1 /*
2 +----------------------------------------------------------------------+
3 | PHP Version 7 |
4 +----------------------------------------------------------------------+
5 | Copyright (c) The PHP Group |
6 +----------------------------------------------------------------------+
7 | This source file is subject to version 3.01 of the PHP license, |
8 | that is bundled with this package in the file LICENSE, and is |
9 | available through the world-wide-web at the following url: |
10 | http://www.php.net/license/3_01.txt |
11 | If you did not receive a copy of the PHP license and are unable to |
12 | obtain it through the world-wide-web, please send a note to |
13 | license@php.net so we can mail you a copy immediately. |
14 +----------------------------------------------------------------------+
15 | Authors: Andrey Hristov <andrey@php.net> |
16 | Ulf Wendel <uw@php.net> |
17 | Dmitry Stogov <dmitry@php.net> |
18 +----------------------------------------------------------------------+
19 */
20
21 #include "php.h"
22 #include "mysqlnd.h"
23 #include "mysqlnd_block_alloc.h"
24 #include "mysqlnd_debug.h"
25 #include "mysqlnd_priv.h"
26
27 /* {{{ mysqlnd_mempool_free_chunk */
28 static void
mysqlnd_mempool_free_chunk(MYSQLND_MEMORY_POOL * pool,void * ptr)29 mysqlnd_mempool_free_chunk(MYSQLND_MEMORY_POOL * pool, void * ptr)
30 {
31 DBG_ENTER("mysqlnd_mempool_free_chunk");
32 /* Try to back-off and guess if this is the last block allocated */
33 #ifndef ZEND_TRACK_ARENA_ALLOC
34 if (ptr == pool->last) {
35 /*
36 This was the last allocation. Lucky us, we can free
37 a bit of memory from the pool. Next time we will return from the same ptr.
38 */
39 pool->arena->ptr = (char*)ptr;
40 pool->last = NULL;
41 }
42 #endif
43 DBG_VOID_RETURN;
44 }
45 /* }}} */
46
47
48 /* {{{ mysqlnd_mempool_resize_chunk */
49 static void *
mysqlnd_mempool_resize_chunk(MYSQLND_MEMORY_POOL * pool,void * ptr,size_t old_size,size_t size)50 mysqlnd_mempool_resize_chunk(MYSQLND_MEMORY_POOL * pool, void * ptr, size_t old_size, size_t size)
51 {
52 DBG_ENTER("mysqlnd_mempool_resize_chunk");
53
54 #ifndef ZEND_TRACK_ARENA_ALLOC
55 /* Try to back-off and guess if this is the last block allocated */
56 if (ptr == pool->last
57 && (ZEND_MM_ALIGNED_SIZE(size) <= ((char*)pool->arena->end - (char*)ptr))) {
58 /*
59 This was the last allocation. Lucky us, we can free
60 a bit of memory from the pool. Next time we will return from the same ptr.
61 */
62 pool->arena->ptr = (char*)ptr + ZEND_MM_ALIGNED_SIZE(size);
63 DBG_RETURN(ptr);
64 }
65 #endif
66
67 void *new_ptr = zend_arena_alloc(&pool->arena, size);
68 memcpy(new_ptr, ptr, MIN(old_size, size));
69 pool->last = ptr = new_ptr;
70 DBG_RETURN(ptr);
71 }
72 /* }}} */
73
74
75 /* {{{ mysqlnd_mempool_get_chunk */
76 static void *
mysqlnd_mempool_get_chunk(MYSQLND_MEMORY_POOL * pool,size_t size)77 mysqlnd_mempool_get_chunk(MYSQLND_MEMORY_POOL * pool, size_t size)
78 {
79 void *ptr = NULL;
80 DBG_ENTER("mysqlnd_mempool_get_chunk");
81
82 ptr = zend_arena_alloc(&pool->arena, size);
83 pool->last = ptr;
84
85 DBG_RETURN(ptr);
86 }
87 /* }}} */
88
89
90 /* {{{ mysqlnd_mempool_create */
91 PHPAPI MYSQLND_MEMORY_POOL *
mysqlnd_mempool_create(size_t arena_size)92 mysqlnd_mempool_create(size_t arena_size)
93 {
94 zend_arena * arena;
95 MYSQLND_MEMORY_POOL * ret;
96
97 DBG_ENTER("mysqlnd_mempool_create");
98 arena = zend_arena_create(MAX(arena_size, ZEND_MM_ALIGNED_SIZE(sizeof(zend_arena))));
99 ret = zend_arena_alloc(&arena, sizeof(MYSQLND_MEMORY_POOL));
100 ret->arena = arena;
101 ret->last = NULL;
102 ret->checkpoint = NULL;
103 ret->get_chunk = mysqlnd_mempool_get_chunk;
104 ret->free_chunk = mysqlnd_mempool_free_chunk;
105 ret->resize_chunk = mysqlnd_mempool_resize_chunk;
106 DBG_RETURN(ret);
107 }
108 /* }}} */
109
110
111 /* {{{ mysqlnd_mempool_destroy */
112 PHPAPI void
mysqlnd_mempool_destroy(MYSQLND_MEMORY_POOL * pool)113 mysqlnd_mempool_destroy(MYSQLND_MEMORY_POOL * pool)
114 {
115 DBG_ENTER("mysqlnd_mempool_destroy");
116 /* mnd_free will reference LOCK_access and might crash, depending on the caller...*/
117 zend_arena_destroy(pool->arena);
118 DBG_VOID_RETURN;
119 }
120 /* }}} */
121
122 /* {{{ mysqlnd_mempool_save_state */
123 PHPAPI void
mysqlnd_mempool_save_state(MYSQLND_MEMORY_POOL * pool)124 mysqlnd_mempool_save_state(MYSQLND_MEMORY_POOL * pool)
125 {
126 DBG_ENTER("mysqlnd_mempool_save_state");
127 pool->checkpoint = zend_arena_checkpoint(pool->arena);
128 DBG_VOID_RETURN;
129 }
130 /* }}} */
131
132 /* {{{ mysqlnd_mempool_restore_state */
133 PHPAPI void
mysqlnd_mempool_restore_state(MYSQLND_MEMORY_POOL * pool)134 mysqlnd_mempool_restore_state(MYSQLND_MEMORY_POOL * pool)
135 {
136 DBG_ENTER("mysqlnd_mempool_restore_state");
137 #if ZEND_DEBUG
138 ZEND_ASSERT(pool->checkpoint);
139 #endif
140 if (pool->checkpoint) {
141 zend_arena_release(&pool->arena, pool->checkpoint);
142 pool->last = NULL;
143 pool->checkpoint = NULL;
144 }
145 DBG_VOID_RETURN;
146 }
147 /* }}} */
148
