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Dependencies:   mbed

NetServices/lwip/core/mem.c@1:f5ac63519541, 2014-03-05 (annotated)

Committer:
Michael J. Spencer
Date:
Wed Mar 05 06:14:02 2014 -0800
Revision:
1:f5ac63519541
Initial commit.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Michael J. Spencer 1:f5ac63519541 1 #pragma diag_remark 177
Michael J. Spencer 1:f5ac63519541 2 /**
Michael J. Spencer 1:f5ac63519541 3 * @file
Michael J. Spencer 1:f5ac63519541 4 * Dynamic memory manager
Michael J. Spencer 1:f5ac63519541 5 *
Michael J. Spencer 1:f5ac63519541 6 * This is a lightweight replacement for the standard C library malloc().
Michael J. Spencer 1:f5ac63519541 7 *
Michael J. Spencer 1:f5ac63519541 8 * If you want to use the standard C library malloc() instead, define
Michael J. Spencer 1:f5ac63519541 9 * MEM_LIBC_MALLOC to 1 in your lwipopts.h
Michael J. Spencer 1:f5ac63519541 10 *
Michael J. Spencer 1:f5ac63519541 11 * To let mem_malloc() use pools (prevents fragmentation and is much faster than
Michael J. Spencer 1:f5ac63519541 12 * a heap but might waste some memory), define MEM_USE_POOLS to 1, define
Michael J. Spencer 1:f5ac63519541 13 * MEM_USE_CUSTOM_POOLS to 1 and create a file "lwippools.h" that includes a list
Michael J. Spencer 1:f5ac63519541 14 * of pools like this (more pools can be added between _START and _END):
Michael J. Spencer 1:f5ac63519541 15 *
Michael J. Spencer 1:f5ac63519541 16 * Define three pools with sizes 256, 512, and 1512 bytes
Michael J. Spencer 1:f5ac63519541 17 * LWIP_MALLOC_MEMPOOL_START
Michael J. Spencer 1:f5ac63519541 18 * LWIP_MALLOC_MEMPOOL(20, 256)
Michael J. Spencer 1:f5ac63519541 19 * LWIP_MALLOC_MEMPOOL(10, 512)
Michael J. Spencer 1:f5ac63519541 20 * LWIP_MALLOC_MEMPOOL(5, 1512)
Michael J. Spencer 1:f5ac63519541 21 * LWIP_MALLOC_MEMPOOL_END
Michael J. Spencer 1:f5ac63519541 22 */
Michael J. Spencer 1:f5ac63519541 23
Michael J. Spencer 1:f5ac63519541 24 /*
Michael J. Spencer 1:f5ac63519541 25 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
Michael J. Spencer 1:f5ac63519541 26 * All rights reserved.
Michael J. Spencer 1:f5ac63519541 27 *
Michael J. Spencer 1:f5ac63519541 28 * Redistribution and use in source and binary forms, with or without modification,
Michael J. Spencer 1:f5ac63519541 29 * are permitted provided that the following conditions are met:
Michael J. Spencer 1:f5ac63519541 30 *
Michael J. Spencer 1:f5ac63519541 31 * 1. Redistributions of source code must retain the above copyright notice,
Michael J. Spencer 1:f5ac63519541 32 * this list of conditions and the following disclaimer.
Michael J. Spencer 1:f5ac63519541 33 * 2. Redistributions in binary form must reproduce the above copyright notice,
Michael J. Spencer 1:f5ac63519541 34 * this list of conditions and the following disclaimer in the documentation
Michael J. Spencer 1:f5ac63519541 35 * and/or other materials provided with the distribution.
Michael J. Spencer 1:f5ac63519541 36 * 3. The name of the author may not be used to endorse or promote products
Michael J. Spencer 1:f5ac63519541 37 * derived from this software without specific prior written permission.
Michael J. Spencer 1:f5ac63519541 38 *
Michael J. Spencer 1:f5ac63519541 39 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
Michael J. Spencer 1:f5ac63519541 40 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
Michael J. Spencer 1:f5ac63519541 41 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
Michael J. Spencer 1:f5ac63519541 42 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
Michael J. Spencer 1:f5ac63519541 43 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
Michael J. Spencer 1:f5ac63519541 44 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
Michael J. Spencer 1:f5ac63519541 45 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
Michael J. Spencer 1:f5ac63519541 46 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
Michael J. Spencer 1:f5ac63519541 47 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
Michael J. Spencer 1:f5ac63519541 48 * OF SUCH DAMAGE.
Michael J. Spencer 1:f5ac63519541 49 *
Michael J. Spencer 1:f5ac63519541 50 * This file is part of the lwIP TCP/IP stack.
Michael J. Spencer 1:f5ac63519541 51 *
Michael J. Spencer 1:f5ac63519541 52 * Author: Adam Dunkels <adam@sics.se>
Michael J. Spencer 1:f5ac63519541 53 * Simon Goldschmidt
Michael J. Spencer 1:f5ac63519541 54 *
Michael J. Spencer 1:f5ac63519541 55 */
Michael J. Spencer 1:f5ac63519541 56
Michael J. Spencer 1:f5ac63519541 57 #include "lwip/opt.h"
Michael J. Spencer 1:f5ac63519541 58
Michael J. Spencer 1:f5ac63519541 59 #if !MEM_LIBC_MALLOC /* don't build if not configured for use in lwipopts.h */
Michael J. Spencer 1:f5ac63519541 60
Michael J. Spencer 1:f5ac63519541 61 #include "lwip/def.h"
Michael J. Spencer 1:f5ac63519541 62 #include "lwip/mem.h"
Michael J. Spencer 1:f5ac63519541 63 #include "lwip/sys.h"
Michael J. Spencer 1:f5ac63519541 64 #include "lwip/stats.h"
Michael J. Spencer 1:f5ac63519541 65 #include "lwip/err.h"
Michael J. Spencer 1:f5ac63519541 66
Michael J. Spencer 1:f5ac63519541 67 #include <string.h>
Michael J. Spencer 1:f5ac63519541 68
Michael J. Spencer 1:f5ac63519541 69 #if MEM_USE_POOLS
Michael J. Spencer 1:f5ac63519541 70 /* lwIP head implemented with different sized pools */
Michael J. Spencer 1:f5ac63519541 71
Michael J. Spencer 1:f5ac63519541 72 /**
Michael J. Spencer 1:f5ac63519541 73 * Allocate memory: determine the smallest pool that is big enough
Michael J. Spencer 1:f5ac63519541 74 * to contain an element of 'size' and get an element from that pool.
