mruby/c memory management. More...

#include "alloc.h"
#include "hal.h"

Include dependency graph for alloc.c:

Data Structures
struct	MEMORY_POOL

Macros
#define	MRBC_ALLOC_FLI_BIT_WIDTH 9
#define	MRBC_ALLOC_SLI_BIT_WIDTH 3
#define	MRBC_ALLOC_IGNORE_LSBS 4
#define	SIZE_FREE_BLOCKS ((MRBC_ALLOC_FLI_BIT_WIDTH + 1) * (1 << MRBC_ALLOC_SLI_BIT_WIDTH))
#define	MRBC_MIN_MEMORY_BLOCK_SIZE sizeof(FREE_BLOCK)
#define	FLI(x)
#define	SLI(x)
#define	RETURN_IF_NULL(ptr)
#define	BLOCK_SIZE(p)
#define	PHYS_NEXT(p)
#define	SET_USED_BLOCK(p)
#define	SET_FREE_BLOCK(p)
#define	IS_USED_BLOCK(p)
#define	IS_FREE_BLOCK(p)
#define	SET_PREV_USED(p)
#define	SET_PREV_FREE(p)
#define	IS_PREV_USED(p)
#define	IS_PREV_FREE(p)
#define	SET_VM_ID(p, id)
#define	GET_VM_ID(p)
#define	BPOOL_TOP(memory_pool)
#define	BPOOL_END(memory_pool)
#define	BLOCK_ADRS(p)
#define	MSB_BIT1_FLI 0x8000
#define	MSB_BIT1_SLI 0x80
#define	NLZ_FLI(x)
#define	NLZ_SLI(x)
#define	alloc_profile()

Typedefs
typedef struct MEMORY_POOL	MEMORY_POOL

Functions
static int	nlz16 (uint16_t x)
static int	nlz8 (uint8_t x)
static unsigned int	calc_index (MRBC_ALLOC_MEMSIZE_T alloc_size)
static void	add_free_block (MEMORY_POOL pool, FREE_BLOCK target)
static void	remove_free_block (MEMORY_POOL pool, FREE_BLOCK target)
static FREE_BLOCK *	split_block (FREE_BLOCK *target, MRBC_ALLOC_MEMSIZE_T size)
static void	merge_block (FREE_BLOCK target, FREE_BLOCK next)
void	mrbc_init_alloc (void *ptr, unsigned int size)
void	mrbc_cleanup_alloc (void)
void *	mrbc_raw_alloc (unsigned int size)
void *	mrbc_raw_alloc_no_free (unsigned int size)
void *	mrbc_raw_calloc (unsigned int nmemb, unsigned int size)
void	mrbc_raw_free (void *ptr)
void *	mrbc_raw_realloc (void *ptr, unsigned int size)
unsigned int	mrbc_alloc_usable_size (void *ptr)
void	mrbc_alloc_statistics (struct MRBC_ALLOC_STATISTICS *ret)

Variables
static MEMORY_POOL *	memory_pool

Detailed Description

mruby/c memory management.

 Copyright (C) 2015-      Kyushu Institute of Technology.
 Copyright (C) 2015-2026  Shimane IT Open-Innovation Center.
 Copyright (C) 2026-      Shimane Institute for Industrial Technology.

 This file is distributed under BSD 3-Clause License.

 Memory management for objects in mruby/c.

 STRATEGY
  Uses the TLSF and first-fit algorithms.

 MEMORY POOL USAGE (see struct MEMORY_POOL)
    | Memory pool header | Memory block pool to provide to application |
    +--------------------+---------------------------------------------+
    | size, bitmap, ...  | USED_BLOCK, FREE_BLOCK, ..., (SentinelBlock)|

 MEMORY BLOCK LINK
     with USED flag and PREV_IN_USE flag in size member's bit 0 and 1.

    |  USED_BLOCK     |  FREE_BLOCK                   |  USED_BLOCK     |...
    +-----------------+-------------------------------+-----------------+---
    |size| (contents) |size|*next|*prev| (empty) |*top|size| (contents) |
USED|   1|            |   0|     |     |         |    |   1|            |
PREV|  1 |            |  1 |     |     |         |    |  0 |            |

                                          Sentinel block at the link tail.
                                     ...              |  USED_BLOCK     |
                                    ------------------+-----------------+
                                                      |size| (contents) |
                                                  USED|   1|            |
                                                  PREV|  ? |            |
   size : block size.
   *next: linked list, pointer to the next free block of same block size.
   *prev: linked list, pointer to the previous free block of same block size.
   *top : pointer to this block's top.

