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Fork of lwip by mbed official

core/mem.c@0:51ac1d130fd4, 2012-06-22 (annotated)

Committer:
mbed_official
Date:
Fri Jun 22 09:25:39 2012 +0000
Revision:
0:51ac1d130fd4
Child:
2:fcd6ac34b3f8
Initial import from lwip-1.4.0: http://download.savannah.gnu.org/releases/lwip/lwip-1.4.0.zip

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 0:51ac1d130fd4 1 /**
mbed_official 0:51ac1d130fd4 2 * @file
mbed_official 0:51ac1d130fd4 3 * Dynamic memory manager
mbed_official 0:51ac1d130fd4 4 *
mbed_official 0:51ac1d130fd4 5 * This is a lightweight replacement for the standard C library malloc().
mbed_official 0:51ac1d130fd4 6 *
mbed_official 0:51ac1d130fd4 7 * If you want to use the standard C library malloc() instead, define
mbed_official 0:51ac1d130fd4 8 * MEM_LIBC_MALLOC to 1 in your lwipopts.h
mbed_official 0:51ac1d130fd4 9 *
mbed_official 0:51ac1d130fd4 10 * To let mem_malloc() use pools (prevents fragmentation and is much faster than
mbed_official 0:51ac1d130fd4 11 * a heap but might waste some memory), define MEM_USE_POOLS to 1, define
mbed_official 0:51ac1d130fd4 12 * MEM_USE_CUSTOM_POOLS to 1 and create a file "lwippools.h" that includes a list
mbed_official 0:51ac1d130fd4 13 * of pools like this (more pools can be added between _START and _END):
mbed_official 0:51ac1d130fd4 14 *
mbed_official 0:51ac1d130fd4 15 * Define three pools with sizes 256, 512, and 1512 bytes
mbed_official 0:51ac1d130fd4 16 * LWIP_MALLOC_MEMPOOL_START
mbed_official 0:51ac1d130fd4 17 * LWIP_MALLOC_MEMPOOL(20, 256)
mbed_official 0:51ac1d130fd4 18 * LWIP_MALLOC_MEMPOOL(10, 512)
mbed_official 0:51ac1d130fd4 19 * LWIP_MALLOC_MEMPOOL(5, 1512)
mbed_official 0:51ac1d130fd4 20 * LWIP_MALLOC_MEMPOOL_END
mbed_official 0:51ac1d130fd4 21 */
mbed_official 0:51ac1d130fd4 22
mbed_official 0:51ac1d130fd4 23 /*
mbed_official 0:51ac1d130fd4 24 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
mbed_official 0:51ac1d130fd4 25 * All rights reserved.
mbed_official 0:51ac1d130fd4 26 *
mbed_official 0:51ac1d130fd4 27 * Redistribution and use in source and binary forms, with or without modification,
mbed_official 0:51ac1d130fd4 28 * are permitted provided that the following conditions are met:
mbed_official 0:51ac1d130fd4 29 *
mbed_official 0:51ac1d130fd4 30 * 1. Redistributions of source code must retain the above copyright notice,
mbed_official 0:51ac1d130fd4 31 * this list of conditions and the following disclaimer.
mbed_official 0:51ac1d130fd4 32 * 2. Redistributions in binary form must reproduce the above copyright notice,
mbed_official 0:51ac1d130fd4 33 * this list of conditions and the following disclaimer in the documentation
mbed_official 0:51ac1d130fd4 34 * and/or other materials provided with the distribution.
mbed_official 0:51ac1d130fd4 35 * 3. The name of the author may not be used to endorse or promote products
mbed_official 0:51ac1d130fd4 36 * derived from this software without specific prior written permission.
mbed_official 0:51ac1d130fd4 37 *
mbed_official 0:51ac1d130fd4 38 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
mbed_official 0:51ac1d130fd4 39 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
mbed_official 0:51ac1d130fd4 40 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
mbed_official 0:51ac1d130fd4 41 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
mbed_official 0:51ac1d130fd4 42 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
mbed_official 0:51ac1d130fd4 43 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
mbed_official 0:51ac1d130fd4 44 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
mbed_official 0:51ac1d130fd4 45 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
mbed_official 0:51ac1d130fd4 46 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
mbed_official 0:51ac1d130fd4 47 * OF SUCH DAMAGE.
mbed_official 0:51ac1d130fd4 48 *
mbed_official 0:51ac1d130fd4 49 * This file is part of the lwIP TCP/IP stack.
mbed_official 0:51ac1d130fd4 50 *
mbed_official 0:51ac1d130fd4 51 * Author: Adam Dunkels <adam@sics.se>
mbed_official 0:51ac1d130fd4 52 * Simon Goldschmidt
mbed_official 0:51ac1d130fd4 53 *
mbed_official 0:51ac1d130fd4 54 */
mbed_official 0:51ac1d130fd4 55
mbed_official 0:51ac1d130fd4 56 #include "lwip/opt.h"
mbed_official 0:51ac1d130fd4 57
mbed_official 0:51ac1d130fd4 58 #if !MEM_LIBC_MALLOC /* don't build if not configured for use in lwipopts.h */
mbed_official 0:51ac1d130fd4 59
mbed_official 0:51ac1d130fd4 60 #include "lwip/def.h"
mbed_official 0:51ac1d130fd4 61 #include "lwip/mem.h"
mbed_official 0:51ac1d130fd4 62 #include "lwip/sys.h"
mbed_official 0:51ac1d130fd4 63 #include "lwip/stats.h"
mbed_official 0:51ac1d130fd4 64 #include "lwip/err.h"
mbed_official 0:51ac1d130fd4 65
mbed_official 0:51ac1d130fd4 66 #include <string.h>
mbed_official 0:51ac1d130fd4 67
mbed_official 0:51ac1d130fd4 68 #if MEM_USE_POOLS
mbed_official 0:51ac1d130fd4 69 /* lwIP head implemented with different sized pools */
mbed_official 0:51ac1d130fd4 70
mbed_official 0:51ac1d130fd4 71 /**
mbed_official 0:51ac1d130fd4 72 * Allocate memory: determine the smallest pool that is big enough
mbed_official 0:51ac1d130fd4 73 * to contain an element of 'size' and get an element from that pool.
