Freechain Handler

The Freechain Handler. More...

Files
file	freechain.h
	Freechain Handler API.
file	freechain.c
	Freechain Handler Implementation.

Data Structures
struct	Freechain_Control
	The freechain control. More...

Typedefs
typedef void *(*	Freechain_Allocator) (size_t size)
	Allocator function.

Functions
RTEMS_INLINE_ROUTINE void	_Freechain_Initialize (Freechain_Control *freechain, void *initial_nodes, size_t number_nodes, size_t node_size)
	Initializes a freechain. More...
RTEMS_INLINE_ROUTINE bool	_Freechain_Is_empty (const Freechain_Control *freechain)
	Return true if the freechain is empty, otherwise false. More...
RTEMS_INLINE_ROUTINE void *	_Freechain_Pop (Freechain_Control *freechain)
	Pop an item from the freechain. More...
void *	_Freechain_Extend (Freechain_Control *freechain, Freechain_Allocator allocator, size_t number_nodes_to_extend, size_t node_size)
	Extend the freechain with new nodes. More...
void *	_Freechain_Get (Freechain_Control *freechain, Freechain_Allocator allocator, size_t number_nodes_to_extend, size_t node_size)
	Gets a node from the freechain. More...
void	_Freechain_Put (Freechain_Control *freechain, void *node)
	Puts a node back onto the freechain. More...

Detailed Description

The Freechain Handler.

The Freechain Handler is used to manage a chain of nodes, of which size can automatically increase when there is no free node left. This handler provides one data structure: Freechain_Control.

Function Documentation

_Freechain_Extend()

void* _Freechain_Extend	(	Freechain_Control *	freechain,
		Freechain_Allocator	allocator,
		size_t	number_nodes_to_extend,
		size_t	node_size
	)

Extend the freechain with new nodes.

Parameters

freechain	The freechain control.
allocator	The allocator function.
number_nodes_to_extend	The number of nodes to extend.
node_size	The node size.

Return values

NULL	The extend operation failed.
nodes	Pointer to the new nodes.

_Freechain_Get()

void* _Freechain_Get	(	Freechain_Control *	freechain,
		Freechain_Allocator	allocator,
		size_t	number_nodes_to_extend,
		size_t	node_size
	)

Gets a node from the freechain.

Parameters

[in,out]	freechain	The freechain control.
	allocator	The allocator function.
	number_nodes_to_extend	The number of nodes in the case an extend is necessary due to an empty freechain.
[in]	node_size	The node size.

Return values

NULL	The freechain is empty and the extend operation failed.
pointer	Pointer to a node. The node ownership passes to the caller.

_Freechain_Initialize()

RTEMS_INLINE_ROUTINE void _Freechain_Initialize	(	Freechain_Control *	freechain,
		void *	initial_nodes,
		size_t	number_nodes,
		size_t	node_size
	)

Initializes a freechain.

This routine initializes the freechain control structure to manage a chain of nodes. In the case the freechain is empty the extend handler is called to get more nodes.

Parameters

[out]	freechain	The freechain control to initialize.
[out]	initial_nodes	Array with the initial nodes.
	number_nodes	The initial number of nodes.
	node_size	The node size.

_Freechain_Is_empty()

RTEMS_INLINE_ROUTINE bool _Freechain_Is_empty

(

const Freechain_Control *

freechain

)

Return true if the freechain is empty, otherwise false.

Parameters

freechain

The freechain control.

_Freechain_Pop()

RTEMS_INLINE_ROUTINE void* _Freechain_Pop

(

Freechain_Control *

freechain

)

Pop an item from the freechain.

The freechain must not be empty.

Parameters

freechain

The freechain control.

_Freechain_Put()

void _Freechain_Put	(	Freechain_Control *	freechain,
		void *	node
	)

Puts a node back onto the freechain.

Parameters

[in,out]	freechain	The freechain control.
[out]	node	The node to put back. The node may be NULL, in this case the function does nothing.