Classes
struct	block_t
	Represents a block of memory within the heap. This structure includes metadata for managing memory allocation and free status. More...

struct	heap_header_t
	Maps the heap memory to easily accessible values. This structure contains pointers to the list of all blocks and the list of free blocks. More...

Macros
#define	__DEBUG_HEADER__ "[KHEAP ]"
	Change header.

#define	__DEBUG_LEVEL__ LOGLEVEL_INFO
	Set log level.

#define	HEAP_SIZE (4 * M)
	The size of the heap in bytes, defined as 4 megabytes.

#define	HEAP_VM_LB 0x40000000
	The lower bound address for virtual memory area placement. This address marks the starting point of the heap.

#define	HEAP_VM_UB 0x50000000
	The upper bound address for virtual memory area placement. This address marks the endpoint of the heap, ensuring no overlap with other memory regions.

#define	OVERHEAD sizeof(block_t)
	The overhead introduced by the block_t structure itself. This is used for memory management and bookkeeping.

#define	ADDR_ALIGN(addr) ((((uint32_t)(addr)) & 0xFFFFF000) + 0x1000)
	Aligns the given address to the nearest upper page boundary. The address will be aligned to 4096 bytes (0x1000). More...

#define	IS_ALIGN(addr) ((((uint32_t)(addr)) & 0x00000FFF) == 0)
	Checks if the given address is aligned to a page boundary. More...

Typedefs
typedef struct block_t	block_t
	Represents a block of memory within the heap. This structure includes metadata for managing memory allocation and free status.

Functions
static uint32_t	__blkmngr_get_rounded_size (uint32_t size)
	Returns the given size, rounded to the nearest multiple of 16. This is useful for ensuring memory alignment requirements are met. More...

static int	__blkmngr_does_it_fit (block_t *block, uint32_t size)
	Checks if the given size fits inside the block. This function verifies whether the specified size can be accommodated within the block's available size. More...

static const char *	__block_to_string (block_t *block)
	Prepares a string that represents the block. This function formats the information of the specified block into a human-readable string. More...

static void	__blkmngr_dump (heap_header_t *header)
	Dumpts debug information about the heap. More...

static block_t *	__blkmngr_find_best_fitting (heap_header_t *header, uint32_t size)
	Find the best fitting block in the memory pool. More...

static block_t *	__blkmngr_get_previous_block (heap_header_t header, block_t block)
	Given a block, finds its previous block. More...

static block_t *	__blkmngr_get_next_block (heap_header_t header, block_t block)
	Given a block, finds its next block in the memory pool. More...

static int	__blkmngr_is_previous_block (block_t block, block_t previous)
	Checks if the given `previous` block is actually the block that comes before `block` in the memory pool. More...

static int	__blkmngr_is_next_block (block_t block, block_t next)
	Checks if the given `next` block is actually the block that comes after `block` in the memory pool. More...

static int	__blkmngr_split_block (heap_header_t header, block_t block, uint32_t size)
	Splits a block into two blocks based on the specified size for the first block. More...

static int	__blkmngr_merge_blocks (heap_header_t header, block_t block, block_t *other)
	Merges two adjacent blocks into the first block, effectively expanding its size. More...

static void *	__do_brk (vm_area_struct_t *heap, uint32_t increment)
	Extends the provided heap by a specified increment. More...

static void *	__do_malloc (vm_area_struct_t *heap, size_t size)
	Allocates a specified number of bytes of uninitialized storage from the heap. More...

static int	__do_free (vm_area_struct_t heap, void ptr)
	Deallocates previously allocated space, returning it to the heap. More...

void *	sys_brk (void *addr)
	User malloc. More...

Detailed Description

Copyright: (c) 2014-2024 This file is distributed under the MIT License. See LICENSE.md for details.

Macro Definition Documentation

◆ ADDR_ALIGN

#define ADDR_ALIGN ( addr ) ((((uint32_t)(addr)) & 0xFFFFF000) + 0x1000)

Aligns the given address to the nearest upper page boundary. The address will be aligned to 4096 bytes (0x1000).

Parameters

addr	The address to align.

Returns: The aligned address.

◆ IS_ALIGN

#define IS_ALIGN ( addr ) ((((uint32_t)(addr)) & 0x00000FFF) == 0)

Checks if the given address is aligned to a page boundary.

Parameters

addr	The address to check.

Returns: Non-zero value if the address is aligned, zero otherwise.

Function Documentation

◆ __blkmngr_does_it_fit()

static int __blkmngr_does_it_fit	(	block_t *	block,
		uint32_t	size
	)

inlinestatic

Checks if the given size fits inside the block. This function verifies whether the specified size can be accommodated within the block's available size.

Parameters

block	The given block to check. Must not be NULL.
size	The size to check against the block's size.

Returns: 1 if the size fits within the block, -1 if the block is NULL.

◆ __blkmngr_dump()

static void __blkmngr_dump ( heap_header_t * header )

inlinestatic

Dumpts debug information about the heap.

Parameters

header the heap header.

◆ __blkmngr_find_best_fitting()

static block_t* __blkmngr_find_best_fitting	(	heap_header_t *	header,
		uint32_t	size
	)

inlinestatic

Find the best fitting block in the memory pool.

