1 | /**
|
---|
2 | * @file
|
---|
3 | * Dynamic memory manager
|
---|
4 | *
|
---|
5 | * This is a lightweight replacement for the standard C library malloc().
|
---|
6 | *
|
---|
7 | * If you want to use the standard C library malloc() instead, define
|
---|
8 | * MEM_LIBC_MALLOC to 1 in your lwipopts.h
|
---|
9 | *
|
---|
10 | * To let mem_malloc() use pools (prevents fragmentation and is much faster than
|
---|
11 | * a heap but might waste some memory), define MEM_USE_POOLS to 1, define
|
---|
12 | * MEM_USE_CUSTOM_POOLS to 1 and create a file "lwippools.h" that includes a list
|
---|
13 | * of pools like this (more pools can be added between _START and _END):
|
---|
14 | *
|
---|
15 | * Define three pools with sizes 256, 512, and 1512 bytes
|
---|
16 | * LWIP_MALLOC_MEMPOOL_START
|
---|
17 | * LWIP_MALLOC_MEMPOOL(20, 256)
|
---|
18 | * LWIP_MALLOC_MEMPOOL(10, 512)
|
---|
19 | * LWIP_MALLOC_MEMPOOL(5, 1512)
|
---|
20 | * LWIP_MALLOC_MEMPOOL_END
|
---|
21 | */
|
---|
22 |
|
---|
23 | /*
|
---|
24 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
|
---|
25 | * All rights reserved.
|
---|
26 | *
|
---|
27 | * Redistribution and use in source and binary forms, with or without modification,
|
---|
28 | * are permitted provided that the following conditions are met:
|
---|
29 | *
|
---|
30 | * 1. Redistributions of source code must retain the above copyright notice,
|
---|
31 | * this list of conditions and the following disclaimer.
|
---|
32 | * 2. Redistributions in binary form must reproduce the above copyright notice,
|
---|
33 | * this list of conditions and the following disclaimer in the documentation
|
---|
34 | * and/or other materials provided with the distribution.
|
---|
35 | * 3. The name of the author may not be used to endorse or promote products
|
---|
36 | * derived from this software without specific prior written permission.
|
---|
37 | *
|
---|
38 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
|
---|
39 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
---|
40 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
|
---|
41 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
---|
42 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
|
---|
43 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
---|
44 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
---|
45 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
|
---|
46 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
|
---|
47 | * OF SUCH DAMAGE.
|
---|
48 | *
|
---|
49 | * This file is part of the lwIP TCP/IP stack.
|
---|
50 | *
|
---|
51 | * Author: Adam Dunkels <adam@sics.se>
|
---|
52 | * Simon Goldschmidt
|
---|
53 | *
|
---|
54 | */
|
---|
55 |
|
---|
56 | #include "lwip/opt.h"
|
---|
57 |
|
---|
58 | #if !MEM_LIBC_MALLOC /* don't build if not configured for use in lwipopts.h */
|
---|
59 |
|
---|
60 | #include "lwip/def.h"
|
---|
61 | #include "lwip/mem.h"
|
---|
62 | #include "lwip/sys.h"
|
---|
63 | #include "lwip/stats.h"
|
---|
64 | #include "lwip/err.h"
|
---|
65 |
|
---|
66 | #include <string.h>
|
---|
67 |
|
---|
68 | #if MEM_USE_POOLS
|
---|
69 | /* lwIP head implemented with different sized pools */
|
---|
70 |
|
---|
71 | /**
|
---|
72 | * Allocate memory: determine the smallest pool that is big enough
|
---|
73 | * to contain an element of 'size' and get an element from that pool.
