To replace c0-*, add a high watermark to the pty event, and also backoff

when the any of the ttys the pane is going to write to has buffered
enough data.

diff --git a/usr.bin/tmux/tmux.h b/usr.bin/tmux/tmux.h
index b1f5d4f..c627af1 100644 (file)
--- a/usr.bin/tmux/tmux.h
+++ b/usr.bin/tmux/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.513 2015/05/12 15:27:46 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.514 2015/05/12 22:40:38 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -56,6 +56,16 @@ extern char   **environ;
  */
 #define UTF8_SIZE 9
 
+/*
+ * READ_SIZE is the maximum size of data to hold from a pty (the event high
+ * watermark). READ_BACKOFF is the amount of data waiting to be output to a tty
+ * before pty reads will be backed off. READ_TIME is how long to back off
+ * before the next read (in microseconds) if a tty is above READ_BACKOFF.
+ */
+#define READ_SIZE 1024
+#define READ_BACKOFF 512
+#define READ_TIME 100
+
 /* Fatal errors. */
 #define fatal(msg) log_fatal("%s: %s", __func__, msg);
 #define fatalx(msg) log_fatalx("%s: %s", __func__, msg);
@@ -847,6 +857,7 @@ struct window_pane {
 
        int              fd;
        struct bufferevent *event;
+       struct event     timer;
 
        struct input_ctx *ictx;
 
@@ -1595,8 +1606,9 @@ void      tty_draw_line(struct tty *, const struct window_pane *, struct screen *,
 int    tty_open(struct tty *, char **);
 void   tty_close(struct tty *);
 void   tty_free(struct tty *);
-void   tty_write(
-           void (*)(struct tty *, const struct tty_ctx *), struct tty_ctx *);
+void   tty_write(void (*)(struct tty *, const struct tty_ctx *),
+           struct tty_ctx *);
+int    tty_client_ready(struct client *, struct window_pane *wp);
 void   tty_cmd_alignmenttest(struct tty *, const struct tty_ctx *);
 void   tty_cmd_cell(struct tty *, const struct tty_ctx *);
 void   tty_cmd_clearendofline(struct tty *, const struct tty_ctx *);

diff --git a/usr.bin/tmux/tty.c b/usr.bin/tmux/tty.c
index cb04de9..4418d0c 100644 (file)
--- a/usr.bin/tmux/tty.c
+++ b/usr.bin/tmux/tty.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty.c,v 1.181 2015/05/06 07:52:06 nicm Exp $ */
+/* $OpenBSD: tty.c,v 1.182 2015/05/12 22:40:38 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -723,9 +723,23 @@ tty_draw_line(struct tty *tty, const struct window_pane *wp,
        tty_update_mode(tty, tty->mode, s);
 }
 
+int
+tty_client_ready(struct client *c, struct window_pane *wp)
+{
+       if (c->session == NULL || c->tty.term == NULL)
+               return (0);
+       if (c->flags & CLIENT_SUSPENDED)
+               return (0);
+       if (c->tty.flags & TTY_FREEZE)
+               return (0);
+       if (c->session->curw->window != wp->window)
+               return (0);
+       return (1);
+}
+
 void
-tty_write(
-    void (*cmdfn)(struct tty *, const struct tty_ctx *), struct tty_ctx *ctx)
+tty_write(void (*cmdfn)(struct tty *, const struct tty_ctx *),
+    struct tty_ctx *ctx)
 {
        struct window_pane      *wp = ctx->wp;
        struct client           *c;
@@ -740,13 +754,7 @@ tty_write(
                return;
 
        TAILQ_FOREACH(c, &clients, entry) {
-               if (c->session == NULL || c->tty.term == NULL)
-                       continue;
-               if (c->flags & CLIENT_SUSPENDED)
-                       continue;
-               if (c->tty.flags & TTY_FREEZE)
-                       continue;
-               if (c->session->curw->window != wp->window)
+               if (!tty_client_ready(c, wp))
                        continue;
 
                ctx->xoff = wp->xoff;

diff --git a/usr.bin/tmux/window.c b/usr.bin/tmux/window.c
index 3bbd193..e7e49ee 100644 (file)
--- a/usr.bin/tmux/window.c
+++ b/usr.bin/tmux/window.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window.c,v 1.130 2015/05/11 10:10:16 nicm Exp $ */
+/* $OpenBSD: window.c,v 1.131 2015/05/12 22:40:38 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -58,6 +58,7 @@ u_int next_window_pane_id;
 u_int  next_window_id;
 u_int  next_active_point;
 
