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LWIPMemoryManager.h
1 /* Copyright (c) 2017 ARM Limited
2  * SPDX-License-Identifier: Apache-2.0
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef LWIP_MEMORY_MANAGER_H
18 #define LWIP_MEMORY_MANAGER_H
19 
20 #include "EMACMemoryManager.h"
21 
22 
23 class LWIPMemoryManager final : public EMACMemoryManager {
24 public:
25 
26  /**
27  * Allocates memory buffer from the heap
28  *
29  * Memory buffer allocated from heap is always contiguous and can be arbitrary size.
30  *
31  * @param size Size of the memory to allocate in bytes
32  * @param align Memory alignment requirement in bytes
33  * @return Allocated memory buffer, or NULL in case of error
34  */
35  net_stack_mem_buf_t *alloc_heap(uint32_t size, uint32_t align) override;
36 
37  /**
38  * Allocates memory buffer chain from a pool
39  *
40  * Memory allocated from pool is contiguous if size is equal or less than
41  * (aligned) allocation unit, otherwise may be chained. Will typically come from
42  * fixed-size packet pool memory.
43  *
44  * @param size Total size of the memory to allocate in bytes
45  * @param align Memory alignment requirement for each buffer in bytes
46  * @return Allocated memory buffer chain, or NULL in case of error
47  */
48  net_stack_mem_buf_t *alloc_pool(uint32_t size, uint32_t align) override;
49 
50  /**
51  * Get memory buffer pool allocation unit
52  *
53  * Returns the maximum size of contiguous memory that can be allocated from a pool.
54  *
55  * @param align Memory alignment requirement in bytes
56  * @return Contiguous memory size
57  */
58  uint32_t get_pool_alloc_unit(uint32_t align) const override;
59 
60  /**
61  * Free memory buffer chain
62  *
63  * If memory buffer is chained must point to the start of the chain. Frees all buffers
64  * from the chained list.
65  *
66  * @param buf Memory buffer chain to be freed.
67  */
68  void free(net_stack_mem_buf_t *buf) override;
69 
70  /**
71  * Return total length of a memory buffer chain
72  *
73  * Returns a total length of this buffer and any following buffers in the chain.
74  *
75  * @param buf Memory buffer chain
76  * @return Total length in bytes
77  */
78  uint32_t get_total_len(const net_stack_mem_buf_t *buf) const override;
79 
80  /**
81  * Copy a memory buffer chain
82  *
83  * Copies data from one buffer chain to another. Copy operation does not adjust the lengths
84  * of the copied-to memory buffer chain, so chain total lengths must be the same.
85  *
86  * @param to_buf Memory buffer chain to copy to
87  * @param from_buf Memory buffer chain to copy from
88  */
89  void copy(net_stack_mem_buf_t *to_buf, const net_stack_mem_buf_t *from_buf) override;
90 
91  /**
92  * Copy to a memory buffer chain
93  *
94  * Copies data to a buffer chain. Copy operation does not adjust the lengths
95  * of the copied-to memory buffer chain, so chain total length must match the
96  * copied length.
97  *
98  * @param to_buf Memory buffer chain to copy to
99  * @param ptr Pointer to data
100  * @param len Data length
101  */
102  void copy_to_buf(net_stack_mem_buf_t *to_buf, const void *ptr, uint32_t len) override;
103 
104  /**
105  * Copy from a memory buffer chain
106  *
107  * Copies data from a memory buffer chain.
108  *
109  * @param len Data length
110  * @param ptr Pointer to data
111  * @param from_buf Memory buffer chain to copy from
112  * @return Length of the data that was copied
113  */
114  uint32_t copy_from_buf(void *ptr, uint32_t len, const net_stack_mem_buf_t *from_buf) const override;
115 
116  /**
117  * Concatenate two memory buffer chains
118  *
119  * Concatenates buffer chain to end of the other buffer chain. Concatenated-to buffer total length
120  * is adjusted accordingly. cat_buf must point to the start of a the chain. After concatenation
121  * to_buf's chain now owns those buffers, and they will be freed when the to_buf chain is freed.
122  *
123  * @param to_buf Memory buffer chain to concatenate to
124  * @param cat_buf Memory buffer chain to concatenate
125  */
126  void cat(net_stack_mem_buf_t *to_buf, net_stack_mem_buf_t *cat_buf) override;
127 
128  /**
129  * Returns the next buffer
130  *
131  * Returns the next buffer from the memory buffer chain.
