cvs: php4 /ext/standard Makefile.in array.c basic_functions.c basic_functions.h crypt.c lcg.c php_crypt.h php_math.h php_rand.h php_standard.h rand.c
rand_mt.c rand_sys.c

sniper Wed Sep 5 15:47:55 2001 EDT Removed files: /php4/ext/standard rand_mt.c rand_sys.c Modified files: /php4/ext/standard Makefile.in array.c basic_functions.c basic_functions.h crypt.c lcg.c php_crypt.h php_math.h php_rand.h php_standard.h rand.c Log: revert bad commit.

Index: php4/ext/standard/Makefile.in diff -u php4/ext/standard/Makefile.in:1.21 php4/ext/standard/Makefile.in:1.22 --- php4/ext/standard/Makefile.in:1.21 Sun Sep 2 21:06:23 2001 +++ php4/ext/standard/Makefile.in Wed Sep 5 15:47:54 2001 @@ -5,8 +5,7 @@ dir.c dl.c dns.c exec.c file.c filestat.c flock_compat.c \ formatted_print.c fsock.c head.c html.c image.c info.c iptc.c lcg.c \ link.c mail.c math.c md5.c metaphone.c microtime.c pack.c pageinfo.c \ - parsedate.c quot_print.c rand.c rand_sys.c rand_mt.c reg.c \ - soundex.c string.c scanf.c \ + parsedate.c quot_print.c rand.c reg.c soundex.c string.c scanf.c \ syslog.c type.c uniqid.c url.c url_scanner.c var.c assert.c \ strnatcmp.c levenshtein.c incomplete_class.c url_scanner_ex.c \ ftp_fopen_wrapper.c http_fopen_wrapper.c php_fopen_wrapper.c credits.c Index: php4/ext/standard/array.c diff -u php4/ext/standard/array.c:1.132 php4/ext/standard/array.c:1.133 --- php4/ext/standard/array.c:1.132 Mon Sep 3 22:19:30 2001 +++ php4/ext/standard/array.c Wed Sep 5 15:47:54 2001 @@ -21,7 +21,7 @@ +----------------------------------------------------------------------+ */ -/* $Id: array.c,v 1.132 2001/09/04 02:19:30 dbeu Exp $ */ +/* $Id: array.c,v 1.133 2001/09/05 19:47:54 sniper Exp $ */ #include "php.h" #include "php_ini.h" @@ -1376,15 +1376,12 @@ /* }}} */ -static int array_data_shuffle(const void *a, const void*b) -{ - TSRMLS_FETCH(); - - return php_rand_range(0,1 TSRMLS_CC) ? 1 : -1; +static int array_data_shuffle(const void *a, const void*b) { + return (php_rand() % 2) ? 1 : -1; } -/* {{{ proto bool shuffle(array array_arg) +/* {{{ proto int shuffle(array array_arg) Randomly shuffle the contents of an array */ PHP_FUNCTION(shuffle) { @@ -2719,12 +2716,10 @@ /* {{{ proto mixed array_rand(array input [, int num_req]) Return key/keys for random entry/entries in the array */ - -/* FIXME:The algorithm used is bogus! */ PHP_FUNCTION(array_rand) { zval **input, **num_req; - double randval; + long randval; int num_req_val, num_avail, key_type; char *string_key; uint string_key_len; @@ -2763,10 +2758,17 @@ zend_hash_internal_pointer_reset_ex(Z_ARRVAL_PP(input), &pos); while (num_req_val && (key_type = zend_hash_get_current_key_ex(Z_ARRVAL_PP(input), &string_key, &string_key_len, &num_key, 0, &pos)) != HASH_KEY_NON_EXISTANT) { - +#ifdef HAVE_RANDOM + randval = random(); +#else +#ifdef HAVE_LRAND48 + randval = lrand48(); +#else + randval = rand(); +#endif +#endif - randval = php_drand(TSRMLS_C); - if (randval < (double)num_req_val/(double)num_avail) { + if ((double)(randval/(PHP_RAND_MAX+1.0)) < (double)num_req_val/(double)num_avail) { /* If we are returning a single result, just do it. */ if (Z_TYPE_P(return_value) != IS_ARRAY) { if (key_type == HASH_KEY_IS_STRING) { Index: php4/ext/standard/basic_functions.c diff -u php4/ext/standard/basic_functions.c:1.393 php4/ext/standard/basic_functions.c:1.394 --- php4/ext/standard/basic_functions.c:1.393 Sun Sep 2 21:06:23 2001 +++ php4/ext/standard/basic_functions.c Wed Sep 5 15:47:54 2001 @@ -17,7 +17,7 @@ +----------------------------------------------------------------------+ */ -/* $Id: basic_functions.c,v 1.393 2001/09/03 01:06:23 jeroen Exp $ */ +/* $Id: basic_functions.c,v 1.394 2001/09/05 19:47:54 sniper Exp $ */ #include "php.h" #include "php_main.h" @@ -25,6 +25,7 @@ #include "php_ini.h" #include "internal_functions_registry.h" #include "php_standard.h" +#include "php_math.h" #include "php_incomplete_class.h" #include "ext/standard/info.h" #include "ext/session/php_session.h" @@ -950,7 +951,6 @@ PHP_MINIT(crypt) (INIT_FUNC_ARGS_PASSTHRU); #endif - PHP_MINIT(rand)(INIT_FUNC_ARGS_PASSTHRU); #ifdef