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lwip/core/mem.c@0:b2805b6888dc, 2016-06-20 (annotated)

Committer:
robert_jw
Date:
Mon Jun 20 01:40:20 2016 +0000
Revision:
0:b2805b6888dc
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Who changed what in which revision?

UserRevisionLine numberNew contents of line
robert_jw 0:b2805b6888dc 1 /**
robert_jw 0:b2805b6888dc 2 * @file
robert_jw 0:b2805b6888dc 3 * Dynamic memory manager
robert_jw 0:b2805b6888dc 4 *
robert_jw 0:b2805b6888dc 5 * This is a lightweight replacement for the standard C library malloc().
robert_jw 0:b2805b6888dc 6 *
robert_jw 0:b2805b6888dc 7 * If you want to use the standard C library malloc() instead, define
robert_jw 0:b2805b6888dc 8 * MEM_LIBC_MALLOC to 1 in your lwipopts.h
robert_jw 0:b2805b6888dc 9 *
robert_jw 0:b2805b6888dc 10 * To let mem_malloc() use pools (prevents fragmentation and is much faster than
robert_jw 0:b2805b6888dc 11 * a heap but might waste some memory), define MEM_USE_POOLS to 1, define
robert_jw 0:b2805b6888dc 12 * MEM_USE_CUSTOM_POOLS to 1 and create a file "lwippools.h" that includes a list
robert_jw 0:b2805b6888dc 13 * of pools like this (more pools can be added between _START and _END):
robert_jw 0:b2805b6888dc 14 *
robert_jw 0:b2805b6888dc 15 * Define three pools with sizes 256, 512, and 1512 bytes
robert_jw 0:b2805b6888dc 16 * LWIP_MALLOC_MEMPOOL_START
robert_jw 0:b2805b6888dc 17 * LWIP_MALLOC_MEMPOOL(20, 256)
robert_jw 0:b2805b6888dc 18 * LWIP_MALLOC_MEMPOOL(10, 512)
robert_jw 0:b2805b6888dc 19 * LWIP_MALLOC_MEMPOOL(5, 1512)
robert_jw 0:b2805b6888dc 20 * LWIP_MALLOC_MEMPOOL_END
robert_jw 0:b2805b6888dc 21 */
robert_jw 0:b2805b6888dc 22
robert_jw 0:b2805b6888dc 23 /*
robert_jw 0:b2805b6888dc 24 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
robert_jw 0:b2805b6888dc 25 * All rights reserved.
robert_jw 0:b2805b6888dc 26 *
robert_jw 0:b2805b6888dc 27 * Redistribution and use in source and binary forms, with or without modification,
robert_jw 0:b2805b6888dc 28 * are permitted provided that the following conditions are met:
robert_jw 0:b2805b6888dc 29 *
robert_jw 0:b2805b6888dc 30 * 1. Redistributions of source code must retain the above copyright notice,
robert_jw 0:b2805b6888dc 31 * this list of conditions and the following disclaimer.
robert_jw 0:b2805b6888dc 32 * 2. Redistributions in binary form must reproduce the above copyright notice,
robert_jw 0:b2805b6888dc 33 * this list of conditions and the following disclaimer in the documentation
robert_jw 0:b2805b6888dc 34 * and/or other materials provided with the distribution.
robert_jw 0:b2805b6888dc 35 * 3. The name of the author may not be used to endorse or promote products
robert_jw 0:b2805b6888dc 36 * derived from this software without specific prior written permission.
robert_jw 0:b2805b6888dc 37 *
robert_jw 0:b2805b6888dc 38 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
robert_jw 0:b2805b6888dc 39 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
robert_jw 0:b2805b6888dc 40 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
robert_jw 0:b2805b6888dc 41 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
robert_jw 0:b2805b6888dc 42 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
robert_jw 0:b2805b6888dc 43 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
robert_jw 0:b2805b6888dc 44 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
robert_jw 0:b2805b6888dc 45 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
robert_jw 0:b2805b6888dc 46 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
robert_jw 0:b2805b6888dc 47 * OF SUCH DAMAGE.
robert_jw 0:b2805b6888dc 48 *
robert_jw 0:b2805b6888dc 49 * This file is part of the lwIP TCP/IP stack.
robert_jw 0:b2805b6888dc 50 *
robert_jw 0:b2805b6888dc 51 * Author: Adam Dunkels <adam@sics.se>
robert_jw 0:b2805b6888dc 52 * Simon Goldschmidt
robert_jw 0:b2805b6888dc 53 *
robert_jw 0:b2805b6888dc 54 */
robert_jw 0:b2805b6888dc 55
robert_jw 0:b2805b6888dc 56 #include "lwip/opt.h"
robert_jw 0:b2805b6888dc 57
robert_jw 0:b2805b6888dc 58 #if !MEM_LIBC_MALLOC /* don't build if not configured for use in lwipopts.h */
robert_jw 0:b2805b6888dc 59
robert_jw 0:b2805b6888dc 60 #include "lwip/def.h"
robert_jw 0:b2805b6888dc 61 #include "lwip/mem.h"
robert_jw 0:b2805b6888dc 62 #include "lwip/sys.h"
robert_jw 0:b2805b6888dc 63 #include "lwip/stats.h"
robert_jw 0:b2805b6888dc 64 #include "lwip/err.h"
robert_jw 0:b2805b6888dc 65
robert_jw 0:b2805b6888dc 66 #include <string.h>
robert_jw 0:b2805b6888dc 67
robert_jw 0:b2805b6888dc 68 #if MEM_USE_POOLS
robert_jw 0:b2805b6888dc 69 /* lwIP head implemented with different sized pools */
robert_jw 0:b2805b6888dc 70
robert_jw 0:b2805b6888dc 71 /**
robert_jw 0:b2805b6888dc 72 * Allocate memory: determine the smallest pool that is big enough
robert_jw 0:b2805b6888dc 73 * to contain an element of 'size' and get an element from that pool.