Definition in file alloc.c.

Macro Definition Documentation

◆ alloc_profile

#define alloc_profile ( )

Value:

((void)0)

Definition at line 403 of file alloc.c.

◆ BLOCK_ADRS

#define BLOCK_ADRS ( p )

Value:

((void *)((uint8_t *)(p) - sizeof(USED_BLOCK)))

Definition at line 231 of file alloc.c.

◆ BLOCK_SIZE

#define BLOCK_SIZE ( p )

Value:

(((p)->size) & ~0x03)

Definition at line 192 of file alloc.c.

◆ BPOOL_END

#define BPOOL_END ( memory_pool )

Value:

((void *)((uint8_t *)(memory_pool) + ((MEMORY_POOL *)(memory_pool))->size))

memory_pool

static MEMORY_POOL * memory_pool

Definition alloc.c:242

MEMORY_POOL

Definition alloc.c:216

Definition at line 230 of file alloc.c.

◆ BPOOL_TOP

#define BPOOL_TOP ( memory_pool )

Value:

((void *)((uint8_t *)(memory_pool) + sizeof(MEMORY_POOL)))

Definition at line 229 of file alloc.c.

◆ FLI

#define FLI ( x )

Value:

((x) >> MRBC_ALLOC_SLI_BIT_WIDTH)

MRBC_ALLOC_SLI_BIT_WIDTH

#define MRBC_ALLOC_SLI_BIT_WIDTH

Definition alloc.c:84

Definition at line 104 of file alloc.c.

◆ GET_VM_ID

#define GET_VM_ID ( p )

Value:

0

Definition at line 209 of file alloc.c.

◆ IS_FREE_BLOCK

#define IS_FREE_BLOCK ( p )

Value:

(!IS_USED_BLOCK(p))

IS_USED_BLOCK

#define IS_USED_BLOCK(p)

Definition alloc.c:196

Definition at line 197 of file alloc.c.

◆ IS_PREV_FREE

#define IS_PREV_FREE ( p )

Value:

(!IS_PREV_USED(p))

IS_PREV_USED

#define IS_PREV_USED(p)

Definition alloc.c:200

Definition at line 201 of file alloc.c.

◆ IS_PREV_USED

#define IS_PREV_USED ( p )

Value:

((p)->size & 0x02)

Definition at line 200 of file alloc.c.

◆ IS_USED_BLOCK

#define IS_USED_BLOCK ( p )

Value:

((p)->size & 0x01)

Definition at line 196 of file alloc.c.

◆ MRBC_ALLOC_FLI_BIT_WIDTH

#define MRBC_ALLOC_FLI_BIT_WIDTH 9

Definition at line 81 of file alloc.c.

◆ MRBC_ALLOC_IGNORE_LSBS

#define MRBC_ALLOC_IGNORE_LSBS 4

Definition at line 87 of file alloc.c.

◆ MRBC_ALLOC_SLI_BIT_WIDTH

#define MRBC_ALLOC_SLI_BIT_WIDTH 3

Definition at line 84 of file alloc.c.

◆ MRBC_MIN_MEMORY_BLOCK_SIZE

#define MRBC_MIN_MEMORY_BLOCK_SIZE sizeof(FREE_BLOCK)

Definition at line 98 of file alloc.c.

◆ MSB_BIT1_FLI

#define MSB_BIT1_FLI 0x8000

Definition at line 233 of file alloc.c.

◆ MSB_BIT1_SLI

#define MSB_BIT1_SLI 0x80

Definition at line 234 of file alloc.c.

◆ NLZ_FLI

#define NLZ_FLI ( x )

Value:

nlz16(x)

nlz16

static int nlz16(uint16_t x)

Definition alloc.c:258

Definition at line 235 of file alloc.c.

◆ NLZ_SLI

#define NLZ_SLI ( x )

Value:

nlz8(x)

nlz8

static int nlz8(uint8_t x)

Definition alloc.c:276

Definition at line 236 of file alloc.c.

