/* * DiskSim Storage Subsystem Simulation Environment (Version 4.0) * Revision Authors: John Bucy, Greg Ganger * Contributors: John Griffin, Jiri Schindler, Steve Schlosser * * Copyright (c) of Carnegie Mellon University, 2001-2008. * * This software is being provided by the copyright holders under the * following license. By obtaining, using and/or copying this software, * you agree that you have read, understood, and will comply with the * following terms and conditions: * * Permission to reproduce, use, and prepare derivative works of this * software is granted provided the copyright and "No Warranty" statements * are included with all reproductions and derivative works and associated * documentation. This software may also be redistributed without charge * provided that the copyright and "No Warranty" statements are included * in all redistributions. * * NO WARRANTY. THIS SOFTWARE IS FURNISHED ON AN "AS IS" BASIS. * CARNEGIE MELLON UNIVERSITY MAKES NO WARRANTIES OF ANY KIND, EITHER * EXPRESSED OR IMPLIED AS TO THE MATTER INCLUDING, BUT NOT LIMITED * TO: WARRANTY OF FITNESS FOR PURPOSE OR MERCHANTABILITY, EXCLUSIVITY * OF RESULTS OR RESULTS OBTAINED FROM USE OF THIS SOFTWARE. CARNEGIE * MELLON UNIVERSITY DOES NOT MAKE ANY WARRANTY OF ANY KIND WITH RESPECT * TO FREEDOM FROM PATENT, TRADEMARK, OR COPYRIGHT INFRINGEMENT. * COPYRIGHT HOLDERS WILL BEAR NO LIABILITY FOR ANY USE OF THIS SOFTWARE * OR DOCUMENTATION. * *//* * DiskSim Storage Subsystem Simulation Environment (Version 2.0) * Revision Authors: Greg Ganger * Contributors: Ross Cohen, John Griffin, Steve Schlosser * * Copyright (c) of Carnegie Mellon University, 1999. * * Permission to reproduce, use, and prepare derivative works of * this software for internal use is granted provided the copyright * and "No Warranty" statements are included with all reproductions * and derivative works. This software may also be redistributed * without charge provided that the copyright and "No Warranty" * statements are included in all redistributions. * * NO WARRANTY. THIS SOFTWARE IS FURNISHED ON AN "AS IS" BASIS. * CARNEGIE MELLON UNIVERSITY MAKES NO WARRANTIES OF ANY KIND, EITHER * EXPRESSED OR IMPLIED AS TO THE MATTER INCLUDING, BUT NOT LIMITED * TO: WARRANTY OF FITNESS FOR PURPOSE OR MERCHANTABILITY, EXCLUSIVITY * OF RESULTS OR RESULTS OBTAINED FROM USE OF THIS SOFTWARE. CARNEGIE * MELLON UNIVERSITY DOES NOT MAKE ANY WARRANTY OF ANY KIND WITH RESPECT * TO FREEDOM FROM PATENT, TRADEMARK, OR COPYRIGHT INFRINGEMENT. *//* * Copyright (c) 1993 Martin Birgmeier * All rights reserved. * * You may redistribute unmodified or modified versions of this source * code provided that the above copyright notice and this and the * following conditions are retained. * * This software is provided ``as is'', and comes with no warranties * of any kind. I shall in no event be liable for anything that happens * to anyone/anything when using this software. */#include "disksim_global.h"#include "disksim_rand48.h"#include <stdio.h>/* FreeBSD's rand48.h */#define	RAND48_SEED_0	(0x330e)#define	RAND48_SEED_1	(0xabcd)#define	RAND48_SEED_2	(0x1234)#define	RAND48_MULT_0	(0xe66d)#define	RAND48_MULT_1	(0xdeec)#define	RAND48_MULT_2	(0x0005)#define	RAND48_ADD	(0x000b)/* stuff added to restrict global variables to the disksim structure */typedef struct rand48_info {   unsigned short _rand48_seed[3];   unsigned short _rand48_mult[3];   unsigned short _rand48_add;} rand48_into_t;/* #defines to remap the rand48_info variables to their original names */#define _rand48_seed   (disksim->rand48_info->_rand48_seed)#define _rand48_mult   (disksim->rand48_info->_rand48_mult)#define _rand48_add    (disksim->rand48_info->_rand48_add)static void disksim_rand48_initialize (){   if (disksim->rand48_info != NULL) {      return;   }   disksim->rand48_info = DISKSIM_malloc (sizeof(rand48_into_t));   bzero ((char *)disksim->rand48_info, sizeof(rand48_into_t));   /* initialization */   _rand48_seed[0] = RAND48_SEED_0;   _rand48_seed[1] = RAND48_SEED_1;   _rand48_seed[2] = RAND48_SEED_2;   _rand48_mult[0] = RAND48_MULT_0;   _rand48_mult[1] = RAND48_MULT_1;   _rand48_mult[2] = RAND48_MULT_2;   _rand48_add     = RAND48_ADD;}/* FreeBSD's _rand48.c */#if 0    /* replaced by rand48_info */static unsigned short _rand48_seed[3] = {	RAND48_SEED_0,	RAND48_SEED_1,	RAND48_SEED_2};static unsigned short _rand48_mult[3] = {	RAND48_MULT_0,	RAND48_MULT_1,	RAND48_MULT_2};static unsigned short _rand48_add = RAND48_ADD;#endifstatic voidDISKSIM__dorand48(unsigned short xseed[3]){	unsigned long accu;	unsigned short temp[2];	disksim_rand48_initialize();	accu = (unsigned long) _rand48_mult[0] * (unsigned long) xseed[0] +	 (unsigned long) _rand48_add;	temp[0] = (unsigned short) accu;	/* lower 16 bits */	accu >>= sizeof(unsigned short) * 8;	accu += (unsigned long) _rand48_mult[0] * (unsigned long) xseed[1] +	 (unsigned long) _rand48_mult[1] * (unsigned long) xseed[0];	temp[1] = (unsigned short) accu;	/* middle 16 bits */	accu >>= sizeof(unsigned short) * 8;	accu += _rand48_mult[0] * xseed[2] + _rand48_mult[1] * xseed[1] + _rand48_mult[2] * xseed[0];	xseed[0] = temp[0];	xseed[1] = temp[1];	xseed[2] = (unsigned short) accu;}/* Made-up ldexp, based on FreeBSD manpage spec.  We have no particular    *//* desire to make this completely robust -- it is only used for erand48(). *//* This function should return a double that is "x" times 2 raised to *//* the "exp" power.                                                   */static doubleDISKSIM_ldexp (double x, int exp){   double start = 1.0;   int iters = (exp > 0) ? exp : -exp;   int i;   disksim_rand48_initialize();   /* hard-core optimization */   if (iters == 16) {      start = (exp > 0) ? (double)65536 : (double)0.0000152587890625 ;      iters = 0;   } else if (exp == -32) {      start = (double)0.00000000023283064365386962890625 ;      //start = (double)((exp > 0) ? (double)4294967296 : (double)0.00000000023283064365386962890625 );      iters = 0;   } else if (exp == -48) {      start = (double)0.000000000000003552713678800500929355621337890625 ;      //start = (exp > 0) ? (double)281474976710656 : (double)0.000000000000003552713678800500929355621337890625 ;      iters = 0;   }   /* lesser optimization (basically loop-unrolling) */   while (iters >= 8) {      start *= (exp > 0) ? 256 : 0.00390625 ;      iters -= 8;   }   /* clean-up */   for (i=0; i<iters; i++) {      start *= (exp > 0) ? (double)2.0 : (double) 0.5;   }   return (x * start);}/* FreeBSD's erand48.c */static doubleDISKSIM_erand48(unsigned short xseed[3]){	disksim_rand48_initialize();	DISKSIM__dorand48(xseed);	return DISKSIM_ldexp((double) xseed[0], -48) +	       DISKSIM_ldexp((double) xseed[1], -32) +	       DISKSIM_ldexp((double) xseed[2], -16);}/* FreeBSD's drand48.c */doubleDISKSIM_drand48(void){  disksim_rand48_initialize();   return DISKSIM_erand48(_rand48_seed);   //  return (double)0.5; }/* FreeBSD's jrand48.c */longDISKSIM_jrand48(unsigned short xseed[3]){	disksim_rand48_initialize();	DISKSIM__dorand48(xseed);	return ((long) xseed[2] << 16) + (long) xseed[1];}/* FreeBSD's lrand48.c */longDISKSIM_lrand48(void){  	disksim_rand48_initialize();   	DISKSIM__dorand48(_rand48_seed); 		return ((long) _rand48_seed[2] << 15) + ((long) _rand48_seed[1] >> 1);     // return 10; }/* FreeBSD's mrand48.c */longDISKSIM_mrand48(void){	disksim_rand48_initialize();	DISKSIM__dorand48(_rand48_seed);	return ((long) _rand48_seed[2] << 16) + (long) _rand48_seed[1];}/* FreeBSD's nrand48.c */longDISKSIM_nrand48(unsigned short xseed[3]){	disksim_rand48_initialize();	DISKSIM__dorand48(xseed);	return ((long) xseed[2] << 15) + ((long) xseed[1] >> 1);}/* FreeBSD's srand48.c */voidDISKSIM_srand48(long seed){	disksim_rand48_initialize();	_rand48_seed[0] = RAND48_SEED_0;	_rand48_seed[1] = (unsigned short) seed;	_rand48_seed[2] = (unsigned short) (seed >> 16);	_rand48_mult[0] = RAND48_MULT_0;	_rand48_mult[1] = RAND48_MULT_1;	_rand48_mult[2] = RAND48_MULT_2;	_rand48_add = RAND48_ADD;}