robert_jw 0:b2805b6888dc 74 *
robert_jw 0:b2805b6888dc 75 * @param size the size in bytes of the memory needed
robert_jw 0:b2805b6888dc 76 * @return a pointer to the allocated memory or NULL if the pool is empty
robert_jw 0:b2805b6888dc 77 */
robert_jw 0:b2805b6888dc 78 void *
robert_jw 0:b2805b6888dc 79 mem_malloc(mem_size_t size)
robert_jw 0:b2805b6888dc 80 {
robert_jw 0:b2805b6888dc 81 struct memp_malloc_helper *element;
robert_jw 0:b2805b6888dc 82 memp_t poolnr;
robert_jw 0:b2805b6888dc 83 mem_size_t required_size = size + sizeof(struct memp_malloc_helper);
robert_jw 0:b2805b6888dc 84
robert_jw 0:b2805b6888dc 85 for (poolnr = MEMP_POOL_FIRST; poolnr <= MEMP_POOL_LAST; poolnr = (memp_t)(poolnr + 1)) {
robert_jw 0:b2805b6888dc 86 #if MEM_USE_POOLS_TRY_BIGGER_POOL
robert_jw 0:b2805b6888dc 87 again:
robert_jw 0:b2805b6888dc 88 #endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
robert_jw 0:b2805b6888dc 89 /* is this pool big enough to hold an element of the required size
robert_jw 0:b2805b6888dc 90 plus a struct memp_malloc_helper that saves the pool this element came from? */
robert_jw 0:b2805b6888dc 91 if (required_size <= memp_sizes[poolnr]) {
robert_jw 0:b2805b6888dc 92 break;
robert_jw 0:b2805b6888dc 93 }
robert_jw 0:b2805b6888dc 94 }
robert_jw 0:b2805b6888dc 95 if (poolnr > MEMP_POOL_LAST) {
robert_jw 0:b2805b6888dc 96 LWIP_ASSERT("mem_malloc(): no pool is that big!", 0);
robert_jw 0:b2805b6888dc 97 return NULL;
robert_jw 0:b2805b6888dc 98 }
robert_jw 0:b2805b6888dc 99 element = (struct memp_malloc_helper*)memp_malloc(poolnr);
robert_jw 0:b2805b6888dc 100 if (element == NULL) {
robert_jw 0:b2805b6888dc 101 /* No need to DEBUGF or ASSERT: This error is already
robert_jw 0:b2805b6888dc 102 taken care of in memp.c */
robert_jw 0:b2805b6888dc 103 #if MEM_USE_POOLS_TRY_BIGGER_POOL
robert_jw 0:b2805b6888dc 104 /** Try a bigger pool if this one is empty! */
robert_jw 0:b2805b6888dc 105 if (poolnr < MEMP_POOL_LAST) {
robert_jw 0:b2805b6888dc 106 poolnr++;
robert_jw 0:b2805b6888dc 107 goto again;
robert_jw 0:b2805b6888dc 108 }
robert_jw 0:b2805b6888dc 109 #endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
robert_jw 0:b2805b6888dc 110 return NULL;
robert_jw 0:b2805b6888dc 111 }
robert_jw 0:b2805b6888dc 112
robert_jw 0:b2805b6888dc 113 /* save the pool number this element came from */
robert_jw 0:b2805b6888dc 114 element->poolnr = poolnr;
robert_jw 0:b2805b6888dc 115 /* and return a pointer to the memory directly after the struct memp_malloc_helper */
robert_jw 0:b2805b6888dc 116 element++;
robert_jw 0:b2805b6888dc 117
robert_jw 0:b2805b6888dc 118 return element;
robert_jw 0:b2805b6888dc 119 }
robert_jw 0:b2805b6888dc 120
robert_jw 0:b2805b6888dc 121 /**
robert_jw 0:b2805b6888dc 122 * Free memory previously allocated by mem_malloc. Loads the pool number
robert_jw 0:b2805b6888dc 123 * and calls memp_free with that pool number to put the element back into
robert_jw 0:b2805b6888dc 124 * its pool
robert_jw 0:b2805b6888dc 125 *
robert_jw 0:b2805b6888dc 126 * @param rmem the memory element to free
robert_jw 0:b2805b6888dc 127 */
robert_jw 0:b2805b6888dc 128 void
robert_jw 0:b2805b6888dc 129 mem_free(void *rmem)
robert_jw 0:b2805b6888dc 130 {
robert_jw 0:b2805b6888dc 131 struct memp_malloc_helper *hmem = (struct memp_malloc_helper*)rmem;
robert_jw 0:b2805b6888dc 132
robert_jw 0:b2805b6888dc 133 LWIP_ASSERT("rmem != NULL", (rmem != NULL));
robert_jw 0:b2805b6888dc 134 LWIP_ASSERT("rmem == MEM_ALIGN(rmem)", (rmem == LWIP_MEM_ALIGN(rmem)));
robert_jw 0:b2805b6888dc 135
robert_jw 0:b2805b6888dc 136 /* get the original struct memp_malloc_helper */
robert_jw 0:b2805b6888dc 137 hmem--;
robert_jw 0:b2805b6888dc 138
robert_jw 0:b2805b6888dc 139 LWIP_ASSERT("hmem != NULL", (hmem != NULL));
robert_jw 0:b2805b6888dc 140 LWIP_ASSERT("hmem == MEM_ALIGN(hmem)", (hmem == LWIP_MEM_ALIGN(hmem)));
robert_jw 0:b2805b6888dc 141 LWIP_ASSERT("hmem->poolnr < MEMP_MAX", (hmem->poolnr < MEMP_MAX));
robert_jw 0:b2805b6888dc 142
robert_jw 0:b2805b6888dc 143 /* and put it in the pool we saved earlier */
robert_jw 0:b2805b6888dc 144 memp_free(hmem->poolnr, hmem);
robert_jw 0:b2805b6888dc 145 }
robert_jw 0:b2805b6888dc 146
robert_jw 0:b2805b6888dc 147 #else /* MEM_USE_POOLS */
robert_jw 0:b2805b6888dc 148 /* lwIP replacement for your libc malloc() */
robert_jw 0:b2805b6888dc 149
robert_jw 0:b2805b6888dc 150 /**
robert_jw 0:b2805b6888dc 151 * The heap is made up as a list of structs of this type.
robert_jw 0:b2805b6888dc 152 * This does not have to be aligned since for getting its size,
robert_jw 0:b2805b6888dc 153 * we only use the macro SIZEOF_STRUCT_MEM, which automatically alignes.
robert_jw 0:b2805b6888dc 154 */
robert_jw 0:b2805b6888dc 155 struct mem {
robert_jw 0:b2805b6888dc 156 /** index (-> ram[next]) of the next struct */
robert_jw 0:b2805b6888dc 157 mem_size_t next;
robert_jw 0:b2805b6888dc 158 /** index (-> ram[prev]) of the previous struct */
robert_jw 0:b2805b6888dc 159 mem_size_t prev;
robert_jw 0:b2805b6888dc 160 /** 1: this area is used; 0: this area is unused */
robert_jw 0:b2805b6888dc 161 u8_t used;
robert_jw 0:b2805b6888dc 162 };
robert_jw 0:b2805b6888dc 163
robert_jw 0:b2805b6888dc 164 /** All allocated blocks will be MIN_SIZE bytes big, at least!
