modules/network/SMSTCPIP/mem.c

   1 /** @file
   2  *
   3  * Dynamic memory manager
   4  *
   5  */
   6
   7 /*
   8  * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without modification,
  12  * are permitted provided that the following conditions are met:
  13  *
  14  * 1. Redistributions of source code must retain the above copyright notice,
  15  *    this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright notice,
  17  *    this list of conditions and the following disclaimer in the documentation
  18  *    and/or other materials provided with the distribution.
  19  * 3. The name of the author may not be used to endorse or promote products
  20  *    derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  25  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  27  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  30  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  31  * OF SUCH DAMAGE.
  32  *
  33  * This file is part of the lwIP TCP/IP stack.
  34  *
  35  * Author: Adam Dunkels <adam@sics.se>
  36  *
  37  */
  38
  39
  40 #include "lwip/arch.h"
  41 #include "lwip/opt.h"
  42 #include "lwip/def.h"
  43 #include "lwip/mem.h"
  44
  45 #include "lwip/sys.h"
  46
  47 #include "lwip/stats.h"
  48
  49 #include <thsemap.h>
  50 #include <sysclib.h>
  51
  52 #include "smsutils.h"
  53
  54 struct mem {
  55   mem_size_t next, prev;
  56 #if MEM_ALIGNMENT == 1
  57   u8_t used;
  58 #elif MEM_ALIGNMENT == 2
  59   u16_t used;
  60 #elif MEM_ALIGNMENT == 4
  61   u32_t used;
  62 #else
  63 #error "unhandled MEM_ALIGNMENT size"
  64 #endif /* MEM_ALIGNMENT */
  65 };
  66
  67 static struct mem *ram_end;
  68 static u8_t* ram;
  69 static u8_t ramblock[MEM_SIZE + sizeof(struct mem) + MEM_ALIGNMENT];
  70
  71 #define MIN_SIZE 12
  72 #if 0 /* this one does not align correctly for some, resulting in crashes */
  73 #define SIZEOF_STRUCT_MEM (unsigned int)MEM_ALIGN_SIZE(sizeof(struct mem))
  74 #else
  75 #define SIZEOF_STRUCT_MEM (sizeof(struct mem) + \
  76                           (((sizeof(struct mem) % MEM_ALIGNMENT) == 0)? 0 : \
  77                           (4 - (sizeof(struct mem) % MEM_ALIGNMENT))))
  78 #endif
  79
  80
  81 static struct mem *lfree;   /* pointer to the lowest free block */
  82
  83 static sys_sem_t mem_sem;
  84
  85 static void
  86 plug_holes(struct mem *mem)
  87 {
  88   struct mem *nmem;
  89   struct mem *pmem;
  90
  91   LWIP_ASSERT("plug_holes: mem >= ram", (u8_t *)mem >= ram);
  92   LWIP_ASSERT("plug_holes: mem < ram_end", (u8_t *)mem < (u8_t *)ram_end);
  93   LWIP_ASSERT("plug_holes: mem->used == 0", mem->used == 0);
  94
  95   /* plug hole forward */
  96   LWIP_ASSERT("plug_holes: mem->next <= MEM_SIZE", mem->next <= MEM_SIZE);
  97
  98   nmem = (struct mem *)&ram[mem->next];
  99   if (mem != nmem && nmem->used == 0 && (u8_t *)nmem != (u8_t *)ram_end) {
 100     if (lfree == nmem) {
 101       lfree = mem;
 102     }
 103     mem->next = nmem->next;
 104     ((struct mem *)&ram[nmem->next])->prev = (u8_t *)mem - ram;
 105   }
 106
 107   /* plug hole backward */
 108   pmem = (struct mem *)&ram[mem->prev];
 109   if (pmem != mem && pmem->used == 0) {
 110     if (lfree == mem) {
 111       lfree = pmem;
 112     }
 113     pmem->next = mem->next;
 114     ((struct mem *)&ram[mem->next])->prev = (u8_t *)pmem - ram;
 115   }
 116
 117 }
 118 void
 119 mem_init(void)
 120 {
 121   struct mem *mem;
 122
 123   //Boman666: Originally ram was the array now called ramblock. I didn't experience any problem but ram could end up incorrecly
 124   //aligned, causing a crash.