Michael J. Spencer 1:f5ac63519541 75 *
Michael J. Spencer 1:f5ac63519541 76 * @param size the size in bytes of the memory needed
Michael J. Spencer 1:f5ac63519541 77 * @return a pointer to the allocated memory or NULL if the pool is empty
Michael J. Spencer 1:f5ac63519541 78 */
Michael J. Spencer 1:f5ac63519541 79 void *
Michael J. Spencer 1:f5ac63519541 80 mem_malloc(mem_size_t size)
Michael J. Spencer 1:f5ac63519541 81 {
Michael J. Spencer 1:f5ac63519541 82 struct memp_malloc_helper *element;
Michael J. Spencer 1:f5ac63519541 83 memp_t poolnr;
Michael J. Spencer 1:f5ac63519541 84 mem_size_t required_size = size + sizeof(struct memp_malloc_helper);
Michael J. Spencer 1:f5ac63519541 85
Michael J. Spencer 1:f5ac63519541 86 for (poolnr = MEMP_POOL_FIRST; poolnr <= MEMP_POOL_LAST; poolnr = (memp_t)(poolnr + 1)) {
Michael J. Spencer 1:f5ac63519541 87 #if MEM_USE_POOLS_TRY_BIGGER_POOL
Michael J. Spencer 1:f5ac63519541 88 again:
Michael J. Spencer 1:f5ac63519541 89 #endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
Michael J. Spencer 1:f5ac63519541 90 /* is this pool big enough to hold an element of the required size
Michael J. Spencer 1:f5ac63519541 91 plus a struct memp_malloc_helper that saves the pool this element came from? */
Michael J. Spencer 1:f5ac63519541 92 if (required_size <= memp_sizes[poolnr]) {
Michael J. Spencer 1:f5ac63519541 93 break;
Michael J. Spencer 1:f5ac63519541 94 }
Michael J. Spencer 1:f5ac63519541 95 }
Michael J. Spencer 1:f5ac63519541 96 if (poolnr > MEMP_POOL_LAST) {
Michael J. Spencer 1:f5ac63519541 97 LWIP_ASSERT("mem_malloc(): no pool is that big!", 0);
Michael J. Spencer 1:f5ac63519541 98 return NULL;
Michael J. Spencer 1:f5ac63519541 99 }
Michael J. Spencer 1:f5ac63519541 100 element = (struct memp_malloc_helper*)memp_malloc(poolnr);
Michael J. Spencer 1:f5ac63519541 101 if (element == NULL) {
Michael J. Spencer 1:f5ac63519541 102 /* No need to DEBUGF or ASSERT: This error is already
Michael J. Spencer 1:f5ac63519541 103 taken care of in memp.c */
Michael J. Spencer 1:f5ac63519541 104 #if MEM_USE_POOLS_TRY_BIGGER_POOL
Michael J. Spencer 1:f5ac63519541 105 /** Try a bigger pool if this one is empty! */
Michael J. Spencer 1:f5ac63519541 106 if (poolnr < MEMP_POOL_LAST) {
Michael J. Spencer 1:f5ac63519541 107 poolnr++;
Michael J. Spencer 1:f5ac63519541 108 goto again;
Michael J. Spencer 1:f5ac63519541 109 }
Michael J. Spencer 1:f5ac63519541 110 #endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
Michael J. Spencer 1:f5ac63519541 111 return NULL;
Michael J. Spencer 1:f5ac63519541 112 }
Michael J. Spencer 1:f5ac63519541 113
Michael J. Spencer 1:f5ac63519541 114 /* save the pool number this element came from */
Michael J. Spencer 1:f5ac63519541 115 element->poolnr = poolnr;
Michael J. Spencer 1:f5ac63519541 116 /* and return a pointer to the memory directly after the struct memp_malloc_helper */
Michael J. Spencer 1:f5ac63519541 117 element++;
Michael J. Spencer 1:f5ac63519541 118
Michael J. Spencer 1:f5ac63519541 119 return element;
Michael J. Spencer 1:f5ac63519541 120 }
Michael J. Spencer 1:f5ac63519541 121
Michael J. Spencer 1:f5ac63519541 122 /**
Michael J. Spencer 1:f5ac63519541 123 * Free memory previously allocated by mem_malloc. Loads the pool number
Michael J. Spencer 1:f5ac63519541 124 * and calls memp_free with that pool number to put the element back into
Michael J. Spencer 1:f5ac63519541 125 * its pool
Michael J. Spencer 1:f5ac63519541 126 *
Michael J. Spencer 1:f5ac63519541 127 * @param rmem the memory element to free
Michael J. Spencer 1:f5ac63519541 128 */
Michael J. Spencer 1:f5ac63519541 129 void
Michael J. Spencer 1:f5ac63519541 130 mem_free(void *rmem)
Michael J. Spencer 1:f5ac63519541 131 {
Michael J. Spencer 1:f5ac63519541 132 struct memp_malloc_helper *hmem = (struct memp_malloc_helper*)rmem;
Michael J. Spencer 1:f5ac63519541 133
Michael J. Spencer 1:f5ac63519541 134 LWIP_ASSERT("rmem != NULL", (rmem != NULL));
Michael J. Spencer 1:f5ac63519541 135 LWIP_ASSERT("rmem == MEM_ALIGN(rmem)", (rmem == LWIP_MEM_ALIGN(rmem)));
Michael J. Spencer 1:f5ac63519541 136
Michael J. Spencer 1:f5ac63519541 137 /* get the original struct memp_malloc_helper */
Michael J. Spencer 1:f5ac63519541 138 hmem--;
Michael J. Spencer 1:f5ac63519541 139
Michael J. Spencer 1:f5ac63519541 140 LWIP_ASSERT("hmem != NULL", (hmem != NULL));
Michael J. Spencer 1:f5ac63519541 141 LWIP_ASSERT("hmem == MEM_ALIGN(hmem)", (hmem == LWIP_MEM_ALIGN(hmem)));
Michael J. Spencer 1:f5ac63519541 142 LWIP_ASSERT("hmem->poolnr < MEMP_MAX", (hmem->poolnr < MEMP_MAX));
Michael J. Spencer 1:f5ac63519541 143
Michael J. Spencer 1:f5ac63519541 144 /* and put it in the pool we saved earlier */
Michael J. Spencer 1:f5ac63519541 145 memp_free(hmem->poolnr, hmem);
Michael J. Spencer 1:f5ac63519541 146 }
Michael J. Spencer 1:f5ac63519541 147
Michael J. Spencer 1:f5ac63519541 148 #else /* MEM_USE_POOLS */
Michael J. Spencer 1:f5ac63519541 149 /* lwIP replacement for your libc malloc() */
Michael J. Spencer 1:f5ac63519541 150
Michael J. Spencer 1:f5ac63519541 151 /**
Michael J. Spencer 1:f5ac63519541 152 * The heap is made up as a list of structs of this type.
Michael J. Spencer 1:f5ac63519541 153 * This does not have to be aligned since for getting its size,
Michael J. Spencer 1:f5ac63519541 154 * we only use the macro SIZEOF_STRUCT_MEM, which automatically alignes.
Michael J. Spencer 1:f5ac63519541 155 */
Michael J. Spencer 1:f5ac63519541 156 struct mem {
Michael J. Spencer 1:f5ac63519541 157 /** index (-> ram[next]) of the next struct */
Michael J. Spencer 1:f5ac63519541 158 mem_size_t next;
Michael J. Spencer 1:f5ac63519541 159 /** index (-> ram[prev]) of the previous struct */
Michael J. Spencer 1:f5ac63519541 160 mem_size_t prev;
Michael J. Spencer 1:f5ac63519541 161 /** 1: this area is used; 0: this area is unused */
Michael J. Spencer 1:f5ac63519541 162 u8_t used;
Michael J. Spencer 1:f5ac63519541 163 };
Michael J. Spencer 1:f5ac63519541 164
Michael J. Spencer 1:f5ac63519541 165 /** All allocated blocks will be MIN_SIZE bytes big, at least!