robert_jw 0:b2805b6888dc 165 * MIN_SIZE can be overridden to suit your needs. Smaller values save space,
robert_jw 0:b2805b6888dc 166 * larger values could prevent too small blocks to fragment the RAM too much. */
robert_jw 0:b2805b6888dc 167 #ifndef MIN_SIZE
robert_jw 0:b2805b6888dc 168 #define MIN_SIZE 12
robert_jw 0:b2805b6888dc 169 #endif /* MIN_SIZE */
robert_jw 0:b2805b6888dc 170 /* some alignment macros: we define them here for better source code layout */
robert_jw 0:b2805b6888dc 171 #define MIN_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MIN_SIZE)
robert_jw 0:b2805b6888dc 172 #define SIZEOF_STRUCT_MEM LWIP_MEM_ALIGN_SIZE(sizeof(struct mem))
robert_jw 0:b2805b6888dc 173 #define MEM_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MEM_SIZE)
robert_jw 0:b2805b6888dc 174
robert_jw 0:b2805b6888dc 175 /** If you want to relocate the heap to external memory, simply define
robert_jw 0:b2805b6888dc 176 * LWIP_RAM_HEAP_POINTER as a void-pointer to that location.
robert_jw 0:b2805b6888dc 177 * If so, make sure the memory at that location is big enough (see below on
robert_jw 0:b2805b6888dc 178 * how that space is calculated). */
robert_jw 0:b2805b6888dc 179 #ifndef LWIP_RAM_HEAP_POINTER
robert_jw 0:b2805b6888dc 180
robert_jw 0:b2805b6888dc 181 #if defined(TARGET_LPC4088) || defined(TARGET_LPC4088_DM)
robert_jw 0:b2805b6888dc 182 # if defined (__ICCARM__)
robert_jw 0:b2805b6888dc 183 # define ETHMEM_SECTION
robert_jw 0:b2805b6888dc 184 # elif defined(TOOLCHAIN_GCC_CR)
robert_jw 0:b2805b6888dc 185 # define ETHMEM_SECTION __attribute__((section(".data.$RamPeriph32")))
robert_jw 0:b2805b6888dc 186 # else
robert_jw 0:b2805b6888dc 187 # define ETHMEM_SECTION __attribute__((section("AHBSRAM1"),aligned))
robert_jw 0:b2805b6888dc 188 # endif
robert_jw 0:b2805b6888dc 189 #elif defined(TARGET_LPC1768)
robert_jw 0:b2805b6888dc 190 # define ETHMEM_SECTION __attribute((section("AHBSRAM0")))
robert_jw 0:b2805b6888dc 191 #else
robert_jw 0:b2805b6888dc 192 # define ETHMEM_SECTION
robert_jw 0:b2805b6888dc 193 #endif
robert_jw 0:b2805b6888dc 194
robert_jw 0:b2805b6888dc 195 /** the heap. we need one struct mem at the end and some room for alignment */
robert_jw 0:b2805b6888dc 196 u8_t ram_heap[MEM_SIZE_ALIGNED + (2*SIZEOF_STRUCT_MEM) + MEM_ALIGNMENT] ETHMEM_SECTION;
robert_jw 0:b2805b6888dc 197 #define LWIP_RAM_HEAP_POINTER ram_heap
robert_jw 0:b2805b6888dc 198 #endif /* LWIP_RAM_HEAP_POINTER */
robert_jw 0:b2805b6888dc 199
robert_jw 0:b2805b6888dc 200 /** pointer to the heap (ram_heap): for alignment, ram is now a pointer instead of an array */
robert_jw 0:b2805b6888dc 201 static u8_t *ram;
robert_jw 0:b2805b6888dc 202 /** the last entry, always unused! */
robert_jw 0:b2805b6888dc 203 static struct mem *ram_end;
robert_jw 0:b2805b6888dc 204 /** pointer to the lowest free block, this is used for faster search */
robert_jw 0:b2805b6888dc 205 static struct mem *lfree;
robert_jw 0:b2805b6888dc 206
robert_jw 0:b2805b6888dc 207 /** concurrent access protection */
robert_jw 0:b2805b6888dc 208 static sys_mutex_t mem_mutex;
robert_jw 0:b2805b6888dc 209
robert_jw 0:b2805b6888dc 210 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
robert_jw 0:b2805b6888dc 211
robert_jw 0:b2805b6888dc 212 static volatile u8_t mem_free_count;
robert_jw 0:b2805b6888dc 213
robert_jw 0:b2805b6888dc 214 /* Allow mem_free from other (e.g. interrupt) context */
robert_jw 0:b2805b6888dc 215 #define LWIP_MEM_FREE_DECL_PROTECT() SYS_ARCH_DECL_PROTECT(lev_free)
robert_jw 0:b2805b6888dc 216 #define LWIP_MEM_FREE_PROTECT() SYS_ARCH_PROTECT(lev_free)
robert_jw 0:b2805b6888dc 217 #define LWIP_MEM_FREE_UNPROTECT() SYS_ARCH_UNPROTECT(lev_free)
robert_jw 0:b2805b6888dc 218 #define LWIP_MEM_ALLOC_DECL_PROTECT() SYS_ARCH_DECL_PROTECT(lev_alloc)
robert_jw 0:b2805b6888dc 219 #define LWIP_MEM_ALLOC_PROTECT() SYS_ARCH_PROTECT(lev_alloc)
robert_jw 0:b2805b6888dc 220 #define LWIP_MEM_ALLOC_UNPROTECT() SYS_ARCH_UNPROTECT(lev_alloc)
robert_jw 0:b2805b6888dc 221
robert_jw 0:b2805b6888dc 222 #else /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
robert_jw 0:b2805b6888dc 223
robert_jw 0:b2805b6888dc 224 /* Protect the heap only by using a semaphore */
robert_jw 0:b2805b6888dc 225 #define LWIP_MEM_FREE_DECL_PROTECT()
robert_jw 0:b2805b6888dc 226 #define LWIP_MEM_FREE_PROTECT() sys_mutex_lock(&mem_mutex)
robert_jw 0:b2805b6888dc 227 #define LWIP_MEM_FREE_UNPROTECT() sys_mutex_unlock(&mem_mutex)
robert_jw 0:b2805b6888dc 228 /* mem_malloc is protected using semaphore AND LWIP_MEM_ALLOC_PROTECT */
robert_jw 0:b2805b6888dc 229 #define LWIP_MEM_ALLOC_DECL_PROTECT()
robert_jw 0:b2805b6888dc 230 #define LWIP_MEM_ALLOC_PROTECT()
robert_jw 0:b2805b6888dc 231 #define LWIP_MEM_ALLOC_UNPROTECT()
robert_jw 0:b2805b6888dc 232
robert_jw 0:b2805b6888dc 233 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
robert_jw 0:b2805b6888dc 234
robert_jw 0:b2805b6888dc 235
robert_jw 0:b2805b6888dc 236 /**
robert_jw 0:b2805b6888dc 237 * "Plug holes" by combining adjacent empty struct mems.
robert_jw 0:b2805b6888dc 238 * After this function is through, there should not exist
robert_jw 0:b2805b6888dc 239 * one empty struct mem pointing to another empty struct mem.
