usr.bin/window/wwiomux.c

   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
  38 static 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  */
  66 void
  67 wwiomux(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 }