From 12b14d5f92e2bee0fda9fe490c89d489d746ede4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tim=20D=C3=BCsterhus?= <tim@bastelstu.be>
Date: Sat, 2 Mar 2024 20:41:20 +0100
Subject: [PATCH] random: Embed the Mt19937 and CombinedLCG state within the
 module globals

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.
---
 ext/random/php_random.h |  6 +++---
 ext/random/random.c     | 18 +++---------------
 2 files changed, 6 insertions(+), 18 deletions(-)

diff --git a/ext/random/php_random.h b/ext/random/php_random.h
index c62761029ddcf..811d75cbfc5a5 100644
--- a/ext/random/php_random.h
+++ b/ext/random/php_random.h
@@ -203,11 +203,11 @@ PHP_MSHUTDOWN_FUNCTION(random);
 PHP_RINIT_FUNCTION(random);
 
 ZEND_BEGIN_MODULE_GLOBALS(random)
-	php_random_status_state_combinedlcg *combined_lcg;
+	int random_fd;
 	bool combined_lcg_seeded;
-	php_random_status_state_mt19937 *mt19937;
 	bool mt19937_seeded;
-	int random_fd;
+	php_random_status_state_combinedlcg combined_lcg;
+	php_random_status_state_mt19937 mt19937;
 ZEND_END_MODULE_GLOBALS(random)
 
 PHPAPI ZEND_EXTERN_MODULE_GLOBALS(random)
diff --git a/ext/random/random.c b/ext/random/random.c
index 28411e4e1a1ef..638e12027fbc6 100644
--- a/ext/random/random.c
+++ b/ext/random/random.c
@@ -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;
 }
 /* }}} */