Page_allocator Class Reference

Page_allocator is the allocator/deallocator for whole pages or ranges of pages. More...

#include <pagealloc.h>

Collaboration diagram for Page_allocator:


Public Member Functions
void	init (void start, Size memory_size, unsigned max_alignment, void metadata_end=NULL, bool managed_pages_are_physical=false)
Page *	alloc_page_within (unsigned alignment, void *owner, unsigned begin, unsigned end)
Page *	alloc_page_above (unsigned alignment, void *owner, unsigned begin)
Page *	alloc_page_below (unsigned alignment, void *owner, unsigned end)
Page *	alloc_page (unsigned alignment, void *owner)
void	free_page (Page *page)
Page *	get_page_info (void *memory) const
void *	get_metadata_start ()
void *	get_max_metadata_start ()
bool	manages (void *memory)
void	print ()
Protected Member Functions
Page *	find_free_page (unsigned alignment, unsigned begin, unsigned end)
Page *	try_to_split_page (unsigned requested_alignment, unsigned begin, unsigned end)
Page *	split_page (Page *page, unsigned requested_alignment, unsigned begin, unsigned end)
Page *	try_to_coalesce_page (unsigned requested_alignment, unsigned begin, unsigned end)
Page *	coalesce_page (Page *page, unsigned requested_alignment, unsigned begin, unsigned end)
Protected Attributes
unsigned	memory_begin
unsigned	memory_end
Page *	pages
unsigned	page_count
unsigned	free_list_count
List< Page > *	free_lists

Detailed Description

Page_allocator is the allocator/deallocator for whole pages or ranges of pages.

It can be used to manage either virtual or physical pages.

The original page allocator was generously contributed by Lee Salzman.

Member Function Documentation

Page * Page_allocator::alloc_page ( unsigned alignment,

void * owner

) [inline]

Allocate a page.

Page * Page_allocator::alloc_page_above ( unsigned alignment,

void * owner,

unsigned begin

) [inline]

Allocate a page greater than or equal to an address.
begin is a page address shifted right by PAGE_ALIGNMENT.

Page * Page_allocator::alloc_page_below ( unsigned alignment,

void * owner,

unsigned end

) [inline]

Allocate a page less than an address.
end is a page address shifted right by PAGE_ALIGNMENT.

Page * Page_allocator::alloc_page_within ( unsigned alignment,

void * owner,

unsigned begin,

unsigned end

)

Allocate a page within an address range.
The range values are page addresses shifted right by PAGE_ALIGNMENT.

Page * Page_allocator::coalesce_page ( Page * page,

unsigned requested_alignment,

unsigned begin,

unsigned end

) [protected]

Coalesce a page to a desired alignment so that it is within the given begin and end range.
The range values are page addresses shifted right by PAGE_ALIGNMENT.

Page * Page_allocator::find_free_page ( unsigned alignment,

unsigned begin,

unsigned end

) [protected]

Attempt to find and allocate a free page in one of the free lists.
The range values are page addresses shifted right by PAGE_ALIGNMENT.

void Page_allocator::free_page ( Page * page )

Return a page to the allocator.

void * Page_allocator::get_max_metadata_start ( )

Return the start address of this allocator's metadata as if it managed the maximum number of pages allowed by this architecture.

void* Page_allocator::get_metadata_start ( ) [inline]

Return the start address of this allocator's metadata.

Page * Page_allocator::get_page_info ( void * memory ) const [inline]

Get the page metadata for a given page address.

void Page_allocator::init ( void * start,

Size memory_size,

unsigned max_alignment,

void * metadata_end = NULL,

bool managed_pages_are_physical = false

)

Initialize this allocator to manage pages from the given memory start address to start + memory_size.
Page spans can be at most of max_alignment. Put allocator metadata in a contiguous range of memory ending at metadata_end or at the end of the managed memory range if metadata_end is NULL.

bool Page_allocator::manages ( void * memory ) [inline]

Return whether this page allocator manages the given page.

void Page_allocator::print ( )

Print out basic info on this allocator.

Page * Page_allocator::split_page ( Page * page,

unsigned requested_alignment,

unsigned begin,

unsigned end

) [protected]

Split a page to a desired alignment so that it is within the given begin and end range.
The range values are page addresses shifted right by PAGE_ALIGNMENT.

Page * Page_allocator::try_to_coalesce_page ( unsigned requested_alignment,

unsigned begin,

unsigned end

) [protected]

Attempt to find a candidate for coalescing pages and if found, do it within the given begin and end range.
The range values are page addresses shifted right by PAGE_ALIGNMENT.

Page * Page_allocator::try_to_split_page ( unsigned requested_alignment,

unsigned begin,

unsigned end

) [protected]

Attempt to find a candidate for splitting pages and if found, do a split within the given begin and end range.
The range values are page addresses shifted right by PAGE_ALIGNMENT.

Member Data Documentation

unsigned Page_allocator::free_list_count [protected]

number of free lists maintained

List<Page>* Page_allocator::free_lists [protected]

array of free page lists for alignments 0 to free_lists_count - 1

unsigned Page_allocator::memory_begin [protected]

address of first managed page, shifted right by PAGE_ALIGNMENT

unsigned Page_allocator::memory_end [protected]

address of last managed page, shifted right by PAGE_ALIGNMENT

unsigned Page_allocator::page_count [protected]

number of managed pages

Page* Page_allocator::pages [protected]

array of Pages this manages

The documentation for this class was generated from the following files:

Page_allocator Class Reference

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

Member Data Documentation