|
---|
74 | *
|
---|
75 | * @param size the size in bytes of the memory needed
|
---|
76 | * @return a pointer to the allocated memory or NULL if the pool is empty
|
---|
77 | */
|
---|
78 | void *
|
---|
79 | mem_malloc(mem_size_t size)
|
---|
80 | {
|
---|
81 | void *ret;
|
---|
82 | struct memp_malloc_helper *element;
|
---|
83 | memp_t poolnr;
|
---|
84 | mem_size_t required_size = size + LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper));
|
---|
85 |
|
---|
86 | for (poolnr = MEMP_POOL_FIRST; poolnr <= MEMP_POOL_LAST; poolnr = (memp_t)(poolnr + 1)) {
|
---|
87 | #if MEM_USE_POOLS_TRY_BIGGER_POOL
|
---|
88 | again:
|
---|
89 | #endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
|
---|
90 | /* is this pool big enough to hold an element of the required size
|
---|
91 | plus a struct memp_malloc_helper that saves the pool this element came from? */
|
---|
92 | if (required_size <= memp_sizes[poolnr]) {
|
---|
93 | break;
|
---|
94 | }
|
---|
95 | }
|
---|
96 | if (poolnr > MEMP_POOL_LAST) {
|
---|
97 | LWIP_ASSERT("mem_malloc(): no pool is that big!", 0);
|
---|
98 | return NULL;
|
---|
99 | }
|
---|
100 | element = (struct memp_malloc_helper*)memp_malloc(poolnr);
|
---|
101 | if (element == NULL) {
|
---|
102 | /* No need to DEBUGF or ASSERT: This error is already
|
---|
103 | taken care of in memp.c */
|
---|
104 | #if MEM_USE_POOLS_TRY_BIGGER_POOL
|
---|
105 | /** Try a bigger pool if this one is empty! */
|
---|
106 | if (poolnr < MEMP_POOL_LAST) {
|
---|
107 | poolnr++;
|
---|
108 | goto again;
|
---|
109 | }
|
---|
110 | #endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
|
---|
111 | return NULL;
|
---|
112 | }
|
---|
113 |
|
---|
114 | /* save the pool number this element came from */
|
---|
115 | element->poolnr = poolnr;
|
---|
116 | /* and return a pointer to the memory directly after the struct memp_malloc_helper */
|
---|
117 | ret = (u8_t*)element + LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper));
|
---|
118 |
|
---|
119 | return ret;
|
---|
120 | }
|
---|
121 |
|
---|
122 | /**
|
---|
123 | * Free memory previously allocated by mem_malloc. Loads the pool number
|
---|
124 | * and calls memp_free with that pool number to put the element back into
|
---|
125 | * its pool
|
---|
126 | *
|
---|
127 | * @param rmem the memory element to free
|
---|
128 | */
|
---|
129 | void
|
---|
130 | mem_free(void *rmem)
|
---|
131 | {
|
---|
132 | struct memp_malloc_helper *hmem;
|
---|
133 |
|
---|
134 | LWIP_ASSERT("rmem != NULL", (rmem != NULL));
|
---|
135 | LWIP_ASSERT("rmem == MEM_ALIGN(rmem)", (rmem == LWIP_MEM_ALIGN(rmem)));
|
---|
136 |
|
---|
137 | /* get the original struct memp_malloc_helper */
|
---|
138 | hmem = (struct memp_malloc_helper*)(void*)((u8_t*)rmem - LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper)));
|
---|
139 |
|
---|
140 | LWIP_ASSERT("hmem != NULL", (hmem != NULL));
|
---|
141 | LWIP_ASSERT("hmem == MEM_ALIGN(hmem)", (hmem == LWIP_MEM_ALIGN(hmem)));
|
---|
142 | LWIP_ASSERT("hmem->poolnr < MEMP_MAX", (hmem->poolnr < MEMP_MAX));
|
---|
143 |
|
---|
144 | /* and put it in the pool we saved earlier */
|
---|
145 | memp_free(hmem->poolnr, hmem);
|
---|
146 | }
|
---|
147 |
|
---|
148 | #else /* MEM_USE_POOLS */
|
---|
149 | /* lwIP replacement for your libc malloc() */
|
---|
150 |
|
---|
151 | /**
|
---|
152 | * The heap is made up as a list of structs of this type.
|
---|
153 | * This does not have to be aligned since for getting its size,
|
---|
154 | * we only use the macro SIZEOF_STRUCT_MEM, which automatically alignes.
|
---|
155 | */
|
---|
156 | struct mem {
|
---|
157 | /** index (-> ram[next]) of the next struct */
|
---|
158 | mem_size_t next;
|
---|
159 | /** index (-> ram[prev]) of the previous struct */
|
---|
160 | mem_size_t prev;
|
---|
161 | /** 1: this area is used; 0: this area is unused */
|
---|
162 | u8_t used;
|
---|
163 | };
|
---|
164 |
|
---|
165 | /** All allocated blocks will be MIN_SIZE bytes big, at least!
|
---|
166 | * MIN_SIZE can be overridden to suit your needs. Smaller values save space,
|
---|
167 | * larger values could prevent too small blocks to fragment the RAM too much. */
|
---|
168 | #ifndef MIN_SIZE
|
---|
169 | #define MIN_SIZE 12
|
---|
170 | #endif /* MIN_SIZE */
|
---|
171 | /* some alignment macros: we define them here for better source code layout */
|
---|
172 | #define MIN_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MIN_SIZE)
|
---|
173 | #define SIZEOF_STRUCT_MEM LWIP_MEM_ALIGN_SIZE(sizeof(struct mem))
|
---|
174 | #define MEM_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MEM_SIZE)
|
---|
175 |
|
---|
176 | /** If you want to relocate the heap to external memory, simply define
|
---|
177 | * LWIP_RAM_HEAP_POINTER as a void-pointer to that location.
