1 /*
2 +----------------------------------------------------------------------+
3 | Copyright (c) The PHP Group |
4 +----------------------------------------------------------------------+
5 | This source file is subject to version 3.01 of the PHP license, |
6 | that is bundled with this package in the file LICENSE, and is |
7 | available through the world-wide-web at the following url: |
8 | http://www.php.net/license/3_01.txt |
9 | If you did not receive a copy of the PHP license and are unable to |
10 | obtain it through the world-wide-web, please send a note to |
11 | license@php.net so we can mail you a copy immediately. |
12 +----------------------------------------------------------------------+
13 | Authors: Andrey Hristov <andrey@php.net> |
14 | Ulf Wendel <uw@php.net> |
15 | Dmitry Stogov <dmitry@php.net> |
16 +----------------------------------------------------------------------+
17 */
18
19 #include "php.h"
20 #include "mysqlnd.h"
21 #include "mysqlnd_block_alloc.h"
22 #include "mysqlnd_debug.h"
23 #include "mysqlnd_priv.h"
24
25 /* {{{ mysqlnd_mempool_free_chunk */
26 static void
mysqlnd_mempool_free_chunk(MYSQLND_MEMORY_POOL * pool,void * ptr)27 mysqlnd_mempool_free_chunk(MYSQLND_MEMORY_POOL * pool, void * ptr)
28 {
29 DBG_ENTER("mysqlnd_mempool_free_chunk");
30 /* Try to back-off and guess if this is the last block allocated */
31 #ifndef ZEND_TRACK_ARENA_ALLOC
32 if (ptr == pool->last) {
33 /*
34 This was the last allocation. Lucky us, we can free
35 a bit of memory from the pool. Next time we will return from the same ptr.
36 */
37 pool->arena->ptr = (char*)ptr;
38 pool->last = NULL;
39 }
40 #endif
41 DBG_VOID_RETURN;
42 }
43 /* }}} */
44
45
46 /* {{{ mysqlnd_mempool_resize_chunk */
47 static void *
mysqlnd_mempool_resize_chunk(MYSQLND_MEMORY_POOL * pool,void * ptr,size_t old_size,size_t size)48 mysqlnd_mempool_resize_chunk(MYSQLND_MEMORY_POOL * pool, void * ptr, size_t old_size, size_t size)
49 {
50 DBG_ENTER("mysqlnd_mempool_resize_chunk");
51
52 #ifndef ZEND_TRACK_ARENA_ALLOC
53 /* Try to back-off and guess if this is the last block allocated */
54 if (ptr == pool->last
55 && (ZEND_MM_ALIGNED_SIZE(size) <= ((char*)pool->arena->end - (char*)ptr))) {
56 /*
57 This was the last allocation. Lucky us, we can free
58 a bit of memory from the pool. Next time we will return from the same ptr.
59 */
60 pool->arena->ptr = (char*)ptr + ZEND_MM_ALIGNED_SIZE(size);
61 DBG_RETURN(ptr);
62 }
63 #endif
64
65 void *new_ptr = zend_arena_alloc(&pool->arena, size);
66 memcpy(new_ptr, ptr, MIN(old_size, size));
67 pool->last = ptr = new_ptr;
68 DBG_RETURN(ptr);
69 }
70 /* }}} */
71
72
73 /* {{{ mysqlnd_mempool_get_chunk */
74 static void *
mysqlnd_mempool_get_chunk(MYSQLND_MEMORY_POOL * pool,size_t size)75 mysqlnd_mempool_get_chunk(MYSQLND_MEMORY_POOL * pool, size_t size)
76 {
77 void *ptr = NULL;
78 DBG_ENTER("mysqlnd_mempool_get_chunk");
79
80 ptr = zend_arena_alloc(&pool->arena, size);
81 pool->last = ptr;
82
83 DBG_RETURN(ptr);
84 }
85 /* }}} */
86
87
88 /* {{{ mysqlnd_mempool_create */
89 PHPAPI MYSQLND_MEMORY_POOL *
mysqlnd_mempool_create(size_t arena_size)90 mysqlnd_mempool_create(size_t arena_size)
91 {
92 zend_arena * arena;
93 MYSQLND_MEMORY_POOL * ret;
94
95 DBG_ENTER("mysqlnd_mempool_create");
96 arena = zend_arena_create(MAX(arena_size, ZEND_MM_ALIGNED_SIZE(sizeof(zend_arena))));
97 ret = zend_arena_alloc(&arena, sizeof(MYSQLND_MEMORY_POOL));
98 ret->arena = arena;
99 ret->last = NULL;
100 ret->checkpoint = NULL;
101 ret->get_chunk = mysqlnd_mempool_get_chunk;
102 ret->free_chunk = mysqlnd_mempool_free_chunk;
103 ret->resize_chunk = mysqlnd_mempool_resize_chunk;
104 DBG_RETURN(ret);
105 }
106 /* }}} */
107
108
109 /* {{{ mysqlnd_mempool_destroy */
110 PHPAPI void
mysqlnd_mempool_destroy(MYSQLND_MEMORY_POOL * pool)111 mysqlnd_mempool_destroy(MYSQLND_MEMORY_POOL * pool)
112 {
113 DBG_ENTER("mysqlnd_mempool_destroy");
114 /* mnd_free will reference LOCK_access and might crash, depending on the caller...*/
115 zend_arena_destroy(pool->arena);
116 DBG_VOID_RETURN;
117 }
118 /* }}} */
119
120 /* {{{ mysqlnd_mempool_save_state */
121 PHPAPI void
mysqlnd_mempool_save_state(MYSQLND_MEMORY_POOL * pool)122 mysqlnd_mempool_save_state(MYSQLND_MEMORY_POOL * pool)
123 {
124 DBG_ENTER("mysqlnd_mempool_save_state");
125 pool->checkpoint = zend_arena_checkpoint(pool->arena);
126 DBG_VOID_RETURN;
127 }
128 /* }}} */
129
130 /* {{{ mysqlnd_mempool_restore_state */
131 PHPAPI void
mysqlnd_mempool_restore_state(MYSQLND_MEMORY_POOL * pool)132 mysqlnd_mempool_restore_state(MYSQLND_MEMORY_POOL * pool)
133 {
134 DBG_ENTER("mysqlnd_mempool_restore_state");
135 #if ZEND_DEBUG
136 ZEND_ASSERT(pool->checkpoint);
137 #endif
138 if (pool->checkpoint) {
139 zend_arena_release(&pool->arena, pool->checkpoint);
140 pool->last = NULL;
141 pool->checkpoint = NULL;
142 }
143 DBG_VOID_RETURN;
144 }
145 /* }}} */
146
