1 // Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 
7 //     http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 #pragma once
15 #include <stdint.h>
16 #include <stdlib.h>
17 #include <stdbool.h>
18 
19 /* multi_heap is a heap implementation for handling multiple
20    heterogenous heaps in a single program.
21 
22    Any contiguous block of memory can be registered as a heap.
23 */
24 
25 #ifdef __cplusplus
26 extern "C" {
27 #endif
28 
29 /** @brief Opaque handle to a registered heap */
30 typedef struct multi_heap_info *multi_heap_handle_t;
31 
32 /**
33  * @brief allocate a chunk of memory with specific alignment
34  *
35  * @param heap  Handle to a registered heap.
36  * @param size  size in bytes of memory chunk
37  * @param alignment  how the memory must be aligned
38  *
39  * @return pointer to the memory allocated, NULL on failure
40  */
41 void *multi_heap_aligned_alloc(multi_heap_handle_t heap, size_t size, size_t alignment);
42 
43 /** @brief malloc() a buffer in a given heap
44  *
45  * Semantics are the same as standard malloc(), only the returned buffer will be allocated in the specified heap.
46  *
47  * @param heap Handle to a registered heap.
48  * @param size Size of desired buffer.
49  *
50  * @return Pointer to new memory, or NULL if allocation fails.
51  */
52 void *multi_heap_malloc(multi_heap_handle_t heap, size_t size);
53 
54 /** @brief free() a buffer aligned in a given heap.
55  *
56  * @param heap Handle to a registered heap.
57  * @param p NULL, or a pointer previously returned from multi_heap_aligned_alloc() for the same heap.
58  * @note This function is deprecated, consider using  multi_heap_free() instead
59  */
60 void __attribute__((deprecated)) multi_heap_aligned_free(multi_heap_handle_t heap, void *p);
61 
62 /** @brief free() a buffer in a given heap.
63  *
64  * Semantics are the same as standard free(), only the argument 'p' must be NULL or have been allocated in the specified heap.
65  *
66  * @param heap Handle to a registered heap.
67  * @param p NULL, or a pointer previously returned from multi_heap_malloc() or multi_heap_realloc() for the same heap.
68  */
69 void multi_heap_free(multi_heap_handle_t heap, void *p);
70 
71 /** @brief realloc() a buffer in a given heap.
72  *
73  * Semantics are the same as standard realloc(), only the argument 'p' must be NULL or have been allocated in the specified heap.
74  *
75  * @param heap Handle to a registered heap.
76  * @param p NULL, or a pointer previously returned from multi_heap_malloc() or multi_heap_realloc() for the same heap.
77  * @param size Desired new size for buffer.
78  *
79  * @return New buffer of 'size' containing contents of 'p', or NULL if reallocation failed.
80  */
81 void *multi_heap_realloc(multi_heap_handle_t heap, void *p, size_t size);
82 
83 
84 /** @brief Return the size that a particular pointer was allocated with.
85  *
86  * @param heap Handle to a registered heap.
87  * @param p Pointer, must have been previously returned from multi_heap_malloc() or multi_heap_realloc() for the same heap.
88  *
89  * @return Size of the memory allocated at this block. May be more than the original size argument, due
90  * to padding and minimum block sizes.
91  */
92 size_t multi_heap_get_allocated_size(multi_heap_handle_t heap, void *p);
93 
94 
95 /** @brief Register a new heap for use
96  *
97  * This function initialises a heap at the specified address, and returns a handle for future heap operations.
98  *
99  * There is no equivalent function for deregistering a heap - if all blocks in the heap are free, you can immediately start using the memory for other purposes.
100  *
101  * @param start Start address of the memory to use for a new heap.
102  * @param size Size (in bytes) of the new heap.
103  *
104  * @return Handle of a new heap ready for use, or NULL if the heap region was too small to be initialised.
105  */
106 multi_heap_handle_t multi_heap_register(void *start, size_t size);
107 
108 
109 /** @brief Associate a private lock pointer with a heap
110  *
111  * The lock argument is supplied to the MULTI_HEAP_LOCK() and MULTI_HEAP_UNLOCK() macros, defined in multi_heap_platform.h.
112  *
113  * The lock in question must be recursive.
114  *
115  * When the heap is first registered, the associated lock is NULL.
116  *
117  * @param heap Handle to a registered heap.
118  * @param lock Optional pointer to a locking structure to associate with this heap.
119  */
120 void multi_heap_set_lock(multi_heap_handle_t heap, void* lock);
121 
122 /** @brief Dump heap information to stdout
123  *
124  * For debugging purposes, this function dumps information about every block in the heap to stdout.
125  *
126  * @param heap Handle to a registered heap.
127  */
128 void multi_heap_dump(multi_heap_handle_t heap);
129 
130 /** @brief Check heap integrity
131  *
132  * Walks the heap and checks all heap data structures are valid. If any errors are detected, an error-specific message
133  * can be optionally printed to stderr. Print behaviour can be overriden at compile time by defining
134  * MULTI_CHECK_FAIL_PRINTF in multi_heap_platform.h.
135  *
136  * @param heap Handle to a registered heap.
137  * @param print_errors If true, errors will be printed to stderr.
138  * @return true if heap is valid, false otherwise.
139  */
140 bool multi_heap_check(multi_heap_handle_t heap, bool print_errors);
141 
142 /** @brief Return free heap size
143  *
144  * Returns the number of bytes available in the heap.
145  *
146  * Equivalent to the total_free_bytes member returned by multi_heap_get_heap_info().
147  *
148  * Note that the heap may be fragmented, so the actual maximum size for a single malloc() may be lower. To know this
149  * size, see the largest_free_block member returned by multi_heap_get_heap_info().
150  *
151  * @param heap Handle to a registered heap.
152  * @return Number of free bytes.
153  */
154 size_t multi_heap_free_size(multi_heap_handle_t heap);
155 
156 /** @brief Return the lifetime minimum free heap size
157  *
158  * Equivalent to the minimum_free_bytes member returned by multi_heap_get_info().
159  *
160  * Returns the lifetime "low water mark" of possible values returned from multi_free_heap_size(), for the specified
161  * heap.
162  *
163  * @param heap Handle to a registered heap.
164  * @return Number of free bytes.
165  */
166 size_t multi_heap_minimum_free_size(multi_heap_handle_t heap);
167 
168 /** @brief Structure to access heap metadata via multi_heap_get_info */
169 typedef struct {
170     size_t total_free_bytes;      ///<  Total free bytes in the heap. Equivalent to multi_free_heap_size().
171     size_t total_allocated_bytes; ///<  Total bytes allocated to data in the heap.
172     size_t largest_free_block;    ///<  Size of largest free block in the heap. This is the largest malloc-able size.
173     size_t minimum_free_bytes;    ///<  Lifetime minimum free heap size. Equivalent to multi_minimum_free_heap_size().
174     size_t allocated_blocks;      ///<  Number of (variable size) blocks allocated in the heap.
175     size_t free_blocks;           ///<  Number of (variable size) free blocks in the heap.
176     size_t total_blocks;          ///<  Total number of (variable size) blocks in the heap.
177 } multi_heap_info_t;
178 
179 /** @brief Return metadata about a given heap
180  *
181  * Fills a multi_heap_info_t structure with information about the specified heap.
182  *
183  * @param heap Handle to a registered heap.
184  * @param info Pointer to a structure to fill with heap metadata.
185  */
186 void multi_heap_get_info(multi_heap_handle_t heap, multi_heap_info_t *info);
187 
188 #ifdef __cplusplus
189 }
190 #endif
191