mbed_official 0:51ac1d130fd4 74 *
mbed_official 0:51ac1d130fd4 75 * @param size the size in bytes of the memory needed
mbed_official 0:51ac1d130fd4 76 * @return a pointer to the allocated memory or NULL if the pool is empty
mbed_official 0:51ac1d130fd4 77 */
mbed_official 0:51ac1d130fd4 78 void *
mbed_official 0:51ac1d130fd4 79 mem_malloc(mem_size_t size)
mbed_official 0:51ac1d130fd4 80 {
mbed_official 0:51ac1d130fd4 81 struct memp_malloc_helper *element;
mbed_official 0:51ac1d130fd4 82 memp_t poolnr;
mbed_official 0:51ac1d130fd4 83 mem_size_t required_size = size + sizeof(struct memp_malloc_helper);
mbed_official 0:51ac1d130fd4 84
mbed_official 0:51ac1d130fd4 85 for (poolnr = MEMP_POOL_FIRST; poolnr <= MEMP_POOL_LAST; poolnr = (memp_t)(poolnr + 1)) {
mbed_official 0:51ac1d130fd4 86 #if MEM_USE_POOLS_TRY_BIGGER_POOL
mbed_official 0:51ac1d130fd4 87 again:
mbed_official 0:51ac1d130fd4 88 #endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
mbed_official 0:51ac1d130fd4 89 /* is this pool big enough to hold an element of the required size
mbed_official 0:51ac1d130fd4 90 plus a struct memp_malloc_helper that saves the pool this element came from? */
mbed_official 0:51ac1d130fd4 91 if (required_size <= memp_sizes[poolnr]) {
mbed_official 0:51ac1d130fd4 92 break;
mbed_official 0:51ac1d130fd4 93 }
mbed_official 0:51ac1d130fd4 94 }
mbed_official 0:51ac1d130fd4 95 if (poolnr > MEMP_POOL_LAST) {
mbed_official 0:51ac1d130fd4 96 LWIP_ASSERT("mem_malloc(): no pool is that big!", 0);
mbed_official 0:51ac1d130fd4 97 return NULL;
mbed_official 0:51ac1d130fd4 98 }
mbed_official 0:51ac1d130fd4 99 element = (struct memp_malloc_helper*)memp_malloc(poolnr);
mbed_official 0:51ac1d130fd4 100 if (element == NULL) {
mbed_official 0:51ac1d130fd4 101 /* No need to DEBUGF or ASSERT: This error is already
mbed_official 0:51ac1d130fd4 102 taken care of in memp.c */
mbed_official 0:51ac1d130fd4 103 #if MEM_USE_POOLS_TRY_BIGGER_POOL
mbed_official 0:51ac1d130fd4 104 /** Try a bigger pool if this one is empty! */
mbed_official 0:51ac1d130fd4 105 if (poolnr < MEMP_POOL_LAST) {
mbed_official 0:51ac1d130fd4 106 poolnr++;
mbed_official 0:51ac1d130fd4 107 goto again;
mbed_official 0:51ac1d130fd4 108 }
mbed_official 0:51ac1d130fd4 109 #endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
mbed_official 0:51ac1d130fd4 110 return NULL;
mbed_official 0:51ac1d130fd4 111 }
mbed_official 0:51ac1d130fd4 112
mbed_official 0:51ac1d130fd4 113 /* save the pool number this element came from */
mbed_official 0:51ac1d130fd4 114 element->poolnr = poolnr;
mbed_official 0:51ac1d130fd4 115 /* and return a pointer to the memory directly after the struct memp_malloc_helper */
mbed_official 0:51ac1d130fd4 116 element++;
mbed_official 0:51ac1d130fd4 117
mbed_official 0:51ac1d130fd4 118 return element;
mbed_official 0:51ac1d130fd4 119 }
mbed_official 0:51ac1d130fd4 120
mbed_official 0:51ac1d130fd4 121 /**
mbed_official 0:51ac1d130fd4 122 * Free memory previously allocated by mem_malloc. Loads the pool number
mbed_official 0:51ac1d130fd4 123 * and calls memp_free with that pool number to put the element back into
mbed_official 0:51ac1d130fd4 124 * its pool
mbed_official 0:51ac1d130fd4 125 *
mbed_official 0:51ac1d130fd4 126 * @param rmem the memory element to free
mbed_official 0:51ac1d130fd4 127 */
mbed_official 0:51ac1d130fd4 128 void
mbed_official 0:51ac1d130fd4 129 mem_free(void *rmem)
mbed_official 0:51ac1d130fd4 130 {
mbed_official 0:51ac1d130fd4 131 struct memp_malloc_helper *hmem = (struct memp_malloc_helper*)rmem;
mbed_official 0:51ac1d130fd4 132
mbed_official 0:51ac1d130fd4 133 LWIP_ASSERT("rmem != NULL", (rmem != NULL));
mbed_official 0:51ac1d130fd4 134 LWIP_ASSERT("rmem == MEM_ALIGN(rmem)", (rmem == LWIP_MEM_ALIGN(rmem)));
mbed_official 0:51ac1d130fd4 135
mbed_official 0:51ac1d130fd4 136 /* get the original struct memp_malloc_helper */
mbed_official 0:51ac1d130fd4 137 hmem--;
mbed_official 0:51ac1d130fd4 138
mbed_official 0:51ac1d130fd4 139 LWIP_ASSERT("hmem != NULL", (hmem != NULL));
mbed_official 0:51ac1d130fd4 140 LWIP_ASSERT("hmem == MEM_ALIGN(hmem)", (hmem == LWIP_MEM_ALIGN(hmem)));
mbed_official 0:51ac1d130fd4 141 LWIP_ASSERT("hmem->poolnr < MEMP_MAX", (hmem->poolnr < MEMP_MAX));
mbed_official 0:51ac1d130fd4 142
mbed_official 0:51ac1d130fd4 143 /* and put it in the pool we saved earlier */
mbed_official 0:51ac1d130fd4 144 memp_free(hmem->poolnr, hmem);
mbed_official 0:51ac1d130fd4 145 }
mbed_official 0:51ac1d130fd4 146
mbed_official 0:51ac1d130fd4 147 #else /* MEM_USE_POOLS */
mbed_official 0:51ac1d130fd4 148 /* lwIP replacement for your libc malloc() */
mbed_official 0:51ac1d130fd4 149
mbed_official 0:51ac1d130fd4 150 /**
mbed_official 0:51ac1d130fd4 151 * The heap is made up as a list of structs of this type.
mbed_official 0:51ac1d130fd4 152 * This does not have to be aligned since for getting its size,
mbed_official 0:51ac1d130fd4 153 * we only use the macro SIZEOF_STRUCT_MEM, which automatically alignes.
mbed_official 0:51ac1d130fd4 154 */
mbed_official 0:51ac1d130fd4 155 struct mem {
mbed_official 0:51ac1d130fd4 156 /** index (-> ram[next]) of the next struct */
mbed_official 0:51ac1d130fd4 157 mem_size_t next;
mbed_official 0:51ac1d130fd4 158 /** index (-> ram[prev]) of the previous struct */
mbed_official 0:51ac1d130fd4 159 mem_size_t prev;
mbed_official 0:51ac1d130fd4 160 /** 1: this area is used; 0: this area is unused */
mbed_official 0:51ac1d130fd4 161 u8_t used;
mbed_official 0:51ac1d130fd4 162 };
mbed_official 0:51ac1d130fd4 163
mbed_official 0:51ac1d130fd4 164 /** All allocated blocks will be MIN_SIZE bytes big, at least!
