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  1. /*  $OpenBSD: input.c,v 1.12 2005/04/13 02:33:08 deraadt Exp $  */
  2. /*    $NetBSD: input.c,v 1.3 1996/02/06 22:47:33 jtc Exp $    */
  3.  
  4. /*-
  5.  * Copyright (c) 1992, 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.  * Chris Torek and Darren F. Provine.
  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.  *  @(#)input.c 8.1 (Berkeley) 5/31/93
  36.  */
  37.  
  38. /** @addtogroup tetris
  39.  * @{
  40.  */
  41. /** @file
  42.  */
  43.  
  44. /*
  45.  * Tetris input.
  46.  */
  47.  
  48. #include <sys/types.h>
  49. #include <sys/time.h>
  50. #include <stdio.h>
  51.  
  52. #include <errno.h>
  53. #include <unistd.h>
  54. #include <string.h>
  55.  
  56. #include "input.h"
  57. #include "tetris.h"
  58.  
  59. #include <async.h>
  60. #include "../../srv/console/console.h"
  61.  
  62. /* return true iff the given timeval is positive */
  63. #define TV_POS(tv) \
  64.     ((tv)->tv_sec > 0 || ((tv)->tv_sec == 0 && (tv)->tv_usec > 0))
  65.  
  66. /* subtract timeval `sub' from `res' */
  67. #define TV_SUB(res, sub) \
  68.     (res)->tv_sec -= (sub)->tv_sec; \
  69.     (res)->tv_usec -= (sub)->tv_usec; \
  70.     if ((res)->tv_usec < 0) { \
  71.         (res)->tv_usec += 1000000; \
  72.         (res)->tv_sec--; \
  73.     }
  74.  
  75. /* We will use a hack here - if lastchar is non-zero, it is
  76.  * the last character read. We will somehow simulate the select
  77.  * semantics.
  78.  */
  79. static aid_t getchar_inprog = 0;
  80. static char lastchar = '\0';
  81.  
  82. /*
  83.  * Do a `read wait': select for reading from stdin, with timeout *tvp.
  84.  * On return, modify *tvp to reflect the amount of time spent waiting.
  85.  * It will be positive only if input appeared before the time ran out;
  86.  * otherwise it will be zero or perhaps negative.
  87.  *
  88.  * If tvp is nil, wait forever, but return if select is interrupted.
  89.  *
  90.  * Return 0 => no input, 1 => can read() from stdin
  91.  *
  92.  */
  93. int
  94. rwait(struct timeval *tvp)
  95. {
  96.     struct timeval starttv, endtv, *s;
  97.     static ipc_call_t charcall;
  98.     ipcarg_t rc;
  99.     int cons_phone;
  100.  
  101.     /*
  102.      * Someday, select() will do this for us.
  103.      * Just in case that day is now, and no one has
  104.      * changed this, we use a temporary.
  105.      */
  106.     if (tvp) {
  107.         (void) gettimeofday(&starttv, NULL);
  108.         endtv = *tvp;
  109.         s = &endtv;
  110.     } else
  111.         s = NULL;
  112.  
  113.     if (!lastchar) {
  114.         if (!getchar_inprog) {
  115.             cons_phone = get_cons_phone();
  116.             getchar_inprog = async_send_2(cons_phone,
  117.                 CONSOLE_GETCHAR, 0, 0, &charcall);
  118.         }
  119.         if (!s)
  120.             async_wait_for(getchar_inprog, &rc);
  121.         else if (async_wait_timeout(getchar_inprog, &rc, s->tv_usec) == ETIMEOUT) {
  122.             tvp->tv_sec = 0;
  123.             tvp->tv_usec = 0;
  124.             return (0);
  125.         }
  126.         getchar_inprog = 0;
  127.         if (rc) {
  128.             stop("end of file, help");
  129.         }
  130.         lastchar = IPC_GET_ARG1(charcall);
  131.     }
  132.     if (tvp) {
  133.         /* since there is input, we may not have timed out */
  134.         (void) gettimeofday(&endtv, NULL);
  135.         TV_SUB(&endtv, &starttv);
  136.         TV_SUB(tvp, &endtv);    /* adjust *tvp by elapsed time */
  137.     }
  138.     return (1);
  139. }
  140.  
  141. /*
  142.  * `sleep' for the current turn time (using select).
  143.  * Eat any input that might be available.
  144.  */
  145. void
  146. tsleep(void)
  147. {
  148.     struct timeval tv;
  149.  
  150.     tv.tv_sec = 0;
  151.     tv.tv_usec = fallrate;
  152.     while (TV_POS(&tv))
  153.         if (rwait(&tv)) {
  154.             lastchar = '\0';
  155.         } else
  156.             break;
  157. }
  158.  
  159. /*
  160.  * getchar with timeout.
  161.  */
  162. int
  163. tgetchar(void)
  164. {
  165.     static struct timeval timeleft;
  166.     char c;
  167.  
  168.     /*
  169.      * Reset timeleft to fallrate whenever it is not positive.
  170.      * In any case, wait to see if there is any input.  If so,
  171.      * take it, and update timeleft so that the next call to
  172.      * tgetchar() will not wait as long.  If there is no input,
  173.      * make timeleft zero or negative, and return -1.
  174.      *
  175.      * Most of the hard work is done by rwait().
  176.      */
  177.     if (!TV_POS(&timeleft)) {
  178.         faster();   /* go faster */
  179.         timeleft.tv_sec = 0;
  180.         timeleft.tv_usec = fallrate;
  181.     }
  182.     if (!rwait(&timeleft))
  183.         return (-1);
  184.     c = lastchar;
  185.     lastchar = '\0';
  186.     return ((int)(unsigned char)c);
  187. }
  188.  
  189. /** @}
  190.  */
  191.  
  192.