/* -r means raw data without LF->CR conversion. */
 		if (data->chflags & CMD_CHFLAG('r'))
-			buffer_write(wp->out, pb->data, pb->size);
+			bufferevent_write(wp->event, pb->data, pb->size);
 		else
-			cmd_paste_buffer_lf2cr(wp->out, pb->data, pb->size);
+			cmd_paste_buffer_lf2cr(wp, pb->data, pb->size);
 	}
 
 	/* Delete the buffer if -d. */
@@ -83,18 +83,18 @@ cmd_paste_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 
 /* Add bytes to a buffer but change every '\n' to '\r'. */
 void
-cmd_paste_buffer_lf2cr(struct buffer *b, const char *data, size_t size)
+cmd_paste_buffer_lf2cr(struct window_pane *wp, const char *data, size_t size)
 {
 	const char	*end = data + size;
 	const char	*lf;
 
 	while ((lf = memchr(data, '\n', end - data)) != NULL) {
 		if (lf != data)
-			buffer_write(b, data, lf - data);
-		buffer_write8(b, '\r');
+			bufferevent_write(wp->event, data, lf - data);
+		bufferevent_write(wp->event, "\r", 1);
 		data = lf + 1;
 	}
 
 	if (end != data)
-		buffer_write(b, data, end - data);
+		bufferevent_write(wp->event, data, end - data);
 }

cmd-pipe-pane.c

@@ -113,7 +113,7 @@ cmd_pipe_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 		close(pipe_fd[1]);
 
 		wp->pipe_fd = pipe_fd[0];
-		wp->pipe_off = BUFFER_USED(wp->in);
+		wp->pipe_off = EVBUFFER_LENGTH(wp->event->input);
 		
 		wp->pipe_event = bufferevent_new(wp->pipe_fd,
 		    NULL, NULL, cmd_pipe_pane_error_callback, wp);

input-keys.c

@@ -163,6 +163,7 @@ input_key(struct window_pane *wp, int key)
 	u_int			i;
 	size_t			dlen;
 	char		       *out;
+	u_char			ch;
 
 	log_debug2("writing key 0x%x", key);
 
@@ -172,8 +173,10 @@ input_key(struct window_pane *wp, int key)
 	 */
 	if (key != KEYC_NONE && (key & ~KEYC_ESCAPE) < 0x100) {
 		if (key & KEYC_ESCAPE)
-			buffer_write8(wp->out, '\033');
-		buffer_write8(wp->out, (uint8_t) (key & ~KEYC_ESCAPE));
+			ch = '\033';
+		else
+			ch = key & ~KEYC_ESCAPE;
+		bufferevent_write(wp->event, &ch, 1);
 		return;
 	}
 
@@ -183,7 +186,7 @@ input_key(struct window_pane *wp, int key)
 	 */
 	if (options_get_number(&wp->window->options, "xterm-keys")) {
 		if ((out = xterm_keys_lookup(key)) != NULL) {
-			buffer_write(wp->out, out, strlen(out));
+			bufferevent_write(wp->event, out, strlen(out));
 			xfree(out);
 			return;
 		}
@@ -214,18 +217,19 @@ input_key(struct window_pane *wp, int key)
 
 	/* Prefix a \033 for escape. */
 	if (key & KEYC_ESCAPE)
-		buffer_write8(wp->out, '\033');
-	buffer_write(wp->out, ike->data, dlen);
+		bufferevent_write(wp->event, "\033", 1);
+	bufferevent_write(wp->event, ike->data, dlen);
 }
 
 /* Translate mouse and output. */
 void
 input_mouse(struct window_pane *wp, struct mouse_event *m)
 {
+	char	out[8];
+
 	if (wp->screen->mode & MODE_MOUSE) {
-		buffer_write(wp->out, "\033[M", 3);
-		buffer_write8(wp->out, m->b + 32);
-		buffer_write8(wp->out, m->x + 33);
-		buffer_write8(wp->out, m->y + 33);
+		xsnprintf(out, sizeof out,
+		    "\033[M%c%c%c", m->b + 32, m->x + 33, m->y + 33);
+		bufferevent_write(wp->event, out, strlen(out));
 	}
 }

input.c

@@ -256,12 +256,12 @@ input_parse(struct window_pane *wp)
 	struct input_ctx	*ictx = &wp->ictx;
 	u_char			 ch;
 
-	if (BUFFER_USED(wp->in) == ictx->was)
+	if (EVBUFFER_LENGTH(wp->event->input) == ictx->was)
 		return;
 	wp->window->flags |= WINDOW_ACTIVITY;
 