mbed_official 0:51ac1d130fd4 165 * MIN_SIZE can be overridden to suit your needs. Smaller values save space,
mbed_official 0:51ac1d130fd4 166 * larger values could prevent too small blocks to fragment the RAM too much. */
mbed_official 0:51ac1d130fd4 167 #ifndef MIN_SIZE
mbed_official 0:51ac1d130fd4 168 #define MIN_SIZE 12
mbed_official 0:51ac1d130fd4 169 #endif /* MIN_SIZE */
mbed_official 0:51ac1d130fd4 170 /* some alignment macros: we define them here for better source code layout */
mbed_official 0:51ac1d130fd4 171 #define MIN_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MIN_SIZE)
mbed_official 0:51ac1d130fd4 172 #define SIZEOF_STRUCT_MEM LWIP_MEM_ALIGN_SIZE(sizeof(struct mem))
mbed_official 0:51ac1d130fd4 173 #define MEM_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MEM_SIZE)
mbed_official 0:51ac1d130fd4 174
mbed_official 0:51ac1d130fd4 175 /** If you want to relocate the heap to external memory, simply define
mbed_official 0:51ac1d130fd4 176 * LWIP_RAM_HEAP_POINTER as a void-pointer to that location.
mbed_official 0:51ac1d130fd4 177 * If so, make sure the memory at that location is big enough (see below on
mbed_official 0:51ac1d130fd4 178 * how that space is calculated). */
mbed_official 0:51ac1d130fd4 179 #ifndef LWIP_RAM_HEAP_POINTER
mbed_official 0:51ac1d130fd4 180 /** the heap. we need one struct mem at the end and some room for alignment */
mbed_official 0:51ac1d130fd4 181 u8_t ram_heap[MEM_SIZE_ALIGNED + (2*SIZEOF_STRUCT_MEM) + MEM_ALIGNMENT];
mbed_official 0:51ac1d130fd4 182 #define LWIP_RAM_HEAP_POINTER ram_heap
mbed_official 0:51ac1d130fd4 183 #endif /* LWIP_RAM_HEAP_POINTER */
mbed_official 0:51ac1d130fd4 184
mbed_official 0:51ac1d130fd4 185 /** pointer to the heap (ram_heap): for alignment, ram is now a pointer instead of an array */
mbed_official 0:51ac1d130fd4 186 static u8_t *ram;
mbed_official 0:51ac1d130fd4 187 /** the last entry, always unused! */
mbed_official 0:51ac1d130fd4 188 static struct mem *ram_end;
mbed_official 0:51ac1d130fd4 189 /** pointer to the lowest free block, this is used for faster search */
mbed_official 0:51ac1d130fd4 190 static struct mem *lfree;
mbed_official 0:51ac1d130fd4 191
mbed_official 0:51ac1d130fd4 192 /** concurrent access protection */
mbed_official 0:51ac1d130fd4 193 static sys_mutex_t mem_mutex;
mbed_official 0:51ac1d130fd4 194
mbed_official 0:51ac1d130fd4 195 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
mbed_official 0:51ac1d130fd4 196
mbed_official 0:51ac1d130fd4 197 static volatile u8_t mem_free_count;
mbed_official 0:51ac1d130fd4 198
mbed_official 0:51ac1d130fd4 199 /* Allow mem_free from other (e.g. interrupt) context */
mbed_official 0:51ac1d130fd4 200 #define LWIP_MEM_FREE_DECL_PROTECT() SYS_ARCH_DECL_PROTECT(lev_free)
mbed_official 0:51ac1d130fd4 201 #define LWIP_MEM_FREE_PROTECT() SYS_ARCH_PROTECT(lev_free)
mbed_official 0:51ac1d130fd4 202 #define LWIP_MEM_FREE_UNPROTECT() SYS_ARCH_UNPROTECT(lev_free)
mbed_official 0:51ac1d130fd4 203 #define LWIP_MEM_ALLOC_DECL_PROTECT() SYS_ARCH_DECL_PROTECT(lev_alloc)
mbed_official 0:51ac1d130fd4 204 #define LWIP_MEM_ALLOC_PROTECT() SYS_ARCH_PROTECT(lev_alloc)
mbed_official 0:51ac1d130fd4 205 #define LWIP_MEM_ALLOC_UNPROTECT() SYS_ARCH_UNPROTECT(lev_alloc)
mbed_official 0:51ac1d130fd4 206
mbed_official 0:51ac1d130fd4 207 #else /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
mbed_official 0:51ac1d130fd4 208
mbed_official 0:51ac1d130fd4 209 /* Protect the heap only by using a semaphore */
mbed_official 0:51ac1d130fd4 210 #define LWIP_MEM_FREE_DECL_PROTECT()
mbed_official 0:51ac1d130fd4 211 #define LWIP_MEM_FREE_PROTECT() sys_mutex_lock(&mem_mutex)
mbed_official 0:51ac1d130fd4 212 #define LWIP_MEM_FREE_UNPROTECT() sys_mutex_unlock(&mem_mutex)
mbed_official 0:51ac1d130fd4 213 /* mem_malloc is protected using semaphore AND LWIP_MEM_ALLOC_PROTECT */
mbed_official 0:51ac1d130fd4 214 #define LWIP_MEM_ALLOC_DECL_PROTECT()
mbed_official 0:51ac1d130fd4 215 #define LWIP_MEM_ALLOC_PROTECT()
mbed_official 0:51ac1d130fd4 216 #define LWIP_MEM_ALLOC_UNPROTECT()
mbed_official 0:51ac1d130fd4 217
mbed_official 0:51ac1d130fd4 218 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
mbed_official 0:51ac1d130fd4 219
mbed_official 0:51ac1d130fd4 220
mbed_official 0:51ac1d130fd4 221 /**
mbed_official 0:51ac1d130fd4 222 * "Plug holes" by combining adjacent empty struct mems.
mbed_official 0:51ac1d130fd4 223 * After this function is through, there should not exist
mbed_official 0:51ac1d130fd4 224 * one empty struct mem pointing to another empty struct mem.
mbed_official 0:51ac1d130fd4 225 *
mbed_official 0:51ac1d130fd4 226 * @param mem this points to a struct mem which just has been freed
mbed_official 0:51ac1d130fd4 227 * @internal this function is only called by mem_free() and mem_trim()
mbed_official 0:51ac1d130fd4 228 *
mbed_official 0:51ac1d130fd4 229 * This assumes access to the heap is protected by the calling function
mbed_official 0:51ac1d130fd4 230 * already.
