NetBSD-5.0.2/usr.bin/window/wwiomux.c
/* $NetBSD: wwiomux.c,v 1.13 2006/12/18 20:04:55 christos Exp $ */
/*
* Copyright (c) 1983, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Edward Wang at The University of California, Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)wwiomux.c 8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: wwiomux.c,v 1.13 2006/12/18 20:04:55 christos Exp $");
#endif
#endif /* not lint */
#include <sys/types.h>
#if !defined(OLD_TTY) && !defined(TIOCPKT_DATA)
#include <sys/ioctl.h>
#endif
#include <sys/time.h>
#include <poll.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <err.h>
#include "ww.h"
/*
* Multiple window output handler.
* The idea is to copy window outputs to the terminal, via the
* display package. We try to give wwcurwin highest priority.
* The only return conditions are when there is keyboard input
* and when a child process dies.
* When there's nothing to do, we sleep in a select().
* The history of this routine is interesting.
*/
void
wwiomux(void)
{
struct ww *w;
int nfd;
int volatile dostdin; /* avoid longjmp clobbering */
char volatile c; /* avoid longjmp clobbering */
char *p;
int millis;
char noblock = 0;
static struct pollfd *pfd = NULL;
static size_t maxfds = 0;
c = 0; /* XXXGCC -Wuninitialized */
for (;;) {
if (wwinterrupt()) {
wwclrintr();
return;
}
nfd = 0;
for (w = wwhead.ww_forw; w != &wwhead; w = w->ww_forw) {
if (w->ww_pty < 0 || w->ww_obq >= w->ww_obe)
continue;
nfd++;
}
if (maxfds <= ++nfd) { /* One more for the fd=0 case below */
struct pollfd *npfd = pfd == NULL ?
malloc(sizeof(*pfd) * nfd) :
realloc(pfd, sizeof(*pfd) * nfd);
if (npfd == NULL) {
warn("will retry");
if (pfd)
free(pfd);
pfd = NULL;
maxfds = 0;
return;
}
pfd = npfd;
maxfds = nfd;
}
nfd = 0;
for (w = wwhead.ww_forw; w != &wwhead; w = w->ww_forw) {
if (w->ww_pty < 0)
continue;
if (w->ww_obq < w->ww_obe) {
pfd[nfd].fd = w->ww_pty;
pfd[nfd++].events = POLLIN;
}
if (w->ww_obq > w->ww_obp &&
!ISSET(w->ww_pflags, WWP_STOPPED))
noblock = 1;
}
if (wwibq < wwibe) {
dostdin = nfd;
pfd[nfd].fd = 0;
pfd[nfd++].events = POLLIN;
} else {
dostdin = -1;
}
if (!noblock) {
if (wwcurwin != 0)
wwcurtowin(wwcurwin);
wwupdate();
wwflush();
(void) setjmp(wwjmpbuf);
wwsetjmp = 1;
if (wwinterrupt()) {
wwsetjmp = 0;
wwclrintr();
return;
}
/* XXXX */
millis = 30000;
} else {
millis = 10;
}
wwnselect++;
nfd = poll(pfd, nfd, millis);
wwsetjmp = 0;
noblock = 0;
if (nfd < 0)
wwnselecte++;
else if (nfd == 0)
wwnselectz++;
else {
if (dostdin != -1 && (pfd[dostdin].revents & POLLIN) != 0)
wwrint();
nfd = 0;
for (w = wwhead.ww_forw; w != &wwhead; w = w->ww_forw) {
int n;
if (w->ww_pty < 0)
continue;
if (w->ww_pty != pfd[nfd].fd)
continue;
if ((pfd[nfd++].revents & POLLIN) == 0)
continue;
wwnwread++;
p = w->ww_obq;
if (w->ww_type == WWT_PTY) {
if (p == w->ww_ob) {
w->ww_obp++;
w->ww_obq++;
} else
p--;
c = *p;
}
n = read(w->ww_pty, p, w->ww_obe - p);
if (n < 0) {
wwnwreade++;
(void) close(w->ww_pty);
w->ww_pty = -1;
} else if (n == 0) {
wwnwreadz++;
(void) close(w->ww_pty);
w->ww_pty = -1;
} else if (w->ww_type != WWT_PTY) {
wwnwreadd++;
wwnwreadc += n;
w->ww_obq += n;
} else if (*p == TIOCPKT_DATA) {
n--;
wwnwreadd++;
wwnwreadc += n;
w->ww_obq += n;
} else {
wwnwreadp++;
if (*p & TIOCPKT_STOP)
SET(w->ww_pflags, WWP_STOPPED);
if (*p & TIOCPKT_START)
CLR(w->ww_pflags, WWP_STOPPED);
if (*p & TIOCPKT_FLUSHWRITE) {
CLR(w->ww_pflags, WWP_STOPPED);
w->ww_obq = w->ww_obp =
w->ww_ob;
}
}
if (w->ww_type == WWT_PTY)
*p = c;
}
}
/*
* Try the current window first, if there is output
* then process it and go back to the top to try again.
* This can lead to starvation of the other windows,
* but presumably that what we want.
* Update will eventually happen when output from wwcurwin
* dies down.
*/
if ((w = wwcurwin) != 0 && w->ww_pty >= 0 &&
w->ww_obq > w->ww_obp &&
!ISSET(w->ww_pflags, WWP_STOPPED)) {
int n = wwwrite(w, w->ww_obp, w->ww_obq - w->ww_obp);
if ((w->ww_obp += n) == w->ww_obq)
w->ww_obq = w->ww_obp = w->ww_ob;
noblock = 1;
continue;
}
for (w = wwhead.ww_forw; w != &wwhead; w = w->ww_forw)
if (w->ww_pty >= 0 && w->ww_obq > w->ww_obp &&
!ISSET(w->ww_pflags, WWP_STOPPED)) {
int n = wwwrite(w, w->ww_obp,
w->ww_obq - w->ww_obp);
if ((w->ww_obp += n) == w->ww_obq)
w->ww_obq = w->ww_obp = w->ww_ob;
if (wwinterrupt())
break;
}
}
}