Parameters

header	header describing the heap.
size	the size we want.

Returns: a block that should fit our needs.

◆ __blkmngr_get_next_block()

static block_t* __blkmngr_get_next_block	(	heap_header_t *	header,
		block_t *	block
	)

inlinestatic

Given a block, finds its next block in the memory pool.

Parameters

header	The heap header containing information about the heap.
block	The current block for which the next block is to be found.

Returns: A pointer to the next block if it exists, or NULL if an error occurs or if the block is the last one.

◆ __blkmngr_get_previous_block()

static block_t* __blkmngr_get_previous_block	(	heap_header_t *	header,
		block_t *	block
	)

inlinestatic

Given a block, finds its previous block.

Parameters

header	the heap header.
block	the block.

Returns: a pointer to the previous block or NULL if an error occurs.

◆ __blkmngr_get_rounded_size()

static uint32_t __blkmngr_get_rounded_size ( uint32_t size )

inlinestatic

Returns the given size, rounded to the nearest multiple of 16. This is useful for ensuring memory alignment requirements are met.

Parameters

size	The given size to be rounded.

Returns: The size rounded to the nearest multiple of 16.

◆ __blkmngr_is_next_block()

static int __blkmngr_is_next_block	(	block_t *	block,
		block_t *	next
	)

inlinestatic

Checks if the given next block is actually the block that comes after block in the memory pool.

Parameters

block	The current block from which we are checking the next block.
next	The block that is supposedly the next block.

Returns: 1 if next is the actual next block of block, 0 otherwise. Returns -1 on error.

◆ __blkmngr_is_previous_block()

static int __blkmngr_is_previous_block	(	block_t *	block,
		block_t *	previous
	)

inlinestatic

Checks if the given previous block is actually the block that comes before block in the memory pool.

Parameters

block	The current block from which we are checking the previous block.
previous	The block that is supposedly the previous block.

Returns: 1 if previous is the actual previous block of block, 0 otherwise. Returns -1 on error.

◆ __blkmngr_merge_blocks()

static int __blkmngr_merge_blocks	(	heap_header_t *	header,
		block_t *	block,
		block_t *	other
	)

inlinestatic

Merges two adjacent blocks into the first block, effectively expanding its size.

Parameters

header	The heap header containing metadata about the memory pool.
block	The first block that will be expanded.
other	The second block that will be merged into the first block, becoming invalid in the process.

Returns: 0 on success, -1 on error.

◆ __blkmngr_split_block()

static int __blkmngr_split_block	(	heap_header_t *	header,
		block_t *	block,
		uint32_t	size
	)

inlinestatic

Splits a block into two blocks based on the specified size for the first block.

Parameters

header	The heap header containing metadata about the memory pool.
block	The block to be split, which must be free.
size	The size of the first of the two new blocks. Must be less than the original block's size minus overhead.

Returns: 0 on success, -1 on error.

◆ __block_to_string()

static const char* __block_to_string ( block_t * block )

inlinestatic

Prepares a string that represents the block. This function formats the information of the specified block into a human-readable string.

Parameters

block The block to represent. Can be NULL.

Returns: A string containing the block's address, size, and free status.

◆ __do_brk()

static void* __do_brk	(	vm_area_struct_t *	heap,
		uint32_t	increment
	)

static

Extends the provided heap by a specified increment.

Parameters

heap	Pointer to the heap structure that tracks the heap's memory area.
increment	The amount by which to increase the heap size.

Returns: Pointer to the old top of the heap, or NULL if an error occurred.

◆ __do_free()

static int __do_free	(	vm_area_struct_t *	heap,
		void *	ptr
	)

static

Deallocates previously allocated space, returning it to the heap.

Parameters

heap	Pointer to the heap to which the allocated memory is returned.
ptr	Pointer to the previously allocated memory to be deallocated.

Returns: 0 on success, -1 on error.

◆ __do_malloc()

static void* __do_malloc	(	vm_area_struct_t *	heap,
		size_t	size
	)

static

Allocates a specified number of bytes of uninitialized storage from the heap.

Parameters

heap	Pointer to the heap from which we will allocate memory.
size	The size of the desired memory area to allocate.

Returns: Pointer to the allocated memory area, or NULL if allocation fails.

◆ sys_brk()

void* sys_brk ( void * addr )

User malloc.

Parameters

addr	This argument is treated as an address of a dynamically allocated memory if falls inside the process heap area. Otherwise, it is treated as an amount of memory that should be allocated.

Returns: NULL if there is no more memory available or we were freeing a previously allocated memory area, the address of the allocated space otherwise.

Classes

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

◆ ADDR_ALIGN

◆ IS_ALIGN

Function Documentation

◆ __blkmngr_does_it_fit()

◆ __blkmngr_dump()

◆ __blkmngr_find_best_fitting()

◆ __blkmngr_get_next_block()

◆ __blkmngr_get_previous_block()

◆ __blkmngr_get_rounded_size()

◆ __blkmngr_is_next_block()

◆ __blkmngr_is_previous_block()

◆ __blkmngr_merge_blocks()

◆ __blkmngr_split_block()

◆ __block_to_string()

◆ __do_brk()

◆ __do_free()

◆ __do_malloc()

◆ sys_brk()