usr.bin/window/wwrint.c

   1 /*
   2  * Copyright (c) 1983, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Edward Wang at The University of California, Berkeley.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * @(#)wwrint.c 8.1 (Berkeley) 6/6/93
  37  * $FreeBSD: src/usr.bin/window/wwrint.c,v 1.1.1.1.14.1 2001/05/17 09:45:01 obrien Exp $
  38  * $DragonFly: src/usr.bin/window/wwrint.c,v 1.2 2003/06/17 04:29:34 dillon Exp $
  39  */
  40
  41 #include "ww.h"
  42 #include "tt.h"
  43 #if defined(OLD_TTY) || defined(VMIN_BUG)
  44 #include <fcntl.h>
  45 #endif
  46
  47 /*
  48  * Tty input interrupt handler.
  49  * (1) Read input into buffer (wwib*).
  50  * (2) Set the interrupt flag if anything is read.
  51  * Currently, the last is used to get out of the blocking
  52  * select() in wwiomux().
  53  * To avoid race conditions, we only modify wwibq in here, except
  54  * when the buffer is empty; and everywhere else, we only change wwibp.
  55  * It should be completely safe.
  56  */
  57 void
  58 wwrint()
  59 {
  60         register n;
  61
  62         if (wwibp == wwibq)
  63                 wwibp = wwibq = wwib;
  64         wwnread++;
  65 #if defined(OLD_TTY) || defined(VMIN_BUG)
  66         /* we have set c_cc[VMIN] to 0 */
  67         (void) fcntl(0, F_SETFL, O_NONBLOCK|wwnewtty.ww_fflags);
  68 #endif
  69         n = read(0, wwibq, wwibe - wwibq);
  70 #if defined(OLD_TTY) || defined(VMIN_BUG)
  71         (void) fcntl(0, F_SETFL, wwnewtty.ww_fflags);
  72 #endif
  73         if (n > 0) {
  74                 if (tt.tt_rint)
  75                         n = (*tt.tt_rint)(wwibq, n);
  76                 if (n > 0) {
  77                         wwibq += n;
  78                         wwnreadc += n;
  79                         /*
  80                          * Hasten or delay the next checkpoint,
  81                          * as the case may be.
  82                          */
  83                         if (tt.tt_checkpoint && !wwdocheckpoint)
  84                                 (void) alarm(1);
  85                         wwsetintr();
  86                 }
  87         } else if (n == 0)
  88                 wwnreadz++;
  89         else
  90                 wwnreade++;
  91 }