@ Make the seed options to srand() and mt_srand() optional, if the seed is

@ not specified, the generate the most random seed possible. (Sterling)

Please, if anyone has any comments on the way I generate this seed, speak up!
This seems to be the most "random" seed I could come up with...

This commit is 100% backwards compatible :)

Add myself to the authors list cause of recent work on the file

diff --git a/ext/standard/rand.c b/ext/standard/rand.c
index 3be2165303767e2b4913bb7f95e9024a240d7300..8cde64300b3d873b5019396214f7ed45aca5e7ca 100644 (file)
--- a/ext/standard/rand.c
+++ b/ext/standard/rand.c
@@ -15,6 +15,7 @@
    | Authors: Rasmus Lerdorf <rasmus@lerdorf.on.ca>                       |
    |          Zeev Suraski <zeev@zend.com>                                |
    |          Pedro Melo <melo@ip.pt>                                     |
+   |          Sterling Hughes <sterling@php.net>                          |
    |                                                                      |
    | Based on code from: Shawn Cokus <Cokus@math.washington.edu>          |
    +----------------------------------------------------------------------+
@@ -112,6 +113,7 @@ PHPAPI void php_mt_srand(php_uint32 seed TSRMLS_DC)
           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,
@@ -190,28 +192,36 @@ PHPAPI php_uint32 php_mt_rand(TSRMLS_D)
        return y ^ (y >> 18);
 }
 
-/* {{{ proto void srand(int seed)
+#define GENERATE_SEED() (time(0) * getpid() * 1000000 * php_combined_lcg(TSRMLS_C))
+
+/* {{{ proto void srand([int seed])
    Seeds random number generator */
 PHP_FUNCTION(srand)
 {
-       long seed;
+       long seed = 0;
 
-       if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "l", &seed) == FAILURE)
+       if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "|l", &seed) == FAILURE)
                return;
 
+       if (!seed)
+               seed = GENERATE_SEED();
+
        php_srand(seed);
 }
 /* }}} */
 
-/* {{{ proto void mt_srand(int seed)
+/* {{{ proto void mt_srand([int seed])
    Seeds Mersenne Twister random number generator */
 PHP_FUNCTION(mt_srand)
 {
-       long seed;
+       long seed = 0;
 
-       if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "l", &seed) == FAILURE) 
+       if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "|l", &seed) == FAILURE) 
                return;
 
+       if (!seed)
+               seed = GENERATE_SEED();
+
        php_mt_srand(seed TSRMLS_CC);
 }
 /* }}} */