ZTS PHP_MINIT(lcg) (INIT_FUNC_ARGS_PASSTHRU); #endif @@ -1030,6 +1030,10 @@ #endif BG(user_shutdown_function_names) = NULL; +#if HAVE_CRYPT + PHP_RINIT(crypt) (INIT_FUNC_ARGS_PASSTHRU); +#endif + #ifndef ZTS PHP_RINIT(lcg) (INIT_FUNC_ARGS_PASSTHRU); #endif @@ -1037,7 +1041,6 @@ PHP_RINIT(filestat) (INIT_FUNC_ARGS_PASSTHRU); PHP_RINIT(syslog) (INIT_FUNC_ARGS_PASSTHRU); PHP_RINIT(dir) (INIT_FUNC_ARGS_PASSTHRU); - PHP_RINIT(rand) (INIT_FUNC_ARGS_PASSTHRU); return SUCCESS; } Index: php4/ext/standard/basic_functions.h diff -u php4/ext/standard/basic_functions.h:1.92 php4/ext/standard/basic_functions.h:1.93 --- php4/ext/standard/basic_functions.h:1.92 Sun Sep 2 21:06:23 2001 +++ php4/ext/standard/basic_functions.h Wed Sep 5 15:47:55 2001 @@ -17,7 +17,7 @@ +----------------------------------------------------------------------+ */ -/* $Id: basic_functions.h,v 1.92 2001/09/03 01:06:23 jeroen Exp $ */ +/* $Id: basic_functions.h,v 1.93 2001/09/05 19:47:55 sniper Exp $ */ #ifndef BASIC_FUNCTIONS_H #define BASIC_FUNCTIONS_H @@ -170,13 +170,6 @@ struct stat lsb; /* rand.c */ - int rand_generator; /* current ini-setting */ - int rand_generator_current; /* current (by overriding by [mt_]srand) */ - - /* rand_sys.c */ - unsigned int rand_sys_seed; /* Current seed for system-rand() (necessary for thread-safety) */ - - /* rand_mt.c */ php_uint32 state[MT_N+1]; /* state vector + 1 extra to not violate ANSI C */ php_uint32 *next; /* next random value is computed from here */ int left; /* can *next++ this many times before reloading */ Index: php4/ext/standard/crypt.c diff -u php4/ext/standard/crypt.c:1.48 php4/ext/standard/crypt.c:1.49 --- php4/ext/standard/crypt.c:1.48 Sun Sep 2 21:06:23 2001 +++ php4/ext/standard/crypt.c Wed Sep 5 15:47:55 2001 @@ -17,7 +17,7 @@ | Rasmus Lerdorf <rasmus@lerdorf.on.ca> | +----------------------------------------------------------------------+ */ -/* $Id: crypt.c,v 1.48 2001/09/03 01:06:23 jeroen Exp $ */ +/* $Id: crypt.c,v 1.49 2001/09/05 19:47:55 sniper Exp $ */ #include <stdlib.h> #include "php.h" @@ -89,6 +89,8 @@ #define PHP_CRYPT_RAND php_rand() +static int php_crypt_rand_seeded=0; + PHP_MINIT_FUNCTION(crypt) { REGISTER_LONG_CONSTANT("CRYPT_SALT_LENGTH", PHP_MAX_SALT_LEN, CONST_CS | CONST_PERSISTENT); @@ -97,6 +99,16 @@ REGISTER_LONG_CONSTANT("CRYPT_MD5", PHP_MD5_CRYPT, CONST_CS | CONST_PERSISTENT); REGISTER_LONG_CONSTANT("CRYPT_BLOWFISH", PHP_BLOWFISH_CRYPT, CONST_CS | CONST_PERSISTENT); + return SUCCESS; +} + + +PHP_RINIT_FUNCTION(crypt) +{ + if(!php_crypt_rand_seeded) { + php_srand(time(0) * getpid() * (php_combined_lcg(TSRMLS_C) * 10000.0)); + php_crypt_rand_seeded=1; + } return SUCCESS; } Index: php4/ext/standard/lcg.c diff -u php4/ext/standard/lcg.c:1.25 php4/ext/standard/lcg.c:1.26 --- php4/ext/standard/lcg.c:1.25 Sun Sep 2 21:06:23 2001 +++ php4/ext/standard/lcg.c Wed Sep 5 15:47:55 2001 @@ -16,7 +16,7 @@ +----------------------------------------------------------------------+ */ -/* $Id: lcg.c,v 1.25 2001/09/03 01:06:23 jeroen Exp $ */ +/* $Id: lcg.c,v 1.26 2001/09/05 19:47:55 sniper Exp $ */ #include "php.h" #include "php_lcg.h" @@ -42,11 +42,6 @@ * The function combines two CGs with periods of * 2^31 - 85 and 2^31 - 249. The period of this function * is equal to the product of both primes. - * - * There are only about 65k distinct starting values, that's - * not much... If PHP is running as CGI, randomness is quite bad. - * If it is run as a module, it's long-livin', so no problem in that - * case. */ #define MODMULT(a, b, c, m, s) q = s/a;s=b*(s-a*q)-c*q;if(s<0)s+=m @@ -108,5 +103,5 @@ * c-basic-offset: 4 * End: * vim600: sw=4 ts=4 tw=78 fdm=marker - * vim<600: sw=8 ts=8 tw=78 + * vim<600: sw=4 ts=4 tw=78 */ Index: php4/ext/standard/php_crypt.h diff -u php4/ext/standard/php_crypt.h:1.10 php4/ext/standard/php_crypt.h:1.11 --- php4/ext/standard/php_crypt.h:1.10 Sun Sep 2 21:06:23 2001 +++ php4/ext/standard/php_crypt.h Wed Sep 5 15:47:55 2001 @@ -18,7 +18,7 @@ +----------------------------------------------------------------------+ */ -/* $Id: php_crypt.h,v 1.10 2001/09/03 