usr.bin/window/wwrint.c

   1 /*      @(#)wwrint.c    8.1 (Berkeley) 6/6/93   */
   2 /*      $NetBSD: wwrint.c,v 1.7 2003/08/07 11:17:44 agc Exp $   */
   3
   4 /*
   5  * Copyright (c) 1983, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * This code is derived from software contributed to Berkeley by
   9  * Edward Wang at The University of California, Berkeley.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <unistd.h>
  37 #include "ww.h"
  38 #include "tt.h"
  39
  40 /*
  41  * Tty input interrupt handler.
  42  * (1) Read input into buffer (wwib*).
  43  * (2) Set the interrupt flag if anything is read.
  44  * Currently, the last is used to get out of the blocking
  45  * select() in wwiomux().
  46  * To avoid race conditions, we only modify wwibq in here, except
  47  * when the buffer is empty; and everywhere else, we only change wwibp.
  48  * It should be completely safe.
  49  */
  50 void
  51 wwrint(void)
  52 {
  53         int n;
  54
  55         wwnread++;
  56         n = read(0, wwibq, wwibe - wwibq);
  57         if (n > 0) {
  58                 if (tt.tt_rint)
  59                         n = (*tt.tt_rint)(wwibq, n);
  60                 if (n > 0) {
  61                         wwibq += n;
  62                         wwnreadc += n;
  63                         /*
  64                          * Hasten or delay the next checkpoint,
  65                          * as the case may be.
  66                          */
  67                         if (tt.tt_checkpoint && !wwdocheckpoint)
  68                                 (void) alarm(1);
  69                         wwsetintr();
  70                 }
  71         } else if (n == 0)
  72                 wwnreadz++;
  73         else
  74                 wwnreade++;
  75 }