Michael J. Spencer 1:f5ac63519541 166 * MIN_SIZE can be overridden to suit your needs. Smaller values save space,
Michael J. Spencer 1:f5ac63519541 167 * larger values could prevent too small blocks to fragment the RAM too much. */
Michael J. Spencer 1:f5ac63519541 168 #ifndef MIN_SIZE
Michael J. Spencer 1:f5ac63519541 169 #define MIN_SIZE 12
Michael J. Spencer 1:f5ac63519541 170 #endif /* MIN_SIZE */
Michael J. Spencer 1:f5ac63519541 171 /* some alignment macros: we define them here for better source code layout */
Michael J. Spencer 1:f5ac63519541 172 #define MIN_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MIN_SIZE)
Michael J. Spencer 1:f5ac63519541 173 #define SIZEOF_STRUCT_MEM LWIP_MEM_ALIGN_SIZE(sizeof(struct mem))
Michael J. Spencer 1:f5ac63519541 174 #define MEM_SIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(MEM_SIZE)
Michael J. Spencer 1:f5ac63519541 175
Michael J. Spencer 1:f5ac63519541 176 /** If you want to relocate the heap to external memory, simply define
Michael J. Spencer 1:f5ac63519541 177 * LWIP_RAM_HEAP_POINTER as a void-pointer to that location.
Michael J. Spencer 1:f5ac63519541 178 * If so, make sure the memory at that location is big enough (see below on
Michael J. Spencer 1:f5ac63519541 179 * how that space is calculated). */
Michael J. Spencer 1:f5ac63519541 180 #ifndef LWIP_RAM_HEAP_POINTER
Michael J. Spencer 1:f5ac63519541 181 /** the heap. we need one struct mem at the end and some room for alignment */
Michael J. Spencer 1:f5ac63519541 182 u8_t ram_heap[MEM_SIZE_ALIGNED + (2*SIZEOF_STRUCT_MEM) + MEM_ALIGNMENT] MEM_POSITION;
Michael J. Spencer 1:f5ac63519541 183 #define LWIP_RAM_HEAP_POINTER ram_heap
Michael J. Spencer 1:f5ac63519541 184 #endif /* LWIP_RAM_HEAP_POINTER */
Michael J. Spencer 1:f5ac63519541 185
Michael J. Spencer 1:f5ac63519541 186 /** pointer to the heap (ram_heap): for alignment, ram is now a pointer instead of an array */
Michael J. Spencer 1:f5ac63519541 187 static u8_t *ram;
Michael J. Spencer 1:f5ac63519541 188 /** the last entry, always unused! */
Michael J. Spencer 1:f5ac63519541 189 static struct mem *ram_end;
Michael J. Spencer 1:f5ac63519541 190 /** pointer to the lowest free block, this is used for faster search */
Michael J. Spencer 1:f5ac63519541 191 static struct mem *lfree;
Michael J. Spencer 1:f5ac63519541 192
Michael J. Spencer 1:f5ac63519541 193 /** concurrent access protection */
Michael J. Spencer 1:f5ac63519541 194 static sys_mutex_t mem_mutex;
Michael J. Spencer 1:f5ac63519541 195
Michael J. Spencer 1:f5ac63519541 196 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
Michael J. Spencer 1:f5ac63519541 197
Michael J. Spencer 1:f5ac63519541 198 static volatile u8_t mem_free_count;
Michael J. Spencer 1:f5ac63519541 199
Michael J. Spencer 1:f5ac63519541 200 /* Allow mem_free from other (e.g. interrupt) context */
Michael J. Spencer 1:f5ac63519541 201 #define LWIP_MEM_FREE_DECL_PROTECT() SYS_ARCH_DECL_PROTECT(lev_free)
Michael J. Spencer 1:f5ac63519541 202 #define LWIP_MEM_FREE_PROTECT() SYS_ARCH_PROTECT(lev_free)
Michael J. Spencer 1:f5ac63519541 203 #define LWIP_MEM_FREE_UNPROTECT() SYS_ARCH_UNPROTECT(lev_free)
Michael J. Spencer 1:f5ac63519541 204 #define LWIP_MEM_ALLOC_DECL_PROTECT() SYS_ARCH_DECL_PROTECT(lev_alloc)
Michael J. Spencer 1:f5ac63519541 205 #define LWIP_MEM_ALLOC_PROTECT() SYS_ARCH_PROTECT(lev_alloc)
Michael J. Spencer 1:f5ac63519541 206 #define LWIP_MEM_ALLOC_UNPROTECT() SYS_ARCH_UNPROTECT(lev_alloc)
Michael J. Spencer 1:f5ac63519541 207
Michael J. Spencer 1:f5ac63519541 208 #else /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
Michael J. Spencer 1:f5ac63519541 209
Michael J. Spencer 1:f5ac63519541 210 /* Protect the heap only by using a semaphore */
Michael J. Spencer 1:f5ac63519541 211 #define LWIP_MEM_FREE_DECL_PROTECT()
Michael J. Spencer 1:f5ac63519541 212 #define LWIP_MEM_FREE_PROTECT() sys_mutex_lock(&mem_mutex)
Michael J. Spencer 1:f5ac63519541 213 #define LWIP_MEM_FREE_UNPROTECT() sys_mutex_unlock(&mem_mutex)
Michael J. Spencer 1:f5ac63519541 214 /* mem_malloc is protected using semaphore AND LWIP_MEM_ALLOC_PROTECT */
Michael J. Spencer 1:f5ac63519541 215 #define LWIP_MEM_ALLOC_DECL_PROTECT()
Michael J. Spencer 1:f5ac63519541 216 #define LWIP_MEM_ALLOC_PROTECT()
Michael J. Spencer 1:f5ac63519541 217 #define LWIP_MEM_ALLOC_UNPROTECT()
Michael J. Spencer 1:f5ac63519541 218
Michael J. Spencer 1:f5ac63519541 219 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
Michael J. Spencer 1:f5ac63519541 220
Michael J. Spencer 1:f5ac63519541 221
Michael J. Spencer 1:f5ac63519541 222 /**
Michael J. Spencer 1:f5ac63519541 223 * "Plug holes" by combining adjacent empty struct mems.
Michael J. Spencer 1:f5ac63519541 224 * After this function is through, there should not exist
Michael J. Spencer 1:f5ac63519541 225 * one empty struct mem pointing to another empty struct mem.
Michael J. Spencer 1:f5ac63519541 226 *
Michael J. Spencer 1:f5ac63519541 227 * @param mem this points to a struct mem which just has been freed
Michael J. Spencer 1:f5ac63519541 228 * @internal this function is only called by mem_free() and mem_trim()
Michael J. Spencer 1:f5ac63519541 229 *
Michael J. Spencer 1:f5ac63519541 230 * This assumes access to the heap is protected by the calling function
Michael J. Spencer 1:f5ac63519541 231 * already.