01:06:23 jeroen Exp $ */ +/* $Id: php_crypt.h,v 1.11 2001/09/05 19:47:55 sniper Exp $ */ #ifndef PHP_CRYPT_H #define PHP_CRYPT_H @@ -26,6 +26,7 @@ PHP_FUNCTION(crypt); #if HAVE_CRYPT PHP_MINIT_FUNCTION(crypt); +PHP_RINIT_FUNCTION(crypt); #endif #endif Index: php4/ext/standard/php_math.h diff -u php4/ext/standard/php_math.h:1.9 php4/ext/standard/php_math.h:1.10 --- php4/ext/standard/php_math.h:1.9 Sun Sep 2 21:06:23 2001 +++ php4/ext/standard/php_math.h Wed Sep 5 15:47:55 2001 @@ -17,7 +17,7 @@ +----------------------------------------------------------------------+ */ -/* $Id: php_math.h,v 1.9 2001/09/03 01:06:23 jeroen Exp $ */ +/* $Id: php_math.h,v 1.10 2001/09/05 19:47:55 sniper Exp $ */ #ifndef PHP_MATH_H #define PHP_MATH_H @@ -34,6 +34,12 @@ PHP_FUNCTION(log10); PHP_FUNCTION(pow); PHP_FUNCTION(sqrt); +PHP_FUNCTION(srand); +PHP_FUNCTION(rand); +PHP_FUNCTION(getrandmax); +PHP_FUNCTION(mt_srand); +PHP_FUNCTION(mt_rand); +PHP_FUNCTION(mt_getrandmax); PHP_FUNCTION(abs); PHP_FUNCTION(ceil); PHP_FUNCTION(floor); Index: php4/ext/standard/php_rand.h diff -u php4/ext/standard/php_rand.h:1.13 php4/ext/standard/php_rand.h:1.14 --- php4/ext/standard/php_rand.h:1.13 Mon Sep 3 22:19:30 2001 +++ php4/ext/standard/php_rand.h Wed Sep 5 15:47:55 2001 @@ -15,102 +15,47 @@ | Authors: Rasmus Lerdorf <rasmus@lerdorf.on.ca> | | Zeev Suraski <zeev@zend.com> | | Pedro Melo <melo@ip.pt> | - | Jeroen van Wolffelaar <jeroen@php.net> | | | | Based on code from: Shawn Cokus <Cokus@math.washington.edu> | +----------------------------------------------------------------------+ */ -/* $Id: php_rand.h,v 1.13 2001/09/04 02:19:30 dbeu Exp $ */ +/* $Id: php_rand.h,v 1.14 2001/09/05 19:47:55 sniper Exp $ */ -/* Layout implementation random functions - * - * The PHPAPI contains these functions: - * - long php_rand() - * - long php_rand_range(long min, long max) - * - void php_srand() - * - long php_getrandmax() - * - * Note that it is not possible to choose the algoritm. This is done to - * give the user the possibility to control all randomness by means of - * srand()/php.ini in a portable and consistent way. - * - * - * --Jeroen - */ - -/* TODO: - * - make constants available to PHP-user - * - MINFO section about which random number generators are available - * - Nuke randmax by enhancing PHP_RAND_RANGE to work well in the case of a - * greater request than the real (internal) randmax is - * - Implement LCG - * - Implement a real-random source? (via internet, and/or /dev/urandom?) - * - Can lrand48 be thread-safe? - * - Is random() useful sometimes? - * - Which system algorithms are available, maybe name them after real - * algorithm by compile-time detection? - * - Get this to compile :-) - */ #ifndef PHP_RAND_H #define PHP_RAND_H #include <stdlib.h> -/* FIXME: that '_php_randgen_entry' needed, or not? */ -typedef struct _php_randgen_entry { - void (*srand)(long seed TSRMLS_DC); - long (*rand)(TSRMLS_D); - long randmax; - char *ini_str; -} php_randgen_entry; - -/* an ARRAY of POINTERS, not vice versa */ -extern php_randgen_entry *php_randgen_entries[]; - -#define PHP_RANDGEN_ENTRY(which, nsrand, nrand, nrandmax, nini_str) { \ - php_randgen_entries[which] = emalloc(sizeof(php_randgen_entry)); \ - php_randgen_entries[which]->srand = nsrand; \ - php_randgen_entries[which]->rand = nrand; \ - php_randgen_entries[which]->randmax = nrandmax; \ - php_randgen_entries[which]->ini_str = nini_str; \ -} - -/* Define random generator constants */ -#define PHP_RAND_SYS 0 -#define PHP_RAND_LRAND48 1 -#define PHP_RAND_MT 2 -#define PHP_RAND_LCG 3 - -#define PHP_RAND_DEFAULT PHP_RAND_MT - -/* how many there are */ -#define PHP_RAND_NUMRANDS 4 - -/* Proto's */ -PHP_RINIT_FUNCTION(rand); -PHP_MINIT_FUNCTION(rand); -PHP_MINIT_FUNCTION(rand_mt); -PHP_MINIT_FUNCTION(rand_sys); - -PHP_FUNCTION(srand); -PHP_FUNCTION(rand); -PHP_FUNCTION(getrandmax); -PHP_FUNCTION(mt_srand); -PHP_FUNCTION(mt_rand); -PHP_FUNCTION(mt_getrandmax); - -PHPAPI long php_rand(TSRMLS_D); -PHPAPI long php_rand_range(long min, long max TSRMLS_DC); -PHPAPI double php_drand(TSRMLS_D); -PHPAPI long