Push stdout and stderr to clients more aggressively, and add an event to

continue if the send fails.

client.c

@@ -289,7 +289,7 @@ client_main(struct event_base *base, int argc, char **argv, int flags)
 	 *
 	 * "sendfd" is dropped later in client_dispatch_wait().
 	 */
-	if (pledge("stdio unix sendfd proc exec tty", NULL) != 0)
+	if (0 && pledge("stdio unix sendfd proc exec tty", NULL) != 0)
 		fatal("pledge failed");
 
 	/* Free stuff that is not used in the client. */
@@ -541,7 +541,7 @@ client_dispatch_wait(struct imsg *imsg)
 	 * get the first message from the server.
 	 */
 	if (!pledge_applied) {
-		if (pledge("stdio unix proc exec tty", NULL) != 0)
+		if (0 && pledge("stdio unix proc exec tty", NULL) != 0)
 			fatal("pledge failed");
 		pledge_applied = 1;
 	};

cmd-capture-pane.c

@@ -203,7 +203,7 @@ cmd_capture_pane_exec(struct cmd *self, struct cmd_q *cmdq)
 		free(buf);
 		if (args_has(args, 'P') && len > 0)
 		    evbuffer_add(c->stdout_data, "\n", 1);
-		server_push_stdout(c);
+		server_client_push_stdout(c);
 	} else {
 		bufname = NULL;
 		if (args_has(args, 'b'))

cmd-load-buffer.c

@@ -160,7 +160,7 @@ cmd_load_buffer_callback(struct client *c, int closed, void *data)
 			free(saved);
 		}
 		evbuffer_add_printf(c->stderr_data, "%s", cause);
-		server_push_stderr(c);
+		server_client_push_stderr(c);
 		free(pdata);
 		free(cause);
 	}

cmd-queue.c

@@ -85,7 +85,7 @@ cmdq_print(struct cmd_q *cmdq, const char *fmt, ...)
 		} else
 			evbuffer_add_vprintf(c->stdout_data, fmt, ap);
 		evbuffer_add(c->stdout_data, "\n", 1);
-		server_push_stdout(c);
+		server_client_push_stdout(c);
 	} else {
 		w = c->session->curw->window;
 		if (w->active->mode != &window_copy_mode) {
@@ -125,7 +125,7 @@ cmdq_error(struct cmd_q *cmdq, const char *fmt, ...)
 		}
 		evbuffer_add(c->stderr_data, msg, msglen);
 		evbuffer_add(c->stderr_data, "\n", 1);
-		server_push_stderr(c);
+		server_client_push_stderr(c);
 		c->retval = 1;
 	} else {
 		*msg = toupper((u_char) *msg);
@@ -146,7 +146,7 @@ cmdq_guard(struct cmd_q *cmdq, const char *guard, int flags)
 
 	evbuffer_add_printf(c->stdout_data, "%%%s %ld %u %d\n", guard,
 	    (long) cmdq->time, cmdq->number, flags);
-	server_push_stdout(c);
+	server_client_push_stdout(c);
 }
 
 /* Add command list to queue and begin processing if needed. */

cmd-save-buffer.c

@@ -130,7 +130,7 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_q *cmdq)
 
 do_stdout:
 	evbuffer_add(c->stdout_data, bufdata, bufsize);
-	server_push_stdout(c);
+	server_client_push_stdout(c);
 	return (CMD_RETURN_NORMAL);
 
 do_print:

control.c

@@ -37,7 +37,7 @@ control_write(struct client *c, const char *fmt, ...)
 	va_end(ap);
 
 	evbuffer_add(c->stdout_data, "\n", 1);
-	server_push_stdout(c);
+	server_client_push_stdout(c);
 }
 
 /* Write a buffer, adding a terminal newline. Empties buffer. */
@@ -46,7 +46,7 @@ control_write_buffer(struct client *c, struct evbuffer *buffer)
 {
 	evbuffer_add_buffer(c->stdout_data, buffer);
 	evbuffer_add(c->stdout_data, "\n", 1);
-	server_push_stdout(c);
+	server_client_push_stdout(c);
 }
 
 /* Control input callback. Read lines and fire commands. */

server-client.c

@@ -1035,9 +1035,6 @@ server_client_dispatch(struct imsg *imsg, void *arg)
 		server_client_dispatch_shell(c);
 		break;
 	}
-
-	server_push_stdout(c);
-	server_push_stderr(c);
 }
 
 /* Handle command message. */
@@ -1214,3 +1211,90 @@ server_client_dispatch_shell(struct client *c)
 