robert_jw 0:b2805b6888dc 240 *
robert_jw 0:b2805b6888dc 241 * @param mem this points to a struct mem which just has been freed
robert_jw 0:b2805b6888dc 242 * @internal this function is only called by mem_free() and mem_trim()
robert_jw 0:b2805b6888dc 243 *
robert_jw 0:b2805b6888dc 244 * This assumes access to the heap is protected by the calling function
robert_jw 0:b2805b6888dc 245 * already.
robert_jw 0:b2805b6888dc 246 */
robert_jw 0:b2805b6888dc 247 static void
robert_jw 0:b2805b6888dc 248 plug_holes(struct mem *mem)
robert_jw 0:b2805b6888dc 249 {
robert_jw 0:b2805b6888dc 250 struct mem *nmem;
robert_jw 0:b2805b6888dc 251 struct mem *pmem;
robert_jw 0:b2805b6888dc 252
robert_jw 0:b2805b6888dc 253 LWIP_ASSERT("plug_holes: mem >= ram", (u8_t *)mem >= ram);
robert_jw 0:b2805b6888dc 254 LWIP_ASSERT("plug_holes: mem < ram_end", (u8_t *)mem < (u8_t *)ram_end);
robert_jw 0:b2805b6888dc 255 LWIP_ASSERT("plug_holes: mem->used == 0", mem->used == 0);
robert_jw 0:b2805b6888dc 256
robert_jw 0:b2805b6888dc 257 /* plug hole forward */
robert_jw 0:b2805b6888dc 258 LWIP_ASSERT("plug_holes: mem->next <= MEM_SIZE_ALIGNED", mem->next <= MEM_SIZE_ALIGNED);
robert_jw 0:b2805b6888dc 259
robert_jw 0:b2805b6888dc 260 nmem = (struct mem *)(void *)&ram[mem->next];
robert_jw 0:b2805b6888dc 261 if (mem != nmem && nmem->used == 0 && (u8_t *)nmem != (u8_t *)ram_end) {
robert_jw 0:b2805b6888dc 262 /* if mem->next is unused and not end of ram, combine mem and mem->next */
robert_jw 0:b2805b6888dc 263 if (lfree == nmem) {
robert_jw 0:b2805b6888dc 264 lfree = mem;
robert_jw 0:b2805b6888dc 265 }
robert_jw 0:b2805b6888dc 266 mem->next = nmem->next;
robert_jw 0:b2805b6888dc 267 ((struct mem *)(void *)&ram[nmem->next])->prev = (mem_size_t)((u8_t *)mem - ram);
robert_jw 0:b2805b6888dc 268 }
robert_jw 0:b2805b6888dc 269
robert_jw 0:b2805b6888dc 270 /* plug hole backward */
robert_jw 0:b2805b6888dc 271 pmem = (struct mem *)(void *)&ram[mem->prev];
robert_jw 0:b2805b6888dc 272 if (pmem != mem && pmem->used == 0) {
robert_jw 0:b2805b6888dc 273 /* if mem->prev is unused, combine mem and mem->prev */
robert_jw 0:b2805b6888dc 274 if (lfree == mem) {
robert_jw 0:b2805b6888dc 275 lfree = pmem;
robert_jw 0:b2805b6888dc 276 }
robert_jw 0:b2805b6888dc 277 pmem->next = mem->next;
robert_jw 0:b2805b6888dc 278 ((struct mem *)(void *)&ram[mem->next])->prev = (mem_size_t)((u8_t *)pmem - ram);
robert_jw 0:b2805b6888dc 279 }
robert_jw 0:b2805b6888dc 280 }
robert_jw 0:b2805b6888dc 281
robert_jw 0:b2805b6888dc 282 /**
robert_jw 0:b2805b6888dc 283 * Zero the heap and initialize start, end and lowest-free
robert_jw 0:b2805b6888dc 284 */
robert_jw 0:b2805b6888dc 285 void
robert_jw 0:b2805b6888dc 286 mem_init(void)
robert_jw 0:b2805b6888dc 287 {
robert_jw 0:b2805b6888dc 288 struct mem *mem;
robert_jw 0:b2805b6888dc 289
robert_jw 0:b2805b6888dc 290 LWIP_ASSERT("Sanity check alignment",
robert_jw 0:b2805b6888dc 291 (SIZEOF_STRUCT_MEM & (MEM_ALIGNMENT-1)) == 0);
robert_jw 0:b2805b6888dc 292
robert_jw 0:b2805b6888dc 293 /* align the heap */
robert_jw 0:b2805b6888dc 294 ram = (u8_t *)LWIP_MEM_ALIGN(LWIP_RAM_HEAP_POINTER);
robert_jw 0:b2805b6888dc 295 /* initialize the start of the heap */
robert_jw 0:b2805b6888dc 296 mem = (struct mem *)(void *)ram;
robert_jw 0:b2805b6888dc 297 mem->next = MEM_SIZE_ALIGNED;
robert_jw 0:b2805b6888dc 298 mem->prev = 0;
robert_jw 0:b2805b6888dc 299 mem->used = 0;
robert_jw 0:b2805b6888dc 300 /* initialize the end of the heap */
robert_jw 0:b2805b6888dc 301 ram_end = (struct mem *)(void *)&ram[MEM_SIZE_ALIGNED];
robert_jw 0:b2805b6888dc 302 ram_end->used = 1;
robert_jw 0:b2805b6888dc 303 ram_end->next = MEM_SIZE_ALIGNED;
robert_jw 0:b2805b6888dc 304 ram_end->prev = MEM_SIZE_ALIGNED;
robert_jw 0:b2805b6888dc 305
robert_jw 0:b2805b6888dc 306 /* initialize the lowest-free pointer to the start of the heap */
robert_jw 0:b2805b6888dc 307 lfree = (struct mem *)(void *)ram;
robert_jw 0:b2805b6888dc 308
robert_jw 0:b2805b6888dc 309 MEM_STATS_AVAIL(avail, MEM_SIZE_ALIGNED);
robert_jw 0:b2805b6888dc 310
robert_jw 0:b2805b6888dc 311 if(sys_mutex_new(&mem_mutex) != ERR_OK) {
robert_jw 0:b2805b6888dc 312 LWIP_ASSERT("failed to create mem_mutex", 0);
robert_jw 0:b2805b6888dc 313 }
robert_jw 0:b2805b6888dc 314 }
robert_jw 0:b2805b6888dc 315
robert_jw 0:b2805b6888dc 316 /**
robert_jw 0:b2805b6888dc 317 * Put a struct mem back on the heap
robert_jw 0:b2805b6888dc 318 *
robert_jw 0:b2805b6888dc 319 * @param rmem is the data portion of a struct mem as returned by a previous
robert_jw 0:b2805b6888dc 320 * call to mem_malloc()
robert_jw 0:b2805b6888dc 321 */
robert_jw 0:b2805b6888dc 322 void
robert_jw 0:b2805b6888dc 323 mem_free(void *rmem)
robert_jw 0:b2805b6888dc 324 {
robert_jw 0:b2805b6888dc 325 struct mem *mem;
robert_jw 0:b2805b6888dc 326 LWIP_MEM_FREE_DECL_PROTECT();
robert_jw 0:b2805b6888dc 327
robert_jw 0:b2805b6888dc 328 if (rmem == NULL) {
robert_jw 0:b2805b6888dc 329 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("mem_free(p == NULL) was called.\n"));
robert_jw 0:b2805b6888dc 330 return;
robert_jw 0:b2805b6888dc 331 }
