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
195
196
197
198
199
200
201
202
|
/*
ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio.
This file is part of ChibiOS.
ChibiOS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file chmempools.c
* @brief Memory Pools code.
*
* @addtogroup pools
* @details Memory Pools related APIs and services.
* <h2>Operation mode</h2>
* The Memory Pools APIs allow to allocate/free fixed size objects in
* <b>constant time</b> and reliably without memory fragmentation
* problems.<br>
* Memory Pools do not enforce any alignment constraint on the
* contained object however the objects must be properly aligned
* to contain a pointer to void.
* @pre In order to use the memory pools APIs the @p CH_CFG_USE_MEMPOOLS option
* must be enabled in @p chconf.h.
* @{
*/
#include "ch.h"
#if (CH_CFG_USE_MEMPOOLS == TRUE) || defined(__DOXYGEN__)
/*===========================================================================*/
/* Module exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local types. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Module exported functions. */
/*===========================================================================*/
/**
* @brief Initializes an empty memory pool.
*
* @param[out] mp pointer to a @p memory_pool_t structure
* @param[in] size the size of the objects contained in this memory pool,
* the minimum accepted size is the size of a pointer to
* void.
* @param[in] provider memory provider function for the memory pool or
* @p NULL if the pool is not allowed to grow
* automatically
*
* @init
*/
void chPoolObjectInit(memory_pool_t *mp, size_t size, memgetfunc_t provider) {
chDbgCheck((mp != NULL) && (size >= sizeof(void *)));
mp->mp_next = NULL;
mp->mp_object_size = size;
mp->mp_provider = provider;
}
/**
* @brief Loads a memory pool with an array of static objects.
* @pre The memory pool must be already been initialized.
* @pre The array elements must be of the right size for the specified
* memory pool.
* @post The memory pool contains the elements of the input array.
*
* @param[in] mp pointer to a @p memory_pool_t structure
* @param[in] p pointer to the array first element
* @param[in] n number of elements in the array
*
* @api
*/
void chPoolLoadArray(memory_pool_t *mp, void *p, size_t n) {
chDbgCheck((mp != NULL) && (n != 0U));
while (n != 0U) {
chPoolAdd(mp, p);
/*lint -save -e9087 [11.3] Safe cast.*/
p = (void *)(((uint8_t *)p) + mp->mp_object_size);
/*lint -restore*/
n--;
}
}
/**
* @brief Allocates an object from a memory pool.
* @pre The memory pool must be already been initialized.
*
* @param[in] mp pointer to a @p memory_pool_t structure
* @return The pointer to the allocated object.
* @retval NULL if pool is empty.
*
* @iclass
*/
void *chPoolAllocI(memory_pool_t *mp) {
void *objp;
chDbgCheckClassI();
chDbgCheck(mp != NULL);
objp = mp->mp_next;
/*lint -save -e9013 [15.7] There is no else because it is not needed.*/
if (objp != NULL) {
mp->mp_next = mp->mp_next->ph_next;
}
else if (mp->mp_provider != NULL) {
objp = mp->mp_provider(mp->mp_object_size);
}
/*lint -restore*/
return objp;
}
/**
* @brief Allocates an object from a memory pool.
* @pre The memory pool must be already been initialized.
*
* @param[in] mp pointer to a @p memory_pool_t structure
* @return The pointer to the allocated object.
* @retval NULL if pool is empty.
*
* @api
*/
void *chPoolAlloc(memory_pool_t *mp) {
void *objp;
chSysLock();
objp = chPoolAllocI(mp);
chSysUnlock();
return objp;
}
/**
* @brief Releases an object into a memory pool.
* @pre The memory pool must be already been initialized.
* @pre The freed object must be of the right size for the specified
* memory pool.
* @pre The object must be properly aligned to contain a pointer to void.
*
* @param[in] mp pointer to a @p memory_pool_t structure
* @param[in] objp the pointer to the object to be released
*
* @iclass
*/
void chPoolFreeI(memory_pool_t *mp, void *objp) {
struct pool_header *php = objp;
chDbgCheckClassI();
chDbgCheck((mp != NULL) && (objp != NULL));
php->ph_next = mp->mp_next;
mp->mp_next = php;
}
/**
* @brief Releases an object into a memory pool.
* @pre The memory pool must be already been initialized.
* @pre The freed object must be of the right size for the specified
* memory pool.
* @pre The object must be properly aligned to contain a pointer to void.
*
* @param[in] mp pointer to a @p memory_pool_t structure
* @param[in] objp the pointer to the object to be released
*
* @api
*/
void chPoolFree(memory_pool_t *mp, void *objp) {
chSysLock();
chPoolFreeI(mp, objp);
chSysUnlock();
}
#endif /* CH_CFG_USE_MEMPOOLS == TRUE */
/** @} */
|
