/** @file | |
* | |
* Dynamic memory manager | |
* | |
*/ | |
/* | |
* Copyright (c) 2001-2004 Swedish Institute of Computer Science. | |
* All rights reserved. | |
* | |
* Redistribution and use in source and binary forms, with or without modification, | |
* are permitted provided that the following conditions are met: | |
* | |
* 1. Redistributions of source code must retain the above copyright notice, | |
* this list of conditions and the following disclaimer. | |
* 2. Redistributions in binary form must reproduce the above copyright notice, | |
* this list of conditions and the following disclaimer in the documentation | |
* and/or other materials provided with the distribution. | |
* 3. The name of the author may not be used to endorse or promote products | |
* derived from this software without specific prior written permission. | |
* | |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED | |
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT | |
* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | |
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT | |
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING | |
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY | |
* OF SUCH DAMAGE. | |
* | |
* This file is part of the lwIP TCP/IP stack. | |
* | |
* Author: Adam Dunkels <adam@sics.se> | |
* | |
*/ | |
#include <string.h> | |
#include "lwip/arch.h" | |
#include "lwip/opt.h" | |
#include "lwip/def.h" | |
#include "lwip/mem.h" | |
#include "lwip/sys.h" | |
#include "lwip/stats.h" | |
#if (MEM_LIBC_MALLOC == 0) | |
/* lwIP replacement for your libc malloc() */ | |
struct mem { | |
mem_size_t next, prev; | |
#if MEM_ALIGNMENT == 1 | |
u8_t used; | |
#elif MEM_ALIGNMENT == 2 | |
u16_t used; | |
#elif MEM_ALIGNMENT == 4 | |
u32_t used; | |
#elif MEM_ALIGNMENT == 8 | |
u64_t used; | |
#else | |
#error "unhandled MEM_ALIGNMENT size" | |
#endif /* MEM_ALIGNMENT */ | |
}; | |
static struct mem *ram_end; | |
#if 1 | |
/* Adam original */ | |
static u8_t ram[MEM_SIZE + sizeof(struct mem) + MEM_ALIGNMENT]; | |
#else | |
/* Christiaan alignment fix */ | |
static u8_t *ram; | |
static struct mem ram_heap[1 + ( (MEM_SIZE + sizeof(struct mem) - 1) / sizeof(struct mem))]; | |
#endif | |
#define MIN_SIZE 12 | |
#if 0 /* this one does not align correctly for some, resulting in crashes */ | |
#define SIZEOF_STRUCT_MEM (unsigned int)MEM_ALIGN_SIZE(sizeof(struct mem)) | |
#else | |
#define SIZEOF_STRUCT_MEM (sizeof(struct mem) + \ | |
(((sizeof(struct mem) % MEM_ALIGNMENT) == 0)? 0 : \ | |
(4 - (sizeof(struct mem) % MEM_ALIGNMENT)))) | |
#endif | |
static struct mem *lfree; /* pointer to the lowest free block */ | |
static sys_sem_t mem_sem; | |
static void | |
plug_holes(struct mem *mem) | |
{ | |
struct mem *nmem; | |
struct mem *pmem; | |
LWIP_ASSERT("plug_holes: mem >= ram", (u8_t *)mem >= ram); | |
LWIP_ASSERT("plug_holes: mem < ram_end", (u8_t *)mem < (u8_t *)ram_end); | |
LWIP_ASSERT("plug_holes: mem->used == 0", mem->used == 0); | |
/* plug hole forward */ | |
LWIP_ASSERT("plug_holes: mem->next <= MEM_SIZE", mem->next <= MEM_SIZE); | |
nmem = (struct mem *)&ram[mem->next]; | |
if (mem != nmem && nmem->used == 0 && (u8_t *)nmem != (u8_t *)ram_end) { | |
if (lfree == nmem) { | |
lfree = mem; | |
} | |
mem->next = nmem->next; | |
((struct mem *)&ram[nmem->next])->prev = (u8_t *)mem - ram; | |
} | |
/* plug hole backward */ | |
pmem = (struct mem *)&ram[mem->prev]; | |
if (pmem != mem && pmem->used == 0) { | |
if (lfree == mem) { | |
lfree = pmem; | |
} | |
pmem->next = mem->next; | |
((struct mem *)&ram[mem->next])->prev = (u8_t *)pmem - ram; | |
} | |
} | |
void | |
mem_init(void) | |
{ | |
struct mem *mem; | |
#if 1 | |
/* Adam original */ | |
#else | |
