From: Jeroen van Wolffelaar Date: Mon, 3 Sep 2001 01:06:23 +0000 (+0000) Subject: Merge RAND_REDESIGN into MAIN X-Git-Tag: PRE_SUBST_Z_MACROS~265 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f7306ce0109b246ff23901ed6b91d58de4c9dd42;p=php Merge RAND_REDESIGN into MAIN --- diff --git a/ext/standard/Makefile.in b/ext/standard/Makefile.in index 123e4cb110..fb6c845467 100644 --- a/ext/standard/Makefile.in +++ b/ext/standard/Makefile.in @@ -5,7 +5,8 @@ LTLIBRARY_SOURCES=\ 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 reg.c soundex.c string.c scanf.c \ + parsedate.c quot_print.c rand.c rand_sys.c rand_mt.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 diff --git a/ext/standard/array.c b/ext/standard/array.c index 83942db409..a453b1fbcf 100644 --- a/ext/standard/array.c +++ b/ext/standard/array.c @@ -2726,6 +2726,8 @@ PHP_FUNCTION(array_rand) ulong num_key; HashPosition pos; + php_error(E_ERROR, "Function array_rand temporarily disabled"); + if (ZEND_NUM_ARGS() < 1 || ZEND_NUM_ARGS() > 2 || zend_get_parameters_ex(ZEND_NUM_ARGS(), &input, &num_req) == FAILURE) { WRONG_PARAM_COUNT; @@ -2767,6 +2769,9 @@ PHP_FUNCTION(array_rand) randval = rand(); #endif #endif + + /* TEMPORARY HACK TO GET IT COMPILE */ +#define PHP_RAND_MAX 1 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. */ diff --git a/ext/standard/basic_functions.c b/ext/standard/basic_functions.c index e7b71ebebf..fca3d4d1ac 100644 --- a/ext/standard/basic_functions.c +++ b/ext/standard/basic_functions.c @@ -25,7 +25,6 @@ #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" @@ -951,6 +950,7 @@ PHP_MINIT_FUNCTION(basic) 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 @@ -1030,10 +1030,6 @@ PHP_RINIT_FUNCTION(basic) #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 @@ -1041,6 +1037,7 @@ PHP_RINIT_FUNCTION(basic) 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; } diff --git a/ext/standard/basic_functions.h b/ext/standard/basic_functions.h index 38a06413eb..c246348c99 100644 --- a/ext/standard/basic_functions.h +++ b/ext/standard/basic_functions.h @@ -170,6 +170,13 @@ typedef struct { 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 */ diff --git a/ext/standard/crypt.c b/ext/standard/crypt.c index 00490f78e4..bdd085b5d3 100644 --- a/ext/standard/crypt.c +++ b/ext/standard/crypt.c @@ -89,8 +89,6 @@ extern char *crypt(char *__key, char *__salt); #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); @@ -103,16 +101,6 @@ PHP_MINIT_FUNCTION(crypt) } -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; -} - - static unsigned char itoa64[] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; static void php_to64(char *s, long v, int n) { diff --git a/ext/standard/lcg.c b/ext/standard/lcg.c index 7ae45a0ef0..f211317d73 100644 --- a/ext/standard/lcg.c +++ b/ext/standard/lcg.c @@ -42,6 +42,11 @@ static int php_lcg_initialized = 0; * 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 @@ -103,5 +108,5 @@ PHP_FUNCTION(lcg_value) * c-basic-offset: 4 * End: * vim600: sw=4 ts=4 tw=78 fdm=marker - * vim<600: sw=4 ts=4 tw=78 + * vim<600: sw=8 ts=8 tw=78 */ diff --git a/ext/standard/php_crypt.h b/ext/standard/php_crypt.h index b4b04bbd51..a977d61055 100644 --- a/ext/standard/php_crypt.h +++ b/ext/standard/php_crypt.h @@ -26,7 +26,6 @@ PHP_FUNCTION(crypt); #if HAVE_CRYPT PHP_MINIT_FUNCTION(crypt); -PHP_RINIT_FUNCTION(crypt); #endif #endif diff --git a/ext/standard/php_math.h b/ext/standard/php_math.h index beef7dd160..71e7d40972 100644 --- a/ext/standard/php_math.h +++ b/ext/standard/php_math.h @@ -34,12 +34,6 @@ PHP_FUNCTION(log); 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); diff --git a/ext/standard/php_rand.h b/ext/standard/php_rand.h index b4d7e991d0..19686a8066 100644 --- a/ext/standard/php_rand.h +++ b/ext/standard/php_rand.h @@ -15,47 +15,116 @@ | Authors: Rasmus Lerdorf | | Zeev Suraski | | Pedro Melo | + | Jeroen