Michael J. Spencer 1:f5ac63519541 232 */
Michael J. Spencer 1:f5ac63519541 233 static void
Michael J. Spencer 1:f5ac63519541 234 plug_holes(struct mem *mem)
Michael J. Spencer 1:f5ac63519541 235 {
Michael J. Spencer 1:f5ac63519541 236 struct mem *nmem;
Michael J. Spencer 1:f5ac63519541 237 struct mem *pmem;
Michael J. Spencer 1:f5ac63519541 238
Michael J. Spencer 1:f5ac63519541 239 LWIP_ASSERT("plug_holes: mem >= ram", (u8_t *)mem >= ram);
Michael J. Spencer 1:f5ac63519541 240 LWIP_ASSERT("plug_holes: mem < ram_end", (u8_t *)mem < (u8_t *)ram_end);
Michael J. Spencer 1:f5ac63519541 241 LWIP_ASSERT("plug_holes: mem->used == 0", mem->used == 0);
Michael J. Spencer 1:f5ac63519541 242
Michael J. Spencer 1:f5ac63519541 243 /* plug hole forward */
Michael J. Spencer 1:f5ac63519541 244 LWIP_ASSERT("plug_holes: mem->next <= MEM_SIZE_ALIGNED", mem->next <= MEM_SIZE_ALIGNED);
Michael J. Spencer 1:f5ac63519541 245
Michael J. Spencer 1:f5ac63519541 246 nmem = (struct mem *)(void *)&ram[mem->next];
Michael J. Spencer 1:f5ac63519541 247 if (mem != nmem && nmem->used == 0 && (u8_t *)nmem != (u8_t *)ram_end) {
Michael J. Spencer 1:f5ac63519541 248 /* if mem->next is unused and not end of ram, combine mem and mem->next */
Michael J. Spencer 1:f5ac63519541 249 if (lfree == nmem) {
Michael J. Spencer 1:f5ac63519541 250 lfree = mem;
Michael J. Spencer 1:f5ac63519541 251 }
Michael J. Spencer 1:f5ac63519541 252 mem->next = nmem->next;
Michael J. Spencer 1:f5ac63519541 253 ((struct mem *)(void *)&ram[nmem->next])->prev = (mem_size_t)((u8_t *)mem - ram);
Michael J. Spencer 1:f5ac63519541 254 }
Michael J. Spencer 1:f5ac63519541 255
Michael J. Spencer 1:f5ac63519541 256 /* plug hole backward */
Michael J. Spencer 1:f5ac63519541 257 pmem = (struct mem *)(void *)&ram[mem->prev];
Michael J. Spencer 1:f5ac63519541 258 if (pmem != mem && pmem->used == 0) {
Michael J. Spencer 1:f5ac63519541 259 /* if mem->prev is unused, combine mem and mem->prev */
Michael J. Spencer 1:f5ac63519541 260 if (lfree == mem) {
Michael J. Spencer 1:f5ac63519541 261 lfree = pmem;
Michael J. Spencer 1:f5ac63519541 262 }
Michael J. Spencer 1:f5ac63519541 263 pmem->next = mem->next;
Michael J. Spencer 1:f5ac63519541 264 ((struct mem *)(void *)&ram[mem->next])->prev = (mem_size_t)((u8_t *)pmem - ram);
Michael J. Spencer 1:f5ac63519541 265 }
Michael J. Spencer 1:f5ac63519541 266 }
Michael J. Spencer 1:f5ac63519541 267
Michael J. Spencer 1:f5ac63519541 268 /**
Michael J. Spencer 1:f5ac63519541 269 * Zero the heap and initialize start, end and lowest-free
Michael J. Spencer 1:f5ac63519541 270 */
Michael J. Spencer 1:f5ac63519541 271 void
Michael J. Spencer 1:f5ac63519541 272 mem_init(void)
Michael J. Spencer 1:f5ac63519541 273 {
Michael J. Spencer 1:f5ac63519541 274 struct mem *mem;
Michael J. Spencer 1:f5ac63519541 275
Michael J. Spencer 1:f5ac63519541 276 LWIP_ASSERT("Sanity check alignment",
Michael J. Spencer 1:f5ac63519541 277 (SIZEOF_STRUCT_MEM & (MEM_ALIGNMENT-1)) == 0);
Michael J. Spencer 1:f5ac63519541 278
Michael J. Spencer 1:f5ac63519541 279 /* align the heap */
Michael J. Spencer 1:f5ac63519541 280 ram = (u8_t *)LWIP_MEM_ALIGN(LWIP_RAM_HEAP_POINTER);
Michael J. Spencer 1:f5ac63519541 281 /* initialize the start of the heap */
Michael J. Spencer 1:f5ac63519541 282 mem = (struct mem *)(void *)ram;
Michael J. Spencer 1:f5ac63519541 283 mem->next = MEM_SIZE_ALIGNED;
Michael J. Spencer 1:f5ac63519541 284 mem->prev = 0;
Michael J. Spencer 1:f5ac63519541 285 mem->used = 0;
Michael J. Spencer 1:f5ac63519541 286 /* initialize the end of the heap */
Michael J. Spencer 1:f5ac63519541 287 ram_end = (struct mem *)(void *)&ram[MEM_SIZE_ALIGNED];
Michael J. Spencer 1:f5ac63519541 288 ram_end->used = 1;
Michael J. Spencer 1:f5ac63519541 289 ram_end->next = MEM_SIZE_ALIGNED;
Michael J. Spencer 1:f5ac63519541 290 ram_end->prev = MEM_SIZE_ALIGNED;
Michael J. Spencer 1:f5ac63519541 291
Michael J. Spencer 1:f5ac63519541 292 /* initialize the lowest-free pointer to the start of the heap */
Michael J. Spencer 1:f5ac63519541 293 lfree = (struct mem *)(void *)ram;
Michael J. Spencer 1:f5ac63519541 294
Michael J. Spencer 1:f5ac63519541 295 MEM_STATS_AVAIL(avail, MEM_SIZE_ALIGNED);
Michael J. Spencer 1:f5ac63519541 296
Michael J. Spencer 1:f5ac63519541 297 if(sys_mutex_new(&mem_mutex) != ERR_OK) {
Michael J. Spencer 1:f5ac63519541 298 LWIP_ASSERT("failed to create mem_mutex", 0);
Michael J. Spencer 1:f5ac63519541 299 }
Michael J. Spencer 1:f5ac63519541 300 }
Michael J. Spencer 1:f5ac63519541 301
Michael J. Spencer 1:f5ac63519541 302 /**
Michael J. Spencer 1:f5ac63519541 303 * Put a struct mem back on the heap
Michael J. Spencer 1:f5ac63519541 304 *
Michael J. Spencer 1:f5ac63519541 305 * @param rmem is the data portion of a struct mem as returned by a previous
Michael J. Spencer 1:f5ac63519541 306 * call to mem_malloc()
Michael J. Spencer 1:f5ac63519541 307 */
Michael J. Spencer 1:f5ac63519541 308 void
Michael J. Spencer 1:f5ac63519541 309 mem_free(void *rmem)
Michael J. Spencer 1:f5ac63519541 310 {
Michael J. Spencer 1:f5ac63519541 311 struct mem *mem;
Michael J. Spencer 1:f5ac63519541 312 LWIP_MEM_FREE_DECL_PROTECT();
Michael J. Spencer 1:f5ac63519541 313
Michael J. Spencer 1:f5ac63519541 314 if (rmem == NULL) {
Michael J. Spencer 1:f5ac63519541 315 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("mem_free(p == NULL) was called.\n"));
Michael J. Spencer 1:f5ac63519541 316 return;
Michael J. Spencer 1:f5ac63519541 317 }
Michael J. Spencer 1:f5ac63519541 318 LWIP_ASSERT("mem_free: sanity check alignment", (((mem_ptr_t)rmem) & (MEM_ALIGNMENT-1)) == 0);
Michael J. Spencer 1:f5ac63519541 319
Michael J. Spencer 1:f5ac63519541 320 LWIP_ASSERT("mem_free: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
