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rt-thread/src/mem.c

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/*
* File : mem.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2008 - 2012, RT-Thread Development Team
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Change Logs:
* Date Author Notes
* 2008-7-12 Bernard the first version
* 2010-06-09 Bernard fix the end stub of heap
* fix memory check in rt_realloc function
* 2010-07-13 Bernard fix RT_ALIGN issue found by kuronca
* 2010-10-14 Bernard fix rt_realloc issue when realloc a NULL pointer.
*/
/*
* 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>
* Simon Goldschmidt
*
*/
#include <rthw.h>
#include <rtthread.h>
#ifndef RT_USING_MEMHEAP_AS_HEAP
/* #define RT_MEM_DEBUG */
#define RT_MEM_STATS
#if defined (RT_USING_HEAP) && defined (RT_USING_SMALL_MEM)
#ifdef RT_USING_HOOK
static void (*rt_malloc_hook)(void *ptr, rt_size_t size);
static void (*rt_free_hook)(void *ptr);
/**
* @addtogroup Hook
*/
/*@{*/
/**
* This function will set a hook function, which will be invoked when a memory
* block is allocated from heap memory.
*
* @param hook the hook function
*/
void rt_malloc_sethook(void (*hook)(void *ptr, rt_size_t size))
{
rt_malloc_hook = hook;
}
/**
* This function will set a hook function, which will be invoked when a memory
* block is released to heap memory.
*
* @param hook the hook function
*/
void rt_free_sethook(void (*hook)(void *ptr))
{
rt_free_hook = hook;
}
/*@}*/
#endif
#define HEAP_MAGIC 0x1ea0
struct heap_mem
{
/* magic and used flag */
rt_uint16_t magic;
rt_uint16_t used;
rt_size_t next, prev;
};
/** pointer to the heap: for alignment, heap_ptr is now a pointer instead of an array */
static rt_uint8_t *heap_ptr;
/** the last entry, always unused! */
static struct heap_mem *heap_end;
#define MIN_SIZE 12
#define MIN_SIZE_ALIGNED RT_ALIGN(MIN_SIZE, RT_ALIGN_SIZE)
#define SIZEOF_STRUCT_MEM RT_ALIGN(sizeof(struct heap_mem), RT_ALIGN_SIZE)
static struct heap_mem *lfree; /* pointer to the lowest free block */
static struct rt_semaphore heap_sem;
static rt_size_t mem_size_aligned;
#ifdef RT_MEM_STATS
static rt_size_t used_mem, max_mem;
#endif
static void plug_holes(struct heap_mem *mem)
{
struct heap_mem *nmem;
struct heap_mem *pmem;
RT_ASSERT((rt_uint8_t *)mem >= heap_ptr);
RT_ASSERT((rt_uint8_t *)mem < (rt_uint8_t *)heap_end);
RT_ASSERT(mem->used == 0);
/* plug hole forward */
nmem = (struct heap_mem *)&heap_ptr[mem->next];
if (mem != nmem &&
nmem->used == 0 &&
(rt_uint8_t *)nmem != (rt_uint8_t *)heap_end)
{
/* if mem->next is unused and not end of heap_ptr,
* combine mem and mem->next
*/
if (lfree == nmem)
{
lfree = mem;
}
mem->next = nmem->next;
((struct heap_mem *)&heap_ptr[nmem->next])->prev = (rt_uint8_t *)mem - heap_ptr;
}
/* plug hole backward */
pmem = (struct heap_mem *)&heap_ptr[mem->prev];
if (pmem != mem && pmem->used == 0)
{
/* if mem->prev is unused, combine mem and mem->prev */
if (lfree == mem)
{
lfree = pmem;
}
pmem->next = mem->next;
((struct heap_mem *)&heap_ptr[mem->next])->prev = (rt_uint8_t *)pmem - heap_ptr;
}
}
/**
* @ingroup SystemInit
*
* This function will init system heap
*
* @param begin_addr the beginning address of system page
* @param end_addr the end address of system page
*/
void rt_system_heap_init(void *begin_addr, void *end_addr)
{
struct heap_mem *mem;
rt_uint32_t begin_align = RT_ALIGN((rt_uint32_t)begin_addr, RT_ALIGN_SIZE);
rt_uint32_t end_align = RT_ALIGN_DOWN((rt_uint32_t)end_addr, RT_ALIGN_SIZE);
RT_DEBUG_NOT_IN_INTERRUPT;
/* alignment addr */
if ((end_align > (2 * SIZEOF_STRUCT_MEM)) &&
((end_align - 2 * SIZEOF_STRUCT_MEM) >= begin_align))
{
/* calculate the aligned memory size */