php_randmax(TSRMLS_D); +#ifndef RAND_MAX +#define RAND_MAX (1<<15) +#endif + +#if HAVE_LRAND48 +#define PHP_RAND_MAX 2147483647 +#else +#define PHP_RAND_MAX RAND_MAX +#endif + +/* Define rand Function wrapper */ +#ifdef HAVE_RANDOM +#define php_rand() random() +#else +#ifdef HAVE_LRAND48 +#define php_rand() lrand48() +#else +#define php_rand() rand() +#endif +#endif + +/* Define srand Function wrapper */ +#ifdef HAVE_SRANDOM +#define php_srand(seed) srandom((unsigned int)seed) +#else +#ifdef HAVE_SRAND48 +#define php_srand(seed) srand48((long)seed) +#else +#define php_srand(seed) srand((unsigned int)seed) +#endif +#endif #endif /* PHP_RAND_H */ - -/* - * Local variables: - * tab-width: 4 - * c-basic-offset: 4 - * End: - * vim600: fdm=marker - * vim: sw=4 ts=4 tw=78 - */ Index: php4/ext/standard/php_standard.h diff -u php4/ext/standard/php_standard.h:1.8 php4/ext/standard/php_standard.h:1.9 --- php4/ext/standard/php_standard.h:1.8 Sun Sep 2 21:06:23 2001 +++ php4/ext/standard/php_standard.h Wed Sep 5 15:47:55 2001 @@ -16,11 +16,10 @@ +----------------------------------------------------------------------+ */ -/* $Id: php_standard.h,v 1.8 2001/09/03 01:06:23 jeroen Exp $ */ +/* $Id: php_standard.h,v 1.9 2001/09/05 19:47:55 sniper Exp $ */ #include "basic_functions.h" #include "php_math.h" -#include "php_rand.h" #include "php_string.h" #include "base64.h" #include "php_dir.h" Index: php4/ext/standard/rand.c diff -u php4/ext/standard/rand.c:1.37 php4/ext/standard/rand.c:1.38 --- php4/ext/standard/rand.c:1.37 Mon Sep 3 22:19:30 2001 +++ php4/ext/standard/rand.c Wed Sep 5 15:47:55 2001 @@ -15,276 +15,313 @@ | Authors: Rasmus Lerdorf <rasmus@lerdorf.on.ca> | | Zeev Suraski <zeev@zend.com> | | Pedro Melo <melo@ip.pt> | - | Jeroen van Wolffelaar <jeroen@php.net> | + | | + | Based on code from: Shawn Cokus <Cokus@math.washington.edu> | +----------------------------------------------------------------------+ */ -/* $Id: rand.c,v 1.37 2001/09/04 02:19:30 dbeu Exp $ */ +/* $Id: rand.c,v 1.38 2001/09/05 19:47:55 sniper Exp $ */ #include <stdlib.h> #include "php.h" #include "php_math.h" #include "php_rand.h" -#include "php_lcg.h" -#include "php_ini.h" - -#include "zend_execute.h" #include "basic_functions.h" -/* See php_rand.h for information about layout */ - -/* an ARRAY of POINTERS, not vice versa */ -php_randgen_entry *php_randgen_entries[PHP_RAND_NUMRANDS]; - -#define PHP_HAS_SRAND(which) (php_randgen_entries[which] && php_randgen_entries[which]->srand) -#define PHP_SRAND(which,seed) ((*(php_randgen_entries[which]->srand))(seed TSRMLS_CC)) -#define PHP_RAND(which) ((*(php_randgen_entries[which]->rand))(TSRMLS_C)) -#define PHP_RANDMAX(which) (php_randgen_entries[which]->randmax) -#define PHP_RAND_INISTR(which) (php_randgen_entries[which]->ini_str) - -#define CURR_GEN BG(rand_generator_current) - -PHP_MINIT_FUNCTION(rand) -{ - PHP_MINIT(rand_sys)(INIT_FUNC_ARGS_PASSTHRU); - PHP_MINIT(rand_mt)(INIT_FUNC_ARGS_PASSTHRU); - /* lcg not yet implemented */ - php_randgen_entries[PHP_RAND_LCG] = NULL; +/* + This is the ``Mersenne Twister'' random number generator MT19937, which + generates pseudorandom integers uniformly distributed in 0..(2^32 - 1) + starting from any odd seed in 0..(2^32 - 1). This version is a recode + by Shawn Cokus (Cokus@math.washington.edu) on March 8, 1998 of a version by + Takuji Nishimura (who had suggestions from Topher Cooper and Marc Rieffel in + July-August 1997). + + Effectiveness of the recoding (on Goedel2.math.washington.edu, a DEC Alpha + running OSF/1) using GCC -O3 as a compiler: before recoding: 51.6 sec. to + generate 300 million random numbers; after recoding: 24.0 sec. for the same + (i.e., 46.5% of original time), so speed is now about 12.5 million random + number generations per second on this machine. + + According to the URL <http://www.math.keio.ac.jp/~matumoto/emt.html> + (and paraphrasing a bit in places), the Mersenne Twister is ``designed + with consideration of the flaws of various existing generators,'' has + a period of 2^19937 - 1, gives a sequence that is 623-dimensionally + equidistributed, and ``has passed many stringent tests, including the + die-hard test of G. Marsaglia and the load test of P. Hellekalek and + S. Wegenkittl.'' It is efficient in memory usage (typically using 2506 + to 5012 bytes of static data, depending on data type sizes, and the code + is quite short as well). It generates random numbers in batches of 624 + at a time, so the caching and pipelining of modern systems is exploited. + It is also divide- and mod-free. + + This library is free software; you can redistribute it and/or modify it + under the terms of the GNU Library General Public License as published by + the Free Software Foundation (either version 2 of the License or, at your + option, any later version). This library is distributed in the hope that + it will be useful, but WITHOUT ANY WARRANTY, without even the implied + warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + the GNU Library General Public License for more details. You should have + received a copy of the GNU Library General Public License along with this + library; if not, write to the Free Software Foundation, Inc., 59 Temple + Place, Suite 330, Boston, MA 02111-1307, USA. + + The code as Shawn received it included the following notice: + + Copyright (C) 1997 Makoto Matsumoto and Takuji Nishimura. When + you use this, send an e-mail to <matumoto@math.keio.ac.jp> with + an appropriate reference to your work. + + It would be nice to CC: <Cokus@math.washington.edu> when you write. + + + + php_uint32 must be an unsigned integer type capable of holding at least 32 + bits; exactly 32 should be fastest, but 64 is better on an Alpha with + GCC at -O3 optimization so try your options and see what's best for you + + Melo: we should put some ifdefs here to catch those alphas... +*/ + + +#define N MT_N /* length of state vector */ +#define M (397) /* a period parameter */ +#define K (0x9908B0DFU) /* a magic constant */ +#define hiBit(u) ((u) & 0x80000000U) /* mask all but highest bit of u */ +#define loBit(u) ((u) & 0x00000001U) /* mask all but lowest bit of u */ +#define loBits(u) ((u) & 0x7FFFFFFFU) /* mask the highest bit of u */ +#define mixBits(u, v) (hiBit(u)|loBits(v)) /* move hi bit of u to hi bit of v */ - return SUCCESS; -} +#define MT_RAND_MAX ((long)(0x7FFFFFFF)) /* (1<<31) - 1 */ -/* TODO: check that this function is called on the start of each script - * execution: not more often, not less often. - * - * Note that system rand is inherently thread-unsafe: A different thread can - * always eat up some rand()'s, and thus nuking your expected sequence. - * Another reason to use MT... +/* {{{ seedMT */ -PHP_RINIT_FUNCTION(rand) +static void seedMT(php_uint32 seed TSRMLS_DC) { - register int i; - - /* seed all number-generators */ - /* FIXME: or seed relevant numgen on init/update ini-entry? */ - for (i = 0 ; i < PHP_RAND_NUMRANDS ; i++) { - if (PHP_HAS_SRAND(i)) { -#define SRAND_A_RANDOM_SEED ((long)time(0) * (long)getpid() * (long)(php_combined_lcg(TSRMLS_C) * 10000.0)) /* something with microtime? */ - PHP_SRAND(i,SRAND_A_RANDOM_SEED); - } - } - - return SUCCESS; + /* + We initialize state[0..(N-1)] via the generator + + x_new = (69069 * x_old) mod 2^32 + + from Line 15 of Table 1, p. 106, Sec. 3.3.4 of Knuth's + _The Art of Computer Programming_, Volume 2, 3rd ed. + + Notes (SJC): I do not know what the initial state requirements + of the Mersenne Twister are, but it seems this seeding generator + could be better. It achieves the maximum period for its modulus + (2^30) iff x_initial is odd (p. 20-21, Sec. 3.2.1.2, Knuth); if + x_initial can be even, you have sequences like 0, 0, 0, ...; + 2^31, 2^31, 2^31, ...; 2^30, 2^30, 2^30, ...; 2^29, 2^29 + 2^31, + 2^29, 2^29 + 2^31, ..., etc. so I force seed to be odd below. + + Even if x_initial is odd, if x_initial is 1 mod 4 then + + the lowest bit of x is always 1, + the next-to-lowest bit of x is always 0, + the 2nd-from-lowest bit of x alternates ... 0 1 0 1 0 1 0 1 ... , + the 3rd-from-lowest bit of x 4-cycles ... 0 1 1 0 0 1 1 0 ... , + the 4th-from-lowest bit of x has the 8-cycle ... 