Michael J. Spencer 1:f5ac63519541 321 (u8_t *)rmem < (u8_t *)ram_end);
Michael J. Spencer 1:f5ac63519541 322
Michael J. Spencer 1:f5ac63519541 323 if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
Michael J. Spencer 1:f5ac63519541 324 SYS_ARCH_DECL_PROTECT(lev);
Michael J. Spencer 1:f5ac63519541 325 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_free: illegal memory\n"));
Michael J. Spencer 1:f5ac63519541 326 /* protect mem stats from concurrent access */
Michael J. Spencer 1:f5ac63519541 327 SYS_ARCH_PROTECT(lev);
Michael J. Spencer 1:f5ac63519541 328 MEM_STATS_INC(illegal);
Michael J. Spencer 1:f5ac63519541 329 SYS_ARCH_UNPROTECT(lev);
Michael J. Spencer 1:f5ac63519541 330 return;
Michael J. Spencer 1:f5ac63519541 331 }
Michael J. Spencer 1:f5ac63519541 332 /* protect the heap from concurrent access */
Michael J. Spencer 1:f5ac63519541 333 LWIP_MEM_FREE_PROTECT();
Michael J. Spencer 1:f5ac63519541 334 /* Get the corresponding struct mem ... */
Michael J. Spencer 1:f5ac63519541 335 mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
Michael J. Spencer 1:f5ac63519541 336 /* ... which has to be in a used state ... */
Michael J. Spencer 1:f5ac63519541 337 LWIP_ASSERT("mem_free: mem->used", mem->used);
Michael J. Spencer 1:f5ac63519541 338 /* ... and is now unused. */
Michael J. Spencer 1:f5ac63519541 339 mem->used = 0;
Michael J. Spencer 1:f5ac63519541 340
Michael J. Spencer 1:f5ac63519541 341 if (mem < lfree) {
Michael J. Spencer 1:f5ac63519541 342 /* the newly freed struct is now the lowest */
Michael J. Spencer 1:f5ac63519541 343 lfree = mem;
Michael J. Spencer 1:f5ac63519541 344 }
Michael J. Spencer 1:f5ac63519541 345
Michael J. Spencer 1:f5ac63519541 346 MEM_STATS_DEC_USED(used, mem->next - (mem_size_t)(((u8_t *)mem - ram)));
Michael J. Spencer 1:f5ac63519541 347
Michael J. Spencer 1:f5ac63519541 348 /* finally, see if prev or next are free also */
Michael J. Spencer 1:f5ac63519541 349 plug_holes(mem);
Michael J. Spencer 1:f5ac63519541 350 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
Michael J. Spencer 1:f5ac63519541 351 mem_free_count = 1;
Michael J. Spencer 1:f5ac63519541 352 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
Michael J. Spencer 1:f5ac63519541 353 LWIP_MEM_FREE_UNPROTECT();
Michael J. Spencer 1:f5ac63519541 354 }
Michael J. Spencer 1:f5ac63519541 355
Michael J. Spencer 1:f5ac63519541 356 /**
Michael J. Spencer 1:f5ac63519541 357 * Shrink memory returned by mem_malloc().
Michael J. Spencer 1:f5ac63519541 358 *
Michael J. Spencer 1:f5ac63519541 359 * @param rmem pointer to memory allocated by mem_malloc the is to be shrinked
Michael J. Spencer 1:f5ac63519541 360 * @param newsize required size after shrinking (needs to be smaller than or
Michael J. Spencer 1:f5ac63519541 361 * equal to the previous size)
Michael J. Spencer 1:f5ac63519541 362 * @return for compatibility reasons: is always == rmem, at the moment
Michael J. Spencer 1:f5ac63519541 363 * or NULL if newsize is > old size, in which case rmem is NOT touched
Michael J. Spencer 1:f5ac63519541 364 * or freed!
Michael J. Spencer 1:f5ac63519541 365 */
Michael J. Spencer 1:f5ac63519541 366 void *
Michael J. Spencer 1:f5ac63519541 367 mem_trim(void *rmem, mem_size_t newsize)
Michael J. Spencer 1:f5ac63519541 368 {
Michael J. Spencer 1:f5ac63519541 369 mem_size_t size;
Michael J. Spencer 1:f5ac63519541 370 mem_size_t ptr, ptr2;
Michael J. Spencer 1:f5ac63519541 371 struct mem *mem, *mem2;
Michael J. Spencer 1:f5ac63519541 372 /* use the FREE_PROTECT here: it protects with sem OR SYS_ARCH_PROTECT */
Michael J. Spencer 1:f5ac63519541 373 LWIP_MEM_FREE_DECL_PROTECT();
Michael J. Spencer 1:f5ac63519541 374
Michael J. Spencer 1:f5ac63519541 375 /* Expand the size of the allocated memory region so that we can
Michael J. Spencer 1:f5ac63519541 376 adjust for alignment. */
Michael J. Spencer 1:f5ac63519541 377 newsize = LWIP_MEM_ALIGN_SIZE(newsize);
Michael J. Spencer 1:f5ac63519541 378
Michael J. Spencer 1:f5ac63519541 379 if(newsize < MIN_SIZE_ALIGNED) {
Michael J. Spencer 1:f5ac63519541 380 /* every data block must be at least MIN_SIZE_ALIGNED long */
Michael J. Spencer 1:f5ac63519541 381 newsize = MIN_SIZE_ALIGNED;
Michael J. Spencer 1:f5ac63519541 382 }
Michael J. Spencer 1:f5ac63519541 383
Michael J. Spencer 1:f5ac63519541 384 if (newsize > MEM_SIZE_ALIGNED) {
Michael J. Spencer 1:f5ac63519541 385 return NULL;
Michael J. Spencer 1:f5ac63519541 386 }
Michael J. Spencer 1:f5ac63519541 387
Michael J. Spencer 1:f5ac63519541 388 LWIP_ASSERT("mem_trim: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
Michael J. Spencer 1:f5ac63519541 389 (u8_t *)rmem < (u8_t *)ram_end);
Michael J. Spencer 1:f5ac63519541 390
Michael J. Spencer 1:f5ac63519541 391 if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
Michael J. Spencer 1:f5ac63519541 392 SYS_ARCH_DECL_PROTECT(lev);
Michael J. Spencer 1:f5ac63519541 393 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_trim: illegal memory\n"));
Michael J. Spencer 1:f5ac63519541 394 /* protect mem stats from concurrent access */
Michael J. Spencer 1:f5ac63519541 395 SYS_ARCH_PROTECT(lev);
Michael J. Spencer 1:f5ac63519541 396 MEM_STATS_INC(illegal);
Michael J. Spencer 1:f5ac63519541 397 SYS_ARCH_UNPROTECT(lev);
Michael J. Spencer 1:f5ac63519541 398 return rmem;
Michael J. Spencer 1:f5ac63519541 399 }
Michael J. Spencer 1:f5ac63519541 400 /* Get the corresponding struct mem ... */
Michael J. Spencer 1:f5ac63519541 401 mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
Michael J. Spencer 1:f5ac63519541 402 /* ... and its offset pointer */
Michael J. Spencer 1:f5ac63519541 403 ptr = (mem_size_t)((u8_t *)mem - ram);
Michael J. Spencer 1:f5ac63519541 404