robert_jw 0:b2805b6888dc 332 LWIP_ASSERT("mem_free: sanity check alignment", (((mem_ptr_t)rmem) & (MEM_ALIGNMENT-1)) == 0);
robert_jw 0:b2805b6888dc 333
robert_jw 0:b2805b6888dc 334 LWIP_ASSERT("mem_free: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
robert_jw 0:b2805b6888dc 335 (u8_t *)rmem < (u8_t *)ram_end);
robert_jw 0:b2805b6888dc 336
robert_jw 0:b2805b6888dc 337 if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
robert_jw 0:b2805b6888dc 338 SYS_ARCH_DECL_PROTECT(lev);
robert_jw 0:b2805b6888dc 339 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_free: illegal memory\n"));
robert_jw 0:b2805b6888dc 340 /* protect mem stats from concurrent access */
robert_jw 0:b2805b6888dc 341 SYS_ARCH_PROTECT(lev);
robert_jw 0:b2805b6888dc 342 MEM_STATS_INC(illegal);
robert_jw 0:b2805b6888dc 343 SYS_ARCH_UNPROTECT(lev);
robert_jw 0:b2805b6888dc 344 return;
robert_jw 0:b2805b6888dc 345 }
robert_jw 0:b2805b6888dc 346 /* protect the heap from concurrent access */
robert_jw 0:b2805b6888dc 347 LWIP_MEM_FREE_PROTECT();
robert_jw 0:b2805b6888dc 348 /* Get the corresponding struct mem ... */
robert_jw 0:b2805b6888dc 349 mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
robert_jw 0:b2805b6888dc 350 /* ... which has to be in a used state ... */
robert_jw 0:b2805b6888dc 351 LWIP_ASSERT("mem_free: mem->used", mem->used);
robert_jw 0:b2805b6888dc 352 /* ... and is now unused. */
robert_jw 0:b2805b6888dc 353 mem->used = 0;
robert_jw 0:b2805b6888dc 354
robert_jw 0:b2805b6888dc 355 if (mem < lfree) {
robert_jw 0:b2805b6888dc 356 /* the newly freed struct is now the lowest */
robert_jw 0:b2805b6888dc 357 lfree = mem;
robert_jw 0:b2805b6888dc 358 }
robert_jw 0:b2805b6888dc 359
robert_jw 0:b2805b6888dc 360 MEM_STATS_DEC_USED(used, mem->next - (mem_size_t)(((u8_t *)mem - ram)));
robert_jw 0:b2805b6888dc 361
robert_jw 0:b2805b6888dc 362 /* finally, see if prev or next are free also */
robert_jw 0:b2805b6888dc 363 plug_holes(mem);
robert_jw 0:b2805b6888dc 364 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
robert_jw 0:b2805b6888dc 365 mem_free_count = 1;
robert_jw 0:b2805b6888dc 366 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
robert_jw 0:b2805b6888dc 367 LWIP_MEM_FREE_UNPROTECT();
robert_jw 0:b2805b6888dc 368 }
robert_jw 0:b2805b6888dc 369
robert_jw 0:b2805b6888dc 370 /**
robert_jw 0:b2805b6888dc 371 * Shrink memory returned by mem_malloc().
robert_jw 0:b2805b6888dc 372 *
robert_jw 0:b2805b6888dc 373 * @param rmem pointer to memory allocated by mem_malloc the is to be shrinked
robert_jw 0:b2805b6888dc 374 * @param newsize required size after shrinking (needs to be smaller than or
robert_jw 0:b2805b6888dc 375 * equal to the previous size)
robert_jw 0:b2805b6888dc 376 * @return for compatibility reasons: is always == rmem, at the moment
robert_jw 0:b2805b6888dc 377 * or NULL if newsize is > old size, in which case rmem is NOT touched
robert_jw 0:b2805b6888dc 378 * or freed!
robert_jw 0:b2805b6888dc 379 */
robert_jw 0:b2805b6888dc 380 void *
robert_jw 0:b2805b6888dc 381 mem_trim(void *rmem, mem_size_t newsize)
robert_jw 0:b2805b6888dc 382 {
robert_jw 0:b2805b6888dc 383 mem_size_t size;
robert_jw 0:b2805b6888dc 384 mem_size_t ptr, ptr2;
robert_jw 0:b2805b6888dc 385 struct mem *mem, *mem2;
robert_jw 0:b2805b6888dc 386 /* use the FREE_PROTECT here: it protects with sem OR SYS_ARCH_PROTECT */
robert_jw 0:b2805b6888dc 387 LWIP_MEM_FREE_DECL_PROTECT();
robert_jw 0:b2805b6888dc 388
robert_jw 0:b2805b6888dc 389 /* Expand the size of the allocated memory region so that we can
robert_jw 0:b2805b6888dc 390 adjust for alignment. */
robert_jw 0:b2805b6888dc 391 newsize = LWIP_MEM_ALIGN_SIZE(newsize);
robert_jw 0:b2805b6888dc 392
robert_jw 0:b2805b6888dc 393 if(newsize < MIN_SIZE_ALIGNED) {
robert_jw 0:b2805b6888dc 394 /* every data block must be at least MIN_SIZE_ALIGNED long */
robert_jw 0:b2805b6888dc 395 newsize = MIN_SIZE_ALIGNED;
robert_jw 0:b2805b6888dc 396 }
robert_jw 0:b2805b6888dc 397
robert_jw 0:b2805b6888dc 398 if (newsize > MEM_SIZE_ALIGNED) {
robert_jw 0:b2805b6888dc 399 return NULL;
robert_jw 0:b2805b6888dc 400 }
robert_jw 0:b2805b6888dc 401
robert_jw 0:b2805b6888dc 402 LWIP_ASSERT("mem_trim: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
robert_jw 0:b2805b6888dc 403 (u8_t *)rmem < (u8_t *)ram_end);
robert_jw 0:b2805b6888dc 404
robert_jw 0:b2805b6888dc 405 if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
robert_jw 0:b2805b6888dc 406 SYS_ARCH_DECL_PROTECT(lev);
robert_jw 0:b2805b6888dc 407 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_trim: illegal memory\n"));
robert_jw 0:b2805b6888dc 408 /* protect mem stats from concurrent access */
robert_jw 0:b2805b6888dc 409 SYS_ARCH_PROTECT(lev);
robert_jw 0:b2805b6888dc 410 MEM_STATS_INC(illegal);
robert_jw 0:b2805b6888dc 411 SYS_ARCH_UNPROTECT(lev);
robert_jw 0:b2805b6888dc 412 return rmem;
robert_jw 0:b2805b6888dc 413 }
robert_jw 0:b2805b6888dc 414 /* Get the corresponding struct mem ... */
robert_jw 0:b2805b6888dc 415 mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
robert_jw 0:b2805b6888dc 416 /* ... and its offset pointer */
