1 /* $NetBSD: random.cc,v 1.3 2008/04/28 20:22:54 martin Exp $ */ 2 3 /*- 4 * Copyright (c) 2003 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * random.C: Randomizer for the dots program 34 */ 35 36 #include "defs.h" 37 RCSID("$NetBSD: random.cc,v 1.3 2008/04/28 20:22:54 martin Exp $") 38 39 #include <time.h> 40 #include <string.h> 41 #include "random.h" 42 43 RANDOM::RANDOM(size_t ns) : 44 _bs(ns) 45 { 46 _bm = new char[(_bs >> 3) + 1]; 47 clear(); 48 } 49 50 RANDOM::~RANDOM() 51 { 52 delete[] _bm; 53 } 54 55 // Reinitialize 56 void RANDOM::clear(void) 57 { 58 _nv = 0; 59 ::srand48(::time(NULL)); 60 (void) ::memset(_bm, 0, (_bs >> 3) + 1); 61 } 62 63 // Return the next random value 64 size_t RANDOM::operator() (void) 65 { 66 // No more values 67 if (_nv == _bs) 68 return _bs; 69 70 for (;;) { 71 size_t r = ::lrand48(); 72 size_t z = r % _bs; 73 if (!isset(z)) { 74 set(z); 75 _nv++; 76 return z; 77 } 78 } 79 } 80