|
---|
178 | * If so, make sure the memory at that location is big enough (see below on
|
---|
179 | * how that space is calculated). */
|
---|
180 | #ifndef LWIP_RAM_HEAP_POINTER
|
---|
181 | /** the heap. we need one struct mem at the end and some room for alignment */
|
---|
182 | u8_t ram_heap[MEM_SIZE_ALIGNED + (2*SIZEOF_STRUCT_MEM) + MEM_ALIGNMENT];
|
---|
183 | #define LWIP_RAM_HEAP_POINTER ram_heap
|
---|
184 | #endif /* LWIP_RAM_HEAP_POINTER */
|
---|
185 |
|
---|
186 | /** pointer to the heap (ram_heap): for alignment, ram is now a pointer instead of an array */
|
---|
187 | static u8_t *ram;
|
---|
188 | /** the last entry, always unused! */
|
---|
189 | static struct mem *ram_end;
|
---|
190 | /** pointer to the lowest free block, this is used for faster search */
|
---|
191 | static struct mem *lfree;
|
---|
192 |
|
---|
193 | /** concurrent access protection */
|
---|
194 | #if !NO_SYS
|
---|
195 | static sys_mutex_t mem_mutex;
|
---|
196 | #endif
|
---|
197 |
|
---|
198 | #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
|
---|
199 |
|
---|
200 | static volatile u8_t mem_free_count;
|
---|
201 |
|
---|
202 | /* Allow mem_free from other (e.g. interrupt) context */
|
---|
203 | #define LWIP_MEM_FREE_DECL_PROTECT() SYS_ARCH_DECL_PROTECT(lev_free)
|
---|
204 | #define LWIP_MEM_FREE_PROTECT() SYS_ARCH_PROTECT(lev_free)
|
---|
205 | #define LWIP_MEM_FREE_UNPROTECT() SYS_ARCH_UNPROTECT(lev_free)
|
---|
206 | #define LWIP_MEM_ALLOC_DECL_PROTECT() SYS_ARCH_DECL_PROTECT(lev_alloc)
|
---|
207 | #define LWIP_MEM_ALLOC_PROTECT() SYS_ARCH_PROTECT(lev_alloc)
|
---|
208 | #define LWIP_MEM_ALLOC_UNPROTECT() SYS_ARCH_UNPROTECT(lev_alloc)
|
---|
209 |
|
---|
210 | #else /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
|
---|
211 |
|
---|
212 | /* Protect the heap only by using a semaphore */
|
---|
213 | #define LWIP_MEM_FREE_DECL_PROTECT()
|
---|
214 | #define LWIP_MEM_FREE_PROTECT() sys_mutex_lock(&mem_mutex)
|
---|
215 | #define LWIP_MEM_FREE_UNPROTECT() sys_mutex_unlock(&mem_mutex)
|
---|
216 | /* mem_malloc is protected using semaphore AND LWIP_MEM_ALLOC_PROTECT */
|
---|
217 | #define LWIP_MEM_ALLOC_DECL_PROTECT()
|
---|
218 | #define LWIP_MEM_ALLOC_PROTECT()
|
---|
219 | #define LWIP_MEM_ALLOC_UNPROTECT()
|
---|
220 |
|
---|
221 | #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
|
---|
222 |
|
---|
223 |
|
---|
224 | /**
|
---|
225 | * "Plug holes" by combining adjacent empty struct mems.
|
---|
226 | * After this function is through, there should not exist
|
---|
227 | * one empty struct mem pointing to another empty struct mem.
|
---|
228 | *
|
---|
229 | * @param mem this points to a struct mem which just has been freed
|
---|
230 | * @internal this function is only called by mem_free() and mem_trim()
|
---|
231 | *
|
---|
232 | * This assumes access to the heap is protected by the calling function
|
---|
233 | * already.
