Inheritance diagram for EMACMemoryManager:

Public Types
enum class	Lifetime { POOL_ALLOCATED , HEAP_ALLOCATED , CONSTANT , VOLATILE }

Public Member Functions
virtual net_stack_mem_buf_t *	alloc_heap (uint32_t size, uint32_t align)=0
	Allocates memory buffer from the heap.

virtual net_stack_mem_buf_t *	alloc_pool (uint32_t size, uint32_t align)=0
	Allocates memory buffer chain from a pool.

virtual uint32_t	get_pool_alloc_unit (uint32_t align) const =0
	Get memory buffer pool allocation unit.

virtual uint32_t	get_pool_size () const =0
	Get memory buffer pool size.

virtual void	free (net_stack_mem_buf_t *buf)=0
	Free memory buffer chain.

virtual uint32_t	get_total_len (const net_stack_mem_buf_t *buf) const =0
	Return total length of a memory buffer chain.

virtual void	copy (net_stack_mem_buf_t to_buf, const net_stack_mem_buf_t from_buf)=0
	Copy a memory buffer chain.

virtual void	copy_to_buf (net_stack_mem_buf_t to_buf, const void ptr, uint32_t len)
	Copy to a memory buffer chain.

virtual uint32_t	copy_from_buf (void ptr, uint32_t len, const net_stack_mem_buf_t from_buf) const
	Copy from a memory buffer chain.

virtual void	cat (net_stack_mem_buf_t to_buf, net_stack_mem_buf_t cat_buf)=0
	Concatenate two memory buffer chains.

virtual net_stack_mem_buf_t *	get_next (const net_stack_mem_buf_t *buf) const =0
	Returns the next buffer.

size_t	count_buffers (const net_stack_mem_buf_t *buf)
	Count the number of buffers in a buffer chain.

virtual void *	get_ptr (const net_stack_mem_buf_t *buf) const =0
	Return pointer to the payload of the buffer.

virtual uint32_t	get_len (const net_stack_mem_buf_t *buf) const =0
	Return payload size of this individual buffer (NOT including any chained buffers)

virtual void	set_len (net_stack_mem_buf_t *buf, uint32_t len)=0
	Sets the payload size of the buffer.

virtual Lifetime	get_lifetime (net_stack_mem_buf_t const *buf) const =0
	Gets the lifetime of the buffer.

void	set_on_pool_space_avail_cb (mbed::Callback< void()> cb)
	Set callback which will be called when pool space becomes available.

Protected Attributes
mbed::Callback< void()>	onPoolSpaceAvailCallback
	Callback which shall be called (if set) by the implementation after one or more buffer spaces become free in the pool.

Detailed Description

Definition at line 45 of file EMACMemoryManager.h.

Member Enumeration Documentation

◆ Lifetime

enum class Lifetime

stronginherited

Enumerator
POOL_ALLOCATED	Allocated from the memory manager's pool.
HEAP_ALLOCATED	Allocated from the memory manager's heap.
CONSTANT	Buffer points to constant data (e.g. in ROM) that will live forever.
VOLATILE	Buffer points to data from the application that will not live past the current network stack call.

Definition at line 235 of file NetStackMemoryManager.h.

Member Function Documentation

◆ alloc_heap()

virtual net_stack_mem_buf_t * alloc_heap	(	uint32_t	size,
		uint32_t	align
	)

pure virtualinherited

Allocates memory buffer from the heap.

Memory buffer allocated from heap is always contiguous and can be arbitrary size.

Parameters

size	Size of the memory to allocate in bytes
align	Memory alignment requirement in bytes

Returns: Allocated memory buffer, or NULL in case of error

Implemented in NanostackMemoryManager.

◆ alloc_pool()

virtual net_stack_mem_buf_t * alloc_pool	(	uint32_t	size,
		uint32_t	align
	)

pure virtualinherited

Allocates memory buffer chain from a pool.

Memory allocated from pool is contiguous if size is equal or less than (aligned) allocation unit, otherwise may be chained. Will typically come from fixed-size packet pool memory.

Parameters

size	Total size of the memory to allocate in bytes
align	Memory alignment requirement for each buffer in bytes

Returns: Allocated memory buffer chain, or NULL in case of error

Implemented in NanostackMemoryManager.

◆ get_pool_alloc_unit()

virtual uint32_t get_pool_alloc_unit ( uint32_t align ) const

pure virtualinherited

Get memory buffer pool allocation unit.

Returns the maximum size of contiguous memory that can be allocated from a pool.

Parameters

align Memory alignment requirement in bytes

Returns: Contiguous memory size

Implemented in NanostackMemoryManager.

◆ get_pool_size()

virtual uint32_t get_pool_size ( ) const

pure virtualinherited

Get memory buffer pool size.

Returns: The maximum size of contiguous memory that can be allocated from a pool.

Implemented in NanostackMemoryManager.

◆ free()

virtual void free ( net_stack_mem_buf_t * buf )

pure virtualinherited

Free memory buffer chain.

Frees all buffers from the chained list.

Parameters

buf	Memory buffer chain to be freed.

Implemented in NanostackMemoryManager.

◆ get_total_len()

virtual uint32_t get_total_len ( const net_stack_mem_buf_t * buf ) const

pure virtualinherited

Return total length of a memory buffer chain.

Returns a total length of this buffer and any following buffers in the chain.

Parameters

buf	Memory buffer chain

Returns: Total length in bytes

Implemented in NanostackMemoryManager.

◆ copy()

virtual void copy	(	net_stack_mem_buf_t *	to_buf,
		const net_stack_mem_buf_t *	from_buf
	)

pure virtualinherited

Copy a memory buffer chain.