 125   ram=MEM_ALIGN(ramblock+MEM_ALIGNMENT-1);
 126   mips_memset(ram, 0, MEM_SIZE);
 127   mem = (struct mem *)ram;
 128   mem->next = MEM_SIZE;
 129   mem->prev = 0;
 130   mem->used = 0;
 131   ram_end = (struct mem *)&ram[MEM_SIZE];
 132   ram_end->used = 1;
 133   ram_end->next = MEM_SIZE;
 134   ram_end->prev = MEM_SIZE;
 135
 136   mem_sem = sys_sem_new(1);
 137
 138   lfree = (struct mem *)ram;
 139
 140 #if MEM_STATS
 141   lwip_stats.mem.avail = MEM_SIZE;
 142 #endif /* MEM_STATS */
 143 }
 144
 145 void
 146 mem_free(void *rmem)
 147 {
 148   struct mem *mem;
 149
 150   if (rmem == NULL) {
 151     LWIP_DEBUGF(MEM_DEBUG | DBG_TRACE | 2, ("mem_free(p == NULL) was called.\n"));
 152     return;
 153   }
 154
 155   sys_sem_wait(mem_sem);
 156
 157   LWIP_ASSERT("mem_free: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
 158     (u8_t *)rmem < (u8_t *)ram_end);
 159
 160   if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
 161     LWIP_DEBUGF(MEM_DEBUG | 3, ("mem_free: illegal memory\n"));
 162 #if MEM_STATS
 163     ++lwip_stats.mem.err;
 164 #endif /* MEM_STATS */
 165     sys_sem_signal(mem_sem);
 166     return;
 167   }
 168   mem = (struct mem *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
 169
 170   LWIP_ASSERT("mem_free: mem->used", mem->used);
 171
 172   mem->used = 0;
 173
 174   if (mem < lfree) {
 175     lfree = mem;
 176   }
 177
 178 #if MEM_STATS
 179   lwip_stats.mem.used -= mem->next - ((u8_t *)mem - ram);
 180
 181 #endif /* MEM_STATS */
 182   plug_holes(mem);
 183   sys_sem_signal(mem_sem);
 184 }
 185 void *
 186 mem_reallocm(void *rmem, mem_size_t newsize)
 187 {
 188   void *nmem;
 189   nmem = mem_malloc(newsize);
 190   if (nmem == NULL) {
 191     return mem_realloc(rmem, newsize);
 192   }
 193   mips_memcpy(nmem, rmem, newsize);
 194   mem_free(rmem);
 195   return nmem;
 196 }
 197
 198 void *
 199 mem_realloc(void *rmem, mem_size_t newsize)
 200 {
 201   mem_size_t size;
 202   mem_size_t ptr, ptr2;
 203   struct mem *mem, *mem2;
 204
 205   /* Expand the size of the allocated memory region so that we can
 206      adjust for alignment. */
 207   if ((newsize % MEM_ALIGNMENT) != 0) {
 208    newsize += MEM_ALIGNMENT - ((newsize + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT);
 209   }
 210
 211   if (newsize > MEM_SIZE) {
 212     return NULL;
 213   }
 214
 215   sys_sem_wait(mem_sem);
 216
 217   LWIP_ASSERT("mem_realloc: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
 218    (u8_t *)rmem < (u8_t *)ram_end);
 219
 220   if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
 221     LWIP_DEBUGF(MEM_DEBUG | 3, ("mem_realloc: illegal memory\n"));
 222     return rmem;
 223   }
 224   mem = (struct mem *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
 225
 226   ptr = (u8_t *)mem - ram;
 227
 228   size = mem->next - ptr - SIZEOF_STRUCT_MEM;
 229 #if MEM_STATS
 230   lwip_stats.mem.used -= (size - newsize);