|
---|
234 | */
|
---|
235 | static void
|
---|
236 | plug_holes(struct mem *mem)
|
---|
237 | {
|
---|
238 | struct mem *nmem;
|
---|
239 | struct mem *pmem;
|
---|
240 |
|
---|
241 | LWIP_ASSERT("plug_holes: mem >= ram", (u8_t *)mem >= ram);
|
---|
242 | LWIP_ASSERT("plug_holes: mem < ram_end", (u8_t *)mem < (u8_t *)ram_end);
|
---|
243 | LWIP_ASSERT("plug_holes: mem->used == 0", mem->used == 0);
|
---|
244 |
|
---|
245 | /* plug hole forward */
|
---|
246 | LWIP_ASSERT("plug_holes: mem->next <= MEM_SIZE_ALIGNED", mem->next <= MEM_SIZE_ALIGNED);
|
---|
247 |
|
---|
248 | nmem = (struct mem *)(void *)&ram[mem->next];
|
---|
249 | if (mem != nmem && nmem->used == 0 && (u8_t *)nmem != (u8_t *)ram_end) {
|
---|
250 | /* if mem->next is unused and not end of ram, combine mem and mem->next */
|
---|
251 | if (lfree == nmem) {
|
---|
252 | lfree = mem;
|
---|
253 | }
|
---|
254 | mem->next = nmem->next;
|
---|
255 | ((struct mem *)(void *)&ram[nmem->next])->prev = (mem_size_t)((u8_t *)mem - ram);
|
---|
256 | }
|
---|
257 |
|
---|
258 | /* plug hole backward */
|
---|
259 | pmem = (struct mem *)(void *)&ram[mem->prev];
|
---|
260 | if (pmem != mem && pmem->used == 0) {
|
---|
261 | /* if mem->prev is unused, combine mem and mem->prev */
|
---|
262 | if (lfree == mem) {
|
---|
263 | lfree = pmem;
|
---|
264 | }
|
---|
265 | pmem->next = mem->next;
|
---|
266 | ((struct mem *)(void *)&ram[mem->next])->prev = (mem_size_t)((u8_t *)pmem - ram);
|
---|
267 | }
|
---|
268 | }
|
---|
269 |
|
---|
270 | /**
|
---|
271 | * Zero the heap and initialize start, end and lowest-free
|
---|
272 | */
|
---|
273 | void
|
---|
274 | mem_init(void)
|
---|
275 | {
|
---|
276 | struct mem *mem;
|
---|
277 |
|
---|
278 | LWIP_ASSERT("Sanity check alignment",
|
---|
279 | (SIZEOF_STRUCT_MEM & (MEM_ALIGNMENT-1)) == 0);
|
---|
280 |
|
---|
281 | /* align the heap */
|
---|
282 | ram = (u8_t *)LWIP_MEM_ALIGN(LWIP_RAM_HEAP_POINTER);
|
---|
283 | /* initialize the start of the heap */
|
---|
284 | mem = (struct mem *)(void *)ram;
|
---|
285 | mem->next = MEM_SIZE_ALIGNED;
|
---|
286 | mem->prev = 0;
|
---|
287 | mem->used = 0;
|
---|
288 | /* initialize the end of the heap */
|
---|
289 | ram_end = (struct mem *)(void *)&ram[MEM_SIZE_ALIGNED];
|
---|
290 | ram_end->used = 1;
|
---|
291 | ram_end->next = MEM_SIZE_ALIGNED;
|
---|
292 | ram_end->prev = MEM_SIZE_ALIGNED;
|
---|
293 |
|
---|
294 | /* initialize the lowest-free pointer to the start of the heap */
|
---|
295 | lfree = (struct mem *)(void *)ram;
|
---|
296 |
|
---|
297 | MEM_STATS_AVAIL(avail, MEM_SIZE_ALIGNED);
|
---|
298 |
|
---|
299 | if(sys_mutex_new(&mem_mutex) != ERR_OK) {
|
---|
300 | LWIP_ASSERT("failed to create mem_mutex", 0);
|
---|
301 | }
|
---|
302 | }
|
---|
303 |
|
---|
304 | /**
|
---|
305 | * Put a struct mem back on the heap
|
---|
306 | *
|
---|
307 | * @param rmem is the data portion of a struct mem as returned by a previous
|
---|
308 | * call to mem_malloc()
|
---|
309 | */
|
---|
310 | void
|
---|
311 | mem_free(void *rmem)
|
---|
312 | {
|
---|
313 | struct mem *mem;
|
---|
314 | LWIP_MEM_FREE_DECL_PROTECT();
|
---|
315 |
|
---|
316 | if (rmem == NULL) {
|
---|
317 | LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("mem_free(p == NULL) was called.\n"));
|
---|
318 | return;
|
---|
319 | }
|
---|
320 | LWIP_ASSERT("mem_free: sanity check alignment", (((mem_ptr_t)rmem) & (MEM_ALIGNMENT-1)) == 0);
|
---|
321 |
|
---|
322 | LWIP_ASSERT("mem_free: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
|
---|
323 | (u8_t *)rmem < (u8_t *)ram_end);
|
---|
324 |
|
---|
325 | if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
|
---|
326 | SYS_ARCH_DECL_PROTECT(lev);
|
---|