+void   window_pane_timer_callback(int, short, void *);
 void   window_pane_read_callback(struct bufferevent *, void *);
 void   window_pane_error_callback(struct bufferevent *, short, void *);
 
@@ -740,6 +741,9 @@ window_pane_destroy(struct window_pane *wp)
 {
        window_pane_reset_mode(wp);
 
+       if (event_initialized(&wp->timer))
+               evtimer_del(&wp->timer);
+
        if (wp->fd != -1) {
                bufferevent_free(wp->event);
                close(wp->fd);
@@ -867,28 +871,53 @@ window_pane_spawn(struct window_pane *wp, int argc, char **argv,
 
        wp->event = bufferevent_new(wp->fd, window_pane_read_callback, NULL,
            window_pane_error_callback, wp);
+
+       bufferevent_setwatermark(wp->event, EV_READ, 0, READ_SIZE);
        bufferevent_enable(wp->event, EV_READ|EV_WRITE);
 
        free(cmd);
        return (0);
 }
 
+void
+window_pane_timer_callback(unused int fd, unused short events, void *data)
+{
+       window_pane_read_callback(NULL, data);
+}
+
 void
 window_pane_read_callback(unused struct bufferevent *bufev, void *data)
 {
-       struct window_pane     *wp = data;
-       char                   *new_data;
-       size_t                  new_size;
+       struct window_pane      *wp = data;
+       struct evbuffer         *evb = wp->event->input;
+       char                    *new_data;
+       size_t                   new_size, available;
+       struct client           *c;
+       struct timeval           tv;
+
+       if (event_initialized(&wp->timer))
+               evtimer_del(&wp->timer);
+
+       log_debug("%%%u has %zu bytes", wp->id, EVBUFFER_LENGTH(evb));
 
-       new_size = EVBUFFER_LENGTH(wp->event->input) - wp->pipe_off;
+       TAILQ_FOREACH(c, &clients, entry) {
+               if (!tty_client_ready(c, wp))
+                       continue;
+
+               available = EVBUFFER_LENGTH(c->tty.event->output);
+               if (available > READ_BACKOFF)
+                       goto start_timer;
+       }
+
+       new_size = EVBUFFER_LENGTH(evb) - wp->pipe_off;
        if (wp->pipe_fd != -1 && new_size > 0) {
-               new_data = EVBUFFER_DATA(wp->event->input);
+               new_data = EVBUFFER_DATA(evb);
                bufferevent_write(wp->pipe_event, new_data, new_size);
        }
 
        input_parse(wp);
 
-       wp->pipe_off = EVBUFFER_LENGTH(wp->event->input);
+       wp->pipe_off = EVBUFFER_LENGTH(evb);
 
        /*
         * If we get here, we're not outputting anymore, so set the silence
@@ -897,11 +926,22 @@ window_pane_read_callback(unused struct bufferevent *bufev, void *data)
        wp->window->flags |= WINDOW_SILENCE;
        if (gettimeofday(&wp->window->silence_timer, NULL) != 0)
                fatal("gettimeofday failed.");
+       return;
+
+start_timer:
+       log_debug("%%%u backing off (%s %zu > %d)", wp->id, c->ttyname,
+           available, READ_BACKOFF);
+
+       tv.tv_sec = 0;
+       tv.tv_usec = READ_TIME;
+
+       evtimer_set(&wp->timer, window_pane_timer_callback, wp);
+       evtimer_add(&wp->timer, &tv);
 }
 
 void
-window_pane_error_callback(
-    unused struct bufferevent *bufev, unused short what, void *data)
+window_pane_error_callback(unused struct bufferevent *bufev, unused short what,
+    void *data)
 {
        struct window_pane *wp = data;