mbed_official 0:51ac1d130fd4 231 */
mbed_official 0:51ac1d130fd4 232 static void
mbed_official 0:51ac1d130fd4 233 plug_holes(struct mem *mem)
mbed_official 0:51ac1d130fd4 234 {
mbed_official 0:51ac1d130fd4 235 struct mem *nmem;
mbed_official 0:51ac1d130fd4 236 struct mem *pmem;
mbed_official 0:51ac1d130fd4 237
mbed_official 0:51ac1d130fd4 238 LWIP_ASSERT("plug_holes: mem >= ram", (u8_t *)mem >= ram);
mbed_official 0:51ac1d130fd4 239 LWIP_ASSERT("plug_holes: mem < ram_end", (u8_t *)mem < (u8_t *)ram_end);
mbed_official 0:51ac1d130fd4 240 LWIP_ASSERT("plug_holes: mem->used == 0", mem->used == 0);
mbed_official 0:51ac1d130fd4 241
mbed_official 0:51ac1d130fd4 242 /* plug hole forward */
mbed_official 0:51ac1d130fd4 243 LWIP_ASSERT("plug_holes: mem->next <= MEM_SIZE_ALIGNED", mem->next <= MEM_SIZE_ALIGNED);
mbed_official 0:51ac1d130fd4 244
mbed_official 0:51ac1d130fd4 245 nmem = (struct mem *)(void *)&ram[mem->next];
mbed_official 0:51ac1d130fd4 246 if (mem != nmem && nmem->used == 0 && (u8_t *)nmem != (u8_t *)ram_end) {
mbed_official 0:51ac1d130fd4 247 /* if mem->next is unused and not end of ram, combine mem and mem->next */
mbed_official 0:51ac1d130fd4 248 if (lfree == nmem) {
mbed_official 0:51ac1d130fd4 249 lfree = mem;
mbed_official 0:51ac1d130fd4 250 }
mbed_official 0:51ac1d130fd4 251 mem->next = nmem->next;
mbed_official 0:51ac1d130fd4 252 ((struct mem *)(void *)&ram[nmem->next])->prev = (mem_size_t)((u8_t *)mem - ram);
mbed_official 0:51ac1d130fd4 253 }
mbed_official 0:51ac1d130fd4 254
mbed_official 0:51ac1d130fd4 255 /* plug hole backward */
mbed_official 0:51ac1d130fd4 256 pmem = (struct mem *)(void *)&ram[mem->prev];
mbed_official 0:51ac1d130fd4 257 if (pmem != mem && pmem->used == 0) {
mbed_official 0:51ac1d130fd4 258 /* if mem->prev is unused, combine mem and mem->prev */
mbed_official 0:51ac1d130fd4 259 if (lfree == mem) {
mbed_official 0:51ac1d130fd4 260 lfree = pmem;
mbed_official 0:51ac1d130fd4 261 }
mbed_official 0:51ac1d130fd4 262 pmem->next = mem->next;
mbed_official 0:51ac1d130fd4 263 ((struct mem *)(void *)&ram[mem->next])->prev = (mem_size_t)((u8_t *)pmem - ram);
mbed_official 0:51ac1d130fd4 264 }
mbed_official 0:51ac1d130fd4 265 }
mbed_official 0:51ac1d130fd4 266
mbed_official 0:51ac1d130fd4 267 /**
mbed_official 0:51ac1d130fd4 268 * Zero the heap and initialize start, end and lowest-free
mbed_official 0:51ac1d130fd4 269 */
mbed_official 0:51ac1d130fd4 270 void
mbed_official 0:51ac1d130fd4 271 mem_init(void)
mbed_official 0:51ac1d130fd4 272 {
mbed_official 0:51ac1d130fd4 273 struct mem *mem;
mbed_official 0:51ac1d130fd4 274
mbed_official 0:51ac1d130fd4 275 LWIP_ASSERT("Sanity check alignment",
mbed_official 0:51ac1d130fd4 276 (SIZEOF_STRUCT_MEM & (MEM_ALIGNMENT-1)) == 0);
mbed_official 0:51ac1d130fd4 277
mbed_official 0:51ac1d130fd4 278 /* align the heap */
mbed_official 0:51ac1d130fd4 279 ram = (u8_t *)LWIP_MEM_ALIGN(LWIP_RAM_HEAP_POINTER);
mbed_official 0:51ac1d130fd4 280 /* initialize the start of the heap */
mbed_official 0:51ac1d130fd4 281 mem = (struct mem *)(void *)ram;
mbed_official 0:51ac1d130fd4 282 mem->next = MEM_SIZE_ALIGNED;
mbed_official 0:51ac1d130fd4 283 mem->prev = 0;
mbed_official 0:51ac1d130fd4 284 mem->used = 0;
mbed_official 0:51ac1d130fd4 285 /* initialize the end of the heap */
mbed_official 0:51ac1d130fd4 286 ram_end = (struct mem *)(void *)&ram[MEM_SIZE_ALIGNED];
mbed_official 0:51ac1d130fd4 287 ram_end->used = 1;
mbed_official 0:51ac1d130fd4 288 ram_end->next = MEM_SIZE_ALIGNED;
mbed_official 0:51ac1d130fd4 289 ram_end->prev = MEM_SIZE_ALIGNED;
mbed_official 0:51ac1d130fd4 290
mbed_official 0:51ac1d130fd4 291 /* initialize the lowest-free pointer to the start of the heap */
mbed_official 0:51ac1d130fd4 292 lfree = (struct mem *)(void *)ram;
mbed_official 0:51ac1d130fd4 293
mbed_official 0:51ac1d130fd4 294 MEM_STATS_AVAIL(avail, MEM_SIZE_ALIGNED);
mbed_official 0:51ac1d130fd4 295
mbed_official 0:51ac1d130fd4 296 if(sys_mutex_new(&mem_mutex) != ERR_OK) {
mbed_official 0:51ac1d130fd4 297 LWIP_ASSERT("failed to create mem_mutex", 0);
mbed_official 0:51ac1d130fd4 298 }
mbed_official 0:51ac1d130fd4 299 }
mbed_official 0:51ac1d130fd4 300
mbed_official 0:51ac1d130fd4 301 /**
mbed_official 0:51ac1d130fd4 302 * Put a struct mem back on the heap
mbed_official 0:51ac1d130fd4 303 *
mbed_official 0:51ac1d130fd4 304 * @param rmem is the data portion of a struct mem as returned by a previous
mbed_official 0:51ac1d130fd4 305 * call to mem_malloc()
mbed_official 0:51ac1d130fd4 306 */
mbed_official 0:51ac1d130fd4 307 void
mbed_official 0:51ac1d130fd4 308 mem_free(void *rmem)
mbed_official 0:51ac1d130fd4 309 {
mbed_official 0:51ac1d130fd4 310 struct mem *mem;
mbed_official 0:51ac1d130fd4 311 LWIP_MEM_FREE_DECL_PROTECT();
mbed_official 0:51ac1d130fd4 312
mbed_official 0:51ac1d130fd4 313 if (rmem == NULL) {
mbed_official 0:51ac1d130fd4 314 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("mem_free(p == NULL) was called.\n"));
mbed_official 0:51ac1d130fd4 315 return;
mbed_official 0:51ac1d130fd4 316 }
mbed_official 0:51ac1d130fd4 317 LWIP_ASSERT("mem_free: sanity check alignment", (((mem_ptr_t)rmem) & (MEM_ALIGNMENT-1)) == 0);
mbed_official 0:51ac1d130fd4 318
mbed_official 0:51ac1d130fd4 319 LWIP_ASSERT("mem_free: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