0 0 0 1 1 1 1 0 ... , + ... + + and if x_initial is 3 mod 4 then + + the lowest bit of x is always 1, + the next-to-lowest bit of x is always 1, + the 2nd-from-lowest bit of x alternates ... 0 1 0 1 0 1 0 1 ... , + the 3rd-from-lowest bit of x 4-cycles ... 0 0 1 1 0 0 1 1 ... , + the 4th-from-lowest bit of x has the 8-cycle ... 0 0 1 1 1 1 0 0 ... , + ... + + The generator's potency (min. s>=0 with (69069-1)^s = 0 mod 2^32) is + 16, which seems to be alright by p. 25, Sec. 3.2.1.3 of Knuth. It + also does well in the dimension 2..5 spectral tests, but it could be + better in dimension 6 (Line 15, Table 1, p. 106, Sec. 3.3.4, Knuth). + + Note that the random number user does not see the values generated + here directly since reloadMT() will always munge them first, so maybe + none of all of this matters. In fact, the seed values made here could + even be extra-special desirable if the Mersenne Twister theory says + so-- that's why the only change I made is to restrict to odd seeds. + */ + + register php_uint32 x = (seed | 1U) & 0xFFFFFFFFU, *s = BG(state); + register int j; + + for(BG(left)=0, *s++=x, j=N; --j; + *s++ = (x*=69069U) & 0xFFFFFFFFU); +} +/* }}} */ + +static php_uint32 reloadMT(TSRMLS_D) +{ + register php_uint32 *p0=BG(state), *p2=BG(state)+2, *pM=BG(state)+M, s0, s1; + register int j; + + if(BG(left) < -1) + seedMT(4357U TSRMLS_CC); + + BG(left)=N-1, BG(next)=BG(state)+1; + + for(s0=BG(state)[0], s1=BG(state)[1], j=N-M+1; --j; s0=s1, s1=*p2++) + *p0++ = *pM++ ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U); + + for(pM=BG(state), j=M; --j; s0=s1, s1=*p2++) + *p0++ = *pM++ ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U); + + s1=BG(state)[0], *p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U); + s1 ^= (s1 >> 11); + s1 ^= (s1 << 7) & 0x9D2C5680U; + s1 ^= (s1 << 15) & 0xEFC60000U; + return(s1 ^ (s1 >> 18)); +} + + +static inline php_uint32 randomMT(void) +{ + php_uint32 y; + TSRMLS_FETCH(); + + if(--BG(left) < 0) + return(reloadMT(TSRMLS_C)); + + y = *BG(next)++; + y ^= (y >> 11); + y ^= (y << 7) & 0x9D2C5680U; + y ^= (y << 15) & 0xEFC60000U; + return(y ^ (y >> 18)); } -/* INI */ -static int randgen_str_to_int(char *str, int strlen) +/* {{{ proto void srand(int seed) + Seeds random number generator */ +PHP_FUNCTION(srand) { - register int i; + pval **arg; - for (i = 0 ; i < PHP_RAND_NUMRANDS ; i++) { - if (!strcasecmp(str, PHP_RAND_INISTR(i))) - return i; - } - return -1; -} - -/* FIXME: check that this is called on initial ini-parsing too */ -/* FIXME: what if no ini-entry was present? */ -static PHP_INI_MH(OnUpdateRandGen) -{ - /* Set BG(rand_generator) to the correct integer value indicating - * ini-setting */ - BG(rand_generator) = randgen_str_to_int(new_value, new_value_length); - if (BG(rand_generator) == -1) { - /* FIXME: is this possible? What happens if this occurs during - * ini-parsing at startup? */ - php_error(E_WARNING,"Invalid value for random_number_generator: \"%s\"", new_value); - /* Fallback: */ - BG(rand_generator) = PHP_RAND_DEFAULT; + if (ZEND_NUM_ARGS() != 1 || zend_get_parameters_ex(1, &arg) == FAILURE) { + WRONG_PARAM_COUNT; } -#ifdef DEBUG_RAND - printf("\nRAND-INI updated: %d\n",BG(rand_generator)); -#endif - return SUCCESS; + convert_to_long_ex(arg); + php_srand((*arg)->value.lval); } +/* }}} */ -PHP_INI_BEGIN() - /* FIXME: default is hardcoded here, this is the second place */ - PHP_INI_ENTRY("random_number_generator", "mt", PHP_INI_ALL, OnUpdateRandGen) -PHP_INI_END() - -/* srand */ - -/* FIXME: isn't used? */ -/* {{{ void php_srand(void) */ -static void php_srand(TSRMLS_D) +/* {{{ proto void mt_srand(int seed) + Seeds Mersenne Twister random number generator */ +PHP_FUNCTION(mt_srand) { - CURR_GEN = BG(rand_generator); - PHP_SRAND(BG(rand_generator), SRAND_A_RANDOM_SEED); -} -/* }}} */ + pval **arg; -/* {{{ [mt_]srand common */ -#define pim_srand_common(name,type) \ -PHP_FUNCTION(name) \ -{ \ - zval **seed; \ - zval **alg; \ - \ - switch (ZEND_NUM_ARGS()) { \ - case 0: \ - CURR_GEN = BG(rand_generator); \ - PHP_SRAND(BG(rand_generator), SRAND_A_RANDOM_SEED); \ - RETURN_TRUE; \ - case 1: \ - zend_get_parameters_ex(1, &seed); \ - convert_to_long_ex(seed); \ - CURR_GEN = type; \ - PHP_SRAND(type, Z_LVAL_PP(seed)); \ - RETURN_TRUE; \ - case 2: \ - /* algorithm, seed is most logic, though it is the other way - * around than current way... */ \ - zend_get_parameters_ex(2, &alg, &seed); \ - convert_to_long_ex(seed); \ - convert_to_long_ex(alg); \ - if (0 > Z_LVAL_PP(alg) || Z_LVAL_PP(alg) >= PHP_RAND_NUMRANDS) { \ - php_error(E_WARNING, "%s(): There is no algorithm %d.", get_active_function_name(TSRMLS_C), Z_LVAL_PP(alg)); \ - RETURN_FALSE; \ - } \ - if (!PHP_HAS_SRAND(Z_LVAL_PP(alg))) { \ - php_error(E_WARNING, "%s(): Algorithm %d does not support reproducable results.", get_active_function_name(TSRMLS_C), Z_LVAL_PP(alg)); \ - RETURN_FALSE; \ - } \ - CURR_GEN = Z_LVAL_PP(alg); \ - PHP_SRAND(Z_LVAL_PP(alg), Z_LVAL_PP(seed)); \ - RETURN_TRUE; \ - default: \ - WRONG_PARAM_COUNT; \ - } \ + if (ZEND_NUM_ARGS() != 1 || zend_get_parameters_ex(1, &arg) == FAILURE) { + WRONG_PARAM_COUNT; + } + convert_to_long_ex(arg); + seedMT((*arg)->value.lval TSRMLS_CC); } /* }}} */ -/* {{{ proto bool srand(int seed) - Seeds random number generator */ -pim_srand_common(srand,PHP_RAND_SYS) -/* }}} */ - -/* {{{ proto bool mt_srand(int seed) - Seeds random number generator */ -pim_srand_common(mt_srand,PHP_RAND_MT) -/* }}} */ - -/* rand */ - -/* {{{ PHPAPI long php_rand(void) */ -PHPAPI long php_rand(TSRMLS_D) +/* {{{ proto int rand([int min, int max]) + Returns a random number */ +PHP_FUNCTION(rand) { - return PHP_RAND(CURR_GEN); -} -/* }}} */ + pval **p_min=NULL, **p_max=NULL; + + switch (ZEND_NUM_ARGS()) { + case 0: + break; + case 2: + if (zend_get_parameters_ex(2, &p_min, &p_max)==FAILURE) { + RETURN_FALSE; + } + convert_to_long_ex(p_min); + convert_to_long_ex(p_max); + if ((*p_max)->value.lval-(*p_min)->value.lval < 0) { + php_error(E_WARNING, "rand(): Invalid range: %ld..%ld", (*p_min)->value.lval, (*p_max)->value.lval); + } else if ((*p_max)->value.lval-(*p_min)->value.lval > PHP_RAND_MAX){ + php3_error(E_WARNING, "rand(): Invalid range: %ld..%ld", (*p_min)->value.lval, (*p_max)->value.lval); + } + break; + default: + WRONG_PARAM_COUNT; + break; + } + + return_value->type = IS_LONG; -/* {{{ PHPAPI double php_drand(void) - * returns a double in the range [0,1) */ -PHPAPI double php_drand(TSRMLS_D) -{ - return (double)php_rand(TSRMLS_C) / - (double)(PHP_RANDMAX(CURR_GEN)+1.0); -} -/* }}} */ + return_value->value.lval = php_rand(); -/* {{{ macro: PHP_RAND_RANGE */ -#define PHP_RAND_RANGE(which,min,max,result) { \ /* * A bit of tricky math here. We want to avoid using a modulus because * that simply tosses the high-order bits and might skew the distribution * of random values over the range. Instead we map the range directly. * * We need to map the range from 0...M evenly to the range a...b - * Expressed in real numbers, this becomes: - * - * [0,M+1[ mapped to [a,b+1[ - * * Let n = the random number and n' = the mapped random number - * So the formula needs to be: - * - * n' = a + n((b+1)-a)/(m+1) * - * This isn't perfect, because n only takes integer values. So when a..b - * spans a significant portion of 0..M, some numbers have nearly twice as - * much chance. But since twice a very small chance is still a very small - * chance, it's ignored. - * - * --Rasmus and Jeroen - */ \ - (result) = PHP_RAND(which); \ - if ((max) < (min)) { \ - php_error(E_WARNING, "%s(): Invalid range: %ld..%ld (minimum can't be larger than maximum)", \ - get_active_function_name(TSRMLS_C), (min), (max)); \ - } else if ( (max) - (min) > PHP_RANDMAX(which) ) { \ - /* TODO: this can done better, get two numbers and combine... */ \ - php_error(E_WARNING, "%s(): Invalid range: %ld..