summaryrefslogtreecommitdiff
path: root/nuttx/include/nuttx/gran.h
blob: 1176735cf14d645ea3d6d5101aeb9bffb6f6232e (plain) (blame)
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
/****************************************************************************
 * include/nuttx/gran.h
 * General purpose granule memory allocator.
 *
 *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

#ifndef __INCLUDE_NUTTX_GRAN_H
#define __INCLUDE_NUTTX_GRAN_H

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <sys/types.h>
#include <stdint.h>

#ifdef CONFIG_GRAN

/****************************************************************************
 * Pre-Processor Definitions
 ****************************************************************************/
/* Configuration ************************************************************/
/* CONFIG_GRAN - Enable granual allocator support
 * CONFIG_GRAN_SINGLE - Select if there is only one instance of the
 *   granule allocator (i.e., gran_initialize will be called only once.
 *   In this case, (1) there are a few optimizations that can can be done
 *   and (2) the GRAN_HANDLE is not needed.
 * CONFIG_DEBUG_GRAN - Just like CONFIG_DEBUG_MM, but only generates ouput
 *   from the gran allocation logic.
 */

/****************************************************************************
 * Public Types
 ****************************************************************************/

#ifndef CONFIG_GRAN_SINGLE
typedef FAR void *GRAN_HANDLE;
#endif

/****************************************************************************
 * Public Function Prototypes
 ****************************************************************************/

#ifdef __cplusplus
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif

/****************************************************************************
 * Name: gran_initialize
 *
 * Description:
 *   Set up one granule allocator instance.  Allocations will be aligned to
 *   the granule size; allocations will be in units of the granule size.
 *   Larger granules will give better performance and less overhead but more
 *   losses of memory due to alignment and quantization waste.
 *
 *   NOTE: The current implementation also restricts the maximum allocation
 *   size to 32 granaules.  That restriction could be eliminated with some
 *   additional coding effort.
 *
 * Input Parameters:
 *   heapstart - Start of the granule allocation heap
 *   heapsize  - Size of heap in bytes
 *   log2gran  - Log base 2 of the size of one granule.  0->1 byte,
 *               1->2 bytes, 2->4 bytes, 3-> 8bytes, etc.
 *
 * Returned Value:
 *   On success, a non-NULL handle is returned that may be used with other
 *   granual allocator interfaces.
 *
 ****************************************************************************/

#ifdef CONFIG_GRAN_SINGLE
EXTERN int gran_initialize(FAR void *heapstart, size_t heapsize,
                           uint8_t log2gran);
#else
EXTERN GRAN_HANDLE gran_initialize(FAR void *heapstart, size_t heapsize,
                                   uint8_t log2gran);
#endif

/****************************************************************************
 * Name: gran_alloc
 *
 * Description:
 *   Allocate memory from the granule heap.
 *
 *   NOTE: The current implementation also restricts the maximum allocation
 *   size to 32 granaules.  That restriction could be eliminated with some
 *   additional coding effort.
 *
 * Input Parameters:
 *   handle - The handle previously returned by gran_initialize
 *   size   - The size of the memory region to allocate.
 *
 * Returned Value:
 *   On success, either a non-NULL pointer to the allocated memory (if
 *   CONFIG_GRAN_SINGLE) or zero  (if !CONFIG_GRAN_SINGLE) is returned.
 *
 ****************************************************************************/

#ifdef CONFIG_GRAN_SINGLE
EXTERN FAR void *gran_alloc(size_t size);
#else
EXTERN FAR void *gran_alloc(GRAN_HANDLE handle, size_t size);
#endif

/****************************************************************************
 * Name: gran_free
 *
 * Description:
 *   Return memory to the granule heap.
 *
 * Input Parameters:
 *   handle - The handle previously returned by gran_initialize
 *   memory - A pointer to memory previoiusly allocated by gran_alloc.
 *
 * Returned Value:
 *   None
 *
 ****************************************************************************/

#ifdef CONFIG_GRAN_SINGLE
EXTERN void gran_free(FAR void *memory, size_t size);
#else
EXTERN void gran_free(GRAN_HANDLE handle, FAR void *memory, size_t size);
#endif

#undef EXTERN
#ifdef __cplusplus
}
#endif

#endif /* CONFIG_GRAN */
#endif /* __INCLUDE_NUTTX_GRAN_H */