mbed_official 0:51ac1d130fd4 320 (u8_t *)rmem < (u8_t *)ram_end);
mbed_official 0:51ac1d130fd4 321
mbed_official 0:51ac1d130fd4 322 if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
mbed_official 0:51ac1d130fd4 323 SYS_ARCH_DECL_PROTECT(lev);
mbed_official 0:51ac1d130fd4 324 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_free: illegal memory\n"));
mbed_official 0:51ac1d130fd4 325 /* protect mem stats from concurrent access */
mbed_official 0:51ac1d130fd4 326 SYS_ARCH_PROTECT(lev);
mbed_official 0:51ac1d130fd4 327 MEM_STATS_INC(illegal);
mbed_official 0:51ac1d130fd4 328 SYS_ARCH_UNPROTECT(lev);
mbed_official 0:51ac1d130fd4 329 return;
mbed_official 0:51ac1d130fd4 330 }
mbed_official 0:51ac1d130fd4 331 /* protect the heap from concurrent access */
mbed_official 0:51ac1d130fd4 332 LWIP_MEM_FREE_PROTECT();
mbed_official 0:51ac1d130fd4 333 /* Get the corresponding struct mem ... */
mbed_official 0:51ac1d130fd4 334 mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
mbed_official 0:51ac1d130fd4 335 /* ... which has to be in a used state ... */
mbed_official 0:51ac1d130fd4 336 LWIP_ASSERT("mem_free: mem->used", mem->used);
mbed_official 0:51ac1d130fd4 337 /* ... and is now unused. */
mbed_official 0:51ac1d130fd4 338 mem->used = 0;
mbed_official 0:51ac1d130fd4 339
mbed_official 0:51ac1d130fd4 340 if (mem < lfree) {
mbed_official 0:51ac1d130fd4 341 /* the newly freed struct is now the lowest */
mbed_official 0:51ac1d130fd4 342 lfree = mem;
mbed_official 0:51ac1d130fd4 343 }
mbed_official 0:51ac1d130fd4 344
mbed_official 0:51ac1d130fd4 345 MEM_STATS_DEC_USED(used, mem->next - (mem_size_t)(((u8_t *)mem - ram)));
mbed_official 0:51ac1d130fd4 346
mbed_official 0:51ac1d130fd4 347 /* finally, see if prev or next are free also */
mbed_official 0:51ac1d130fd4 348 plug_holes(mem);
mbed_official 0:51ac1d130fd4 349 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
mbed_official 0:51ac1d130fd4 350 mem_free_count = 1;
mbed_official 0:51ac1d130fd4 351 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
mbed_official 0:51ac1d130fd4 352 LWIP_MEM_FREE_UNPROTECT();
mbed_official 0:51ac1d130fd4 353 }
mbed_official 0:51ac1d130fd4 354
mbed_official 0:51ac1d130fd4 355 /**
mbed_official 0:51ac1d130fd4 356 * Shrink memory returned by mem_malloc().
mbed_official 0:51ac1d130fd4 357 *
mbed_official 0:51ac1d130fd4 358 * @param rmem pointer to memory allocated by mem_malloc the is to be shrinked
mbed_official 0:51ac1d130fd4 359 * @param newsize required size after shrinking (needs to be smaller than or
mbed_official 0:51ac1d130fd4 360 * equal to the previous size)
mbed_official 0:51ac1d130fd4 361 * @return for compatibility reasons: is always == rmem, at the moment
mbed_official 0:51ac1d130fd4 362 * or NULL if newsize is > old size, in which case rmem is NOT touched
mbed_official 0:51ac1d130fd4 363 * or freed!
mbed_official 0:51ac1d130fd4 364 */
mbed_official 0:51ac1d130fd4 365 void *
mbed_official 0:51ac1d130fd4 366 mem_trim(void *rmem, mem_size_t newsize)
mbed_official 0:51ac1d130fd4 367 {
mbed_official 0:51ac1d130fd4 368 mem_size_t size;
mbed_official 0:51ac1d130fd4 369 mem_size_t ptr, ptr2;
mbed_official 0:51ac1d130fd4 370 struct mem *mem, *mem2;
mbed_official 0:51ac1d130fd4 371 /* use the FREE_PROTECT here: it protects with sem OR SYS_ARCH_PROTECT */
mbed_official 0:51ac1d130fd4 372 LWIP_MEM_FREE_DECL_PROTECT();
mbed_official 0:51ac1d130fd4 373
mbed_official 0:51ac1d130fd4 374 /* Expand the size of the allocated memory region so that we can
mbed_official 0:51ac1d130fd4 375 adjust for alignment. */
mbed_official 0:51ac1d130fd4 376 newsize = LWIP_MEM_ALIGN_SIZE(newsize);
mbed_official 0:51ac1d130fd4 377
mbed_official 0:51ac1d130fd4 378 if(newsize < MIN_SIZE_ALIGNED) {
mbed_official 0:51ac1d130fd4 379 /* every data block must be at least MIN_SIZE_ALIGNED long */
mbed_official 0:51ac1d130fd4 380 newsize = MIN_SIZE_ALIGNED;
mbed_official 0:51ac1d130fd4 381 }
mbed_official 0:51ac1d130fd4 382
mbed_official 0:51ac1d130fd4 383 if (newsize > MEM_SIZE_ALIGNED) {
mbed_official 0:51ac1d130fd4 384 return NULL;
mbed_official 0:51ac1d130fd4 385 }
mbed_official 0:51ac1d130fd4 386
mbed_official 0:51ac1d130fd4 387 LWIP_ASSERT("mem_trim: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
mbed_official 0:51ac1d130fd4 388 (u8_t *)rmem < (u8_t *)ram_end);
mbed_official 0:51ac1d130fd4 389
mbed_official 0:51ac1d130fd4 390 if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
mbed_official 0:51ac1d130fd4 391 SYS_ARCH_DECL_PROTECT(lev);
mbed_official 0:51ac1d130fd4 392 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_trim: illegal memory\n"));
mbed_official 0:51ac1d130fd4 393 /* protect mem stats from concurrent access */
mbed_official 0:51ac1d130fd4 394 SYS_ARCH_PROTECT(lev);
mbed_official 0:51ac1d130fd4 395 MEM_STATS_INC(illegal);
mbed_official 0:51ac1d130fd4 396 SYS_ARCH_UNPROTECT(lev);
mbed_official 0:51ac1d130fd4 397 return rmem;
mbed_official 0:51ac1d130fd4 398 }
mbed_official 0:51ac1d130fd4 399 /* Get the corresponding struct mem ... */
mbed_official 0:51ac1d130fd4 400 mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
mbed_official 0:51ac1d130fd4 401 /* ... and its offset pointer */
mbed_official 0:51ac1d130fd4 402 ptr = (mem_size_t)((u8_t *)mem - ram);
mbed_official 0:51ac1d130fd4 403
