archive/php-src
1
0
Fork 0
mirror of https://github.com/php/php-src.git synced 2025-08-16 05:58:45 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

random: Embed the Mt19937 and CombinedLCG state within the module globals (#13579)

Browse source 
These are always dynamically allocated in GINIT, thus always take up memory. By
embedding them here we can avoid the dynamic allocation and additional pointer
indirection accessing them.

The test script:

    <?php
    for ($i = 0; $i < 9999999; $i++) mt_rand(1, 100);

Appears to run slightly faster with this change applied: Before this change it
always ran in just over 3 seconds, after this change I was also seeing times
below 3 seconds. Howver results are too close and too jittery to state this
performance improvement as a fact.
This commit is contained in:
Tim Düsterhus 2024-03-04 17:51:40 +01:00 • committed by GitHub
parent ad1dfa35f2
commit 650a8fb098
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
2 changed files with 7 additions and 19 deletions
Download patch file Download diff file Expand all files Collapse all files

18
ext/random/random.c
View file

@ -309,7 +309,7 @@ PHPAPI const php_random_algo *php_random_default_algo(void)
/* {{{ php_random_default_status */
PHPAPI void *php_random_default_status(void)
{
php_random_status_state_mt19937 *state = RANDOM_G(mt19937);
php_random_status_state_mt19937 *state = &RANDOM_G(mt19937);
if (!RANDOM_G(mt19937_seeded)) {
php_random_mt19937_seed_default(state);
@ -390,7 +390,7 @@ PHPAPI bool php_random_hex2bin_le(zend_string *hexstr, void *dest)
/* {{{ php_combined_lcg */
PHPAPI double php_combined_lcg(void)
{
php_random_status_state_combinedlcg *state = RANDOM_G(combined_lcg);
php_random_status_state_combinedlcg *state = &RANDOM_G(combined_lcg);
if (!RANDOM_G(combined_lcg_seeded)) {
php_random_combinedlcg_seed_default(state);
@ -472,7 +472,7 @@ PHP_FUNCTION(mt_srand)
zend_long seed = 0;
bool seed_is_null = true;
zend_long mode = MT_RAND_MT19937;
php_random_status_state_mt19937 *state = RANDOM_G(mt19937);
php_random_status_state_mt19937 *state = &RANDOM_G(mt19937);
ZEND_PARSE_PARAMETERS_START(0, 2)
Z_PARAM_OPTIONAL
@ -615,12 +615,6 @@ PHP_FUNCTION(random_int)
static PHP_GINIT_FUNCTION(random)
{
random_globals->random_fd = -1;
random_globals->combined_lcg = php_random_status_alloc(&php_random_algo_combinedlcg, true);
random_globals->combined_lcg_seeded = false;
random_globals->mt19937 = php_random_status_alloc(&php_random_algo_mt19937, true);
random_globals->mt19937_seeded = false;
}
/* }}} */
@ -631,12 +625,6 @@ static PHP_GSHUTDOWN_FUNCTION(random)
close(random_globals->random_fd);
random_globals->random_fd = -1;
}
php_random_status_free(random_globals->combined_lcg, true);
random_globals->combined_lcg = NULL;
php_random_status_free(random_globals->mt19937, true);
random_globals->mt19937 = NULL;
}
/* }}} */