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