◆ PHYS_NEXT

#define PHYS_NEXT ( p )

Value:

((void *)((uint8_t *)(p) + BLOCK_SIZE(p)))

BLOCK_SIZE

#define BLOCK_SIZE(p)

Definition alloc.c:192

Definition at line 193 of file alloc.c.

◆ RETURN_IF_NULL

#define RETURN_IF_NULL ( ptr )

Value:

(void)0

Definition at line 113 of file alloc.c.

◆ SET_FREE_BLOCK

#define SET_FREE_BLOCK ( p )

Value:

((p)->size &= ~0x01)

Definition at line 195 of file alloc.c.

◆ SET_PREV_FREE

#define SET_PREV_FREE ( p )

Value:

((p)->size &= ~0x02)

Definition at line 199 of file alloc.c.

◆ SET_PREV_USED

#define SET_PREV_USED ( p )

Value:

((p)->size |= 0x02)

Definition at line 198 of file alloc.c.

◆ SET_USED_BLOCK

#define SET_USED_BLOCK ( p )

Value:

((p)->size |= 0x01)

Definition at line 194 of file alloc.c.

◆ SET_VM_ID

#define SET_VM_ID	(		p,
			id )

Value:

((void)0)

Definition at line 208 of file alloc.c.

◆ SIZE_FREE_BLOCKS

#define SIZE_FREE_BLOCKS ((MRBC_ALLOC_FLI_BIT_WIDTH + 1) * (1 << MRBC_ALLOC_SLI_BIT_WIDTH))

Definition at line 90 of file alloc.c.

◆ SLI

#define SLI ( x )

Value:

((x) & ((1 << MRBC_ALLOC_SLI_BIT_WIDTH) - 1))

Definition at line 105 of file alloc.c.

Typedef Documentation

◆ MEMORY_POOL

typedef struct MEMORY_POOL MEMORY_POOL

Function Documentation

◆ add_free_block()

void add_free_block	(	MEMORY_POOL *	pool,
		FREE_BLOCK *	target )

static

Mark that block free and register it in the free index table.

Parameters

pool	Pointer to memory pool.
target	Pointer to target block.

Definition at line 326 of file alloc.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ calc_index()

unsigned int calc_index ( MRBC_ALLOC_MEMSIZE_T alloc_size )

inlinestatic

calc f and s, and returns fli,sli of free_blocks

Parameters

alloc_size alloc size

Return values

unsigned int index of free_blocks

Definition at line 293 of file alloc.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ merge_block()

void merge_block	(	FREE_BLOCK *	target,
		FREE_BLOCK *	next )

inlinestatic

merge target and next block. next will disappear

Parameters

target	pointer to free block 1
next	pointer to free block 2

Definition at line 436 of file alloc.c.

Here is the caller graph for this function:

◆ mrbc_alloc_statistics()

void mrbc_alloc_statistics ( struct MRBC_ALLOC_STATISTICS * ret )

statistics

Parameters

ret	pointer to return value.

Definition at line 984 of file alloc.c.

◆ mrbc_alloc_usable_size()

unsigned int mrbc_alloc_usable_size ( void * ptr )

allocated memory size

Parameters

ptr	Return value of mrbc_alloc()

Return values

unsigned int pointer to allocated memory.

Definition at line 883 of file alloc.c.

◆ mrbc_cleanup_alloc()

void mrbc_cleanup_alloc ( void )

cleanup memory pool

Definition at line 495 of file alloc.c.

Here is the caller graph for this function:

◆ mrbc_init_alloc()

void mrbc_init_alloc	(	void *	ptr,
		unsigned int	size )

initialize

Parameters

ptr	pointer to free memory block.
size	size. (max 64KB. see MRBC_ALLOC_MEMSIZE_T)

Definition at line 452 of file alloc.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ mrbc_raw_alloc()

void * mrbc_raw_alloc ( unsigned int size )

allocate memory

Parameters

size	request size.

Returns: void * pointer to allocated memory.

Return values

NULL error.

Definition at line 514 of file alloc.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ mrbc_raw_alloc_no_free()

void * mrbc_raw_alloc_no_free ( unsigned int size )

allocate memory that cannot free and realloc

Parameters

size	request size.