 231 #endif /* MEM_STATS */
 232
 233   if (newsize + SIZEOF_STRUCT_MEM + MIN_SIZE < size) {
 234     ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
 235     mem2 = (struct mem *)&ram[ptr2];
 236     mem2->used = 0;
 237     mem2->next = mem->next;
 238     mem2->prev = ptr;
 239     mem->next = ptr2;
 240     if (mem2->next != MEM_SIZE) {
 241       ((struct mem *)&ram[mem2->next])->prev = ptr2;
 242     }
 243
 244     plug_holes(mem2);
 245   }
 246   sys_sem_signal(mem_sem);
 247   return rmem;
 248 }
 249 void *
 250 mem_malloc(mem_size_t size)
 251 {
 252   mem_size_t ptr, ptr2;
 253   struct mem *mem, *mem2;
 254
 255   if (size == 0) {
 256     return NULL;
 257   }
 258
 259   /* Expand the size of the allocated memory region so that we can
 260      adjust for alignment. */
 261   if ((size % MEM_ALIGNMENT) != 0) {
 262     size += MEM_ALIGNMENT - ((size + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT);
 263   }
 264
 265   if (size > MEM_SIZE) {
 266     return NULL;
 267   }
 268
 269   sys_sem_wait(mem_sem);
 270
 271   for (ptr = (u8_t *)lfree - ram; ptr < MEM_SIZE; ptr = ((struct mem *)&ram[ptr])->next) {
 272     mem = (struct mem *)&ram[ptr];
 273     if (!mem->used &&
 274        mem->next - (ptr + SIZEOF_STRUCT_MEM) >= size + SIZEOF_STRUCT_MEM) {
 275
 276                 ptr2 = ptr + SIZEOF_STRUCT_MEM + size;
 277       mem2 = (struct mem *)&ram[ptr2];
 278
 279       mem2->prev = ptr;
 280       mem2->next = mem->next;
 281       mem->next = ptr2;
 282       if (mem2->next != MEM_SIZE) {
 283         ((struct mem *)&ram[mem2->next])->prev = ptr2;
 284       }
 285
 286       mem2->used = 0;
 287       mem->used = 1;
 288 #if MEM_STATS
 289       lwip_stats.mem.used += (size + SIZEOF_STRUCT_MEM);
 290       /*      if (lwip_stats.mem.max < lwip_stats.mem.used) {
 291         lwip_stats.mem.max = lwip_stats.mem.used;
 292   } */
 293       if (lwip_stats.mem.max < ptr2) {
 294         lwip_stats.mem.max = ptr2;
 295       }
 296 #endif /* MEM_STATS */
 297
 298       if (mem == lfree) {
 299   /* Find next free block after mem */
 300         while (lfree->used && lfree != ram_end) {
 301     lfree = (struct mem *)&ram[lfree->next];
 302         }
 303         LWIP_ASSERT("mem_malloc: !lfree->used", !lfree->used);
 304       }
 305       sys_sem_signal(mem_sem);
 306
 307                 LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.",
 308        (u32_t)mem + SIZEOF_STRUCT_MEM + size <= (u32_t)ram_end);
 309       LWIP_ASSERT("mem_malloc: allocated memory properly aligned.",
 310        (unsigned long)((u8_t *)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0);
 311       return (u8_t *)mem + SIZEOF_STRUCT_MEM;
 312     }
 313   }
 314   LWIP_DEBUGF(MEM_DEBUG | 2, ("mem_malloc: could not allocate %d bytes\n", (int)size));
 315 #if MEM_STATS
 316   ++lwip_stats.mem.err;
 317 #endif /* MEM_STATS */
 318   sys_sem_signal(mem_sem);
 319   return NULL;
 320 }