van Wolffelaar | | | | Based on code from: Shawn Cokus | +----------------------------------------------------------------------+ */ /* $Id$ */ +/* 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. + * + * rand.c: (the only rand*.c file with PHP_API and PHP_FUNCTION functions) + * + * - PHP_FUNCTION([mt_]srand) + * +-> void php_srand(void) + * +-> void php_srand2(long seed, int alg) + * +-> (rand_sys.c) long php_rand_sys() + * +-> (rand_mt.c ) long php_rand_mt() + * + * - PHP_FUNCTION([mt_]rand) + * +-> long php_rand() + * +-> (rand_sys.c) long php_rand_sys() + * +-> (rand_mt.c ) long php_rand_mt() + * +-> long php_rand_range(long min, long max) + * +-> calls php_rand() + * + * - PHP_FUNCTION([mt_]getrandmax) + * +-> PHPAPI long php_randmax(void) + * +-> (rand_sys.c) long php_randmax_sys() + * +-> (rand_mt.c ) long php_randmax_mt() + * + * --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 -#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 +/* FIXME: that '_php_randgen_entry' needed, or not? */ +typedef struct _php_randgen_entry { + void (*srand)(long seed); + long (*rand)(void); + 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_FUNCTION(srand); +PHP_FUNCTION(rand); +PHP_FUNCTION(getrandmax); +PHP_FUNCTION(mt_srand); +PHP_FUNCTION(mt_rand); +PHP_FUNCTION(mt_getrandmax); + +PHPAPI long php_rand(void); +PHPAPI long php_rand_range(long min, long max); +PHPAPI double php_drand(void); +PHPAPI long php_randmax(void); #endif /* PHP_RAND_H */ + +/* + * Local variables: + * tab-width: 4 + * c-basic-offset: 4 + * End: + * vim600: fdm=marker + * vim: sw=4 ts=4 tw=78 + */ diff --git a/ext/standard/php_standard.h b/ext/standard/php_standard.h index 536c13807e..2a05b61be7 100644 --- a/ext/standard/php_standard.h +++ b/ext/standard/php_standard.h @@ -20,6 +20,7 @@ #include "basic_functions.h" #include "php_math.h" +#include "php_rand.h" #include "php_string.h" #include "base64.h" #include "php_dir.h" diff --git a/ext/standard/rand.c b/ext/standard/rand.c index 4ac3bc0507..531d502182 100644 --- a/ext/standard/rand.c +++ b/ext/standard/rand.c @@ -15,8 +15,6 @@ | Authors: Rasmus Lerdorf | | Zeev Suraski | | Pedro Melo | - | | - | Based on code from: Shawn Cokus | +----------------------------------------------------------------------+ */ /* $Id$ */ @@ -26,302 +24,258 @@ #include "php.h" #include "php_math.h" #include "php_rand.h" +#include "php_ini.h" -#include "basic_functions.h" +#include "zend_execute.h" -/* - 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 - (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 with - an appropriate reference to your work. - - It would be nice to CC: 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 */ - -#define MT_RAND_MAX ((long)(0x7FFFFFFF)) /* (1<<31) - 1 */ - -/* {{{ seedMT - */ -static void seedMT(php_uint32 seed TSRMLS_DC) -{ - /* - 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); -} -/* }}} */ +#include "basic_functions.h" -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; +/* See php_rand.h for information about layout */ - if(BG(left) < -1) - seedMT(4357U TSRMLS_CC); +/* an ARRAY of POINTERS, not vice versa */ +php_randgen_entry *php_randgen_entries[PHP_RAND_NUMRANDS]; - BG(left)=N-1, BG(next)=BG(state)+1; +#define PHP_HAS_SRAND(which) (php_randgen_entries[which]->srand) +#define PHP_SRAND(which,seed) ((*(php_randgen_entries[which]->srand))(seed)) +#define PHP_RAND(which) ((*(php_randgen_entries[which]->rand))()) +#define PHP_RANDMAX(which) (php_randgen_entries[which]->randmax) +#define PHP_RAND_INISTR(which) (php_randgen_entries[which]->ini_str) - 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); +#define CURR_GEN BG(rand_generator_current) - for(pM=BG(state), j=M; --j; s0=s1, s1=*p2++) - *p0++ = *pM++ ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U); +PHP_MINIT_FUNCTION(rand) +{ + PHP_MINIT(rand_sys)(INIT_FUNC_ARGS_PASSTHRU); + PHP_MINIT(rand_mt)(INIT_FUNC_ARGS_PASSTHRU); +} - 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)); +/* 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... + */ +PHP_RINIT_FUNCTION(rand) +{ + 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 (time(0) * getpid() * (php_combined_lcg(TSRMLS_C) * 10000.0)) /* something with microtime? */ + PHP_SRAND(i,SRAND_A_RANDOM_SEED); + } + } } +/* INI */ +static int randgen_str_to_int(char *str, int strlen) +{ + register int i; -static inline php_uint32 randomMT(void) + 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) { - php_uint32 y; - TSRMLS_FETCH(); + /* 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; + } +#ifdef DEBUG_RAND + printf("\nRAND-INI updated: %d\n",BG(rand_generator)); +#endif + return SUCCESS; +} - if(--BG(left) < 0) - return(reloadMT(TSRMLS_C)); +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() - y = *BG(next)++; - y ^= (y >> 11); - y ^= (y << 7) & 0x9D2C5680U; - y ^= (y << 15) & 0xEFC60000U; - return(y ^ (y >> 18)); -} +/* srand */ -/* {{{ proto void srand(int seed) - Seeds random number generator */ -PHP_FUNCTION(srand) +/* {{{ PHPAPI void php_srand(void) */ +PHPAPI void php_srand(void) { - pval **arg; + CURR_GEN = BG(rand_generator); + PHP_SRAND(BG(rand_generator), SRAND_A_RANDOM_SEED); +} +/* }}} */ - if (ZEND_NUM_ARGS() != 1 || zend_get_parameters_ex(1, &arg) == FAILURE) { - WRONG_PARAM_COUNT; - } - convert_to_long_ex(arg); - php_srand((*arg)->value.lval); +/* {{{ [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; \ + } \ } /* }}} */ -/* {{{ proto void mt_srand(int seed) - Seeds Mersenne Twister random number generator */ -PHP_FUNCTION(mt_srand) -{ - pval **arg; +/* {{{ proto bool srand(int seed) + Seeds random number generator */ +pim_srand_common(srand,PHP_RAND_SYS) +/* }}} */ - 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 mt_srand(int seed) + Seeds random number generator */ +pim_srand_common(mt_srand,PHP_RAND_MT) /* }}} */ -/* {{{ proto int rand([int min, int max]) - Returns a random number */ -PHP_FUNCTION(rand) +/* rand */ + +/* {{{ PHPAPI long php_rand(void) */ +PHPAPI long php_rand(void) { - 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; + return PHP_RAND(CURR_GEN); +} +/* }}} */ - return_value->value.lval = php_rand(); +/* {{{ PHPAPI double php_drand(void) + * returns a double in the range [0,1) */ +PHPAPI double php_drand(void) +{ + return (double)php_rand() / + (double)(PHP_RANDMAX(CURR_GEN)+1.0); +} +/* }}} */ +/* {{{ 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) * - * 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)); - } + * 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)); \ } /* }}} */ -/* {{{ proto int mt_rand([int min, int max]) - Returns a random number from Mersenne Twister */ -PHP_FUNCTION(mt_rand) +/* {{{ PHPAPI long php_rand_range(long min, long max) */ +PHPAPI long php_rand_range(long min, long max) { - 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)); - } + 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; \ + } \ +} +/* }}} */ + +/* {{{ 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(void) +{ + return PHP_RANDMAX(CURR_GEN); } /* }}} */ @@ -333,25 +287,19 @@ PHP_FUNCTION(getrandmax) WRONG_PARAM_COUNT; } - return_value->type = IS_LONG; - return_value->value.lval = PHP_RAND_MAX; + RETURN_LONG( php_randmax()); } /* }}} */ /* {{{ proto int mt_getrandmax(void) - Returns the maximum value a random number from Mersenne Twister can have */ + Returns the maximum value a random number can have */ PHP_FUNCTION(mt_getrandmax) { if (ZEND_NUM_ARGS() != 0) { WRONG_PARAM_COUNT; } - 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 */ + RETURN_LONG( php_randmax() ); } /* }}} */ @@ -361,5 +309,5 @@ PHP_FUNCTION(mt_getrandmax) * c-basic-offset: 4 * End: * vim600: sw=4 ts=4 tw=78 fdm=marker - * vim<600: sw=4 ts=4 tw=78 + * vim: sw=4 ts=4 tw=78 */