blockpool
["Little Useful Bits" Library]

This interface provides a facility to manage the allocation and deallocation of fixed sized blocks of memory. More...

Data Structures
struct	_lub_blockpool
struct	_lub_blockpool_stats
Typedefs
typedef _lub_blockpool_block	lub_blockpool_block_t
typedef _lub_blockpool	lub_blockpool_t
typedef _lub_blockpool_stats	lub_blockpool_stats_t
Functions
void	lub_blockpool_init (lub_blockpool_t *blockpool, void *memory, size_t blocksize, unsigned blockcount)
void *	lub_blockpool_alloc (lub_blockpool_t *blockpool)
void	lub_blockpool_free (lub_blockpool_t *blockpool, void *block)
void	lub_blockpool__get_stats (lub_blockpool_t *instance, lub_blockpool_stats_t *stats)

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Detailed Description

This interface provides a facility to manage the allocation and deallocation of fixed sized blocks of memory.

This type of memory manager is very fast and doesn't suffer from any memory fragmentation problems.

This allocator uses block in the order in which they are freed, this is significant for some applications where you don't want to re-use a particular freed block too soon. e.g. hardware timing limits on re-use.

The client is responsible for providing the memory to be managed.

Author:

Graeme McKerrell

Date:

Created On : Fri Jan 23 12:50:18 2004

Version:

TESTED

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Typedef Documentation

typedef struct _lub_blockpool_stats lub_blockpool_stats_t

This type defines the statistics available for each blockpool.

typedef struct _lub_blockpool lub_blockpool_t

This type represents a "blockpool" instance.

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Function Documentation

void lub_blockpool__get_stats	(	lub_blockpool_t *	instance,
		lub_blockpool_stats_t *	stats
	)

This operation fills out a statistics structure with the details for the specified blockpool.

Precondition:

• none

Postcondition:

• the results filled out are a snapshot of the statistics as the time of the call.

Parameters:

instance	The instance on which to operate
stats	A client provided structure to fill out with the blockpool details

void* lub_blockpool_alloc

(

lub_blockpool_t *

blockpool

)

This operation allocates a "block" of memory from a "blockpool"

Precondition:

The blockpool must have been initialised.

Returns:

A pointer to a "block" of memory, or NULL if there is none left for allocation.

Postcondition:

The behaviour is undefined if the "blockpool" is uninitialised.

Parameters:

blockpool

the "blockpool" instance to invoke this operation upon

void lub_blockpool_free	(	lub_blockpool_t *	blockpool,
		void *	block
	)

This operation de-allocates a "block" of memory back into a "blockpool"

Precondition:

The specified block must have been previously allocated using lub_blockpool_alloc()

Postcondition:

The de-allocated block become available for subsequent lub_blockpool_alloc() requests.

Parameters:

blockpool	the "blockpool" instance to invoke this operation upon
block	the "block" to release back to the pool

void lub_blockpool_init	(	lub_blockpool_t *	blockpool,
		void *	memory,
		size_t	blocksize,
		unsigned	blockcount
	)

This operation initialises an instance of a blockpool.

Precondition:

'blocksize' must be an multiple of 'sizeof(void *)'. (If the client declares a structure for the block this should be handled automatically by the compiler)

Postcondition:

If the size constraint is not met an assert will fire.

Following initialisation the allocation of memory can be performed.

Parameters:

blockpool	the "blockpool" instance to initialise.
memory	the memory to be managed.
blocksize	The size in bytes of each block.
blockcount	The number of blocks to be managed. NB the client is responsible for ensuring that (blocksize x blockcount) bytes of memory are available for use.

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