Copies data from one buffer chain to another. Copy operation does not adjust the lengths of the copied-to memory buffer chain, so chain total lengths must be the same.

Parameters

to_buf	Memory buffer chain to copy to
from_buf	Memory buffer chain to copy from

Implemented in NanostackMemoryManager.

◆ copy_to_buf()

virtual void copy_to_buf	(	net_stack_mem_buf_t *	to_buf,
		const void *	ptr,
		uint32_t	len
	)

virtualinherited

Copy to a memory buffer chain.

Copies data to a buffer chain. Copy operation does not adjust the lengths of the copied-to memory buffer chain, so chain total length must match the copied length.

Parameters

to_buf	Memory buffer chain to copy to
ptr	Pointer to data
len	Data length

◆ copy_from_buf()

virtual uint32_t copy_from_buf	(	void *	ptr,
		uint32_t	len,
		const net_stack_mem_buf_t *	from_buf
	)		const

virtualinherited

Copy from a memory buffer chain.

Copies data from a memory buffer chain.

Parameters

len	Data length
ptr	Pointer to data
from_buf	Memory buffer chain to copy from

Returns: Length of the data that was copied

◆ cat()

virtual void cat	(	net_stack_mem_buf_t *	to_buf,
		net_stack_mem_buf_t *	cat_buf
	)

pure virtualinherited

Concatenate two memory buffer chains.

Concatenates buffer chain to end of the other buffer chain. Concatenated-to buffer total length is adjusted accordingly. cat_buf must point to the start of a the chain. After concatenation to_buf's chain now owns those buffers, and they will be freed when the to_buf chain is freed.

Parameters

to_buf	Memory buffer chain to concatenate to
cat_buf	Memory buffer chain to concatenate

Implemented in NanostackMemoryManager.

◆ get_next()

virtual net_stack_mem_buf_t * get_next ( const net_stack_mem_buf_t * buf ) const

pure virtualinherited

Returns the next buffer.

Returns the next buffer from the memory buffer chain.

Parameters

buf	Memory buffer

Returns: The next memory buffer, or NULL if last

Implemented in NanostackMemoryManager.

◆ count_buffers()

size_t count_buffers ( const net_stack_mem_buf_t * buf )

inherited

Count the number of buffers in a buffer chain.

Parameters

buf	Memory buffer

Returns: The number of buffers in the chain

Definition at line 190 of file NetStackMemoryManager.h.

◆ get_ptr()

virtual void * get_ptr ( const net_stack_mem_buf_t * buf ) const

pure virtualinherited

Return pointer to the payload of the buffer.

Parameters

buf	Memory buffer

Returns: Pointer to the payload

Implemented in NanostackMemoryManager.

◆ get_len()

virtual uint32_t get_len ( const net_stack_mem_buf_t * buf ) const

pure virtualinherited

Return payload size of this individual buffer (NOT including any chained buffers)

Parameters

buf	Memory buffer

Returns: Size in bytes

Implemented in NanostackMemoryManager.

◆ set_len()

virtual void set_len	(	net_stack_mem_buf_t *	buf,
		uint32_t	len
	)

pure virtualinherited

Sets the payload size of the buffer.

The allocated payload size will not change. It is not permitted to change the length of a buffer that is not the first (or only) in a chain.

*Note as of Dec 2024: Different implementations (Nanostack vs LwIP) disagree about how to implement this operation. Specifically, if called on the head of a buffer chain, the LwIP implementation allows changing the length of the chain as a whole. However, the Nanostack implementation does not and only can change the length of the head buffer. For fear of breaking existing code, I do not want to change this behavior. So, if constructing a buffer chain, it is safest to set the buffer lengths first before building the chain.

Parameters

buf	Memory buffer
len	Payload size, must be less or equal to the allocated size

Implemented in NanostackMemoryManager.

◆ get_lifetime()

virtual Lifetime get_lifetime ( net_stack_mem_buf_t const * buf ) const

pure virtualinherited

Gets the lifetime of the buffer.

Parameters

buf	Memory buffer

Implemented in NanostackMemoryManager.

◆ set_on_pool_space_avail_cb()

void set_on_pool_space_avail_cb ( mbed::Callback< void()> cb )

inherited

Set callback which will be called when pool space becomes available.

Warning: The callback could be called from any thread, and should make no assumptions about being in the same thread as anything else.

Parameters

cb	Callback to call

Definition at line 257 of file NetStackMemoryManager.h.

Field Documentation

◆ onPoolSpaceAvailCallback

mbed::Callback<void()> onPoolSpaceAvailCallback

protectedinherited

Callback which shall be called (if set) by the implementation after one or more buffer spaces become free in the pool.

This is used by zero-copy Ethernet MACs as a hint that now is a good time to allocate fresh buffers off the pool into Ethernet descriptors. It is legal to call this function if you aren't totally sure new memory is available – the mac will try to allocate more buffers, and if it can't, oh well. However, it is not legal for memory to become available without a call to this function. Such a situation might lead to a lockup of the MAC due to not having memory allocated for Rx.

Definition at line 62 of file NetStackMemoryManager.h.

Public Types

Public Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

◆ Lifetime

Member Function Documentation

◆ alloc_heap()

◆ alloc_pool()

◆ get_pool_alloc_unit()

◆ get_pool_size()

◆ free()

◆ get_total_len()

◆ copy()

◆ copy_to_buf()

◆ copy_from_buf()

◆ cat()

◆ get_next()

◆ count_buffers()

◆ get_ptr()

◆ get_len()

◆ set_len()

◆ get_lifetime()

◆ set_on_pool_space_avail_cb()

Field Documentation

◆ onPoolSpaceAvailCallback