Returns: void * pointer to allocated memory.

Return values

NULL error.

Definition at line 631 of file alloc.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ mrbc_raw_calloc()

void * mrbc_raw_calloc	(	unsigned int	nmemb,
		unsigned int	size )

allocate memory for compatibility with calloc

Parameters

nmemb	number of elements.
size	size of an element.

Returns: void * pointer to allocated memory.

Return values

NULL error.

Definition at line 686 of file alloc.c.

Here is the call graph for this function:

◆ mrbc_raw_free()

void mrbc_raw_free ( void * ptr )

release memory

Parameters

ptr	Return value of mrbc_raw_alloc()

Definition at line 707 of file alloc.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ mrbc_raw_realloc()

void * mrbc_raw_realloc	(	void *	ptr,
		unsigned int	size )

re-allocate memory

Parameters

ptr	Return value of mrbc_raw_alloc()
size	request size

Returns: void * pointer to allocated memory.

Return values

NULL error.

Definition at line 806 of file alloc.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ nlz16()

int nlz16 ( uint16_t x )

inlinestatic

Number of leading zeros. 16bit version.

Parameters

x	target (16bit unsigned)

Return values

int nlz value

Definition at line 258 of file alloc.c.

Here is the caller graph for this function:

◆ nlz8()

int nlz8 ( uint8_t x )

inlinestatic

Number of leading zeros. 8bit version.

Parameters

x	target (8bit unsigned)

Return values

int nlz value

Definition at line 276 of file alloc.c.

◆ remove_free_block()

void remove_free_block	(	MEMORY_POOL *	pool,
		FREE_BLOCK *	target )

static

just remove the free_block *target from index

Parameters

pool	Pointer to memory pool.
target	pointer to target block.

Definition at line 356 of file alloc.c.

Here is the call graph for this function:

Here is the caller graph for this function:

◆ split_block()

FREE_BLOCK * split_block	(	FREE_BLOCK *	target,
		MRBC_ALLOC_MEMSIZE_T	size )

inlinestatic

Split block by size

Parameters

target	pointer to target block
size	size

Return values

NULL	no split.
FREE_BLOCK	* pointer to splitted free block.

Definition at line 414 of file alloc.c.

Here is the caller graph for this function:

Variable Documentation

◆ memory_pool

MEMORY_POOL* memory_pool

static

Definition at line 242 of file alloc.c.

Data Structures

Macros

Typedefs

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ alloc_profile

◆ BLOCK_ADRS

◆ BLOCK_SIZE

◆ BPOOL_END

◆ BPOOL_TOP

◆ FLI

◆ GET_VM_ID

◆ IS_FREE_BLOCK

◆ IS_PREV_FREE

◆ IS_PREV_USED

◆ IS_USED_BLOCK

◆ MRBC_ALLOC_FLI_BIT_WIDTH

◆ MRBC_ALLOC_IGNORE_LSBS

◆ MRBC_ALLOC_SLI_BIT_WIDTH

◆ MRBC_MIN_MEMORY_BLOCK_SIZE

◆ MSB_BIT1_FLI

◆ MSB_BIT1_SLI

◆ NLZ_FLI

◆ NLZ_SLI

◆ PHYS_NEXT

◆ RETURN_IF_NULL

◆ SET_FREE_BLOCK

◆ SET_PREV_FREE

◆ SET_PREV_USED

◆ SET_USED_BLOCK

◆ SET_VM_ID

◆ SIZE_FREE_BLOCKS

◆ SLI

Typedef Documentation

◆ MEMORY_POOL

Function Documentation

◆ add_free_block()

◆ calc_index()

◆ merge_block()

◆ mrbc_alloc_statistics()

◆ mrbc_alloc_usable_size()

◆ mrbc_cleanup_alloc()

◆ mrbc_init_alloc()

◆ mrbc_raw_alloc()

◆ mrbc_raw_alloc_no_free()

◆ mrbc_raw_calloc()

◆ mrbc_raw_free()

◆ mrbc_raw_realloc()

◆ nlz16()

◆ nlz8()

◆ remove_free_block()

◆ split_block()

Variable Documentation

◆ memory_pool