327 | LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_free: illegal memory\n"));
|
---|
328 | /* protect mem stats from concurrent access */
|
---|
329 | SYS_ARCH_PROTECT(lev);
|
---|
330 | MEM_STATS_INC(illegal);
|
---|
331 | SYS_ARCH_UNPROTECT(lev);
|
---|
332 | return;
|
---|
333 | }
|
---|
334 | /* protect the heap from concurrent access */
|
---|
335 | LWIP_MEM_FREE_PROTECT();
|
---|
336 | /* Get the corresponding struct mem ... */
|
---|
337 | mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
|
---|
338 | /* ... which has to be in a used state ... */
|
---|
339 | LWIP_ASSERT("mem_free: mem->used", mem->used);
|
---|
340 | /* ... and is now unused. */
|
---|
341 | mem->used = 0;
|
---|
342 |
|
---|
343 | if (mem < lfree) {
|
---|
344 | /* the newly freed struct is now the lowest */
|
---|
345 | lfree = mem;
|
---|
346 | }
|
---|
347 |
|
---|
348 | MEM_STATS_DEC_USED(used, mem->next - (mem_size_t)(((u8_t *)mem - ram)));
|
---|
349 |
|
---|
350 | /* finally, see if prev or next are free also */
|
---|
351 | plug_holes(mem);
|
---|
352 | #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
|
---|
353 | mem_free_count = 1;
|
---|
354 | #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
|
---|
355 | LWIP_MEM_FREE_UNPROTECT();
|
---|
356 | }
|
---|
357 |
|
---|
358 | /**
|
---|
359 | * Shrink memory returned by mem_malloc().
|
---|
360 | *
|
---|
361 | * @param rmem pointer to memory allocated by mem_malloc the is to be shrinked
|
---|
362 | * @param newsize required size after shrinking (needs to be smaller than or
|
---|
363 | * equal to the previous size)
|
---|
364 | * @return for compatibility reasons: is always == rmem, at the moment
|
---|
365 | * or NULL if newsize is > old size, in which case rmem is NOT touched
|
---|
366 | * or freed!
|
---|
367 | */
|
---|
368 | void *
|
---|
369 | mem_trim(void *rmem, mem_size_t newsize)
|
---|
370 | {
|
---|
371 | mem_size_t size;
|
---|
372 | mem_size_t ptr, ptr2;
|
---|
373 | struct mem *mem, *mem2;
|
---|
374 | /* use the FREE_PROTECT here: it protects with sem OR SYS_ARCH_PROTECT */
|
---|
375 | LWIP_MEM_FREE_DECL_PROTECT();
|
---|
376 |
|
---|
377 | /* Expand the size of the allocated memory region so that we can
|
---|
378 | adjust for alignment. */
|
---|
379 | newsize = LWIP_MEM_ALIGN_SIZE(newsize);
|
---|
380 |
|
---|
381 | if(newsize < MIN_SIZE_ALIGNED) {
|
---|
382 | /* every data block must be at least MIN_SIZE_ALIGNED long */
|
---|
383 | newsize = MIN_SIZE_ALIGNED;
|
---|
384 | }
|
---|
385 |
|
---|
386 | if (newsize > MEM_SIZE_ALIGNED) {
|
---|
387 | return NULL;
|
---|
388 | }
|
---|
389 |
|
---|
390 | LWIP_ASSERT("mem_trim: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
|
---|
391 | (u8_t *)rmem < (u8_t *)ram_end);
|
---|
392 |
|
---|
393 | if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
|
---|
394 | SYS_ARCH_DECL_PROTECT(lev);
|
---|
395 | LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_trim: illegal memory\n"));
|
---|
396 | /* protect mem stats from concurrent access */
|
---|
397 | SYS_ARCH_PROTECT(lev);
|
---|
398 | MEM_STATS_INC(illegal);
|
---|
399 | SYS_ARCH_UNPROTECT(lev);
|
---|
400 | return rmem;
|
---|
401 | }
|
---|
402 | /* Get the corresponding struct mem ... */
|
---|
403 | mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
|
---|
404 | /* ... and its offset pointer */
|
---|
405 | ptr = (mem_size_t)((u8_t *)mem - ram);
|
---|
406 |
|
---|
407 | size = mem->next - ptr - SIZEOF_STRUCT_MEM;
|
---|
408 | LWIP_ASSERT("mem_trim can only shrink memory", newsize <= size);
|
---|
409 | if (newsize > size) {
|
---|
410 | /* not supported */
|
---|
411 | return NULL;
|
---|
412 | }
|
---|
413 | if (newsize == size) {
|
---|
