Internal Memory Allocation

Collaboration diagram for Internal Memory Allocation:

Data Structures
struct	apr_memnode_t

Macros
#define	APR_MEMNODE_T_SIZE   APR_ALIGN_DEFAULT(sizeof(apr_memnode_t))
#define	APR_ALLOCATOR_MAX_FREE_UNLIMITED   0

Typedefs
typedef struct apr_allocator_t	apr_allocator_t
typedef struct apr_memnode_t	apr_memnode_t

Functions
apr_status_t	apr_allocator_create (apr_allocator_t **allocator)
void	apr_allocator_destroy (apr_allocator_t *allocator)
apr_memnode_t *	apr_allocator_alloc (apr_allocator_t *allocator, apr_size_t size)
void	apr_allocator_free (apr_allocator_t *allocator, apr_memnode_t *memnode)
apr_size_t	apr_allocator_page_size (void)
apr_status_t	apr_allocator_min_order_set (unsigned int order)
apr_size_t	apr_allocator_align (apr_allocator_t *allocator, apr_size_t size)
void	apr_allocator_owner_set (apr_allocator_t *allocator, apr_pool_t *pool)
apr_pool_t *	apr_allocator_owner_get (apr_allocator_t *allocator)
void	apr_allocator_max_free_set (apr_allocator_t *allocator, apr_size_t size)
void	apr_allocator_mutex_set (apr_allocator_t *allocator, apr_thread_mutex_t *mutex)
apr_thread_mutex_t *	apr_allocator_mutex_get (apr_allocator_t *allocator)

Detailed Description

Macro Definition Documentation

APR_ALLOCATOR_MAX_FREE_UNLIMITED

#define APR_ALLOCATOR_MAX_FREE_UNLIMITED   0

Symbolic constants

APR_MEMNODE_T_SIZE

#define APR_MEMNODE_T_SIZE   APR_ALIGN_DEFAULT(sizeof(apr_memnode_t))

The base size of a memory node - aligned.

Typedef Documentation

apr_allocator_t

typedef struct apr_allocator_t apr_allocator_t

the allocator structure

apr_memnode_t

typedef struct apr_memnode_t apr_memnode_t

the structure which holds information about the allocation

Function Documentation

apr_allocator_align()

apr_size_t apr_allocator_align	(	apr_allocator_t *	allocator,
		apr_size_t	size
	)

Get the true size that would be allocated for the given size (including the header and alignment).

Parameters

allocator	The allocator from which to the memory would be allocated
size	The size to align

Returns

The aligned size (or zero on apr_size_t overflow)

apr_allocator_alloc()

apr_memnode_t * apr_allocator_alloc	(	apr_allocator_t *	allocator,
		apr_size_t	size
	)

Allocate a block of mem from the allocator

Parameters

allocator	The allocator to allocate from
size	The size of the mem to allocate (excluding the memnode structure)

apr_allocator_create()

apr_status_t apr_allocator_create

(

apr_allocator_t **

allocator

)

Create a new allocator

Parameters

allocator

The allocator we have just created.

apr_allocator_destroy()

void apr_allocator_destroy

(

apr_allocator_t *

allocator

)

Destroy an allocator

Parameters

allocator

The allocator to be destroyed

Remarks

Any memnodes not given back to the allocator prior to destroying will not be free()d.

apr_allocator_free()

void apr_allocator_free	(	apr_allocator_t *	allocator,
		apr_memnode_t *	memnode
	)

Free a list of blocks of mem, giving them back to the allocator. The list is typically terminated by a memnode with its next field set to NULL.

Parameters

allocator	The allocator to give the mem back to
memnode	The memory node to return

apr_allocator_max_free_set()

void apr_allocator_max_free_set	(	apr_allocator_t *	allocator,
		apr_size_t	size
	)

Set the current threshold at which the allocator should start giving blocks back to the system.

Parameters

allocator	The allocator to set the threshold on
size	The threshold. 0 == unlimited.

apr_allocator_min_order_set()

apr_status_t apr_allocator_min_order_set

(

unsigned int

order

)

Setup the minimum allocation order (in 2^order pages).

Parameters

order

The order to set

Returns

APR_SUCCESS, or APR_EINVAL if order above 9.

Note

Default is order-1 (e.g. 8K on systems with 4K pages).

Remarks

Should be done at initialization time, never concurrently.

apr_allocator_mutex_get()

apr_thread_mutex_t * apr_allocator_mutex_get

(

apr_allocator_t *

allocator

)

Get the mutex currently set for the allocator

Parameters

allocator

The allocator

apr_allocator_mutex_set()

void apr_allocator_mutex_set	(	apr_allocator_t *	allocator,
		apr_thread_mutex_t *	mutex
	)

Set a mutex for the allocator to use

Parameters

allocator	The allocator to set the mutex for
mutex	The mutex

apr_allocator_owner_get()

apr_pool_t * apr_allocator_owner_get

(

apr_allocator_t *

allocator

)

Get the current owner of the allocator

Parameters

allocator

The allocator to get the owner from

apr_allocator_owner_set()

void apr_allocator_owner_set	(	apr_allocator_t *	allocator,
		apr_pool_t *	pool
	)

Set the owner of the allocator

Parameters

allocator	The allocator to set the owner for
pool	The pool that is to own the allocator

Remarks

Typically pool is the highest level pool using the allocator

apr_allocator_page_size()

apr_size_t apr_allocator_page_size

(

void

)

Get the page/boundary size.

Returns

The page size