Dynamic memory allocation services

This code implements a variant of the allocator described in "Design of a General Purpose Memory Allocator for the 4.3BSD Unix Kernel" by Marshall K. More...

Collaboration diagram for Dynamic memory allocation services:

Functions
void	xnheap_destroy (struct xnheap *heap)
	Destroys a memory heap. More...
void *	xnheap_alloc (struct xnheap *heap, size_t size)
	Allocate a memory block from a memory heap. More...
void	xnheap_free (struct xnheap *heap, void *block)
	Release a block to a memory heap. More...
void	xnheap_set_name (struct xnheap *heap, const char *name,...)
	Set the heap's name string. More...

Detailed Description

This code implements a variant of the allocator described in "Design of a General Purpose Memory Allocator for the 4.3BSD Unix Kernel" by Marshall K.

McKusick and Michael J. Karels (USENIX 1988), see http://docs.FreeBSD.org/44doc/papers/kernmalloc.pdf. The free page list is maintained in rbtrees for fast lookups of multi-page memory ranges, and pages holding bucketed memory have a fast allocation bitmap to manage their blocks internally.

Function Documentation

xnheap_alloc()

void * xnheap_alloc	(	struct xnheap *	heap,
		size_t	size
	)

Allocate a memory block from a memory heap.

Allocates a contiguous region of memory from an active memory heap. Such allocation is guaranteed to be time-bounded.

Parameters

heap	The descriptor address of the heap to get memory from.
size	The size in bytes of the requested block.

Returns

The address of the allocated region upon success, or NULL if no memory is available from the specified heap.

Tags

unrestricted

xnheap_destroy()

void xnheap_destroy

(

struct xnheap *

heap

)

Destroys a memory heap.

Destroys a memory heap.

Parameters

heap	The heap descriptor.

Tags

secondary-only

xnheap_free()

void xnheap_free	(	struct xnheap *	heap,
		void *	block
	)

Release a block to a memory heap.

Releases a memory block to a heap.

Parameters

heap	The heap descriptor.
block	The block to be returned to the heap.

Tags

unrestricted

xnheap_set_name()

void xnheap_set_name	(	struct xnheap *	heap,
		const char *	name,
			...
	)

Set the heap's name string.

Set the heap name that will be used in statistic outputs.

Parameters

heap	The address of a heap descriptor.
name	Name displayed in statistic outputs. This parameter can be a printk()-like format argument list.

Tags

task-unrestricted