414 | /* No change in size, simply return */
|
---|
415 | return rmem;
|
---|
416 | }
|
---|
417 |
|
---|
418 | /* protect the heap from concurrent access */
|
---|
419 | LWIP_MEM_FREE_PROTECT();
|
---|
420 |
|
---|
421 | mem2 = (struct mem *)(void *)&ram[mem->next];
|
---|
422 | if(mem2->used == 0) {
|
---|
423 | /* The next struct is unused, we can simply move it at little */
|
---|
424 | mem_size_t next;
|
---|
425 | /* remember the old next pointer */
|
---|
426 | next = mem2->next;
|
---|
427 | /* create new struct mem which is moved directly after the shrinked mem */
|
---|
428 | ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
|
---|
429 | if (lfree == mem2) {
|
---|
430 | lfree = (struct mem *)(void *)&ram[ptr2];
|
---|
431 | }
|
---|
432 | mem2 = (struct mem *)(void *)&ram[ptr2];
|
---|
433 | mem2->used = 0;
|
---|
434 | /* restore the next pointer */
|
---|
435 | mem2->next = next;
|
---|
436 | /* link it back to mem */
|
---|
437 | mem2->prev = ptr;
|
---|
438 | /* link mem to it */
|
---|
439 | mem->next = ptr2;
|
---|
440 | /* last thing to restore linked list: as we have moved mem2,
|
---|
441 | * let 'mem2->next->prev' point to mem2 again. but only if mem2->next is not
|
---|
442 | * the end of the heap */
|
---|
443 | if (mem2->next != MEM_SIZE_ALIGNED) {
|
---|
444 | ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
|
---|
445 | }
|
---|
446 | MEM_STATS_DEC_USED(used, (size - newsize));
|
---|
447 | /* no need to plug holes, we've already done that */
|
---|
448 | } else if (newsize + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED <= size) {
|
---|
449 | /* Next struct is used but there's room for another struct mem with
|
---|
450 | * at least MIN_SIZE_ALIGNED of data.
|
---|
451 | * Old size ('size') must be big enough to contain at least 'newsize' plus a struct mem
|
---|
452 | * ('SIZEOF_STRUCT_MEM') with some data ('MIN_SIZE_ALIGNED').
|
---|
453 | * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
|
---|
454 | * region that couldn't hold data, but when mem->next gets freed,
|
---|
455 | * the 2 regions would be combined, resulting in more free memory */
|
---|
456 | ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
|
---|
457 | mem2 = (struct mem *)(void *)&ram[ptr2];
|
---|
458 | if (mem2 < lfree) {
|
---|
459 | lfree = mem2;
|
---|
460 | }
|
---|
461 | mem2->used = 0;
|
---|
462 | mem2->next = mem->next;
|
---|
463 | mem2->prev = ptr;
|
---|
464 | mem->next = ptr2;
|
---|
465 | if (mem2->next != MEM_SIZE_ALIGNED) {
|
---|
466 | ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
|
---|
467 | }
|
---|
468 | MEM_STATS_DEC_USED(used, (size - newsize));
|
---|
469 | /* the original mem->next is used, so no need to plug holes! */
|
---|
470 | }
|
---|
471 | /* else {
|
---|
472 | next struct mem is used but size between mem and mem2 is not big enough
|
---|
473 | to create another struct mem
|
---|
474 | -> don't do anyhting.
|
---|
475 | -> the remaining space stays unused since it is too small
|
---|
476 | } */
|
---|
477 | #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
|
---|
478 | mem_free_count = 1;
|
---|
479 | #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
|
---|
480 | LWIP_MEM_FREE_UNPROTECT();
|
---|
481 | return rmem;
|
---|
482 | }
|
---|
483 |
|
---|
484 | /**
|
---|
485 | * Adam's mem_malloc() plus solution for bug #17922
|
---|
486 | * Allocate a block of memory with a minimum of 'size' bytes.
|
---|
487 | *
|
---|
488 | * @param size is the minimum size of the requested block in bytes.
|
---|
489 | * @return pointer to allocated memory or NULL if no free memory was found.
|
---|
490 | *
|
---|
491 | * Note that the returned value will always be aligned (as defined by MEM_ALIGNMENT).