robert_jw 0:b2805b6888dc 417 ptr = (mem_size_t)((u8_t *)mem - ram);
robert_jw 0:b2805b6888dc 418
robert_jw 0:b2805b6888dc 419 size = mem->next - ptr - SIZEOF_STRUCT_MEM;
robert_jw 0:b2805b6888dc 420 LWIP_ASSERT("mem_trim can only shrink memory", newsize <= size);
robert_jw 0:b2805b6888dc 421 if (newsize > size) {
robert_jw 0:b2805b6888dc 422 /* not supported */
robert_jw 0:b2805b6888dc 423 return NULL;
robert_jw 0:b2805b6888dc 424 }
robert_jw 0:b2805b6888dc 425 if (newsize == size) {
robert_jw 0:b2805b6888dc 426 /* No change in size, simply return */
robert_jw 0:b2805b6888dc 427 return rmem;
robert_jw 0:b2805b6888dc 428 }
robert_jw 0:b2805b6888dc 429
robert_jw 0:b2805b6888dc 430 /* protect the heap from concurrent access */
robert_jw 0:b2805b6888dc 431 LWIP_MEM_FREE_PROTECT();
robert_jw 0:b2805b6888dc 432
robert_jw 0:b2805b6888dc 433 mem2 = (struct mem *)(void *)&ram[mem->next];
robert_jw 0:b2805b6888dc 434 if(mem2->used == 0) {
robert_jw 0:b2805b6888dc 435 /* The next struct is unused, we can simply move it at little */
robert_jw 0:b2805b6888dc 436 mem_size_t next;
robert_jw 0:b2805b6888dc 437 /* remember the old next pointer */
robert_jw 0:b2805b6888dc 438 next = mem2->next;
robert_jw 0:b2805b6888dc 439 /* create new struct mem which is moved directly after the shrinked mem */
robert_jw 0:b2805b6888dc 440 ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
robert_jw 0:b2805b6888dc 441 if (lfree == mem2) {
robert_jw 0:b2805b6888dc 442 lfree = (struct mem *)(void *)&ram[ptr2];
robert_jw 0:b2805b6888dc 443 }
robert_jw 0:b2805b6888dc 444 mem2 = (struct mem *)(void *)&ram[ptr2];
robert_jw 0:b2805b6888dc 445 mem2->used = 0;
robert_jw 0:b2805b6888dc 446 /* restore the next pointer */
robert_jw 0:b2805b6888dc 447 mem2->next = next;
robert_jw 0:b2805b6888dc 448 /* link it back to mem */
robert_jw 0:b2805b6888dc 449 mem2->prev = ptr;
robert_jw 0:b2805b6888dc 450 /* link mem to it */
robert_jw 0:b2805b6888dc 451 mem->next = ptr2;
robert_jw 0:b2805b6888dc 452 /* last thing to restore linked list: as we have moved mem2,
robert_jw 0:b2805b6888dc 453 * let 'mem2->next->prev' point to mem2 again. but only if mem2->next is not
robert_jw 0:b2805b6888dc 454 * the end of the heap */
robert_jw 0:b2805b6888dc 455 if (mem2->next != MEM_SIZE_ALIGNED) {
robert_jw 0:b2805b6888dc 456 ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
robert_jw 0:b2805b6888dc 457 }
robert_jw 0:b2805b6888dc 458 MEM_STATS_DEC_USED(used, (size - newsize));
robert_jw 0:b2805b6888dc 459 /* no need to plug holes, we've already done that */
robert_jw 0:b2805b6888dc 460 } else if (newsize + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED <= size) {
robert_jw 0:b2805b6888dc 461 /* Next struct is used but there's room for another struct mem with
robert_jw 0:b2805b6888dc 462 * at least MIN_SIZE_ALIGNED of data.
robert_jw 0:b2805b6888dc 463 * Old size ('size') must be big enough to contain at least 'newsize' plus a struct mem
robert_jw 0:b2805b6888dc 464 * ('SIZEOF_STRUCT_MEM') with some data ('MIN_SIZE_ALIGNED').
robert_jw 0:b2805b6888dc 465 * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
robert_jw 0:b2805b6888dc 466 * region that couldn't hold data, but when mem->next gets freed,
robert_jw 0:b2805b6888dc 467 * the 2 regions would be combined, resulting in more free memory */
robert_jw 0:b2805b6888dc 468 ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
robert_jw 0:b2805b6888dc 469 mem2 = (struct mem *)(void *)&ram[ptr2];
robert_jw 0:b2805b6888dc 470 if (mem2 < lfree) {
robert_jw 0:b2805b6888dc 471 lfree = mem2;
robert_jw 0:b2805b6888dc 472 }
robert_jw 0:b2805b6888dc 473 mem2->used = 0;
robert_jw 0:b2805b6888dc 474 mem2->next = mem->next;
robert_jw 0:b2805b6888dc 475 mem2->prev = ptr;
robert_jw 0:b2805b6888dc 476 mem->next = ptr2;
robert_jw 0:b2805b6888dc 477 if (mem2->next != MEM_SIZE_ALIGNED) {
robert_jw 0:b2805b6888dc 478 ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
robert_jw 0:b2805b6888dc 479 }
robert_jw 0:b2805b6888dc 480 MEM_STATS_DEC_USED(used, (size - newsize));
robert_jw 0:b2805b6888dc 481 /* the original mem->next is used, so no need to plug holes! */
robert_jw 0:b2805b6888dc 482 }
robert_jw 0:b2805b6888dc 483 /* else {
robert_jw 0:b2805b6888dc 484 next struct mem is used but size between mem and mem2 is not big enough
robert_jw 0:b2805b6888dc 485 to create another struct mem
robert_jw 0:b2805b6888dc 486 -> don't do anyhting.
robert_jw 0:b2805b6888dc 487 -> the remaining space stays unused since it is too small
robert_jw 0:b2805b6888dc 488 } */
robert_jw 0:b2805b6888dc 489 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
robert_jw 0:b2805b6888dc 490 mem_free_count = 1;
robert_jw 0:b2805b6888dc 491 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
robert_jw 0:b2805b6888dc 492 LWIP_MEM_FREE_UNPROTECT();
robert_jw 0:b2805b6888dc 493 return rmem;
robert_jw 0:b2805b6888dc 494 }
robert_jw 0:b2805b6888dc 495
robert_jw 0:b2805b6888dc 496 /**
robert_jw 0:b2805b6888dc 497 * Adam's mem_malloc() plus solution for bug #17922
robert_jw 0:b2805b6888dc 498 * Allocate a block of memory with a minimum of 'size' bytes.
