usr.bin/window/wwrint.c

   1 /*      $NetBSD: wwrint.c,v 1.7 2003/08/07 11:17:44 agc 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[] = "@(#)wwrint.c    8.1 (Berkeley) 6/6/93";
  39 #else
  40 __RCSID("$NetBSD: wwrint.c,v 1.7 2003/08/07 11:17:44 agc Exp $");
  41 #endif
  42 #endif /* not lint */
  43
  44 #include <unistd.h>
  45 #include "ww.h"
  46 #include "tt.h"
  47
  48 /*
  49  * Tty input interrupt handler.
  50  * (1) Read input into buffer (wwib*).
  51  * (2) Set the interrupt flag if anything is read.
  52  * Currently, the last is used to get out of the blocking
  53  * select() in wwiomux().
  54  * To avoid race conditions, we only modify wwibq in here, except
  55  * when the buffer is empty; and everywhere else, we only change wwibp.
  56  * It should be completely safe.
  57  */
  58 void
  59 wwrint(void)
  60 {
  61         int n;
  62
  63         wwnread++;
  64         n = read(0, wwibq, wwibe - wwibq);
  65         if (n > 0) {
  66                 if (tt.tt_rint)
  67                         n = (*tt.tt_rint)(wwibq, n);
  68                 if (n > 0) {
  69                         wwibq += n;
  70                         wwnreadc += n;
  71                         /*
  72                          * Hasten or delay the next checkpoint,
  73                          * as the case may be.
  74                          */
  75                         if (tt.tt_checkpoint && !wwdocheckpoint)
  76                                 (void) alarm(1);
  77                         wwsetintr();
  78                 }
  79         } else if (n == 0)
  80                 wwnreadz++;
  81         else
  82                 wwnreade++;
  83 }