|
---|
492 | */
|
---|
493 | void *
|
---|
494 | mem_malloc(mem_size_t size)
|
---|
495 | {
|
---|
496 | mem_size_t ptr, ptr2;
|
---|
497 | struct mem *mem, *mem2;
|
---|
498 | #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
|
---|
499 | u8_t local_mem_free_count = 0;
|
---|
500 | #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
|
---|
501 | LWIP_MEM_ALLOC_DECL_PROTECT();
|
---|
502 |
|
---|
503 | if (size == 0) {
|
---|
504 | return NULL;
|
---|
505 | }
|
---|
506 |
|
---|
507 | /* Expand the size of the allocated memory region so that we can
|
---|
508 | adjust for alignment. */
|
---|
509 | size = LWIP_MEM_ALIGN_SIZE(size);
|
---|
510 |
|
---|
511 | if(size < MIN_SIZE_ALIGNED) {
|
---|
512 | /* every data block must be at least MIN_SIZE_ALIGNED long */
|
---|
513 | size = MIN_SIZE_ALIGNED;
|
---|
514 | }
|
---|
515 |
|
---|
516 | if (size > MEM_SIZE_ALIGNED) {
|
---|
517 | return NULL;
|
---|
518 | }
|
---|
519 |
|
---|
520 | /* protect the heap from concurrent access */
|
---|
521 | sys_mutex_lock(&mem_mutex);
|
---|
522 | LWIP_MEM_ALLOC_PROTECT();
|
---|
523 | #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
|
---|
524 | /* run as long as a mem_free disturbed mem_malloc or mem_trim */
|
---|
525 | do {
|
---|
526 | local_mem_free_count = 0;
|
---|
527 | #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
|
---|
528 |
|
---|
529 | /* Scan through the heap searching for a free block that is big enough,
|
---|
530 | * beginning with the lowest free block.
|
---|
531 | */
|
---|
532 | for (ptr = (mem_size_t)((u8_t *)lfree - ram); ptr < MEM_SIZE_ALIGNED - size;
|
---|
533 | ptr = ((struct mem *)(void *)&ram[ptr])->next) {
|
---|
534 | mem = (struct mem *)(void *)&ram[ptr];
|
---|
535 | #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
|
---|
536 | mem_free_count = 0;
|
---|
537 | LWIP_MEM_ALLOC_UNPROTECT();
|
---|
538 | /* allow mem_free or mem_trim to run */
|
---|
539 | LWIP_MEM_ALLOC_PROTECT();
|
---|
540 | if (mem_free_count != 0) {
|
---|
541 | /* If mem_free or mem_trim have run, we have to restart since they
|
---|
542 | could have altered our current struct mem. */
|
---|
543 | local_mem_free_count = 1;
|
---|
544 | break;
|
---|
545 | }
|
---|
546 | #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
|
---|
547 |
|
---|
548 | if ((!mem->used) &&
|
---|
549 | (mem->next - (ptr + SIZEOF_STRUCT_MEM)) >= size) {
|
---|
550 | /* mem is not used and at least perfect fit is possible:
|
---|
551 | * mem->next - (ptr + SIZEOF_STRUCT_MEM) gives us the 'user data size' of mem */
|
---|
552 |
|
---|
553 | if (mem->next - (ptr + SIZEOF_STRUCT_MEM) >= (size + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED)) {
|
---|
554 | /* (in addition to the above, we test if another struct mem (SIZEOF_STRUCT_MEM) containing
|
---|
555 | * at least MIN_SIZE_ALIGNED of data also fits in the 'user data space' of 'mem')
|
---|
556 | * -> split large block, create empty remainder,
|
---|
557 | * remainder must be large enough to contain MIN_SIZE_ALIGNED data: if
|
---|
558 | * mem->next - (ptr + (2*SIZEOF_STRUCT_MEM)) == size,
|
---|
559 | * struct mem would fit in but no data between mem2 and mem2->next
|
---|
560 | * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
|
---|
561 | * region that couldn't hold data, but when mem->next gets freed,
|
---|
562 | * the 2 regions would be combined, resulting in more free memory
|
---|
563 | */
|
---|
564 | ptr2 = ptr + SIZEOF_STRUCT_MEM + size;
|
---|
565 | /* create mem2 struct */
|
---|
566 | mem2 = (struct mem *)(void *)&ram[ptr2];
|
---|
567 | mem2->used = 0;
|
---|
568 | mem2->next = mem->next;
|
---|
569 | mem2->prev = ptr;
|
---|
570 | /* and insert it between mem and mem->next */
|
---|
571 | mem->next = ptr2;
|
---|
572 | mem->used = 1;
|
---|
573 |
|
---|
574 | if (mem2->next != MEM_SIZE_ALIGNED) {
|
---|
575 | ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
|
---|
576 | }
|
---|
577 | MEM_STATS_INC_USED(used, (size + SIZEOF_STRUCT_MEM));
|
---|
578 | } else {
|
---|
579 | /* (a mem2 struct does no fit into the user data space of mem and mem->next will always
|
---|
580 | * be used at this point: if not we have 2 unused structs in a row, plug_holes should have
|
---|
581 | * take care of this).