Michael J. Spencer 1:f5ac63519541 405 size = mem->next - ptr - SIZEOF_STRUCT_MEM;
Michael J. Spencer 1:f5ac63519541 406 LWIP_ASSERT("mem_trim can only shrink memory", newsize <= size);
Michael J. Spencer 1:f5ac63519541 407 if (newsize > size) {
Michael J. Spencer 1:f5ac63519541 408 /* not supported */
Michael J. Spencer 1:f5ac63519541 409 return NULL;
Michael J. Spencer 1:f5ac63519541 410 }
Michael J. Spencer 1:f5ac63519541 411 if (newsize == size) {
Michael J. Spencer 1:f5ac63519541 412 /* No change in size, simply return */
Michael J. Spencer 1:f5ac63519541 413 return rmem;
Michael J. Spencer 1:f5ac63519541 414 }
Michael J. Spencer 1:f5ac63519541 415
Michael J. Spencer 1:f5ac63519541 416 /* protect the heap from concurrent access */
Michael J. Spencer 1:f5ac63519541 417 LWIP_MEM_FREE_PROTECT();
Michael J. Spencer 1:f5ac63519541 418
Michael J. Spencer 1:f5ac63519541 419 mem2 = (struct mem *)(void *)&ram[mem->next];
Michael J. Spencer 1:f5ac63519541 420 if(mem2->used == 0) {
Michael J. Spencer 1:f5ac63519541 421 /* The next struct is unused, we can simply move it at little */
Michael J. Spencer 1:f5ac63519541 422 mem_size_t next;
Michael J. Spencer 1:f5ac63519541 423 /* remember the old next pointer */
Michael J. Spencer 1:f5ac63519541 424 next = mem2->next;
Michael J. Spencer 1:f5ac63519541 425 /* create new struct mem which is moved directly after the shrinked mem */
Michael J. Spencer 1:f5ac63519541 426 ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
Michael J. Spencer 1:f5ac63519541 427 if (lfree == mem2) {
Michael J. Spencer 1:f5ac63519541 428 lfree = (struct mem *)(void *)&ram[ptr2];
Michael J. Spencer 1:f5ac63519541 429 }
Michael J. Spencer 1:f5ac63519541 430 mem2 = (struct mem *)(void *)&ram[ptr2];
Michael J. Spencer 1:f5ac63519541 431 mem2->used = 0;
Michael J. Spencer 1:f5ac63519541 432 /* restore the next pointer */
Michael J. Spencer 1:f5ac63519541 433 mem2->next = next;
Michael J. Spencer 1:f5ac63519541 434 /* link it back to mem */
Michael J. Spencer 1:f5ac63519541 435 mem2->prev = ptr;
Michael J. Spencer 1:f5ac63519541 436 /* link mem to it */
Michael J. Spencer 1:f5ac63519541 437 mem->next = ptr2;
Michael J. Spencer 1:f5ac63519541 438 /* last thing to restore linked list: as we have moved mem2,
Michael J. Spencer 1:f5ac63519541 439 * let 'mem2->next->prev' point to mem2 again. but only if mem2->next is not
Michael J. Spencer 1:f5ac63519541 440 * the end of the heap */
Michael J. Spencer 1:f5ac63519541 441 if (mem2->next != MEM_SIZE_ALIGNED) {
Michael J. Spencer 1:f5ac63519541 442 ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
Michael J. Spencer 1:f5ac63519541 443 }
Michael J. Spencer 1:f5ac63519541 444 MEM_STATS_DEC_USED(used, (size - newsize));
Michael J. Spencer 1:f5ac63519541 445 /* no need to plug holes, we've already done that */
Michael J. Spencer 1:f5ac63519541 446 } else if (newsize + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED <= size) {
Michael J. Spencer 1:f5ac63519541 447 /* Next struct is used but there's room for another struct mem with
Michael J. Spencer 1:f5ac63519541 448 * at least MIN_SIZE_ALIGNED of data.
Michael J. Spencer 1:f5ac63519541 449 * Old size ('size') must be big enough to contain at least 'newsize' plus a struct mem
Michael J. Spencer 1:f5ac63519541 450 * ('SIZEOF_STRUCT_MEM') with some data ('MIN_SIZE_ALIGNED').
Michael J. Spencer 1:f5ac63519541 451 * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
Michael J. Spencer 1:f5ac63519541 452 * region that couldn't hold data, but when mem->next gets freed,
Michael J. Spencer 1:f5ac63519541 453 * the 2 regions would be combined, resulting in more free memory */
Michael J. Spencer 1:f5ac63519541 454 ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
Michael J. Spencer 1:f5ac63519541 455 mem2 = (struct mem *)(void *)&ram[ptr2];
Michael J. Spencer 1:f5ac63519541 456 if (mem2 < lfree) {
Michael J. Spencer 1:f5ac63519541 457 lfree = mem2;
Michael J. Spencer 1:f5ac63519541 458 }
Michael J. Spencer 1:f5ac63519541 459 mem2->used = 0;
Michael J. Spencer 1:f5ac63519541 460 mem2->next = mem->next;
Michael J. Spencer 1:f5ac63519541 461 mem2->prev = ptr;
Michael J. Spencer 1:f5ac63519541 462 mem->next = ptr2;
Michael J. Spencer 1:f5ac63519541 463 if (mem2->next != MEM_SIZE_ALIGNED) {
Michael J. Spencer 1:f5ac63519541 464 ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
Michael J. Spencer 1:f5ac63519541 465 }
Michael J. Spencer 1:f5ac63519541 466 MEM_STATS_DEC_USED(used, (size - newsize));
Michael J. Spencer 1:f5ac63519541 467 /* the original mem->next is used, so no need to plug holes! */
Michael J. Spencer 1:f5ac63519541 468 }
Michael J. Spencer 1:f5ac63519541 469 /* else {
Michael J. Spencer 1:f5ac63519541 470 next struct mem is used but size between mem and mem2 is not big enough
Michael J. Spencer 1:f5ac63519541 471 to create another struct mem
Michael J. Spencer 1:f5ac63519541 472 -> don't do anyhting.
Michael J. Spencer 1:f5ac63519541 473 -> the remaining space stays unused since it is too small
Michael J. Spencer 1:f5ac63519541 474 } */
Michael J. Spencer 1:f5ac63519541 475 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
Michael J. Spencer 1:f5ac63519541 476 mem_free_count = 1;
Michael J. Spencer 1:f5ac63519541 477 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
Michael J. Spencer 1:f5ac63519541 478 LWIP_MEM_FREE_UNPROTECT();
Michael J. Spencer 1:f5ac63519541 479 return rmem;
Michael J. Spencer 1:f5ac63519541 480 }
Michael J. Spencer 1:f5ac63519541 481
Michael J. Spencer 1:f5ac63519541 482 /**
Michael J. Spencer 1:f5ac63519541 483 * Adam's mem_malloc() plus solution for bug #17922
Michael J. Spencer 1:f5ac63519541 484 * Allocate a block of memory with a minimum of 'size' bytes.