mbed_official 0:51ac1d130fd4 404 size = mem->next - ptr - SIZEOF_STRUCT_MEM;
mbed_official 0:51ac1d130fd4 405 LWIP_ASSERT("mem_trim can only shrink memory", newsize <= size);
mbed_official 0:51ac1d130fd4 406 if (newsize > size) {
mbed_official 0:51ac1d130fd4 407 /* not supported */
mbed_official 0:51ac1d130fd4 408 return NULL;
mbed_official 0:51ac1d130fd4 409 }
mbed_official 0:51ac1d130fd4 410 if (newsize == size) {
mbed_official 0:51ac1d130fd4 411 /* No change in size, simply return */
mbed_official 0:51ac1d130fd4 412 return rmem;
mbed_official 0:51ac1d130fd4 413 }
mbed_official 0:51ac1d130fd4 414
mbed_official 0:51ac1d130fd4 415 /* protect the heap from concurrent access */
mbed_official 0:51ac1d130fd4 416 LWIP_MEM_FREE_PROTECT();
mbed_official 0:51ac1d130fd4 417
mbed_official 0:51ac1d130fd4 418 mem2 = (struct mem *)(void *)&ram[mem->next];
mbed_official 0:51ac1d130fd4 419 if(mem2->used == 0) {
mbed_official 0:51ac1d130fd4 420 /* The next struct is unused, we can simply move it at little */
mbed_official 0:51ac1d130fd4 421 mem_size_t next;
mbed_official 0:51ac1d130fd4 422 /* remember the old next pointer */
mbed_official 0:51ac1d130fd4 423 next = mem2->next;
mbed_official 0:51ac1d130fd4 424 /* create new struct mem which is moved directly after the shrinked mem */
mbed_official 0:51ac1d130fd4 425 ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
mbed_official 0:51ac1d130fd4 426 if (lfree == mem2) {
mbed_official 0:51ac1d130fd4 427 lfree = (struct mem *)(void *)&ram[ptr2];
mbed_official 0:51ac1d130fd4 428 }
mbed_official 0:51ac1d130fd4 429 mem2 = (struct mem *)(void *)&ram[ptr2];
mbed_official 0:51ac1d130fd4 430 mem2->used = 0;
mbed_official 0:51ac1d130fd4 431 /* restore the next pointer */
mbed_official 0:51ac1d130fd4 432 mem2->next = next;
mbed_official 0:51ac1d130fd4 433 /* link it back to mem */
mbed_official 0:51ac1d130fd4 434 mem2->prev = ptr;
mbed_official 0:51ac1d130fd4 435 /* link mem to it */
mbed_official 0:51ac1d130fd4 436 mem->next = ptr2;
mbed_official 0:51ac1d130fd4 437 /* last thing to restore linked list: as we have moved mem2,
mbed_official 0:51ac1d130fd4 438 * let 'mem2->next->prev' point to mem2 again. but only if mem2->next is not
mbed_official 0:51ac1d130fd4 439 * the end of the heap */
mbed_official 0:51ac1d130fd4 440 if (mem2->next != MEM_SIZE_ALIGNED) {
mbed_official 0:51ac1d130fd4 441 ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
mbed_official 0:51ac1d130fd4 442 }
mbed_official 0:51ac1d130fd4 443 MEM_STATS_DEC_USED(used, (size - newsize));
mbed_official 0:51ac1d130fd4 444 /* no need to plug holes, we've already done that */
mbed_official 0:51ac1d130fd4 445 } else if (newsize + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED <= size) {
mbed_official 0:51ac1d130fd4 446 /* Next struct is used but there's room for another struct mem with
mbed_official 0:51ac1d130fd4 447 * at least MIN_SIZE_ALIGNED of data.
mbed_official 0:51ac1d130fd4 448 * Old size ('size') must be big enough to contain at least 'newsize' plus a struct mem
mbed_official 0:51ac1d130fd4 449 * ('SIZEOF_STRUCT_MEM') with some data ('MIN_SIZE_ALIGNED').
mbed_official 0:51ac1d130fd4 450 * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
mbed_official 0:51ac1d130fd4 451 * region that couldn't hold data, but when mem->next gets freed,
mbed_official 0:51ac1d130fd4 452 * the 2 regions would be combined, resulting in more free memory */
mbed_official 0:51ac1d130fd4 453 ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
mbed_official 0:51ac1d130fd4 454 mem2 = (struct mem *)(void *)&ram[ptr2];
mbed_official 0:51ac1d130fd4 455 if (mem2 < lfree) {
mbed_official 0:51ac1d130fd4 456 lfree = mem2;
mbed_official 0:51ac1d130fd4 457 }
mbed_official 0:51ac1d130fd4 458 mem2->used = 0;
mbed_official 0:51ac1d130fd4 459 mem2->next = mem->next;
mbed_official 0:51ac1d130fd4 460 mem2->prev = ptr;
mbed_official 0:51ac1d130fd4 461 mem->next = ptr2;
mbed_official 0:51ac1d130fd4 462 if (mem2->next != MEM_SIZE_ALIGNED) {
mbed_official 0:51ac1d130fd4 463 ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
mbed_official 0:51ac1d130fd4 464 }
mbed_official 0:51ac1d130fd4 465 MEM_STATS_DEC_USED(used, (size - newsize));
mbed_official 0:51ac1d130fd4 466 /* the original mem->next is used, so no need to plug holes! */
mbed_official 0:51ac1d130fd4 467 }
mbed_official 0:51ac1d130fd4 468 /* else {
mbed_official 0:51ac1d130fd4 469 next struct mem is used but size between mem and mem2 is not big enough
mbed_official 0:51ac1d130fd4 470 to create another struct mem
mbed_official 0:51ac1d130fd4 471 -> don't do anyhting.
mbed_official 0:51ac1d130fd4 472 -> the remaining space stays unused since it is too small
mbed_official 0:51ac1d130fd4 473 } */
mbed_official 0:51ac1d130fd4 474 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
mbed_official 0:51ac1d130fd4 475 mem_free_count = 1;
mbed_official 0:51ac1d130fd4 476 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
mbed_official 0:51ac1d130fd4 477 LWIP_MEM_FREE_UNPROTECT();
mbed_official 0:51ac1d130fd4 478 return rmem;
mbed_official 0:51ac1d130fd4 479 }
mbed_official 0:51ac1d130fd4 480
mbed_official 0:51ac1d130fd4 481 /**
mbed_official 0:51ac1d130fd4 482 * Adam's mem_malloc() plus solution for bug #17922
mbed_official 0:51ac1d130fd4 483 * Allocate a block of memory with a minimum of 'size' bytes.