|
---|
582 | * -> near fit or excact fit: do not split, no mem2 creation
|
---|
583 | * also can't move mem->next directly behind mem, since mem->next
|
---|
584 | * will always be used at this point!
|
---|
585 | */
|
---|
586 | mem->used = 1;
|
---|
587 | MEM_STATS_INC_USED(used, mem->next - (mem_size_t)((u8_t *)mem - ram));
|
---|
588 | }
|
---|
589 | #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
|
---|
590 | mem_malloc_adjust_lfree:
|
---|
591 | #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
|
---|
592 | if (mem == lfree) {
|
---|
593 | struct mem *cur = lfree;
|
---|
594 | /* Find next free block after mem and update lowest free pointer */
|
---|
595 | while (cur->used && cur != ram_end) {
|
---|
596 | #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
|
---|
597 | mem_free_count = 0;
|
---|
598 | LWIP_MEM_ALLOC_UNPROTECT();
|
---|
599 | /* prevent high interrupt latency... */
|
---|
600 | LWIP_MEM_ALLOC_PROTECT();
|
---|
601 | if (mem_free_count != 0) {
|
---|
602 | /* If mem_free or mem_trim have run, we have to restart since they
|
---|
603 | could have altered our current struct mem or lfree. */
|
---|
604 | goto mem_malloc_adjust_lfree;
|
---|
605 | }
|
---|
606 | #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
|
---|
607 | cur = (struct mem *)(void *)&ram[cur->next];
|
---|
608 | }
|
---|
609 | lfree = cur;
|
---|
610 | LWIP_ASSERT("mem_malloc: !lfree->used", ((lfree == ram_end) || (!lfree->used)));
|
---|
611 | }
|
---|
612 | LWIP_MEM_ALLOC_UNPROTECT();
|
---|
613 | sys_mutex_unlock(&mem_mutex);
|
---|
614 | LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.",
|
---|
615 | (mem_ptr_t)mem + SIZEOF_STRUCT_MEM + size <= (mem_ptr_t)ram_end);
|
---|
616 | LWIP_ASSERT("mem_malloc: allocated memory properly aligned.",
|
---|
617 | ((mem_ptr_t)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0);
|
---|
618 | LWIP_ASSERT("mem_malloc: sanity check alignment",
|
---|
619 | (((mem_ptr_t)mem) & (MEM_ALIGNMENT-1)) == 0);
|
---|
620 |
|
---|
621 | return (u8_t *)mem + SIZEOF_STRUCT_MEM;
|
---|
622 | }
|
---|
623 | }
|
---|
624 | #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
|
---|
625 | /* if we got interrupted by a mem_free, try again */
|
---|
626 | } while(local_mem_free_count != 0);
|
---|
627 | #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
|
---|
628 | LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("mem_malloc: could not allocate %"S16_F" bytes\n", (s16_t)size));
|
---|
629 | MEM_STATS_INC(err);
|
---|
630 | LWIP_MEM_ALLOC_UNPROTECT();
|
---|
631 | sys_mutex_unlock(&mem_mutex);
|
---|
632 | return NULL;
|
---|
633 | }
|
---|
634 |
|
---|
635 | #endif /* MEM_USE_POOLS */
|
---|
636 | /**
|
---|
637 | * Contiguously allocates enough space for count objects that are size bytes
|
---|
638 | * of memory each and returns a pointer to the allocated memory.
|
---|
639 | *
|
---|
640 | * The allocated memory is filled with bytes of value zero.
|
---|
641 | *
|
---|
642 | * @param count number of objects to allocate
|
---|
643 | * @param size size of the objects to allocate
|
---|
644 | * @return pointer to allocated memory / NULL pointer if there is an error
|
---|
645 | */
|
---|
646 | void *mem_calloc(mem_size_t count, mem_size_t size)
|
---|
647 | {
|
---|
648 | void *p;
|
---|
649 |
|
---|
650 | /* allocate 'count' objects of size 'size' */
|
---|
651 | p = mem_malloc(count * size);
|
---|
652 | if (p) {
|
---|
653 | /* zero the memory */
|
---|
654 | memset(p, 0, count * size);
|
---|
655 | }
|
---|
656 | return p;
|
---|
657 | }
|
---|
658 |
|
---|
659 | #endif /* !MEM_LIBC_MALLOC */
|
---|