src/include/lwip/mem.h File Reference

#include "lwip/opt.h"

Macros
#define	LWIP_MEM_ALIGN(addr)   ((void *)(((mem_ptr_t)(addr) + MEM_ALIGNMENT - 1) & ~(mem_ptr_t)(MEM_ALIGNMENT-1)))
	Align a memory pointer to the alignment defined by MEM_ALIGNMENT so that ADDR % MEM_ALIGNMENT == 0. More...
#define	LWIP_MEM_ALIGN_BUFFER(size)   (((size) + MEM_ALIGNMENT - 1))
	Calculate safe memory size for an aligned buffer when using an unaligned type as storage. More...
#define	LWIP_MEM_ALIGN_SIZE(size)   (((size) + MEM_ALIGNMENT - 1) & ~(MEM_ALIGNMENT-1))
	Calculate memory size for an aligned buffer - returns the next highest multiple of MEM_ALIGNMENT (e.g. More...
#define	MEM_SIZE_F   U16_F

Typedefs
typedef u16_t	mem_size_t

Functions
void *	mem_calloc (mem_size_t count, mem_size_t size)
	Contiguously allocates enough space for count objects that are size bytes of memory each and returns a pointer to the allocated memory. More...
void	mem_free (void *mem)
	Put a struct mem back on the heap. More...
void	mem_init (void)
	Zero the heap and initialize start, end and lowest-free. More...
void *	mem_malloc (mem_size_t size)
	Adam's mem_malloc() plus solution for bug #17922 Allocate a block of memory with a minimum of 'size' bytes. More...
void *	mem_trim (void *mem, mem_size_t size)
	Shrink memory returned by mem_malloc(). More...

#define LWIP_MEM_ALIGN

(

addr

)

((void *)(((mem_ptr_t)(addr) + MEM_ALIGNMENT - 1) & ~(mem_ptr_t)(MEM_ALIGNMENT-1)))

Align a memory pointer to the alignment defined by MEM_ALIGNMENT so that ADDR % MEM_ALIGNMENT == 0.

Referenced by mem_init(), memp_init(), and pbuf_alloc().

#define LWIP_MEM_ALIGN_BUFFER

(

size

)

(((size) + MEM_ALIGNMENT - 1))

Calculate safe memory size for an aligned buffer when using an unaligned type as storage.

This includes a safety-margin on (MEM_ALIGNMENT - 1) at the start (e.g. if buffer is u8_t[] and actual data will be u32_t*)

#define LWIP_MEM_ALIGN_SIZE

(

size

)

(((size) + MEM_ALIGNMENT - 1) & ~(MEM_ALIGNMENT-1))

Calculate memory size for an aligned buffer - returns the next highest multiple of MEM_ALIGNMENT (e.g.

LWIP_MEM_ALIGN_SIZE(3) and LWIP_MEM_ALIGN_SIZE(4) will both yield 4 for MEM_ALIGNMENT == 4).

Referenced by mem_malloc(), mem_trim(), and pbuf_alloc().

#define MEM_SIZE_F   U16_F

typedef u16_t mem_size_t

void* mem_calloc	(	mem_size_t	count,
		mem_size_t	size
	)

Contiguously allocates enough space for count objects that are size bytes of memory each and returns a pointer to the allocated memory.

The allocated memory is filled with bytes of value zero.

Parameters

count	number of objects to allocate
size	size of the objects to allocate

Returns

pointer to allocated memory / NULL pointer if there is an error

void mem_free

(

void *

rmem

)

Put a struct mem back on the heap.

Parameters

rmem	is the data portion of a struct mem as returned by a previous call to mem_malloc()

void mem_init

(

void

)

Zero the heap and initialize start, end and lowest-free.

void* mem_malloc

(

mem_size_t

size

)

Adam's mem_malloc() plus solution for bug #17922 Allocate a block of memory with a minimum of 'size' bytes.

Parameters

size	is the minimum size of the requested block in bytes.

Returns

pointer to allocated memory or NULL if no free memory was found.

Note that the returned value will always be aligned (as defined by MEM_ALIGNMENT).

void* mem_trim	(	void *	rmem,
		mem_size_t	newsize
	)

Shrink memory returned by mem_malloc().

Parameters

rmem	pointer to memory allocated by mem_malloc the is to be shrinked
newsize	required size after shrinking (needs to be smaller than or equal to the previous size)

Returns

for compatibility reasons: is always == rmem, at the moment or NULL if newsize is > old size, in which case rmem is NOT touched or freed!