1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
/*
+----------------------------------------------------------------------+
| PHP Version 5 |
+----------------------------------------------------------------------+
| Copyright (c) 2006-2012 The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| http://www.php.net/license/3_01.txt |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Georg Richter <georg@mysql.com> |
| Andrey Hristov <andrey@mysql.com> |
| Ulf Wendel <uwendel@mysql.com> |
+----------------------------------------------------------------------+
*/
/* $Id$ */
#include "php.h"
#include "mysqlnd.h"
#include "mysqlnd_block_alloc.h"
#include "mysqlnd_debug.h"
#include "mysqlnd_priv.h"
/* {{{ mysqlnd_mempool_free_chunk */
static void
mysqlnd_mempool_free_chunk(MYSQLND_MEMORY_POOL_CHUNK * chunk TSRMLS_DC)
{
MYSQLND_MEMORY_POOL * pool = chunk->pool;
DBG_ENTER("mysqlnd_mempool_free_chunk");
if (chunk->from_pool) {
/* Try to back-off and guess if this is the last block allocated */
if (chunk->ptr == (pool->arena + (pool->arena_size - pool->free_size - chunk->size))) {
/*
This was the last allocation. Lucky us, we can free
a bit of memory from the pool. Next time we will return from the same ptr.
*/
pool->free_size += chunk->size;
}
pool->refcount--;
} else {
mnd_free(chunk->ptr);
}
mnd_free(chunk);
DBG_VOID_RETURN;
}
/* }}} */
/* {{{ mysqlnd_mempool_resize_chunk */
static enum_func_status
mysqlnd_mempool_resize_chunk(MYSQLND_MEMORY_POOL_CHUNK * chunk, unsigned int size TSRMLS_DC)
{
DBG_ENTER("mysqlnd_mempool_resize_chunk");
if (chunk->from_pool) {
MYSQLND_MEMORY_POOL * pool = chunk->pool;
/* Try to back-off and guess if this is the last block allocated */
if (chunk->ptr == (pool->arena + (pool->arena_size - pool->free_size - chunk->size))) {
/*
This was the last allocation. Lucky us, we can free
a bit of memory from the pool. Next time we will return from the same ptr.
*/
if ((chunk->size + pool->free_size) < size) {
zend_uchar *new_ptr;
new_ptr = mnd_malloc(size);
if (!new_ptr) {
DBG_RETURN(FAIL);
}
memcpy(new_ptr, chunk->ptr, chunk->size);
chunk->ptr = new_ptr;
pool->free_size += chunk->size;
chunk->size = size;
chunk->pool = NULL; /* now we have no pool memory */
pool->refcount--;
} else {
/* If the chunk is > than asked size then free_memory increases, otherwise decreases*/
pool->free_size += (chunk->size - size);
}
} else {
/* Not last chunk, if the user asks for less, give it to him */
if (chunk->size >= size) {
; /* nop */
} else {
zend_uchar *new_ptr;
new_ptr = mnd_malloc(size);
if (!new_ptr) {
DBG_RETURN(FAIL);
}
memcpy(new_ptr, chunk->ptr, chunk->size);
chunk->ptr = new_ptr;
chunk->size = size;
chunk->pool = NULL; /* now we have non-pool memory */
pool->refcount--;
}
}
} else {
zend_uchar *new_ptr = mnd_realloc(chunk->ptr, size);
if (!new_ptr) {
DBG_RETURN(FAIL);
}
chunk->ptr = new_ptr;
}
DBG_RETURN(PASS);
}
/* }}} */
/* {{{ mysqlnd_mempool_get_chunk */
static
MYSQLND_MEMORY_POOL_CHUNK * mysqlnd_mempool_get_chunk(MYSQLND_MEMORY_POOL * pool, unsigned int size TSRMLS_DC)
{
MYSQLND_MEMORY_POOL_CHUNK *chunk = NULL;
DBG_ENTER("mysqlnd_mempool_get_chunk");
chunk = mnd_malloc(sizeof(MYSQLND_MEMORY_POOL_CHUNK));
if (chunk) {
chunk->free_chunk = mysqlnd_mempool_free_chunk;
chunk->resize_chunk = mysqlnd_mempool_resize_chunk;
chunk->size = size;
/*
Should not go over MYSQLND_MAX_PACKET_SIZE, since we
expect non-arena memory in mysqlnd_wireprotocol.c . We
realloc the non-arena memory.
*/
chunk->pool = pool;
if (size > pool->free_size) {
chunk->from_pool = FALSE;
chunk->ptr = mnd_malloc(size);
if (!chunk->ptr) {
chunk->free_chunk(chunk TSRMLS_CC);
chunk = NULL;
}
} else {
chunk->from_pool = TRUE;
++pool->refcount;
chunk->ptr = pool->arena + (pool->arena_size - pool->free_size);
/* Last step, update free_size */
pool->free_size -= size;
}
}
DBG_RETURN(chunk);
}
/* }}} */
/* {{{ mysqlnd_mempool_create */
PHPAPI MYSQLND_MEMORY_POOL *
mysqlnd_mempool_create(size_t arena_size TSRMLS_DC)
{
/* We calloc, because we free(). We don't mnd_calloc() for a reason. */
MYSQLND_MEMORY_POOL * ret = mnd_calloc(1, sizeof(MYSQLND_MEMORY_POOL));
DBG_ENTER("mysqlnd_mempool_create");
if (ret) {
ret->get_chunk = mysqlnd_mempool_get_chunk;
ret->free_size = ret->arena_size = arena_size ? arena_size : 0;
ret->refcount = 0;
/* OOM ? */
ret->arena = mnd_malloc(ret->arena_size);
if (!ret->arena) {
mysqlnd_mempool_destroy(ret TSRMLS_CC);
ret = NULL;
}
}
DBG_RETURN(ret);
}
/* }}} */
/* {{{ mysqlnd_mempool_destroy */
PHPAPI void
mysqlnd_mempool_destroy(MYSQLND_MEMORY_POOL * pool TSRMLS_DC)
{
DBG_ENTER("mysqlnd_mempool_destroy");
/* mnd_free will reference LOCK_access and might crash, depending on the caller...*/
mnd_free(pool->arena);
mnd_free(pool);
DBG_VOID_RETURN;
}
/* }}} */
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
* vim600: noet sw=4 ts=4 fdm=marker
* vim<600: noet sw=4 ts=4
*/
|