132  *
133  * @param buf Memory buffer
134  * @return The next memory buffer, or NULL if last
135  */
136  net_stack_mem_buf_t *get_next(const net_stack_mem_buf_t *buf) const override;
137 
138  /**
139  * Return pointer to the payload of the buffer
140  *
141  * @param buf Memory buffer
142  * @return Pointer to the payload
143  */
144  void *get_ptr(const net_stack_mem_buf_t *buf) const override;
145 
146  /**
147  * Return payload size of the buffer
148  *
149  * @param buf Memory buffer
150  * @return Size in bytes
151  */
152  uint32_t get_len(const net_stack_mem_buf_t *buf) const override;
153 
154  /**
155  * Sets the payload size of the buffer
156  *
157  * The allocated payload size will not change. It is not permitted
158  * to change the length of a buffer that is not the first (or only) in a chain.
159  *
160  * @param buf Memory buffer
161  * @param len Payload size, must be less or equal allocated size
162  */
163  void set_len(net_stack_mem_buf_t *buf, uint32_t len) override;
164 
165 private:
166 
167  /**
168  * Returns a total memory alignment size
169  *
170  * Calculates the total memory alignment size for a memory buffer chain.
171  * Used internally on pool allocation.
172  *
173  * @param size Size of the memory to allocate in bytes
174  * @param align Memory alignment requirement for each buffer in bytes
175  * @return Total alignment needed in bytes
176  */
177  uint32_t count_total_align(uint32_t size, uint32_t align);
178 
179  /**
180  * Aligns a memory buffer chain
181  *
182  * Aligns a memory buffer chain and updates lengths and total lengths
183  * accordingly. There needs to be enough overhead to do the alignment
184  * for all buffers.
185  *
186  * @param pbuf Memory buffer
187  * @param align Memory alignment requirement for each buffer in bytes
188  */
189  void align_memory(struct pbuf *pbuf, uint32_t align);
190 
191  /**
192  * Sets total lengths of a memory buffer chain
193  *
194  * Sets total length fields for a memory buffer chain based on buffer
195  * length fields. All total lengths are calculated again.
196  *
197  * @param pbuf Memory buffer
198  */
199  void set_total_len(struct pbuf *pbuf);
200 };
201 
202 #endif /* LWIP_MEMORY_MANAGER_H */
LWIPMemoryManager::get_ptr
void * get_ptr(const net_stack_mem_buf_t *buf) const override
Return pointer to the payload of the buffer.
LWIPMemoryManager::alloc_pool
net_stack_mem_buf_t * alloc_pool(uint32_t size, uint32_t align) override
Allocates memory buffer chain from a pool.
LWIPMemoryManager::copy
void copy(net_stack_mem_buf_t *to_buf, const net_stack_mem_buf_t *from_buf) override
Copy a memory buffer chain.
LWIPMemoryManager::copy_to_buf
void copy_to_buf(net_stack_mem_buf_t *to_buf, const void *ptr, uint32_t len) override
Copy to a memory buffer chain.
LWIPMemoryManager::set_len
void set_len(net_stack_mem_buf_t *buf, uint32_t len) override
Sets the payload size of the buffer.
LWIPMemoryManager::get_total_len
uint32_t get_total_len(const net_stack_mem_buf_t *buf) const override
Return total length of a memory buffer chain.
LWIPMemoryManager::free
void free(net_stack_mem_buf_t *buf) override
Free memory buffer chain.
LWIPMemoryManager::get_pool_alloc_unit
uint32_t get_pool_alloc_unit(uint32_t align) const override
Get memory buffer pool allocation unit.
LWIPMemoryManager::alloc_heap
net_stack_mem_buf_t * alloc_heap(uint32_t size, uint32_t align) override
Allocates memory buffer from the heap.
LWIPMemoryManager::get_next
net_stack_mem_buf_t * get_next(const net_stack_mem_buf_t *buf) const override
Returns the next buffer.
pbuf
Main packet buffer struct.
Definition: ppp_service_if.h:136
LWIPMemoryManager::copy_from_buf
uint32_t copy_from_buf(void *ptr, uint32_t len, const net_stack_mem_buf_t *from_buf) const override
Copy from a memory buffer chain.
LWIPMemoryManager::cat
void cat(net_stack_mem_buf_t *to_buf, net_stack_mem_buf_t *cat_buf) override
Concatenate two memory buffer chains.
LWIPMemoryManager::get_len
uint32_t get_len(const net_stack_mem_buf_t *buf) const override
Return payload size of the buffer.
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