124 lines
4.6 KiB
C
124 lines
4.6 KiB
C
|
/**
|
||
|
|
* \file
|
||
|
|
*
|
||
|
|
* \brief Memory Bag allocator for 8-bit AVR, 32-bit AVR, SAM
|
||
|
|
*
|
||
|
|
* Copyright (c) 2014-2015 Atmel Corporation. All rights reserved.
|
||
|
|
*
|
||
|
|
* \asf_license_start
|
||
|
|
*
|
||
|
|
* \page License
|
||
|
|
*
|
||
|
|
* 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 Atmel may not be used to endorse or promote products derived
|
||
|
|
* from this software without specific prior written permission.
|
||
|
|
*
|
||
|
|
* 4. This software may only be redistributed and used in connection with an
|
||
|
|
* Atmel microcontroller product.
|
||
|
|
*
|
||
|
|
* THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
|
||
|
|
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
||
|
|
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
|
||
|
|
* EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL 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.
|
||
|
|
*
|
||
|
|
* \asf_license_stop
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
/*
|
||
|
|
* Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef UTILS_MEMBAG_H
|
||
|
|
#define UTILS_MEMBAG_H
|
||
|
|
|
||
|
|
#include <stddef.h>
|
||
|
|
|
||
|
|
/**
|
||
|
|
* \defgroup membag_group Memory Bag Allocator
|
||
|
|
*
|
||
|
|
* The Membag allocator is a optimized, fragmentationless general purpose
|
||
|
|
* memory allocator utility module designed to replace the standard C library
|
||
|
|
* \c malloc() and \c free() functions in resource constrained environments.
|
||
|
|
*
|
||
|
|
*
|
||
|
|
* Internally, the Membag allocator uses several user defined "bags" of one or
|
||
|
|
* more fixed-size blocks to form a memory pool for use in a user application.
|
||
|
|
* When an allocation is requested, the Membag module will search all available
|
||
|
|
* bags and find the smallest unallocated block of sufficient size, and return
|
||
|
|
* this block to the calling function. The size of each bag and number of blocks
|
||
|
|
* in each bag is user configurable, via the \ref conf_membag.h header file
|
||
|
|
* added to the user project.
|
||
|
|
*
|
||
|
|
* The allocator also has basic statistics functionality to obtain the size of
|
||
|
|
* the entire memory pool, amount of free memory, and the size of the smallest
|
||
|
|
* and largest free memory block.
|
||
|
|
*
|
||
|
|
* The memory bag allocator always allocates memory as a block from a fixed size
|
||
|
|
* bag/pool. This helps reduce memory fragmentation compared to an generic
|
||
|
|
* allocator that gives exactly the bytes requested. While this gives a
|
||
|
|
* trade-off of the maximum number of concurrent allocations and the size of
|
||
|
|
* allocations that are allowable, the allocator prevents memory fragmentation
|
||
|
|
* from occuring in an embedded application.
|
||
|
|
*
|
||
|
|
* The allocation and deallocation of memory with the Membag module is
|
||
|
|
* non-deterministic, however the module functions all have a maximum run time
|
||
|
|
* that is dependent on the number of bags that have been configured.
|
||
|
|
*
|
||
|
|
* @{
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Macro used to create memory bags in conf_membag.h
|
||
|
|
*
|
||
|
|
* \note Multiple bags of the same size are allowed, if more than 32 bags of a
|
||
|
|
* given size are required in an application.
|
||
|
|
*
|
||
|
|
* \param objsize Size of each block in the bag
|
||
|
|
* \param nr_objs Number of blocks in the bag, a value less than 32
|
||
|
|
*/
|
||
|
|
#define MEMBAG(objsize, nr_objs)\
|
||
|
|
{ .block_size = objsize, .num_blocks = nr_objs }
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Macro used to store the size of the membags in conf_membag.h
|
||
|
|
*
|
||
|
|
* \note Multiple bags of the same size are allowed, if more than 32 bags of a
|
||
|
|
* given size are required in an application.
|
||
|
|
*
|
||
|
|
* \param objsize Size of each block in the bag
|
||
|
|
* \param nr_objs Number of blocks in the bag, a value less than 32
|
||
|
|
*/
|
||
|
|
#define MEMBAG_SIZE(objsize, nr_objs)\
|
||
|
|
(objsize * nr_objs)
|
||
|
|
|
||
|
|
void membag_init(void);
|
||
|
|
|
||
|
|
size_t membag_get_total(void);
|
||
|
|
size_t membag_get_total_free(void);
|
||
|
|
|
||
|
|
size_t membag_get_smallest_free_block_size(void);
|
||
|
|
size_t membag_get_largest_free_block_size(void);
|
||
|
|
|
||
|
|
void *membag_alloc(const size_t size);
|
||
|
|
void membag_free(const void *ptr);
|
||
|
|
|
||
|
|
/** @} */
|
||
|
|
|
||
|
|
#endif /* UTILS_MEMBAG_H */
|