/* Christiaan alignment fix */ | |
ram = (u8_t*)ram_heap; | |
#endif | |
memset(ram, 0, MEM_SIZE); | |
mem = (struct mem *)ram; | |
mem->next = MEM_SIZE; | |
mem->prev = 0; | |
mem->used = 0; | |
ram_end = (struct mem *)&ram[MEM_SIZE]; | |
ram_end->used = 1; | |
ram_end->next = MEM_SIZE; | |
ram_end->prev = MEM_SIZE; | |
mem_sem = sys_sem_new(1); | |
lfree = (struct mem *)ram; | |
#if MEM_STATS | |
lwip_stats.mem.avail = MEM_SIZE; | |
#endif /* MEM_STATS */ | |
} | |
void | |
mem_free(void *rmem) | |
{ | |
struct mem *mem; | |
if (rmem == NULL) { | |
LWIP_DEBUGF(MEM_DEBUG | DBG_TRACE | 2, ("mem_free(p == NULL) was called.\n")); | |
return; | |
} | |
sys_sem_wait(mem_sem); | |
LWIP_ASSERT("mem_free: legal memory", (u8_t *)rmem >= (u8_t *)ram && | |
(u8_t *)rmem < (u8_t *)ram_end); | |
if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) { | |
LWIP_DEBUGF(MEM_DEBUG | 3, ("mem_free: illegal memory\n")); | |
#if MEM_STATS | |
++lwip_stats.mem.err; | |
#endif /* MEM_STATS */ | |
sys_sem_signal(mem_sem); | |
return; | |
} | |
mem = (struct mem *)((u8_t *)rmem - SIZEOF_STRUCT_MEM); | |
LWIP_ASSERT("mem_free: mem->used", mem->used); | |
mem->used = 0; | |
if (mem < lfree) { | |
lfree = mem; | |
} | |
#if MEM_STATS | |
lwip_stats.mem.used -= mem->next - ((u8_t *)mem - ram); | |
#endif /* MEM_STATS */ | |
plug_holes(mem); | |
sys_sem_signal(mem_sem); | |
} | |
void * | |
mem_realloc(void *rmem, mem_size_t newsize) | |
{ | |
mem_size_t size; | |
mem_size_t ptr, ptr2; | |
struct mem *mem, *mem2; | |
/* Expand the size of the allocated memory region so that we can | |
adjust for alignment. */ | |
if ((newsize % MEM_ALIGNMENT) != 0) { | |
newsize += MEM_ALIGNMENT - ((newsize + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT); | |
} | |
if (newsize > MEM_SIZE) { | |
return NULL; | |
} | |
sys_sem_wait(mem_sem); | |
LWIP_ASSERT("mem_realloc: legal memory", (u8_t *)rmem >= (u8_t *)ram && | |
(u8_t *)rmem < (u8_t *)ram_end); | |
if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) { | |
LWIP_DEBUGF(MEM_DEBUG | 3, ("mem_realloc: illegal memory\n")); | |
return rmem; | |
} | |
mem = (struct mem *)((u8_t *)rmem - SIZEOF_STRUCT_MEM); | |
ptr = (u8_t *)mem - ram; | |
size = mem->next - ptr - SIZEOF_STRUCT_MEM; | |
#if MEM_STATS | |
lwip_stats.mem.used -= (size - newsize); | |
#endif /* MEM_STATS */ | |
if (newsize + SIZEOF_STRUCT_MEM + MIN_SIZE < size) { | |
ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize; | |
mem2 = (struct mem *)&ram[ptr2]; | |
mem2->used = 0; | |
mem2->next = mem->next; | |
mem2->prev = ptr; | |
mem->next = ptr2; | |
if (mem2->next != MEM_SIZE) { | |
((struct mem *)&ram[mem2->next])->prev = ptr2; | |
} | |
plug_holes(mem2); | |
} | |
sys_sem_signal(mem_sem); | |
return rmem; | |
} | |
#if 1 | |
/** | |
* Adam's mem_malloc(), suffers from bug #17922 | |
* Set if to 0 for alternative mem_malloc(). | |
*/ | |
void * | |
mem_malloc(mem_size_t size) | |
{ | |
mem_size_t ptr, ptr2; | |
struct mem *mem, *mem2; | |
if (size == 0) { | |
return NULL; | |
} | |
/* Expand the size of the allocated memory region so that we can | |
adjust for alignment. */ | |
if ((size % MEM_ALIGNMENT) != 0) { | |
size += MEM_ALIGNMENT - ((size + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT); | |
} | |
if (size > MEM_SIZE) { | |
return NULL; | |
} | |
sys_sem_wait(mem_sem); | |
for (ptr = (u8_t *)lfree - ram; ptr < MEM_SIZE; ptr = ((struct mem *)&ram[ptr])->next) { | |
mem = (struct mem *)&ram[ptr]; | |
if (!mem->used && | |
mem->next - (ptr + SIZEOF_STRUCT_MEM) >= size + SIZEOF_STRUCT_MEM) { | |
ptr2 = ptr + SIZEOF_STRUCT_MEM + size; | |
mem2 = (struct mem *)&ram[ptr2]; | |
mem2->prev = ptr; | |
mem2->next = mem->next; | |
mem->next = ptr2; | |
if (mem2->next != MEM_SIZE) { | |
