Memory Management

Collaboration diagram for Memory Management:

Detailed Description

Data Structures
struct	bj_memory_callbacks
	Custom allocation callbacks. More...

Typedefs
typedef void *(*	bj_malloc_fn) (void *p_user_data, size_t size)
	Memory allocation callback.
typedef void *(*	bj_realloc_fn) (void *p_user_data, void *p_original, size_t size)
	Memory reallocation callback.
typedef void(*	bj_free_fn) (void *p_user_data, void *p_memory)
	Memory free callback.
typedef struct bj_memory_callbacks	bj_memory_callbacks
	Custom allocation callbacks.

Functions
void *	bj_malloc (size_t size)
	Allocate size bytes of memory.
void *	bj_calloc (size_t size)
	Allocate size bytes of zero-initialized memory.
void *	bj_realloc (void *p_memory, size_t size)
	Reallocate a memory block to a new size.
void	bj_free (void *p_memory)
	Free a previously allocated memory block.
void	bj_memory_set_defaults (const bj_memory_callbacks *p_allocator)
	Set the global default memory allocators.
void	bj_memory_unset_defaults (void)
	Reset the global default allocators to system defaults.
void *	bj_memcpy (void *p_dest, const void *p_src, size_t mem_size)
	Copy mem_size bytes from p_src to p_dest.
void *	bj_memmove (void *p_dest, const void *p_src, size_t mem_size)
	Move mem_size bytes from p_src to p_dest.
int	bj_memcmp (const void *p_block_a, const void *p_block_b, size_t size)
	Compare two memory blocks.
void	bj_memset (void *p_dest, uint8_t value, size_t mem_size)
	Fill mem_size bytes at p_dest with value.
void	bj_memzero (void *p_dest, size_t mem_size)
	Zero out mem_size bytes at p_dest.

---

Data Structure Documentation

bj_memory_callbacks

struct bj_memory_callbacks

This structure holds function pointers for allocation, reallocation, and deallocation callbacks along with user data.

These callbacks can be assigned per-object or set globally with bj_memory_set_defaults.

Data Fields
bj_malloc_fn	fn_allocation	Allocation function pointer.
bj_free_fn	fn_free	Deallocation function pointer.
bj_realloc_fn	fn_reallocation	Reallocation function pointer.
void *	p_user_data	General purpose context data.

Typedef Documentation

bj_free_fn

typedef void(* bj_free_fn) (void *p_user_data, void *p_memory)

Used in bj_memory_callbacks to set the function used for custom deallocations.

Parameters

p_user_data	General purpose context data.
p_memory	Object memory to dispose.

bj_malloc_fn

typedef void *(* bj_malloc_fn) (void *p_user_data, size_t size)

Used in bj_memory_callbacks to set the function used for custom allocations.

Parameters

p_user_data	General purpose context data.
size	Allocation size in bytes requested by the caller.

Returns

Pointer to allocated memory block.

bj_memory_callbacks

typedef struct bj_memory_callbacks bj_memory_callbacks

This structure holds function pointers for allocation, reallocation, and deallocation callbacks along with user data.

These callbacks can be assigned per-object or set globally with bj_memory_set_defaults.

bj_realloc_fn

typedef void *(* bj_realloc_fn) (void *p_user_data, void *p_original, size_t size)

Used in bj_memory_callbacks to set the function used for custom reallocations.

Parameters

p_user_data	General purpose context data.
p_original	Initial object to reallocate.
size	Allocation size in bytes requested by the caller.

Returns

Pointer to reallocated memory block.

Function Documentation

bj_calloc()

void * bj_calloc

(

size_t

size

)

The returned memory is set to zero bytes.

Parameters

[in]

size

Number of bytes to allocate.

Returns

Pointer to newly allocated zeroed memory block.

bj_free()

void bj_free

(

void *

p_memory

)

Parameters

[in]

p_memory

Pointer to memory to free.

Note

p_memory must have been allocated by bj_malloc or bj_realloc.

bj_malloc()

void * bj_malloc

(

size_t

size

)

Parameters

[in]

size

Number of bytes to allocate.

Returns

Pointer to newly allocated memory block.

bj_memcmp()

int bj_memcmp	(	const void *	p_block_a,
		const void *	p_block_b,
		size_t	size )

Parameters

[in]	p_block_a	Pointer to first memory block.
[in]	p_block_b	Pointer to second memory block.
[in]	size	Number of bytes to compare.

Returns

Zero if equal, negative if a < b, positive if a > b.

bj_memcpy()

void * bj_memcpy	(	void *	p_dest,
		const void *	p_src,
		size_t	mem_size )

Parameters

[in]	p_dest	Destination pointer.
[in]	p_src	Source pointer.
[in]	mem_size	Number of bytes to copy.

Returns

Pointer to p_dest.

bj_memmove()

void * bj_memmove	(	void *	p_dest,
		const void *	p_src,
		size_t	mem_size )

Similar to bj_memcpy but handles overlapping memory regions safely.

Parameters

[in]	p_dest	Destination pointer.
[in]	p_src	Source pointer.
[in]	mem_size	Number of bytes to move.

Returns

Pointer to p_dest.

bj_memory_set_defaults()

void bj_memory_set_defaults

(

const bj_memory_callbacks *

p_allocator

)

If p_allocator is NULL, resets to system defaults (malloc, realloc, free).

Parameters

[in]

p_allocator

Pointer to custom allocator callbacks.

bj_memory_unset_defaults()

void bj_memory_unset_defaults

(

void

)

Sets allocators back to standard system functions (malloc, realloc, free).

bj_memset()

void bj_memset	(	void *	p_dest,
		uint8_t	value,
		size_t	mem_size )

Parameters

[in]	p_dest	Destination pointer.
[in]	value	Byte value to fill.
[in]	mem_size	Number of bytes to fill.

bj_memzero()

void bj_memzero	(	void *	p_dest,
		size_t	mem_size )

Effectively calls bj_memset with zero.

Parameters

[in]	p_dest	Destination pointer.
[in]	mem_size	Number of bytes to zero.

bj_realloc()

void * bj_realloc	(	void *	p_memory,
		size_t	size )

Parameters

[in]	p_memory	Pointer to previously allocated memory.
[in]	size	Number of bytes to allocate.

Returns

Pointer to newly reallocated memory block.

Note

p_memory must have been allocated by bj_malloc or bj_realloc.