1/* $NetBSD: wwiomux.c,v 1.13 2006/12/18 20:04:55 christos Exp $ */ 2 3/* 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Edward Wang at The University of California, Berkeley. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35#include <sys/cdefs.h> 36#ifndef lint 37#if 0 38static char sccsid[] = "@(#)wwiomux.c 8.1 (Berkeley) 6/6/93"; 39#else 40__RCSID("$NetBSD: wwiomux.c,v 1.13 2006/12/18 20:04:55 christos Exp $"); 41#endif 42#endif /* not lint */ 43 44#include <sys/types.h> 45#if !defined(OLD_TTY) && !defined(TIOCPKT_DATA) 46#include <sys/ioctl.h> 47#endif 48#include <sys/time.h> 49#include <poll.h> 50#include <stdlib.h> 51#include <fcntl.h> 52#include <string.h> 53#include <unistd.h> 54#include <err.h> 55#include "ww.h" 56 57/* 58 * Multiple window output handler. 59 * The idea is to copy window outputs to the terminal, via the 60 * display package. We try to give wwcurwin highest priority. 61 * The only return conditions are when there is keyboard input 62 * and when a child process dies. 63 * When there's nothing to do, we sleep in a select(). 64 * The history of this routine is interesting. 65 */ 66void 67wwiomux(void) 68{ 69 struct ww *w; 70 nfds_t nfd; 71 int i; 72 int volatile dostdin; /* avoid longjmp clobbering */ 73 char volatile c; /* avoid longjmp clobbering */ 74 char *p; 75 int millis; 76 char noblock = 0; 77 static struct pollfd *pfd = NULL; 78 static nfds_t maxfds = 0; 79 80 c = 0; /* XXXGCC -Wuninitialized */ 81 82 for (;;) { 83 if (wwinterrupt()) { 84 wwclrintr(); 85 return; 86 } 87 88 nfd = 0; 89 for (w = wwhead.ww_forw; w != &wwhead; w = w->ww_forw) { 90 if (w->ww_pty < 0 || w->ww_obq >= w->ww_obe) 91 continue; 92 nfd++; 93 } 94 95 if (maxfds <= ++nfd) { /* One more for the fd=0 case below */ 96 struct pollfd *npfd = pfd == NULL ? 97 malloc(sizeof(*pfd) * nfd) : 98 realloc(pfd, sizeof(*pfd) * nfd); 99 if (npfd == NULL) { 100 warn("will retry"); 101 if (pfd) 102 free(pfd); 103 pfd = NULL; 104 maxfds = 0; 105 return; 106 } 107 pfd = npfd; 108 maxfds = nfd; 109 } 110 111 nfd = 0; 112 for (w = wwhead.ww_forw; w != &wwhead; w = w->ww_forw) { 113 if (w->ww_pty < 0) 114 continue; 115 if (w->ww_obq < w->ww_obe) { 116 pfd[nfd].fd = w->ww_pty; 117 pfd[nfd++].events = POLLIN; 118 } 119 if (w->ww_obq > w->ww_obp && 120 !ISSET(w->ww_pflags, WWP_STOPPED)) 121 noblock = 1; 122 } 123 if (wwibq < wwibe) { 124 dostdin = nfd; 125 pfd[nfd].fd = 0; 126 pfd[nfd++].events = POLLIN; 127 } else { 128 dostdin = -1; 129 } 130 131 if (!noblock) { 132 if (wwcurwin != 0) 133 wwcurtowin(wwcurwin); 134 wwupdate(); 135 wwflush(); 136 (void) setjmp(wwjmpbuf); 137 wwsetjmp = 1; 138 if (wwinterrupt()) { 139 wwsetjmp = 0; 140 wwclrintr(); 141 return; 142 } 143 /* XXXX */ 144 millis = 30000; 145 } else { 146 millis = 10; 147 } 148 wwnselect++; 149 i = poll(pfd, nfd, millis); 150 wwsetjmp = 0; 151 noblock = 0; 152 153 if (i < 0) 154 wwnselecte++; 155 else if (i == 0) 156 wwnselectz++; 157 else { 158 if (dostdin != -1 && (pfd[dostdin].revents & POLLIN) != 0) 159 wwrint(); 160 161 nfd = 0; 162 for (w = wwhead.ww_forw; w != &wwhead; w = w->ww_forw) { 163 int n; 164 165 if (w->ww_pty < 0) 166 continue; 167 if (w->ww_pty != pfd[nfd].fd) 168 continue; 169 if ((pfd[nfd++].revents & POLLIN) == 0) 170 continue; 171 wwnwread++; 172 p = w->ww_obq; 173 if (w->ww_type == WWT_PTY) { 174 if (p == w->ww_ob) { 175 w->ww_obp++; 176 w->ww_obq++; 177 } else 178 p--; 179 c = *p; 180 } 181 n = read(w->ww_pty, p, w->ww_obe - p); 182 if (n < 0) { 183 wwnwreade++; 184 (void) close(w->ww_pty); 185 w->ww_pty = -1; 186 } else if (n == 0) { 187 wwnwreadz++; 188 (void) close(w->ww_pty); 189 w->ww_pty = -1; 190 } else if (w->ww_type != WWT_PTY) { 191 wwnwreadd++; 192 wwnwreadc += n; 193 w->ww_obq += n; 194 } else if (*p == TIOCPKT_DATA) { 195 n--; 196 wwnwreadd++; 197 wwnwreadc += n; 198 w->ww_obq += n; 199 } else { 200 wwnwreadp++; 201 if (*p & TIOCPKT_STOP) 202 SET(w->ww_pflags, WWP_STOPPED); 203 if (*p & TIOCPKT_START) 204 CLR(w->ww_pflags, WWP_STOPPED); 205 if (*p & TIOCPKT_FLUSHWRITE) { 206 CLR(w->ww_pflags, WWP_STOPPED); 207 w->ww_obq = w->ww_obp = 208 w->ww_ob; 209 } 210 } 211 if (w->ww_type == WWT_PTY) 212 *p = c; 213 } 214 } 215 /* 216 * Try the current window first, if there is output 217 * then process it and go back to the top to try again. 218 * This can lead to starvation of the other windows, 219 * but presumably that what we want. 220 * Update will eventually happen when output from wwcurwin 221 * dies down. 222 */ 223 if ((w = wwcurwin) != 0 && w->ww_pty >= 0 && 224 w->ww_obq > w->ww_obp && 225 !ISSET(w->ww_pflags, WWP_STOPPED)) { 226 int n = wwwrite(w, w->ww_obp, w->ww_obq - w->ww_obp); 227 if ((w->ww_obp += n) == w->ww_obq) 228 w->ww_obq = w->ww_obp = w->ww_ob; 229 noblock = 1; 230 continue; 231 } 232 for (w = wwhead.ww_forw; w != &wwhead; w = w->ww_forw) 233 if (w->ww_pty >= 0 && w->ww_obq > w->ww_obp && 234 !ISSET(w->ww_pflags, WWP_STOPPED)) { 235 int n = wwwrite(w, w->ww_obp, 236 w->ww_obq - w->ww_obp); 237 if ((w->ww_obp += n) == w->ww_obq) 238 w->ww_obq = w->ww_obp = w->ww_ob; 239 if (wwinterrupt()) 240 break; 241 } 242 } 243} 244