mem_size_aligned = end_align - begin_align - 2 * SIZEOF_STRUCT_MEM;
}
else
{
rt_kprintf("mem init, error begin address 0x%x, and end address 0x%x\n",
(rt_uint32_t)begin_addr, (rt_uint32_t)end_addr);
return;
}
/* point to begin address of heap */
heap_ptr = (rt_uint8_t *)begin_align;
RT_DEBUG_LOG(RT_DEBUG_MEM, ("mem init, heap begin address 0x%x, size %d\n",
(rt_uint32_t)heap_ptr, mem_size_aligned));
/* initialize the start of the heap */
mem = (struct heap_mem *)heap_ptr;
mem->magic = HEAP_MAGIC;
mem->next = mem_size_aligned + SIZEOF_STRUCT_MEM;
mem->prev = 0;
mem->used = 0;
/* initialize the end of the heap */
heap_end = (struct heap_mem *)&heap_ptr[mem->next];
heap_end->magic = HEAP_MAGIC;
heap_end->used = 1;
heap_end->next = mem_size_aligned + SIZEOF_STRUCT_MEM;
heap_end->prev = mem_size_aligned + SIZEOF_STRUCT_MEM;
rt_sem_init(&heap_sem, "heap", 1, RT_IPC_FLAG_FIFO);
/* initialize the lowest-free pointer to the start of the heap */
lfree = (struct heap_mem *)heap_ptr;
}
/**
* @addtogroup MM
*/
/*@{*/
/**
* Allocate a block of memory with a minimum of 'size' bytes.
*
* @param size is the minimum size of the requested block in bytes.
*
* @return pointer to allocated memory or NULL if no free memory was found.
*/
void *rt_malloc(rt_size_t size)
{
rt_size_t ptr, ptr2;
struct heap_mem *mem, *mem2;
RT_DEBUG_NOT_IN_INTERRUPT;
if (size == 0)
return RT_NULL;
if (size != RT_ALIGN(size, RT_ALIGN_SIZE))
RT_DEBUG_LOG(RT_DEBUG_MEM, ("malloc size %d, but align to %d\n",
size, RT_ALIGN(size, RT_ALIGN_SIZE)));
else
RT_DEBUG_LOG(RT_DEBUG_MEM, ("malloc size %d\n", size));
/* alignment size */
size = RT_ALIGN(size, RT_ALIGN_SIZE);
if (size > mem_size_aligned)
{
RT_DEBUG_LOG(RT_DEBUG_MEM, ("no memory\n"));
return RT_NULL;
}
/* every data block must be at least MIN_SIZE_ALIGNED long */
if (size < MIN_SIZE_ALIGNED)
size = MIN_SIZE_ALIGNED;
/* take memory semaphore */
rt_sem_take(&heap_sem, RT_WAITING_FOREVER);
for (ptr = (rt_uint8_t *)lfree - heap_ptr;
ptr < mem_size_aligned - size;
ptr = ((struct heap_mem *)&heap_ptr[ptr])->next)
{
mem = (struct heap_mem *)&heap_ptr[ptr];
if ((!mem->used) && (mem->next - (ptr + SIZEOF_STRUCT_MEM)) >= size)
{
/* mem is not used and at least perfect fit is possible:
* mem->next - (ptr + SIZEOF_STRUCT_MEM) gives us the 'user data size' of mem */
if (mem->next - (ptr + SIZEOF_STRUCT_MEM) >=
(size + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED))
{
/* (in addition to the above, we test if another struct heap_mem (SIZEOF_STRUCT_MEM) containing
* at least MIN_SIZE_ALIGNED of data also fits in the 'user data space' of 'mem')
* -> split large block, create empty remainder,
* remainder must be large enough to contain MIN_SIZE_ALIGNED data: if
* mem->next - (ptr + (2*SIZEOF_STRUCT_MEM)) == size,
* struct heap_mem would fit in but no data between mem2 and mem2->next
* @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
* region that couldn't hold data, but when mem->next gets freed,
* the 2 regions would be combined, resulting in more free memory
*/
ptr2 = ptr + SIZEOF_STRUCT_MEM + size;
/* create mem2 struct */
mem2 = (struct heap_mem *)&heap_ptr[ptr2];
mem2->used = 0;
mem2->next = mem->next;
mem2->prev = ptr;
/* and insert it between mem and mem->next */
mem->next = ptr2;
mem->used = 1;
if (mem2->next != mem_size_aligned + SIZEOF_STRUCT_MEM)
{
((struct heap_mem *)&heap_ptr[mem2->next])->prev = ptr2;
}
#ifdef RT_MEM_STATS
used_mem += (size + SIZEOF_STRUCT_MEM);
if (max_mem < used_mem)
max_mem = used_mem;
#endif
}
else
{
/* (a mem2 struct does no fit into the user data space of mem and mem->next will always
* be used at this point: if not we have 2 unused structs in a row, plug_holes should have
* take care of this).