((struct mem *)&ram[mem2->next])->prev = ptr2; | |
} | |
mem2->used = 0; | |
mem->used = 1; | |
#if MEM_STATS | |
lwip_stats.mem.used += (size + SIZEOF_STRUCT_MEM); | |
/* if (lwip_stats.mem.max < lwip_stats.mem.used) { | |
lwip_stats.mem.max = lwip_stats.mem.used; | |
} */ | |
if (lwip_stats.mem.max < ptr2) { | |
lwip_stats.mem.max = ptr2; | |
} | |
#endif /* MEM_STATS */ | |
if (mem == lfree) { | |
/* Find next free block after mem */ | |
while (lfree->used && lfree != ram_end) { | |
lfree = (struct mem *)&ram[lfree->next]; | |
} | |
LWIP_ASSERT("mem_malloc: !lfree->used", !lfree->used); | |
} | |
sys_sem_signal(mem_sem); | |
LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.", | |
(mem_ptr_t)mem + SIZEOF_STRUCT_MEM + size <= (mem_ptr_t)ram_end); | |
LWIP_ASSERT("mem_malloc: allocated memory properly aligned.", | |
(unsigned long)((u8_t *)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0); | |
return (u8_t *)mem + SIZEOF_STRUCT_MEM; | |
} | |
} | |
LWIP_DEBUGF(MEM_DEBUG | 2, ("mem_malloc: could not allocate %"S16_F" bytes\n", (s16_t)size)); | |
#if MEM_STATS | |
++lwip_stats.mem.err; | |
#endif /* MEM_STATS */ | |
sys_sem_signal(mem_sem); | |
return NULL; | |
} | |
#else | |
/** | |
* Adam's mem_malloc() plus solution for bug #17922 | |
*/ | |
void * | |
mem_malloc(mem_size_t size) | |
{ | |
mem_size_t ptr, ptr2; | |
struct mem *mem, *mem2; | |
if (size == 0) { | |
return NULL; | |
} | |
/* Expand the size of the allocated memory region so that we can | |
adjust for alignment. */ | |
if ((size % MEM_ALIGNMENT) != 0) { | |
size += MEM_ALIGNMENT - ((size + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT); | |
} | |
if (size > MEM_SIZE) { | |
return NULL; | |
} | |
sys_sem_wait(mem_sem); | |
for (ptr = (u8_t *)lfree - ram; ptr < MEM_SIZE - size; ptr = ((struct mem *)&ram[ptr])->next) { | |
mem = (struct mem *)&ram[ptr]; | |
if (!mem->used) { | |
ptr2 = ptr + SIZEOF_STRUCT_MEM + size; | |
if (mem->next - (ptr + (2*SIZEOF_STRUCT_MEM)) >= size) { | |
/* split large block, create empty remainder */ | |
mem->next = ptr2; | |
mem->used = 1; | |
/* create mem2 struct */ | |
mem2 = (struct mem *)&ram[ptr2]; | |
mem2->used = 0; | |
mem2->next = mem->next; | |
mem2->prev = ptr; | |
if (mem2->next != MEM_SIZE) { | |
((struct mem *)&ram[mem2->next])->prev = ptr2; | |
} | |
} | |
else if (mem->next - (ptr + SIZEOF_STRUCT_MEM) > size) { | |
/* near fit, no split, no mem2 creation, | |
round up to mem->next */ | |
ptr2 = mem->next; | |
mem->used = 1; | |
} | |
else if (mem->next - (ptr + SIZEOF_STRUCT_MEM) == size) { | |
/* exact fit, do not split, no mem2 creation */ | |
mem->next = ptr2; | |
mem->used = 1; | |
} | |
if (mem->used) { | |
#if MEM_STATS | |
lwip_stats.mem.used += (size + SIZEOF_STRUCT_MEM); | |
if (lwip_stats.mem.max < ptr2) { | |
lwip_stats.mem.max = ptr2; | |
} | |
#endif /* MEM_STATS */ | |
if (mem == lfree) { | |
/* Find next free block after mem */ | |
while (lfree->used && lfree != ram_end) { | |
lfree = (struct mem *)&ram[lfree->next]; | |
} | |
LWIP_ASSERT("mem_malloc: !lfree->used", !lfree->used); | |
} | |
sys_sem_signal(mem_sem); | |
LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.", | |
(mem_ptr_t)mem + SIZEOF_STRUCT_MEM + size <= (mem_ptr_t)ram_end); | |
LWIP_ASSERT("mem_malloc: allocated memory properly aligned.", | |
(unsigned long)((u8_t *)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0); | |
return (u8_t *)mem + SIZEOF_STRUCT_MEM; | |
} | |
} | |
} | |
LWIP_DEBUGF(MEM_DEBUG | 2, ("mem_malloc: could not allocate %"S16_F" bytes\n", (s16_t)size)); | |
#if MEM_STATS | |
++lwip_stats.mem.err; | |
#endif /* MEM_STATS */ | |
sys_sem_signal(mem_sem); | |
return NULL; | |
} | |
#endif | |
#endif /* MEM_LIBC_MALLOC == 0 */ | |