-	ictx->buf = BUFFER_OUT(wp->in);
-	ictx->len = BUFFER_USED(wp->in);
+	ictx->buf = EVBUFFER_DATA(wp->event->input);
+	ictx->len = EVBUFFER_LENGTH(wp->event->input);
 	ictx->off = 0;
 
 	ictx->wp = wp;
@@ -278,8 +278,8 @@ input_parse(struct window_pane *wp)
 
 	screen_write_stop(&ictx->ctx);
 
-	buffer_remove(wp->in, ictx->len);
-	ictx->was = BUFFER_USED(wp->in);
+	evbuffer_drain(wp->event->input, ictx->len);
+	ictx->was = EVBUFFER_LENGTH(wp->event->input);
 }
 
 void
@@ -932,7 +932,8 @@ input_handle_sequence_cbt(struct input_ctx *ictx)
 void
 input_handle_sequence_da(struct input_ctx *ictx)
 {
-	uint16_t	n;
+	struct window_pane	*wp = ictx->wp;
+	uint16_t		 n;
 
 	if (ictx->private != '\0')
 		return;
@@ -944,7 +945,7 @@ input_handle_sequence_da(struct input_ctx *ictx)
 	if (n != 0)
 		return;
 	
-	buffer_write(ictx->wp->out, "\033[?1;2c", (sizeof "\033[?1;2c") - 1);
+	bufferevent_write(wp->event, "\033[?1;2c", (sizeof "\033[?1;2c") - 1);
 }
 
 void
@@ -1314,9 +1315,10 @@ input_handle_sequence_rm(struct input_ctx *ictx)
 void
 input_handle_sequence_dsr(struct input_ctx *ictx)
 {
-	struct screen  *s = ictx->ctx.s;
-	uint16_t	n;
-	char		reply[32];
+	struct window_pane	*wp = ictx->wp;
+	struct screen		*s = ictx->ctx.s;
+	uint16_t		 n;
+	char			reply[32];
 
 	if (ARRAY_LENGTH(&ictx->args) > 1)
 		return;
@@ -1329,7 +1331,7 @@ input_handle_sequence_dsr(struct input_ctx *ictx)
 			xsnprintf(reply, sizeof reply,
 			    "\033[%u;%uR", s->cy + 1, s->cx + 1);
 			log_debug("cursor request, reply: %s", reply);
-			buffer_write(ictx->wp->out, reply, strlen(reply));
+			bufferevent_write(wp->event, reply, strlen(reply));
 			break;
 		}
 	}

server-window.c

@@ -30,35 +30,6 @@ int	server_window_check_content(
 	    struct session *, struct window *, struct window_pane *);
 void	server_window_check_alive(struct window *);
 
-/* Register windows for poll. */
-void
-server_window_prepare(void)
-{
-	struct window		*w;
-	struct window_pane	*wp;
-	u_int		 	 i;
-	int			 events;
-
-	for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
-		if ((w = ARRAY_ITEM(&windows, i)) == NULL)
-			continue;
-
-		TAILQ_FOREACH(wp, &w->panes, entry) {	
-			if (wp->fd == -1)
-				continue;
-			events = 0;
-			if (!server_window_backoff(wp))
-				events |= EV_READ;
-			if (BUFFER_USED(wp->out) > 0)
-				events |= EV_WRITE;
-			event_del(&wp->event);
-			event_set(&wp->event,
-			    wp->fd, events, server_window_callback, wp);
-			event_add(&wp->event, NULL);
-		}
-	}
-}
-
 /* Check if this window should suspend reading. */
 int
 server_window_backoff(struct window_pane *wp)
@@ -84,24 +55,6 @@ server_window_backoff(struct window_pane *wp)
 	return (0);
 }
 
-/* Process a single window pane event. */
-void
-server_window_callback(int fd, short events, void *data)
-{
-	struct window_pane	*wp = data;
-
-	if (wp->fd == -1)
-		return;
-
-	if (fd == wp->fd) {
-		if (buffer_poll(fd, events, wp->in, wp->out) != 0) {
-			close(wp->fd);
-			wp->fd = -1;
-		} else
-			window_pane_parse(wp);
-	}
-}
-
 /* Window functions that need to happen every loop. */
 void
 server_window_loop(void)
@@ -116,6 +69,13 @@ server_window_loop(void)
 		if (w == NULL)
 			continue;
 
+		TAILQ_FOREACH(wp, &w->panes, entry) {
+			if (server_window_backoff(wp))
+				bufferevent_disable(wp->event, EV_READ);
+			else
+				bufferevent_enable(wp->event, EV_READ);
+		}
+
 		for (j = 0; j < ARRAY_LENGTH(&sessions); j++) {
 			s = ARRAY_ITEM(&sessions, j);
 			if (s == NULL || !session_has(s, w))

server.c

@@ -214,7 +214,6 @@ server_loop(void)
 	while (!server_should_shutdown()) {
 		server_update_socket();
 