robert_jw 0:b2805b6888dc 499 *
robert_jw 0:b2805b6888dc 500 * @param size is the minimum size of the requested block in bytes.
robert_jw 0:b2805b6888dc 501 * @return pointer to allocated memory or NULL if no free memory was found.
robert_jw 0:b2805b6888dc 502 *
robert_jw 0:b2805b6888dc 503 * Note that the returned value will always be aligned (as defined by MEM_ALIGNMENT).
robert_jw 0:b2805b6888dc 504 */
robert_jw 0:b2805b6888dc 505 void *
robert_jw 0:b2805b6888dc 506 mem_malloc(mem_size_t size)
robert_jw 0:b2805b6888dc 507 {
robert_jw 0:b2805b6888dc 508 mem_size_t ptr, ptr2;
robert_jw 0:b2805b6888dc 509 struct mem *mem, *mem2;
robert_jw 0:b2805b6888dc 510 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
robert_jw 0:b2805b6888dc 511 u8_t local_mem_free_count = 0;
robert_jw 0:b2805b6888dc 512 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
robert_jw 0:b2805b6888dc 513 LWIP_MEM_ALLOC_DECL_PROTECT();
robert_jw 0:b2805b6888dc 514
robert_jw 0:b2805b6888dc 515 if (size == 0) {
robert_jw 0:b2805b6888dc 516 return NULL;
robert_jw 0:b2805b6888dc 517 }
robert_jw 0:b2805b6888dc 518
robert_jw 0:b2805b6888dc 519 /* Expand the size of the allocated memory region so that we can
robert_jw 0:b2805b6888dc 520 adjust for alignment. */
robert_jw 0:b2805b6888dc 521 size = LWIP_MEM_ALIGN_SIZE(size);
robert_jw 0:b2805b6888dc 522
robert_jw 0:b2805b6888dc 523 if(size < MIN_SIZE_ALIGNED) {
robert_jw 0:b2805b6888dc 524 /* every data block must be at least MIN_SIZE_ALIGNED long */
robert_jw 0:b2805b6888dc 525 size = MIN_SIZE_ALIGNED;
robert_jw 0:b2805b6888dc 526 }
robert_jw 0:b2805b6888dc 527
robert_jw 0:b2805b6888dc 528 if (size > MEM_SIZE_ALIGNED) {
robert_jw 0:b2805b6888dc 529 return NULL;
robert_jw 0:b2805b6888dc 530 }
robert_jw 0:b2805b6888dc 531
robert_jw 0:b2805b6888dc 532 /* protect the heap from concurrent access */
robert_jw 0:b2805b6888dc 533 sys_mutex_lock(&mem_mutex);
robert_jw 0:b2805b6888dc 534 LWIP_MEM_ALLOC_PROTECT();
robert_jw 0:b2805b6888dc 535 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
robert_jw 0:b2805b6888dc 536 /* run as long as a mem_free disturbed mem_malloc */
robert_jw 0:b2805b6888dc 537 do {
robert_jw 0:b2805b6888dc 538 local_mem_free_count = 0;
robert_jw 0:b2805b6888dc 539 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
robert_jw 0:b2805b6888dc 540
robert_jw 0:b2805b6888dc 541 /* Scan through the heap searching for a free block that is big enough,
robert_jw 0:b2805b6888dc 542 * beginning with the lowest free block.
robert_jw 0:b2805b6888dc 543 */
robert_jw 0:b2805b6888dc 544 for (ptr = (mem_size_t)((u8_t *)lfree - ram); ptr < MEM_SIZE_ALIGNED - size;
robert_jw 0:b2805b6888dc 545 ptr = ((struct mem *)(void *)&ram[ptr])->next) {
robert_jw 0:b2805b6888dc 546 mem = (struct mem *)(void *)&ram[ptr];
robert_jw 0:b2805b6888dc 547 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
robert_jw 0:b2805b6888dc 548 mem_free_count = 0;
robert_jw 0:b2805b6888dc 549 LWIP_MEM_ALLOC_UNPROTECT();
robert_jw 0:b2805b6888dc 550 /* allow mem_free to run */
robert_jw 0:b2805b6888dc 551 LWIP_MEM_ALLOC_PROTECT();
robert_jw 0:b2805b6888dc 552 if (mem_free_count != 0) {
robert_jw 0:b2805b6888dc 553 local_mem_free_count = mem_free_count;
robert_jw 0:b2805b6888dc 554 }
robert_jw 0:b2805b6888dc 555 mem_free_count = 0;
robert_jw 0:b2805b6888dc 556 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
robert_jw 0:b2805b6888dc 557
robert_jw 0:b2805b6888dc 558 if ((!mem->used) &&
robert_jw 0:b2805b6888dc 559 (mem->next - (ptr + SIZEOF_STRUCT_MEM)) >= size) {
robert_jw 0:b2805b6888dc 560 /* mem is not used and at least perfect fit is possible:
robert_jw 0:b2805b6888dc 561 * mem->next - (ptr + SIZEOF_STRUCT_MEM) gives us the 'user data size' of mem */
robert_jw 0:b2805b6888dc 562
robert_jw 0:b2805b6888dc 563 if (mem->next - (ptr + SIZEOF_STRUCT_MEM) >= (size + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED)) {
robert_jw 0:b2805b6888dc 564 /* (in addition to the above, we test if another struct mem (SIZEOF_STRUCT_MEM) containing
robert_jw 0:b2805b6888dc 565 * at least MIN_SIZE_ALIGNED of data also fits in the 'user data space' of 'mem')
robert_jw 0:b2805b6888dc 566 * -> split large block, create empty remainder,
robert_jw 0:b2805b6888dc 567 * remainder must be large enough to contain MIN_SIZE_ALIGNED data: if
robert_jw 0:b2805b6888dc 568 * mem->next - (ptr + (2*SIZEOF_STRUCT_MEM)) == size,
robert_jw 0:b2805b6888dc 569 * struct mem would fit in but no data between mem2 and mem2->next
robert_jw 0:b2805b6888dc 570 * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
robert_jw 0:b2805b6888dc 571 * region that couldn't hold data, but when mem->next gets freed,
robert_jw 0:b2805b6888dc 572 * the 2 regions would be combined, resulting in more free memory
robert_jw 0:b2805b6888dc 573 */
robert_jw 0:b2805b6888dc 574 ptr2 = ptr + SIZEOF_STRUCT_MEM + size;
robert_jw 0:b2805b6888dc 575 /* create mem2 struct */
robert_jw 0:b2805b6888dc 576 mem2 = (struct mem *)(void *)&ram[ptr2];
robert_jw 0:b2805b6888dc 577 mem2->used = 0;
robert_jw 0:b2805b6888dc 578 mem2->next = mem->next;
robert_jw 0:b2805b6888dc 579 mem2->prev = ptr;
robert_jw 0:b2805b6888dc 580 /* and insert it between mem and mem->next */
robert_jw 0:b2805b6888dc 581 mem->next = ptr2;
robert_jw 0:b2805b6888dc 582 mem->used = 1;
robert_jw 0:b2805b6888dc 583
robert_jw 0:b2805b6888dc 584 if (mem2->next != MEM_SIZE_ALIGNED) {
robert_jw 0:b2805b6888dc 585 ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
robert_jw 0:b2805b6888dc 586 }
robert_jw 0:b2805b6888dc 587 MEM_STATS_INC_USED(used, (size + SIZEOF_STRUCT_MEM));
robert_jw 0:b2805b6888dc 588 } else {
robert_jw 0:b2805b6888dc 589 /* (a mem2 struct does no fit into the user data space of mem and mem->next will always
robert_jw 0:b2805b6888dc 590 * be used at this point: if not we have 2 unused structs in a row, plug_holes should have
robert_jw 0:b2805b6888dc 591 * take care of this).