* -> near fit or excact fit: do not split, no mem2 creation
* also can't move mem->next directly behind mem, since mem->next
* will always be used at this point!
*/
mem->used = 1;
#ifdef RT_MEM_STATS
used_mem += mem->next - ((rt_uint8_t*)mem - heap_ptr);
if (max_mem < used_mem)
max_mem = used_mem;
#endif
}
/* set memory block magic */
mem->magic = HEAP_MAGIC;
if (mem == lfree)
{
/* Find next free block after mem and update lowest free pointer */
while (lfree->used && lfree != heap_end)
lfree = (struct heap_mem *)&heap_ptr[lfree->next];
RT_ASSERT(((lfree == heap_end) || (!lfree->used)));
}
rt_sem_release(&heap_sem);
RT_ASSERT((rt_uint32_t)mem + SIZEOF_STRUCT_MEM + size <= (rt_uint32_t)heap_end);
RT_ASSERT((rt_uint32_t)((rt_uint8_t *)mem + SIZEOF_STRUCT_MEM) % RT_ALIGN_SIZE == 0);
RT_ASSERT((((rt_uint32_t)mem) & (RT_ALIGN_SIZE-1)) == 0);
RT_DEBUG_LOG(RT_DEBUG_MEM,
("allocate memory at 0x%x, size: %d\n",
(rt_uint32_t)((rt_uint8_t *)mem + SIZEOF_STRUCT_MEM),
(rt_uint32_t)(mem->next - ((rt_uint8_t *)mem - heap_ptr))));
RT_OBJECT_HOOK_CALL(rt_malloc_hook,
(((void *)((rt_uint8_t *)mem + SIZEOF_STRUCT_MEM)), size));
/* return the memory data except mem struct */
return (rt_uint8_t *)mem + SIZEOF_STRUCT_MEM;
}
}
rt_sem_release(&heap_sem);
return RT_NULL;
}
RTM_EXPORT(rt_malloc);
/**
* This function will change the previously allocated memory block.
*
* @param rmem pointer to memory allocated by rt_malloc
* @param newsize the required new size
*
* @return the changed memory block address
*/
void *rt_realloc(void *rmem, rt_size_t newsize)
{
rt_size_t size;
rt_size_t ptr, ptr2;
struct heap_mem *mem, *mem2;
void *nmem;
RT_DEBUG_NOT_IN_INTERRUPT;
/* alignment size */
newsize = RT_ALIGN(newsize, RT_ALIGN_SIZE);
if (newsize > mem_size_aligned)
{
RT_DEBUG_LOG(RT_DEBUG_MEM, ("realloc: out of memory\n"));
return RT_NULL;
}
/* allocate a new memory block */
if (rmem == RT_NULL)
return rt_malloc(newsize);
rt_sem_take(&heap_sem, RT_WAITING_FOREVER);
if ((rt_uint8_t *)rmem < (rt_uint8_t *)heap_ptr ||
(rt_uint8_t *)rmem >= (rt_uint8_t *)heap_end)
{
/* illegal memory */
rt_sem_release(&heap_sem);
return rmem;
}
mem = (struct heap_mem *)((rt_uint8_t *)rmem - SIZEOF_STRUCT_MEM);
ptr = (rt_uint8_t *)mem - heap_ptr;
size = mem->next - ptr - SIZEOF_STRUCT_MEM;
if (size == newsize)
{
/* the size is the same as */
rt_sem_release(&heap_sem);
return rmem;
}
if (newsize + SIZEOF_STRUCT_MEM + MIN_SIZE < size)
{
/* split memory block */
#ifdef RT_MEM_STATS
used_mem -= (size - newsize);
#endif
ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
mem2 = (struct heap_mem *)&heap_ptr[ptr2];
mem2->magic= HEAP_MAGIC;
mem2->used = 0;
mem2->next = mem->next;
mem2->prev = ptr;
mem->next = ptr2;
if (mem2->next != mem_size_aligned + SIZEOF_STRUCT_MEM)
{
((struct heap_mem *)&heap_ptr[mem2->next])->prev = ptr2;
}
plug_holes(mem2);
rt_sem_release(&heap_sem);
return rmem;
}
rt_sem_release(&heap_sem);
/* expand memory */
nmem = rt_malloc(newsize);
if (nmem != RT_NULL) /* check memory */
{
rt_memcpy(nmem, rmem, size < newsize ? size : newsize);
rt_free(rmem);
}
return nmem;
}
RTM_EXPORT(rt_realloc);
/**
* This function will contiguously allocate enough space for count objects
* that are size bytes of memory each and returns a pointer to the allocated
* memory.