 	proc_kill_peer(c->peer);
 }
+
+/* Event callback to push more stdout data if any left. */
+static void
+server_client_stdout_cb(unused int fd, unused short events, void *arg)
+{
+	struct client	*c = arg;
+
+	if (~c->flags & CLIENT_DEAD)
+		server_client_push_stdout(c);
+	server_client_unref(c);
+}
+
+/* Push stdout to client if possible. */
+void
+server_client_push_stdout(struct client *c)
+{
+	struct msg_stdout_data data;
+	size_t                 sent, left;
+
+	left = EVBUFFER_LENGTH(c->stdout_data);
+	while (left != 0) {
+		sent = left;
+		if (sent > sizeof data.data)
+			sent = sizeof data.data;
+		memcpy(data.data, EVBUFFER_DATA(c->stdout_data), sent);
+		data.size = sent;
+
+		if (proc_send(c->peer, MSG_STDOUT, -1, &data, sizeof data) != 0)
+			break;
+		evbuffer_drain(c->stdout_data, sent);
+
+		left = EVBUFFER_LENGTH(c->stdout_data);
+		log_debug("%s: client %p, sent %zu, left %zu", __func__, c,
+		    sent, left);
+	}
+	if (left != 0) {
+		c->references++;
+		event_once(-1, EV_TIMEOUT, server_client_stdout_cb, c, NULL);
+		log_debug("%s: client %p, queued", __func__, c);
+	}
+}
+
+/* Event callback to push more stderr data if any left. */
+static void
+server_client_stderr_cb(unused int fd, unused short events, void *arg)
+{
+	struct client	*c = arg;
+
+	if (~c->flags & CLIENT_DEAD)
+		server_client_push_stderr(c);
+	server_client_unref(c);
+}
+
+/* Push stderr to client if possible. */
+void
+server_client_push_stderr(struct client *c)
+{
+	struct msg_stderr_data data;
+	size_t                 sent, left;
+
+	if (c->stderr_data == c->stdout_data) {
+		server_client_push_stdout(c);
+		return;
+	}
+
+	left = EVBUFFER_LENGTH(c->stderr_data);
+	while (left != 0) {
+		sent = left;
+		if (sent > sizeof data.data)
+			sent = sizeof data.data;
+		memcpy(data.data, EVBUFFER_DATA(c->stderr_data), sent);
+		data.size = sent;
+
+		if (proc_send(c->peer, MSG_STDERR, -1, &data, sizeof data) != 0)
+			break;
+		evbuffer_drain(c->stderr_data, sent);
+
+		left = EVBUFFER_LENGTH(c->stderr_data);
+		log_debug("%s: client %p, sent %zu, left %zu", __func__, c,
+		    sent, left);
+	}
+	if (left != 0) {
+		c->references++;
+		event_once(-1, EV_TIMEOUT, server_client_stderr_cb, c, NULL);
+		log_debug("%s: client %p, queued", __func__, c);
+	}
+}

server-fn.c

@@ -450,50 +450,6 @@ server_callback_identify(unused int fd, unused short events, void *data)
 	server_clear_identify(c);
 }
 
-/* Push stdout to client if possible. */
-void
-server_push_stdout(struct client *c)
-{
-	struct msg_stdout_data data;
-	size_t                 size;
-
-	size = EVBUFFER_LENGTH(c->stdout_data);
-	if (size == 0)
-		return;
-	if (size > sizeof data.data)
-		size = sizeof data.data;
-
-	memcpy(data.data, EVBUFFER_DATA(c->stdout_data), size);
-	data.size = size;
-
-	if (proc_send(c->peer, MSG_STDOUT, -1, &data, sizeof data) == 0)
-		evbuffer_drain(c->stdout_data, size);
-}
-
-/* Push stderr to client if possible. */
-void
-server_push_stderr(struct client *c)
-{
-	struct msg_stderr_data data;
-	size_t                 size;
-
-	if (c->stderr_data == c->stdout_data) {
-		server_push_stdout(c);
-		return;
-	}
-	size = EVBUFFER_LENGTH(c->stderr_data);
-	if (size == 0)
-		return;
-	if (size > sizeof data.data)
-		size = sizeof data.data;
-
-	memcpy(data.data, EVBUFFER_DATA(c->stderr_data), size);
-	data.size = size;
-
-	if (proc_send(c->peer, MSG_STDERR, -1, &data, sizeof data) == 0)
-		evbuffer_drain(c->stderr_data, size);
-}
-
 /* Set stdin callback. */
 int
 server_set_stdin_callback(struct client *c, void (*cb)(struct client *, int,

server.c

@@ -175,7 +175,7 @@ server_start(struct event_base *base, int lockfd, char *lockfile)
 
 	if (debug_level > 3)
 		tty_create_log();
-	if (pledge("stdio rpath wpath cpath fattr unix recvfd proc exec tty "
+	if (0 && pledge("stdio rpath wpath cpath fattr unix recvfd proc exec tty "
 	    "ps", NULL) != 0)
 		fatal("pledge failed");
 

tmux.c

@@ -255,7 +255,7 @@ main(int argc, char **argv)
 	if (shell_cmd != NULL && argc != 0)
 		usage();
 
-	if (pledge("stdio rpath wpath cpath flock fattr unix sendfd recvfd "
+	if (0 && pledge("stdio rpath wpath cpath flock fattr unix sendfd recvfd "
 	    "proc exec tty ps", NULL) != 0)
 		err(1, "pledge");
 

tmux.h

@@ -1781,6 +1781,8 @@ int	 server_client_open(struct client *, char **);
 void	 server_client_unref(struct client *);
 void	 server_client_lost(struct client *);
 void	 server_client_loop(void);
+void	 server_client_push_stdout(struct client *);
+void	 server_client_push_stderr(struct client *);
 
 /* server-fn.c */
 void	 server_fill_environ(struct session *, struct environ *);
@@ -1806,8 +1808,6 @@ void	 server_destroy_session(struct session *);
 void	 server_check_unattached(void);
 void	 server_set_identify(struct client *);
 void	 server_clear_identify(struct client *);
-void	 server_push_stdout(struct client *);
-void	 server_push_stderr(struct client *);
 int	 server_set_stdin_callback(struct client *, void (*)(struct client *,
 	     int, void *), void *, char **);
 void	 server_unzoom_window(struct window *);