Michael J. Spencer 1:f5ac63519541 485 *
Michael J. Spencer 1:f5ac63519541 486 * @param size is the minimum size of the requested block in bytes.
Michael J. Spencer 1:f5ac63519541 487 * @return pointer to allocated memory or NULL if no free memory was found.
Michael J. Spencer 1:f5ac63519541 488 *
Michael J. Spencer 1:f5ac63519541 489 * Note that the returned value will always be aligned (as defined by MEM_ALIGNMENT).
Michael J. Spencer 1:f5ac63519541 490 */
Michael J. Spencer 1:f5ac63519541 491 void *
Michael J. Spencer 1:f5ac63519541 492 mem_malloc(mem_size_t size)
Michael J. Spencer 1:f5ac63519541 493 {
Michael J. Spencer 1:f5ac63519541 494 mem_size_t ptr, ptr2;
Michael J. Spencer 1:f5ac63519541 495 struct mem *mem, *mem2;
Michael J. Spencer 1:f5ac63519541 496 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
Michael J. Spencer 1:f5ac63519541 497 u8_t local_mem_free_count = 0;
Michael J. Spencer 1:f5ac63519541 498 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
Michael J. Spencer 1:f5ac63519541 499 LWIP_MEM_ALLOC_DECL_PROTECT();
Michael J. Spencer 1:f5ac63519541 500
Michael J. Spencer 1:f5ac63519541 501 if (size == 0) {
Michael J. Spencer 1:f5ac63519541 502 return NULL;
Michael J. Spencer 1:f5ac63519541 503 }
Michael J. Spencer 1:f5ac63519541 504
Michael J. Spencer 1:f5ac63519541 505 /* Expand the size of the allocated memory region so that we can
Michael J. Spencer 1:f5ac63519541 506 adjust for alignment. */
Michael J. Spencer 1:f5ac63519541 507 size = LWIP_MEM_ALIGN_SIZE(size);
Michael J. Spencer 1:f5ac63519541 508
Michael J. Spencer 1:f5ac63519541 509 if(size < MIN_SIZE_ALIGNED) {
Michael J. Spencer 1:f5ac63519541 510 /* every data block must be at least MIN_SIZE_ALIGNED long */
Michael J. Spencer 1:f5ac63519541 511 size = MIN_SIZE_ALIGNED;
Michael J. Spencer 1:f5ac63519541 512 }
Michael J. Spencer 1:f5ac63519541 513
Michael J. Spencer 1:f5ac63519541 514 if (size > MEM_SIZE_ALIGNED) {
Michael J. Spencer 1:f5ac63519541 515 return NULL;
Michael J. Spencer 1:f5ac63519541 516 }
Michael J. Spencer 1:f5ac63519541 517
Michael J. Spencer 1:f5ac63519541 518 /* protect the heap from concurrent access */
Michael J. Spencer 1:f5ac63519541 519 sys_mutex_lock(&mem_mutex);
Michael J. Spencer 1:f5ac63519541 520 LWIP_MEM_ALLOC_PROTECT();
Michael J. Spencer 1:f5ac63519541 521 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
Michael J. Spencer 1:f5ac63519541 522 /* run as long as a mem_free disturbed mem_malloc */
Michael J. Spencer 1:f5ac63519541 523 do {
Michael J. Spencer 1:f5ac63519541 524 local_mem_free_count = 0;
Michael J. Spencer 1:f5ac63519541 525 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
Michael J. Spencer 1:f5ac63519541 526
Michael J. Spencer 1:f5ac63519541 527 /* Scan through the heap searching for a free block that is big enough,
Michael J. Spencer 1:f5ac63519541 528 * beginning with the lowest free block.
Michael J. Spencer 1:f5ac63519541 529 */
Michael J. Spencer 1:f5ac63519541 530 for (ptr = (mem_size_t)((u8_t *)lfree - ram); ptr < MEM_SIZE_ALIGNED - size;
Michael J. Spencer 1:f5ac63519541 531 ptr = ((struct mem *)(void *)&ram[ptr])->next) {
Michael J. Spencer 1:f5ac63519541 532 mem = (struct mem *)(void *)&ram[ptr];
Michael J. Spencer 1:f5ac63519541 533 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
Michael J. Spencer 1:f5ac63519541 534 mem_free_count = 0;
Michael J. Spencer 1:f5ac63519541 535 LWIP_MEM_ALLOC_UNPROTECT();
Michael J. Spencer 1:f5ac63519541 536 /* allow mem_free to run */
Michael J. Spencer 1:f5ac63519541 537 LWIP_MEM_ALLOC_PROTECT();
Michael J. Spencer 1:f5ac63519541 538 if (mem_free_count != 0) {
Michael J. Spencer 1:f5ac63519541 539 local_mem_free_count = mem_free_count;
Michael J. Spencer 1:f5ac63519541 540 }
Michael J. Spencer 1:f5ac63519541 541 mem_free_count = 0;
Michael J. Spencer 1:f5ac63519541 542 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
Michael J. Spencer 1:f5ac63519541 543
Michael J. Spencer 1:f5ac63519541 544 if ((!mem->used) &&
Michael J. Spencer 1:f5ac63519541 545 (mem->next - (ptr + SIZEOF_STRUCT_MEM)) >= size) {
Michael J. Spencer 1:f5ac63519541 546 /* mem is not used and at least perfect fit is possible:
Michael J. Spencer 1:f5ac63519541 547 * mem->next - (ptr + SIZEOF_STRUCT_MEM) gives us the 'user data size' of mem */
Michael J. Spencer 1:f5ac63519541 548
Michael J. Spencer 1:f5ac63519541 549 if (mem->next - (ptr + SIZEOF_STRUCT_MEM) >= (size + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED)) {
Michael J. Spencer 1:f5ac63519541 550 /* (in addition to the above, we test if another struct mem (SIZEOF_STRUCT_MEM) containing
Michael J. Spencer 1:f5ac63519541 551 * at least MIN_SIZE_ALIGNED of data also fits in the 'user data space' of 'mem')
Michael J. Spencer 1:f5ac63519541 552 * -> split large block, create empty remainder,
Michael J. Spencer 1:f5ac63519541 553 * remainder must be large enough to contain MIN_SIZE_ALIGNED data: if
Michael J. Spencer 1:f5ac63519541 554 * mem->next - (ptr + (2*SIZEOF_STRUCT_MEM)) == size,
Michael J. Spencer 1:f5ac63519541 555 * struct mem would fit in but no data between mem2 and mem2->next
Michael J. Spencer 1:f5ac63519541 556 * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
Michael J. Spencer 1:f5ac63519541 557 * region that couldn't hold data, but when mem->next gets freed,
Michael J. Spencer 1:f5ac63519541 558 * the 2 regions would be combined, resulting in more free memory
Michael J. Spencer 1:f5ac63519541 559 */
Michael J. Spencer 1:f5ac63519541 560 ptr2 = ptr + SIZEOF_STRUCT_MEM + size;
Michael J. Spencer 1:f5ac63519541 561 /* create mem2 struct */
Michael J. Spencer 1:f5ac63519541 562 mem2 = (struct mem *)(void *)&ram[ptr2];
Michael J. Spencer 1:f5ac63519541 563 mem2->used = 0;
Michael J. Spencer 1:f5ac63519541 564 mem2->next = mem->next;
Michael J. Spencer 1:f5ac63519541 565 mem2->prev = ptr;
Michael J. Spencer 1:f5ac63519541 566 /* and insert it between mem and mem->next */
Michael J. Spencer 1:f5ac63519541 567 mem->next = ptr2;
Michael J. Spencer 1:f5ac63519541 568 mem->used = 1;
Michael J. Spencer 1:f5ac63519541 569
Michael J. Spencer 1:f5ac63519541 570 if (mem2->next != MEM_SIZE_ALIGNED) {
Michael J. Spencer 1:f5ac63519541 571 ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
Michael J. Spencer 1:f5ac63519541 572 }
Michael J. Spencer 1:f5ac63519541 573 MEM_STATS_INC_USED(used, (size + SIZEOF_STRUCT_MEM));
Michael J. Spencer 1:f5ac63519541 574 } else {
Michael J. Spencer 1:f5ac63519541 575 /* (a mem2 struct does no fit into the user data space of mem and mem->next will always
Michael J. Spencer 1:f5ac63519541 576 * be used at this point: if not we have 2 unused structs in a row, plug_holes should have
Michael J. Spencer 1:f5ac63519541 577 * take care of this).