mbed_official 0:51ac1d130fd4 484 *
mbed_official 0:51ac1d130fd4 485 * @param size is the minimum size of the requested block in bytes.
mbed_official 0:51ac1d130fd4 486 * @return pointer to allocated memory or NULL if no free memory was found.
mbed_official 0:51ac1d130fd4 487 *
mbed_official 0:51ac1d130fd4 488 * Note that the returned value will always be aligned (as defined by MEM_ALIGNMENT).
mbed_official 0:51ac1d130fd4 489 */
mbed_official 0:51ac1d130fd4 490 void *
mbed_official 0:51ac1d130fd4 491 mem_malloc(mem_size_t size)
mbed_official 0:51ac1d130fd4 492 {
mbed_official 0:51ac1d130fd4 493 mem_size_t ptr, ptr2;
mbed_official 0:51ac1d130fd4 494 struct mem *mem, *mem2;
mbed_official 0:51ac1d130fd4 495 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
mbed_official 0:51ac1d130fd4 496 u8_t local_mem_free_count = 0;
mbed_official 0:51ac1d130fd4 497 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
mbed_official 0:51ac1d130fd4 498 LWIP_MEM_ALLOC_DECL_PROTECT();
mbed_official 0:51ac1d130fd4 499
mbed_official 0:51ac1d130fd4 500 if (size == 0) {
mbed_official 0:51ac1d130fd4 501 return NULL;
mbed_official 0:51ac1d130fd4 502 }
mbed_official 0:51ac1d130fd4 503
mbed_official 0:51ac1d130fd4 504 /* Expand the size of the allocated memory region so that we can
mbed_official 0:51ac1d130fd4 505 adjust for alignment. */
mbed_official 0:51ac1d130fd4 506 size = LWIP_MEM_ALIGN_SIZE(size);
mbed_official 0:51ac1d130fd4 507
mbed_official 0:51ac1d130fd4 508 if(size < MIN_SIZE_ALIGNED) {
mbed_official 0:51ac1d130fd4 509 /* every data block must be at least MIN_SIZE_ALIGNED long */
mbed_official 0:51ac1d130fd4 510 size = MIN_SIZE_ALIGNED;
mbed_official 0:51ac1d130fd4 511 }
mbed_official 0:51ac1d130fd4 512
mbed_official 0:51ac1d130fd4 513 if (size > MEM_SIZE_ALIGNED) {
mbed_official 0:51ac1d130fd4 514 return NULL;
mbed_official 0:51ac1d130fd4 515 }
mbed_official 0:51ac1d130fd4 516
mbed_official 0:51ac1d130fd4 517 /* protect the heap from concurrent access */
mbed_official 0:51ac1d130fd4 518 sys_mutex_lock(&mem_mutex);
mbed_official 0:51ac1d130fd4 519 LWIP_MEM_ALLOC_PROTECT();
mbed_official 0:51ac1d130fd4 520 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
mbed_official 0:51ac1d130fd4 521 /* run as long as a mem_free disturbed mem_malloc */
mbed_official 0:51ac1d130fd4 522 do {
mbed_official 0:51ac1d130fd4 523 local_mem_free_count = 0;
mbed_official 0:51ac1d130fd4 524 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
mbed_official 0:51ac1d130fd4 525
mbed_official 0:51ac1d130fd4 526 /* Scan through the heap searching for a free block that is big enough,
mbed_official 0:51ac1d130fd4 527 * beginning with the lowest free block.
mbed_official 0:51ac1d130fd4 528 */
mbed_official 0:51ac1d130fd4 529 for (ptr = (mem_size_t)((u8_t *)lfree - ram); ptr < MEM_SIZE_ALIGNED - size;
mbed_official 0:51ac1d130fd4 530 ptr = ((struct mem *)(void *)&ram[ptr])->next) {
mbed_official 0:51ac1d130fd4 531 mem = (struct mem *)(void *)&ram[ptr];
mbed_official 0:51ac1d130fd4 532 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
mbed_official 0:51ac1d130fd4 533 mem_free_count = 0;
mbed_official 0:51ac1d130fd4 534 LWIP_MEM_ALLOC_UNPROTECT();
mbed_official 0:51ac1d130fd4 535 /* allow mem_free to run */
mbed_official 0:51ac1d130fd4 536 LWIP_MEM_ALLOC_PROTECT();
mbed_official 0:51ac1d130fd4 537 if (mem_free_count != 0) {
mbed_official 0:51ac1d130fd4 538 local_mem_free_count = mem_free_count;
mbed_official 0:51ac1d130fd4 539 }
mbed_official 0:51ac1d130fd4 540 mem_free_count = 0;
mbed_official 0:51ac1d130fd4 541 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
mbed_official 0:51ac1d130fd4 542
mbed_official 0:51ac1d130fd4 543 if ((!mem->used) &&
mbed_official 0:51ac1d130fd4 544 (mem->next - (ptr + SIZEOF_STRUCT_MEM)) >= size) {
mbed_official 0:51ac1d130fd4 545 /* mem is not used and at least perfect fit is possible:
mbed_official 0:51ac1d130fd4 546 * mem->next - (ptr + SIZEOF_STRUCT_MEM) gives us the 'user data size' of mem */
mbed_official 0:51ac1d130fd4 547
mbed_official 0:51ac1d130fd4 548 if (mem->next - (ptr + SIZEOF_STRUCT_MEM) >= (size + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED)) {
mbed_official 0:51ac1d130fd4 549 /* (in addition to the above, we test if another struct mem (SIZEOF_STRUCT_MEM) containing
mbed_official 0:51ac1d130fd4 550 * at least MIN_SIZE_ALIGNED of data also fits in the 'user data space' of 'mem')
mbed_official 0:51ac1d130fd4 551 * -> split large block, create empty remainder,
mbed_official 0:51ac1d130fd4 552 * remainder must be large enough to contain MIN_SIZE_ALIGNED data: if
mbed_official 0:51ac1d130fd4 553 * mem->next - (ptr + (2*SIZEOF_STRUCT_MEM)) == size,
mbed_official 0:51ac1d130fd4 554 * struct mem would fit in but no data between mem2 and mem2->next
mbed_official 0:51ac1d130fd4 555 * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
mbed_official 0:51ac1d130fd4 556 * region that couldn't hold data, but when mem->next gets freed,
mbed_official 0:51ac1d130fd4 557 * the 2 regions would be combined, resulting in more free memory
mbed_official 0:51ac1d130fd4 558 */
mbed_official 0:51ac1d130fd4 559 ptr2 = ptr + SIZEOF_STRUCT_MEM + size;
mbed_official 0:51ac1d130fd4 560 /* create mem2 struct */
mbed_official 0:51ac1d130fd4 561 mem2 = (struct mem *)(void *)&ram[ptr2];
mbed_official 0:51ac1d130fd4 562 mem2->used = 0;
mbed_official 0:51ac1d130fd4 563 mem2->next = mem->next;
mbed_official 0:51ac1d130fd4 564 mem2->prev = ptr;
mbed_official 0:51ac1d130fd4 565 /* and insert it between mem and mem->next */
mbed_official 0:51ac1d130fd4 566 mem->next = ptr2;
mbed_official 0:51ac1d130fd4 567 mem->used = 1;
mbed_official 0:51ac1d130fd4 568
mbed_official 0:51ac1d130fd4 569 if (mem2->next != MEM_SIZE_ALIGNED) {
mbed_official 0:51ac1d130fd4 570 ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
mbed_official 0:51ac1d130fd4 571 }
mbed_official 0:51ac1d130fd4 572 MEM_STATS_INC_USED(used, (size + SIZEOF_STRUCT_MEM));
mbed_official 0:51ac1d130fd4 573 } else {
mbed_official 0:51ac1d130fd4 574 /* (a mem2 struct does no fit into the user data space of mem and mem->next will always
mbed_official 0:51ac1d130fd4 575 * be used at this point: if not we have 2 unused structs in a row, plug_holes should have
mbed_official 0:51ac1d130fd4 576 * take care of this).
