| Tristan Matthews | 0a329cc | 2013-07-17 13:20:14 -0400 | [diff] [blame] | 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 | ut_compar(const void *a, const void *b) { |
| 53 | return rand() > (RAND_MAX/2) ? -1 : 1; |
| 54 | } |
| 55 | |
| 56 | void |
| 57 | ut_init(ut_connection *utc) { |
| 58 | int i; |
| 59 | utc->index = 0; |
| 60 | |
| 61 | for (i=0; i < UT_BUF; i++) |
| 62 | utc->buffer[i] = i; |
| 63 | |
| 64 | qsort(utc->buffer, UT_BUF, sizeof(uint32_t), ut_compar); |
| 65 | |
| 66 | utc->index = UT_BUF - 1; |
| 67 | } |
| 68 | |
| 69 | uint32_t |
| 70 | ut_next_index(ut_connection *utc) { |
| 71 | uint32_t tmp; |
| 72 | |
| 73 | tmp = utc->buffer[0]; |
| 74 | utc->index++; |
| 75 | utc->buffer[0] = utc->index; |
| 76 | |
| 77 | qsort(utc->buffer, UT_BUF, sizeof(uint32_t), ut_compar); |
| 78 | |
| 79 | 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 |