Michael J. Spencer 1:f5ac63519541 578 * -> near fit or excact fit: do not split, no mem2 creation
Michael J. Spencer 1:f5ac63519541 579 * also can't move mem->next directly behind mem, since mem->next
Michael J. Spencer 1:f5ac63519541 580 * will always be used at this point!
Michael J. Spencer 1:f5ac63519541 581 */
Michael J. Spencer 1:f5ac63519541 582 mem->used = 1;
Michael J. Spencer 1:f5ac63519541 583 MEM_STATS_INC_USED(used, mem->next - (mem_size_t)((u8_t *)mem - ram));
Michael J. Spencer 1:f5ac63519541 584 }
Michael J. Spencer 1:f5ac63519541 585
Michael J. Spencer 1:f5ac63519541 586 if (mem == lfree) {
Michael J. Spencer 1:f5ac63519541 587 /* Find next free block after mem and update lowest free pointer */
Michael J. Spencer 1:f5ac63519541 588 while (lfree->used && lfree != ram_end) {
Michael J. Spencer 1:f5ac63519541 589 LWIP_MEM_ALLOC_UNPROTECT();
Michael J. Spencer 1:f5ac63519541 590 /* prevent high interrupt latency... */
Michael J. Spencer 1:f5ac63519541 591 LWIP_MEM_ALLOC_PROTECT();
Michael J. Spencer 1:f5ac63519541 592 lfree = (struct mem *)(void *)&ram[lfree->next];
Michael J. Spencer 1:f5ac63519541 593 }
Michael J. Spencer 1:f5ac63519541 594 LWIP_ASSERT("mem_malloc: !lfree->used", ((lfree == ram_end) || (!lfree->used)));
Michael J. Spencer 1:f5ac63519541 595 }
Michael J. Spencer 1:f5ac63519541 596 LWIP_MEM_ALLOC_UNPROTECT();
Michael J. Spencer 1:f5ac63519541 597 sys_mutex_unlock(&mem_mutex);
Michael J. Spencer 1:f5ac63519541 598 LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.",
Michael J. Spencer 1:f5ac63519541 599 (mem_ptr_t)mem + SIZEOF_STRUCT_MEM + size <= (mem_ptr_t)ram_end);
Michael J. Spencer 1:f5ac63519541 600 LWIP_ASSERT("mem_malloc: allocated memory properly aligned.",
Michael J. Spencer 1:f5ac63519541 601 ((mem_ptr_t)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0);
Michael J. Spencer 1:f5ac63519541 602 LWIP_ASSERT("mem_malloc: sanity check alignment",
Michael J. Spencer 1:f5ac63519541 603 (((mem_ptr_t)mem) & (MEM_ALIGNMENT-1)) == 0);
Michael J. Spencer 1:f5ac63519541 604
Michael J. Spencer 1:f5ac63519541 605 return (u8_t *)mem + SIZEOF_STRUCT_MEM;
Michael J. Spencer 1:f5ac63519541 606 }
Michael J. Spencer 1:f5ac63519541 607 }
Michael J. Spencer 1:f5ac63519541 608 #if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
Michael J. Spencer 1:f5ac63519541 609 /* if we got interrupted by a mem_free, try again */
Michael J. Spencer 1:f5ac63519541 610 } while(local_mem_free_count != 0);
Michael J. Spencer 1:f5ac63519541 611 #endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
Michael J. Spencer 1:f5ac63519541 612 LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("mem_malloc: could not allocate %"S16_F" bytes\n", (s16_t)size));
Michael J. Spencer 1:f5ac63519541 613 MEM_STATS_INC(err);
Michael J. Spencer 1:f5ac63519541 614 LWIP_MEM_ALLOC_UNPROTECT();
Michael J. Spencer 1:f5ac63519541 615 sys_mutex_unlock(&mem_mutex);
Michael J. Spencer 1:f5ac63519541 616 return NULL;
Michael J. Spencer 1:f5ac63519541 617 }
Michael J. Spencer 1:f5ac63519541 618
Michael J. Spencer 1:f5ac63519541 619 #endif /* MEM_USE_POOLS */
Michael J. Spencer 1:f5ac63519541 620 /**
Michael J. Spencer 1:f5ac63519541 621 * Contiguously allocates enough space for count objects that are size bytes
Michael J. Spencer 1:f5ac63519541 622 * of memory each and returns a pointer to the allocated memory.
Michael J. Spencer 1:f5ac63519541 623 *
Michael J. Spencer 1:f5ac63519541 624 * The allocated memory is filled with bytes of value zero.
Michael J. Spencer 1:f5ac63519541 625 *
Michael J. Spencer 1:f5ac63519541 626 * @param count number of objects to allocate
Michael J. Spencer 1:f5ac63519541 627 * @param size size of the objects to allocate
Michael J. Spencer 1:f5ac63519541 628 * @return pointer to allocated memory / NULL pointer if there is an error
Michael J. Spencer 1:f5ac63519541 629 */
Michael J. Spencer 1:f5ac63519541 630 void *mem_calloc(mem_size_t count, mem_size_t size)
Michael J. Spencer 1:f5ac63519541 631 {
Michael J. Spencer 1:f5ac63519541 632 void *p;
Michael J. Spencer 1:f5ac63519541 633
Michael J. Spencer 1:f5ac63519541 634 /* allocate 'count' objects of size 'size' */
Michael J. Spencer 1:f5ac63519541 635 p = mem_malloc(count * size);
Michael J. Spencer 1:f5ac63519541 636 if (p) {
Michael J. Spencer 1:f5ac63519541 637 /* zero the memory */
Michael J. Spencer 1:f5ac63519541 638 memset(p, 0, count * size);
Michael J. Spencer 1:f5ac63519541 639 }
Michael J. Spencer 1:f5ac63519541 640 return p;
Michael J. Spencer 1:f5ac63519541 641 }
Michael J. Spencer 1:f5ac63519541 642
Michael J. Spencer 1:f5ac63519541 643 #endif /* !MEM_LIBC_MALLOC */