From 650a8fb098006ec1c7feef3f825fca10e46897a1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tim=20D=C3=BCsterhus?= <tim@bastelstu.be>
Date: Mon, 4 Mar 2024 17:51:40 +0100
Subject: [PATCH] random: Embed the Mt19937 and CombinedLCG state within the
 module globals (#13579)

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 |  8 ++++----
 ext/random/random.c     | 18 +++---------------
 2 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/ext/random/php_random.h b/ext/random/php_random.h
index c62761029dd..811d75cbfc5 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;
-	bool combined_lcg_seeded;
-	php_random_status_state_mt19937 *mt19937;
-	bool mt19937_seeded;
 	int random_fd;
+	bool combined_lcg_seeded;
+	bool mt19937_seeded;
+	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 28411e4e1a1..638e12027fb 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;
 }
 /* }}} */