When the data we have buffered to write to a terminal grows beyond a

reasonable amount (currently width * height * 8 bytes), discard all
output to the terminal and start trying to redraw periodically
instead. Continue with this until the amount of data we are trying to
write falls to a low level again.

This helps to prevent tmux sitting on a huge buffer of data when there
are processes with fast output running inside tmux but the outside
terminal is slow.

A new client_discarded format holds the amount of data that has been
discarded due to this mechanism.

The three variables (when to start this, when to stop, and how often to
redraw) are basically "works for me" at the moment, this is going in to
see how it goes and if it causes problems for anyone else.

1 files changed, 3 insertions, 2 deletions

diff --git a/usr.bin/tmux/tmux.1 b/usr.bin/tmux/tmux.1
index efb0ef8d557..8f18660aebb 100644
--- a/usr.bin/tmux/tmux.1
+++ b/usr.bin/tmux/tmux.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: tmux.1,v 1.541 2017/04/18 15:44:17 nicm Exp $
+.\" $OpenBSD: tmux.1,v 1.542 2017/04/19 06:52:27 nicm Exp $
 .\"
 .\" Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 .\"
@@ -14,7 +14,7 @@
 .\" IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 .\" OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: April 18 2017 $
+.Dd $Mdocdate: April 19 2017 $
 .Dt TMUX 1
 .Os
 .Sh NAME
@@ -3508,6 +3508,7 @@ The following variables are available, where appropriate:
 .It Li "client_activity" Ta "" Ta "Integer time client last had activity"
 .It Li "client_created" Ta "" Ta "Integer time client created"
 .It Li "client_control_mode" Ta "" Ta "1 if client is in control mode"
+.It Li "client_discarded" Ta "" Ta "Bytes discarded when client behind"
 .It Li "client_height" Ta "" Ta "Height of client"
 .It Li "client_key_table" Ta "" Ta "Current key table"
 .It Li "client_last_session" Ta "" Ta "Name of the client's last session"