michael@0: /*
michael@0:  * ut_sim.c
michael@0:  *
michael@0:  * an unreliable transport simulator
michael@0:  * (for testing replay databases and suchlike)
michael@0:  * 
michael@0:  * David A. McGrew
michael@0:  * Cisco Systems, Inc.
michael@0:  */
michael@0: 
michael@0: /*
michael@0:  *	
michael@0:  * Copyright (c) 2001-2006, Cisco Systems, Inc.
michael@0:  * All rights reserved.
michael@0:  * 
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  * 
michael@0:  *   Redistributions of source code must retain the above copyright
michael@0:  *   notice, this list of conditions and the following disclaimer.
michael@0:  * 
michael@0:  *   Redistributions in binary form must reproduce the above
michael@0:  *   copyright notice, this list of conditions and the following
michael@0:  *   disclaimer in the documentation and/or other materials provided
michael@0:  *   with the distribution.
michael@0:  * 
michael@0:  *   Neither the name of the Cisco Systems, Inc. nor the names of its
michael@0:  *   contributors may be used to endorse or promote products derived
michael@0:  *   from this software without specific prior written permission.
michael@0:  * 
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0:  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0:  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
michael@0:  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
michael@0:  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
michael@0:  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
michael@0:  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
michael@0:  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
michael@0:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
michael@0:  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
michael@0:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
michael@0:  * OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: 
michael@0: #include "ut_sim.h"
michael@0: 
michael@0: 
michael@0: int
michael@0: ut_compar(const void *a, const void *b) {
michael@0:   return rand() > (RAND_MAX/2) ? -1 : 1;
michael@0: }
michael@0: 
michael@0: void
michael@0: ut_init(ut_connection *utc) {
michael@0:   int i;
michael@0:   utc->index = 0;
michael@0: 
michael@0:   for (i=0; i < UT_BUF; i++)
michael@0:     utc->buffer[i] = i;
michael@0:   
michael@0:   qsort(utc->buffer, UT_BUF, sizeof(uint32_t), ut_compar);
michael@0: 
michael@0:   utc->index = UT_BUF - 1;
michael@0: }
michael@0: 
michael@0: uint32_t
michael@0: ut_next_index(ut_connection *utc) {
michael@0:   uint32_t tmp;
michael@0: 
michael@0:   tmp = utc->buffer[0];
michael@0:   utc->index++;
michael@0:   utc->buffer[0] = utc->index;
michael@0: 
michael@0:   qsort(utc->buffer, UT_BUF, sizeof(uint32_t), ut_compar);
michael@0:   
michael@0:   return tmp;
michael@0: }
michael@0: 
michael@0: 
michael@0: 
michael@0: #ifdef UT_TEST
michael@0: 
michael@0: #include <stdio.h>
michael@0: 
michael@0: int
michael@0: main() {
michael@0:   uint32_t i, irecvd, idiff;
michael@0:   ut_connection utc;
michael@0: 
michael@0:   ut_init(&utc);
michael@0: 
michael@0:   for (i=0; i < 1000; i++) {
michael@0:     irecvd = ut_next_index(&utc);
michael@0:     idiff = i - irecvd;
michael@0:     printf("%lu\t%lu\t%d\n", i, irecvd, idiff);
michael@0:   }
michael@0:   
michael@0:   return 0;
michael@0: }
michael@0: 
michael@0: 
michael@0: #endif