-		server_window_prepare();
 		server_client_prepare();
 
 		event_loopexit(&tv);

tmux.h

@@ -798,9 +798,7 @@ struct window_pane {
 	char		 tty[TTY_NAME_MAX];
 
 	int		 fd;
-	struct event	 event;
-	struct buffer	*in;
-	struct buffer	*out;
+	struct bufferevent *event;
 
 	struct input_ctx ictx;
 
@@ -1586,8 +1584,6 @@ void	 server_client_callback(int, short, void *);
 void	 server_client_loop(void);
 
 /* server-window.c */
-void	 server_window_prepare(void);
-void	 server_window_callback(int, short, void *);
 void	 server_window_loop(void);
 
 /* server-fn.c */

window.c

@@ -56,6 +56,9 @@
 /* Global window list. */
 struct windows windows;
 
+void	window_pane_read_callback(struct bufferevent *, void *);
+void	window_pane_error_callback(struct bufferevent *, short, void *);
+
 RB_GENERATE(winlinks, winlink, entry, winlink_cmp);
 
 int
@@ -412,8 +415,7 @@ window_pane_create(struct window *w, u_int sx, u_int sy, u_int hlimit)
 	wp->cwd = NULL;
 
 	wp->fd = -1;
-	wp->in = buffer_create(BUFSIZ);
-	wp->out = buffer_create(BUFSIZ);
+	wp->event = NULL;
 
 	wp->mode = NULL;
 
@@ -442,8 +444,10 @@ window_pane_create(struct window *w, u_int sx, u_int sy, u_int hlimit)
 void
 window_pane_destroy(struct window_pane *wp)
 {
-	if (wp->fd != -1)
+	if (wp->fd != -1) {
 		close(wp->fd);
+		bufferevent_free(wp->event);
+	}
 
 	input_free(wp);
 
@@ -457,10 +461,6 @@ window_pane_destroy(struct window_pane *wp)
 		bufferevent_free(wp->pipe_event);
 	}
 
-	buffer_destroy(wp->in);
-	buffer_destroy(wp->out);
-	event_del(&wp->event);
-
 	if (wp->cwd != NULL)
 		xfree(wp->cwd);
 	if (wp->shell != NULL)
@@ -484,8 +484,10 @@ window_pane_spawn(struct window_pane *wp, const char *cmd, const char *shell,
 	struct termios		 tio2;
 	u_int		 	 i;
 
-	if (wp->fd != -1)
+	if (wp->fd != -1) {
 		close(wp->fd);
+		bufferevent_free(wp->event);
+	}
 	if (cmd != NULL) {
 		if (wp->cmd != NULL)
 			xfree(wp->cmd);
@@ -574,10 +576,32 @@ window_pane_spawn(struct window_pane *wp, const char *cmd, const char *shell,
 		fatal("fcntl failed");
 	if (fcntl(wp->fd, F_SETFD, FD_CLOEXEC) == -1)
 		fatal("fcntl failed");
+	wp->event = bufferevent_new(wp->fd,
+	    window_pane_read_callback, NULL, window_pane_error_callback, wp);
+	bufferevent_enable(wp->event, EV_READ|EV_WRITE);
 
 	return (0);
 }
 
+void
+window_pane_read_callback(unused struct bufferevent *bufev, void *data)
+{
+	struct window_pane *wp = data;
+
+	window_pane_parse(wp);
+}
+
+void
+window_pane_error_callback(
+    unused struct bufferevent *bufev, unused short what, void *data)
+{
+	struct window_pane *wp = data;
+
+	close(wp->fd);
+	bufferevent_free(wp->event);
+	wp->fd = -1;
+}
+
 void
 window_pane_resize(struct window_pane *wp, u_int sx, u_int sy)
 {
@@ -631,18 +655,21 @@ window_pane_reset_mode(struct window_pane *wp)
 void
 window_pane_parse(struct window_pane *wp)
 {
+	char   *data;
 	size_t	new_size;
 
 	if (wp->mode != NULL)
 		return;
 
-	new_size = BUFFER_USED(wp->in) - wp->pipe_off;
-	if (wp->pipe_fd != -1 && new_size > 0)
-		bufferevent_write(wp->pipe_event, BUFFER_OUT(wp->in), new_size);
+	new_size = EVBUFFER_LENGTH(wp->event->input) - wp->pipe_off;
+	if (wp->pipe_fd != -1 && new_size > 0) {
+		data = EVBUFFER_DATA(wp->event->input);
+		bufferevent_write(wp->pipe_event, data, new_size);
+	}
 	
 	input_parse(wp);
 
-	wp->pipe_off = BUFFER_USED(wp->in);
+	wp->pipe_off = EVBUFFER_LENGTH(wp->event->input);
 }
 
 void