Initialization
[Slab Memory Allocator API]

Slab cache initialization. More...

Typedefs
typedef struct l4slab_cache	l4slab_cache_t
	Slab cache descriptor type.
typedef L4_CV void *(*	l4slab_grow_fn_t )(l4slab_cache_t *cache, void **data)
	Cache grow callback function.
typedef L4_CV void(*	l4slab_release_fn_t )(l4slab_cache_t *cache, void *buffer, void *data)
	Cache release callback function.
Functions
L4_CV int	l4slab_cache_init (l4slab_cache_t *cache, l4_size_t size, unsigned int max_free, l4slab_grow_fn_t grow_fn, l4slab_release_fn_t release_fn)
	Initialize slab cache.
L4_CV void	l4slab_destroy (l4slab_cache_t *cache)
	Destroy slab cache.
L4_CV void	l4slab_add_slab (l4slab_cache_t *cache, void *buffer, void *data)
	Add a slab to the slab cache.
L4_CV void	l4slab_set_data (l4slab_cache_t *cache, void *data)
	Set cache application data pointer.
L4_CV void *	l4slab_get_data (l4slab_cache_t *cache)
	Get cache application data.

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Detailed Description

Slab cache initialization.

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Typedef Documentation

typedef struct l4slab_cache l4slab_cache_t

Slab cache descriptor type.

Definition at line 45 of file slab.h.

typedef L4_CV void*(* l4slab_grow_fn_t)(l4slab_cache_t *cache, void **data)

Cache grow callback function.

Parameters:

cache

Descriptor of the slab cache which requests the memory

Return values:

data

Slab user data pointer, the contents is returned with the slab to the release callback function.

Returns:

Pointer to the allocated slab.

This function is called by a slab cache to allocate a new slab for the cache. It must return a pointer to a memory area with the size of cache->slab_size and which is slab_size aligned.

Definition at line 62 of file slab.h.

typedef L4_CV void(* l4slab_release_fn_t)(l4slab_cache_t *cache, void *buffer, void *data)

Cache release callback function.

Parameters:

	cache	Slab cache descriptor
	buffer	Slab address
	data	Slab user data pointer

Cache release callback function. It is called by a slab cache to release slabs which are no longer needed by the cache. Slab have a size of cache->slab_size!

Definition at line 77 of file slab.h.

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Function Documentation

L4_CV int l4slab_cache_init	(	l4slab_cache_t *	cache,
		l4_size_t	size,
		unsigned int	max_free,
		l4slab_grow_fn_t	grow_fn,
		l4slab_release_fn_t	release_fn
	)

Initialize slab cache.

Parameters:

	cache	Slab cache descriptor
	size	Size of the cache objects
	max_free	Maximum number of free slabs allowed in the cache. If more slabs in the slab cache are freed, they are released (if a release callback function is specified).
	grow_fn	Cache grow callback function, called by the slab cache to allocate new buffers for the cache. If no function is specified the cache cannot allocate buffers on demand.
	release_fn	Slab release callback function, called by the cache to release unused buffers. If no function is specified unused buffers are not released.

Returns:

0 on success (initialized cache descriptor), error code otherwise:

• -L4_EINVAL size too big / invalid cache descriptor

Setup cache descriptor. The function initializes the internal cache descriptor structures, but does not allocate any memory. Memory can be added using the l4slab_add_slab() function or memory is allocated on demand by the cache if the grow callback function is specified.

L4_CV void l4slab_destroy

(

l4slab_cache_t *

cache

)

Destroy slab cache.

Parameters:

cache

Cache descriptor

Release slab descriptor and free all allocated memory. This function is only useful if a release callback function is specified for the cache, otherwise it has no effect.

L4_CV void l4slab_add_slab	(	l4slab_cache_t *	cache,
		void *	buffer,
		void *	data
	)

Add a slab to the slab cache.

Parameters:

	cache	Cache descriptor
	buffer	Pointer to new slab
	data	Application data

Add the slab (buffer) to the slab cache. Buffer must be cache->slab_size-sized and slab_size aligned in memory.

L4_CV void l4slab_set_data	(	l4slab_cache_t *	cache,
		void *	data
	)

Set cache application data pointer.

Parameters:

	cache	Cache descriptor
	data	Application data pointer

L4_CV void* l4slab_get_data

(

l4slab_cache_t *

cache

)

Get cache application data.

Parameters:

cache

Cache descriptor

Returns:

Application data pointer, NULL if invalid cache descriptor or no data pointer set.