Limited number of iterations in rote_vt_update to avoid infinite loop with ever-avail...

[apps/madtty.git] / rote.c

diff --git a/rote.c b/rote.c
index e6b6bda..322e8eb 100644 (file)
--- a/rote.c
+++ b/rote.c
@@ -1,3 +1,24 @@
+/*
+LICENSE INFORMATION:
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License (LGPL) as published by the Free Software Foundation.
+
+Please refer to the COPYING file for more information.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+
+Copyright (c) 2004 Bruno T. C. de Oliveira
+*/
+
+
 #include "rote.h"
 #include "roteprivate.h"
 #include <stdlib.h>
@@ -5,6 +26,8 @@
 #include <stdio.h>
 #include <string.h>
 
+#define ROTE_VT_UPDATE_ITERATIONS 5
+
 RoteTerm *rote_vt_create(int rows, int cols) {
    RoteTerm *rt;
    int i, j;
@@ -137,9 +160,17 @@ void rote_vt_update(RoteTerm *rt) {
    struct timeval tvzero;
    char buf[512];
    int bytesread;
+   int n = ROTE_VT_UPDATE_ITERATIONS;
    if (rt->pd->pty < 0) return;  /* nothing to pump */
 
-   while (1) {
+   while (n--) { /* iterate at most ROVE_VT_UPDATE_ITERATIONS times.
+                  * As Phil Endecott pointed out, if we don't restrict this,
+                  * a program that floods the terminal with output
+                  * could cause this loop to iterate forever, never
+                  * being able to catch up. So we'll rely on the client
+                  * calling rote_vt_update often, as the documentation
+                  * recommends :-) */
+
       /* check if pty has something to say */
       FD_ZERO(&ifs); FD_SET(rt->pd->pty, &ifs);
       tvzero.tv_sec = 0; tvzero.tv_usec = 0;