mbed_official 0:51ac1d130fd4 577 * -> near fit or excact fit: do not split, no mem2 creation
mbed_official 0:51ac1d130fd4 578 * also can't move mem->next directly behind mem, since mem->next
mbed_official 0:51ac1d130fd4 579 * will always be used at this point!
mbed_official 0:51ac1d130fd4 580 */
mbed_official 0:51ac1d130fd4 581 mem->used = 1;
mbed_official 0:51ac1d130fd4 582 MEM_STATS_INC_USED(used, mem->next - (mem_size_t)((u8_t *)mem - ram));
mbed_official 0:51ac1d130fd4 583 }
mbed_official 0:51ac1d130fd4 584
mbed_official 0:51ac1d130fd4 585 if (mem == lfree) {
mbed_official 0:51ac1d130fd4 586 /* Find next free block after mem and update lowest free pointer */
mbed_official 0:51ac1d130fd4 587 while (lfree->used && lfree != ram_end) {
mbed_official 0:51ac1d130fd4 588 LWIP_MEM_ALLOC_UNPROTECT();
mbed_official 0:51ac1d130fd4 589 /* prevent high interrupt latency... */
mbed_official 0:51ac1d130fd4 590 LWIP_MEM_ALLOC_PROTECT();
mbed_official 0:51ac1d130fd4 591 lfree = (struct mem *)(void *)&ram[lfree->next];
mbed_official 0:51ac1d130fd4 592 }
mbed_official 0:51ac1d130fd4 593 LWIP_ASSERT("mem_malloc: !lfree->used", ((lfree == ram_end) || (!lfree->used)));
mbed_official 0:51ac1d130fd4 594 }
mbed_official 0:51ac1d130fd4 595 LWIP_MEM_ALLOC_UNPROTECT();
mbed_official 0:51ac1d130fd4 596 sys_mutex_unlock(&mem_mutex);
mbed_official 0:51ac1d130fd4 597 LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.",
mbed_official 0:51ac1d130fd4 598 (mem_ptr_t)mem + SIZEOF_STRUCT_MEM + size <= (mem_ptr_t)ram_end);
mbed_official 0:51ac1d130fd4 599 LWIP_ASSERT("mem_malloc: allocated memory properly aligned.",
mbed_official 0:51ac1d130fd4 600 ((mem_ptr_t)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0);
mbed_official 0:51ac1d130fd4 601 LWIP_ASSERT("mem_malloc: sanity check alignment",
mbed_official 0:51ac1d130fd4 602 (((mem_ptr_t)mem) & (MEM_ALIGNMENT-1)) == 0);
mbed_official 0:51ac1d130fd4 603
mbed_official 0:51ac1d130fd4 604 return (u8_t *)mem + SIZEOF_STRUCT_MEM;
mbed_official 0:51ac1d130fd4 605 }
mbed_official 0:51ac1d130fd4 606 }
mbed_official 0:51ac1d130fd4 607 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
mbed_official 0:51ac1d130fd4 608 /* if we got interrupted by a mem_free, try again */
mbed_official 0:51ac1d130fd4 609 } while(local_mem_free_count != 0);
mbed_official 0:51ac1d130fd4 610 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
mbed_official 0:51ac1d130fd4 611 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("mem_malloc: could not allocate %"S16_F" bytes\n", (s16_t)size));
mbed_official 0:51ac1d130fd4 612 MEM_STATS_INC(err);
mbed_official 0:51ac1d130fd4 613 LWIP_MEM_ALLOC_UNPROTECT();
mbed_official 0:51ac1d130fd4 614 sys_mutex_unlock(&mem_mutex);
mbed_official 0:51ac1d130fd4 615 return NULL;
mbed_official 0:51ac1d130fd4 616 }
mbed_official 0:51ac1d130fd4 617
mbed_official 0:51ac1d130fd4 618 #endif /* MEM_USE_POOLS */
mbed_official 0:51ac1d130fd4 619 /**
mbed_official 0:51ac1d130fd4 620 * Contiguously allocates enough space for count objects that are size bytes
mbed_official 0:51ac1d130fd4 621 * of memory each and returns a pointer to the allocated memory.
mbed_official 0:51ac1d130fd4 622 *
mbed_official 0:51ac1d130fd4 623 * The allocated memory is filled with bytes of value zero.
mbed_official 0:51ac1d130fd4 624 *
mbed_official 0:51ac1d130fd4 625 * @param count number of objects to allocate
mbed_official 0:51ac1d130fd4 626 * @param size size of the objects to allocate
mbed_official 0:51ac1d130fd4 627 * @return pointer to allocated memory / NULL pointer if there is an error
mbed_official 0:51ac1d130fd4 628 */
mbed_official 0:51ac1d130fd4 629 void *mem_calloc(mem_size_t count, mem_size_t size)
mbed_official 0:51ac1d130fd4 630 {
mbed_official 0:51ac1d130fd4 631 void *p;
mbed_official 0:51ac1d130fd4 632
mbed_official 0:51ac1d130fd4 633 /* allocate 'count' objects of size 'size' */
mbed_official 0:51ac1d130fd4 634 p = mem_malloc(count * size);
mbed_official 0:51ac1d130fd4 635 if (p) {
mbed_official 0:51ac1d130fd4 636 /* zero the memory */
mbed_official 0:51ac1d130fd4 637 memset(p, 0, count * size);
mbed_official 0:51ac1d130fd4 638 }
mbed_official 0:51ac1d130fd4 639 return p;
mbed_official 0:51ac1d130fd4 640 }
mbed_official 0:51ac1d130fd4 641
mbed_official 0:51ac1d130fd4 642 #endif /* !MEM_LIBC_MALLOC */