Line data    Source code

       1             : /*
       2             :  * ut_sim.c
       3             :  *
       4             :  * an unreliable transport simulator
       5             :  * (for testing replay databases and suchlike)
       6             :  * 
       7             :  * David A. McGrew
       8             :  * Cisco Systems, Inc.
       9             :  */
      10             : 
      11             : /*
      12             :  *      
      13             :  * Copyright (c) 2001-2006, Cisco Systems, Inc.
      14             :  * All rights reserved.
      15             :  * 
      16             :  * Redistribution and use in source and binary forms, with or without
      17             :  * modification, are permitted provided that the following conditions
      18             :  * are met:
      19             :  * 
      20             :  *   Redistributions of source code must retain the above copyright
      21             :  *   notice, this list of conditions and the following disclaimer.
      22             :  * 
      23             :  *   Redistributions in binary form must reproduce the above
      24             :  *   copyright notice, this list of conditions and the following
      25             :  *   disclaimer in the documentation and/or other materials provided
      26             :  *   with the distribution.
      27             :  * 
      28             :  *   Neither the name of the Cisco Systems, Inc. nor the names of its
      29             :  *   contributors may be used to endorse or promote products derived
      30             :  *   from this software without specific prior written permission.
      31             :  * 
      32             :  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      33             :  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      34             :  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
      35             :  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
      36             :  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
      37             :  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
      38             :  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
      39             :  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      40             :  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
      41             :  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
      42             :  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
      43             :  * OF THE POSSIBILITY OF SUCH DAMAGE.
      44             :  *
      45             :  */
      46             : 
      47             : 
      48             : #include "ut_sim.h"
      49             : 
      50             : 
      51             : int
      52           0 : ut_compar(const void *a, const void *b) {
      53           0 :   return rand() > (RAND_MAX/2) ? -1 : 1;
      54             : }
      55             : 
      56             : void
      57           0 : ut_init(ut_connection *utc) {
      58             :   int i;
      59           0 :   utc->index = 0;
      60             : 
      61           0 :   for (i=0; i < UT_BUF; i++)
      62           0 :     utc->buffer[i] = i;
      63             :   
      64           0 :   qsort(utc->buffer, UT_BUF, sizeof(uint32_t), ut_compar);
      65             : 
      66           0 :   utc->index = UT_BUF - 1;
      67           0 : }
      68             : 
      69             : uint32_t
      70           0 : ut_next_index(ut_connection *utc) {
      71             :   uint32_t tmp;
      72             : 
      73           0 :   tmp = utc->buffer[0];
      74           0 :   utc->index++;
      75           0 :   utc->buffer[0] = utc->index;
      76             : 
      77           0 :   qsort(utc->buffer, UT_BUF, sizeof(uint32_t), ut_compar);
      78             :   
      79           0 :   return tmp;
      80             : }
      81             : 
      82             : 
      83             : 
      84             : #ifdef UT_TEST
      85             : 
      86             : #include <stdio.h>
      87             : 
      88             : int
      89             : main() {
      90             :   uint32_t i, irecvd, idiff;
      91             :   ut_connection utc;
      92             : 
      93             :   ut_init(&utc);
      94             : 
      95             :   for (i=0; i < 1000; i++) {
      96             :     irecvd = ut_next_index(&utc);
      97             :     idiff = i - irecvd;
      98             :     printf("%lu\t%lu\t%d\n", i, irecvd, idiff);
      99             :   }
     100             :   
     101             :   return 0;
     102             : }
     103             : 
     104             : 
     105             : #endif