robert_jw 0:b2805b6888dc 592 * -> near fit or excact fit: do not split, no mem2 creation
robert_jw 0:b2805b6888dc 593 * also can't move mem->next directly behind mem, since mem->next
robert_jw 0:b2805b6888dc 594 * will always be used at this point!
robert_jw 0:b2805b6888dc 595 */
robert_jw 0:b2805b6888dc 596 mem->used = 1;
robert_jw 0:b2805b6888dc 597 MEM_STATS_INC_USED(used, mem->next - (mem_size_t)((u8_t *)mem - ram));
robert_jw 0:b2805b6888dc 598 }
robert_jw 0:b2805b6888dc 599
robert_jw 0:b2805b6888dc 600 if (mem == lfree) {
robert_jw 0:b2805b6888dc 601 /* Find next free block after mem and update lowest free pointer */
robert_jw 0:b2805b6888dc 602 while (lfree->used && lfree != ram_end) {
robert_jw 0:b2805b6888dc 603 LWIP_MEM_ALLOC_UNPROTECT();
robert_jw 0:b2805b6888dc 604 /* prevent high interrupt latency... */
robert_jw 0:b2805b6888dc 605 LWIP_MEM_ALLOC_PROTECT();
robert_jw 0:b2805b6888dc 606 lfree = (struct mem *)(void *)&ram[lfree->next];
robert_jw 0:b2805b6888dc 607 }
robert_jw 0:b2805b6888dc 608 LWIP_ASSERT("mem_malloc: !lfree->used", ((lfree == ram_end) || (!lfree->used)));
robert_jw 0:b2805b6888dc 609 }
robert_jw 0:b2805b6888dc 610 LWIP_MEM_ALLOC_UNPROTECT();
robert_jw 0:b2805b6888dc 611 sys_mutex_unlock(&mem_mutex);
robert_jw 0:b2805b6888dc 612 LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.",
robert_jw 0:b2805b6888dc 613 (mem_ptr_t)mem + SIZEOF_STRUCT_MEM + size <= (mem_ptr_t)ram_end);
robert_jw 0:b2805b6888dc 614 LWIP_ASSERT("mem_malloc: allocated memory properly aligned.",
robert_jw 0:b2805b6888dc 615 ((mem_ptr_t)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0);
robert_jw 0:b2805b6888dc 616 LWIP_ASSERT("mem_malloc: sanity check alignment",
robert_jw 0:b2805b6888dc 617 (((mem_ptr_t)mem) & (MEM_ALIGNMENT-1)) == 0);
robert_jw 0:b2805b6888dc 618
robert_jw 0:b2805b6888dc 619 return (u8_t *)mem + SIZEOF_STRUCT_MEM;
robert_jw 0:b2805b6888dc 620 }
robert_jw 0:b2805b6888dc 621 }
robert_jw 0:b2805b6888dc 622 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
robert_jw 0:b2805b6888dc 623 /* if we got interrupted by a mem_free, try again */
robert_jw 0:b2805b6888dc 624 } while(local_mem_free_count != 0);
robert_jw 0:b2805b6888dc 625 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
robert_jw 0:b2805b6888dc 626 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("mem_malloc: could not allocate %"S16_F" bytes\n", (s16_t)size));
robert_jw 0:b2805b6888dc 627 MEM_STATS_INC(err);
robert_jw 0:b2805b6888dc 628 LWIP_MEM_ALLOC_UNPROTECT();
robert_jw 0:b2805b6888dc 629 sys_mutex_unlock(&mem_mutex);
robert_jw 0:b2805b6888dc 630 return NULL;
robert_jw 0:b2805b6888dc 631 }
robert_jw 0:b2805b6888dc 632
robert_jw 0:b2805b6888dc 633 #endif /* MEM_USE_POOLS */
robert_jw 0:b2805b6888dc 634 /**
robert_jw 0:b2805b6888dc 635 * Contiguously allocates enough space for count objects that are size bytes
robert_jw 0:b2805b6888dc 636 * of memory each and returns a pointer to the allocated memory.
robert_jw 0:b2805b6888dc 637 *
robert_jw 0:b2805b6888dc 638 * The allocated memory is filled with bytes of value zero.
robert_jw 0:b2805b6888dc 639 *
robert_jw 0:b2805b6888dc 640 * @param count number of objects to allocate
robert_jw 0:b2805b6888dc 641 * @param size size of the objects to allocate
robert_jw 0:b2805b6888dc 642 * @return pointer to allocated memory / NULL pointer if there is an error
robert_jw 0:b2805b6888dc 643 */
robert_jw 0:b2805b6888dc 644 void *mem_calloc(mem_size_t count, mem_size_t size)
robert_jw 0:b2805b6888dc 645 {
robert_jw 0:b2805b6888dc 646 void *p;
robert_jw 0:b2805b6888dc 647
robert_jw 0:b2805b6888dc 648 /* allocate 'count' objects of size 'size' */
robert_jw 0:b2805b6888dc 649 p = mem_malloc(count * size);
robert_jw 0:b2805b6888dc 650 if (p) {
robert_jw 0:b2805b6888dc 651 /* zero the memory */
robert_jw 0:b2805b6888dc 652 memset(p, 0, count * size);
robert_jw 0:b2805b6888dc 653 }
robert_jw 0:b2805b6888dc 654 return p;
robert_jw 0:b2805b6888dc 655 }
robert_jw 0:b2805b6888dc 656
robert_jw 0:b2805b6888dc 657 #endif /* !MEM_LIBC_MALLOC */