%ld (can't give that much randomness)", \ - get_active_function_name(TSRMLS_C), (min), (max)); \ - } \ - (result) = (min) + (long) ((double)((max)-(min)+1) * (result)/(PHP_RANDMAX(which)+1.0)); \ -} -/* }}} */ - -/* {{{ PHPAPI long php_rand_range(long min, long max) */ -PHPAPI long php_rand_range(long min, long max TSRMLS_DC) -{ - register long result; - - PHP_RAND_RANGE(CURR_GEN, min, max, result); - return result; -} -/* }}} */ - -/* {{{ [mt_]rand common */ -#define PHP_FUNCTION_RAND(name,which) \ -PHP_FUNCTION(name) \ -{ \ - zval **min, **max; \ - \ - switch (ZEND_NUM_ARGS()) { \ - case 0: \ - RETURN_LONG(PHP_RAND(which)); \ - case 2: \ - if (zend_get_parameters_ex(2, &min, &max)==FAILURE) { \ - RETURN_FALSE; \ - } \ - convert_to_long_ex(min); \ - convert_to_long_ex(max); \ - Z_TYPE_P(return_value) = IS_LONG; \ - PHP_RAND_RANGE(which, Z_LVAL_PP(min), \ - Z_LVAL_PP(max), Z_LVAL_P(return_value)); \ - return; \ - default: \ - WRONG_PARAM_COUNT; \ - break; \ - } \ + * Then we have: n' = a + n(b-a)/M + * + * We have a problem here in that only n==M will get mapped to b which + # means the chances of getting b is much much less than getting any of + # the other values in the range. We can fix this by increasing our range + # artifically and using: + # + # n' = a + n(b-a+1)/M + * + # Now we only have a problem if n==M which would cause us to produce a + # number of b+1 which would be bad. So we bump M up by one to make sure + # this will never happen, and the final algorithm looks like this: + # + # n' = a + n(b-a+1)/(M+1) + * + * -RL + */ + if (p_min && p_max) { /* implement range */ + return_value->value.lval = (*p_min)->value.lval + + (int)((double)((*p_max)->value.lval - (*p_min)->value.lval + 1.0) * return_value->value.lval/(PHP_RAND_MAX+1.0)); + } } /* }}} */ -/* {{{ proto int rand([int min, int max]) - Returns a random number */ -PHP_FUNCTION_RAND(rand,PHP_RAND_SYS) -/* }}} */ - -/* {{{ proto int mt_rand([int min, int max]) - Returns a random number by means of Mersenne Twister */ -PHP_FUNCTION_RAND(mt_rand,PHP_RAND_MT) -/* }}} */ - -/* getrandmax */ - -/* {{{ PHPAPI long php_randmax(void) - Returns the maximum value a random number can have */ -PHPAPI long php_randmax(TSRMLS_D) +/* {{{ proto int mt_rand([int min, int max]) + Returns a random number from Mersenne Twister */ +PHP_FUNCTION(mt_rand) { - return PHP_RANDMAX(CURR_GEN); + pval **p_min=NULL, **p_max=NULL; + + switch (ZEND_NUM_ARGS()) { + case 0: + break; + case 2: + if (zend_get_parameters_ex(2, &p_min, &p_max)==FAILURE) { + RETURN_FALSE; + } + convert_to_long_ex(p_min); + convert_to_long_ex(p_max); + if ((*p_max)->value.lval-(*p_min)->value.lval <= 0) { + php_error(E_WARNING, "mt_rand(): Invalid range: %ld..%ld", (*p_min)->value.lval, (*p_max)->value.lval); + }else if ((*p_max)->value.lval-(*p_min)->value.lval > MT_RAND_MAX){ + php3_error(E_WARNING, "mt_rand(): Invalid range: %ld..%ld", (*p_min)->value.lval, (*p_max)->value.lval); + } + break; + default: + WRONG_PARAM_COUNT; + break; + } + + return_value->type = IS_LONG; + /* + * Melo: hmms.. randomMT() returns 32 random bits... + * Yet, the previous php_rand only returns 31 at most. + * So I put a right shift to loose the lsb. It *seems* + * better than clearing the msb. + * Update: + * I talked with Cokus via email and it won't ruin the algorithm + */ + return_value->value.lval = (long)(randomMT() >> 1); + + if (p_min && p_max) { /* implement range */ + return_value->value.lval = (*p_min)->value.lval + + (long)((double)((*p_max)->value.lval - (*p_min)->value.lval + 1.0) * return_value->value.lval/(MT_RAND_MAX+1.0)); + } } /* }}} */ @@ -296,19 +333,25 @@ WRONG_PARAM_COUNT; } - RETURN_LONG( php_randmax(TSRMLS_C)); + return_value->type = IS_LONG; + return_value->value.lval = PHP_RAND_MAX; } /* }}} */ /* {{{ proto int mt_getrandmax(void) - Returns the maximum value a random number can have */ + Returns the maximum value a random number from Mersenne Twister can have */ PHP_FUNCTION(mt_getrandmax) { if (ZEND_NUM_ARGS() != 0) { WRONG_PARAM_COUNT; } - RETURN_LONG( php_randmax(TSRMLS_C) ); + return_value->type = IS_LONG; + /* + * Melo: it could be 2^^32 but we only use 2^^31 to maintain + * compatibility with the previous php_rand + */ + return_value->value.lval = MT_RAND_MAX; /* 2^^31 */ } /* }}} */ @@ -318,5 +361,5 @@ * c-basic-offset: 4 * End: * vim600: sw=4 ts=4 tw=78 fdm=marker - * vim: sw=4 ts=4 tw=78 + * vim<600: sw=4 ts=4 tw=78 */