esp-idf/components/heap/heap_tlsf.h

/*
** Two Level Segregated Fit memory allocator, version 3.1.
** Written by Matthew Conte
**	http://tlsf.baisoku.org
**
** Based on the original documentation by Miguel Masmano:
**	http://www.gii.upv.es/tlsf/main/docs
**
** This implementation was written to the specification
** of the document, therefore no GPL restrictions apply.
**
** Copyright (c) 2006-2016, Matthew Conte
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are met:
**     * Redistributions of source code must retain the above copyright
**       notice, this list of conditions and the following disclaimer.
**     * 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.
**     * Neither the name of the copyright holder nor the
**       names of its contributors may be used to endorse or promote products
**       derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 MATTHEW CONTE 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.
*/

#pragma once
#include <assert.h>
#include <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stddef.h>
#include "heap_tlsf_config.h"

#if defined(__cplusplus)
extern "C" {
#endif

/*
** Cast and min/max macros.
*/
#define tlsf_cast(t, exp)	((t) (exp))
#define tlsf_min(a, b)		((a) < (b) ? (a) : (b))
#define tlsf_max(a, b)		((a) > (b) ? (a) : (b))

/* A type used for casting when doing pointer arithmetic. */
typedef ptrdiff_t tlsfptr_t;

typedef struct block_header_t
{
	/* Points to the previous physical block. */
	struct block_header_t* prev_phys_block;

	/* The size of this block, excluding the block header. */
	size_t size;

	/* Next and previous free blocks. */
	struct block_header_t* next_free;
	struct block_header_t* prev_free;
} block_header_t;

/* The TLSF control structure. */
typedef struct control_t
{
	/* Empty lists point at this block to indicate they are free. */
	block_header_t block_null;

 	/* Local parameter for the pool. Given the maximum
	 * value of each field, all the following parameters
	 * can fit on 4 bytes when using bitfields
	 */
	unsigned int fl_index_count : 5; // 5 cumulated bits
	unsigned int fl_index_shift : 3; // 8 cumulated bits
	unsigned int fl_index_max : 6; // 14 cumulated bits
	unsigned int sl_index_count : 6; // 20 cumulated bits

	/* log2 of number of linear subdivisions of block sizes. Larger
	** values require more memory in the control structure. Values of
	** 4 or 5 are typical.
	*/
	unsigned int sl_index_count_log2 : 3; // 23 cumulated bits
	unsigned int small_block_size : 8; // 31 cumulated bits

	/* size of the metadata ( size of control block,
	 * sl_bitmap and blocks )
	 */
	size_t size;

	/* Bitmaps for free lists. */
	unsigned int fl_bitmap;
	unsigned int *sl_bitmap;

	/* Head of free lists. */
	block_header_t** blocks;
} control_t;

#include "heap_tlsf_block_functions.h"

/* tlsf_t: a TLSF structure. Can contain 1 to N pools. */
/* pool_t: a block of memory that TLSF can manage. */
typedef void* tlsf_t;
typedef void* pool_t;

/* Create/destroy a memory pool. */
tlsf_t tlsf_create(void* mem, size_t max_bytes);
tlsf_t tlsf_create_with_pool(void* mem, size_t pool_bytes, size_t max_bytes);
pool_t tlsf_get_pool(tlsf_t tlsf);

/* Add/remove memory pools. */
pool_t tlsf_add_pool(tlsf_t tlsf, void* mem, size_t bytes);
void tlsf_remove_pool(tlsf_t tlsf, pool_t pool);

/* malloc/memalign/realloc/free replacements. */
void* tlsf_malloc(tlsf_t tlsf, size_t size);
void* tlsf_memalign(tlsf_t tlsf, size_t align, size_t size);
void* tlsf_memalign_offs(tlsf_t tlsf, size_t align, size_t size, size_t offset);
void* tlsf_realloc(tlsf_t tlsf, void* ptr, size_t size);
void tlsf_free(tlsf_t tlsf, void* ptr);

/* Returns internal block size, not original request size */
size_t tlsf_block_size(void* ptr);

/* Overheads/limits of internal structures. */
size_t tlsf_size(tlsf_t tlsf);
size_t tlsf_align_size(void);
size_t tlsf_block_size_min(void);
size_t tlsf_block_size_max(tlsf_t tlsf);
size_t tlsf_pool_overhead(void);
size_t tlsf_alloc_overhead(void);

/**
 * @brief Return the allocable size based on the size passed
 * as parameter
 *
 * @param tlsf Pointer to the tlsf structure
 * @param size The allocation size
 * @return size_t The updated allocation size
 */
size_t tlsf_fit_size(tlsf_t tlsf, size_t size);

/* Debugging. */
typedef void (*tlsf_walker)(void* ptr, size_t size, int used, void* user);
void tlsf_walk_pool(pool_t pool, tlsf_walker walker, void* user);
/* Returns nonzero if any internal consistency check fails. */
int tlsf_check(tlsf_t tlsf);
int tlsf_check_pool(pool_t pool);

#if defined(__cplusplus)
};
#endif