*
* The allocated memory is filled with bytes of value zero.
*
* @param count number of objects to allocate
* @param size size of the objects to allocate
*
* @return pointer to allocated memory / NULL pointer if there is an error
*/
void *rt_calloc(rt_size_t count, rt_size_t size)
{
void *p;
RT_DEBUG_NOT_IN_INTERRUPT;
/* allocate 'count' objects of size 'size' */
p = rt_malloc(count * size);
/* zero the memory */
if (p)
rt_memset(p, 0, count * size);
return p;
}
RTM_EXPORT(rt_calloc);
/**
* This function will release the previously allocated memory block by
* rt_malloc. The released memory block is taken back to system heap.
*
* @param rmem the address of memory which will be released
*/
void rt_free(void *rmem)
{
struct heap_mem *mem;
RT_DEBUG_NOT_IN_INTERRUPT;
if (rmem == RT_NULL)
return;
RT_ASSERT((((rt_uint32_t)rmem) & (RT_ALIGN_SIZE-1)) == 0);
RT_ASSERT((rt_uint8_t *)rmem >= (rt_uint8_t *)heap_ptr &&
(rt_uint8_t *)rmem < (rt_uint8_t *)heap_end);
RT_OBJECT_HOOK_CALL(rt_free_hook, (rmem));
if ((rt_uint8_t *)rmem < (rt_uint8_t *)heap_ptr ||
(rt_uint8_t *)rmem >= (rt_uint8_t *)heap_end)
{
RT_DEBUG_LOG(RT_DEBUG_MEM, ("illegal memory\n"));
return;
}
/* Get the corresponding struct heap_mem ... */
mem = (struct heap_mem *)((rt_uint8_t *)rmem - SIZEOF_STRUCT_MEM);
RT_DEBUG_LOG(RT_DEBUG_MEM,
("release memory 0x%x, size: %d\n",
(rt_uint32_t)rmem,
(rt_uint32_t)(mem->next - ((rt_uint8_t *)mem - heap_ptr))));
/* protect the heap from concurrent access */
rt_sem_take(&heap_sem, RT_WAITING_FOREVER);
/* ... which has to be in a used state ... */
RT_ASSERT(mem->used);
RT_ASSERT(mem->magic == HEAP_MAGIC);
/* ... and is now unused. */
mem->used = 0;
mem->magic = 0;
if (mem < lfree)
{
/* the newly freed struct is now the lowest */
lfree = mem;
}
#ifdef RT_MEM_STATS
used_mem -= (mem->next - ((rt_uint8_t*)mem - heap_ptr));
#endif
/* finally, see if prev or next are free also */
plug_holes(mem);
rt_sem_release(&heap_sem);
}
RTM_EXPORT(rt_free);
#ifdef RT_MEM_STATS
void rt_memory_info(rt_uint32_t *total,
rt_uint32_t *used,
rt_uint32_t *max_used)
{
if (total != RT_NULL)
*total = mem_size_aligned;
if (used != RT_NULL)
*used = used_mem;
if (max_used != RT_NULL)
*max_used = max_mem;
}
#ifdef RT_USING_FINSH
#include <finsh.h>
void list_mem(void)
{
rt_kprintf("total memory: %d\n", mem_size_aligned);
rt_kprintf("used memory : %d\n", used_mem);
rt_kprintf("maximum allocated memory: %d\n", max_mem);
}
FINSH_FUNCTION_EXPORT(list_mem, list memory usage information)
#endif
#endif
/*@}*/
#endif /* end of RT_USING_HEAP */
#endif /* end of RT_USING_MEMHEAP_AS_HEAP */
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