PageAllocator Class Reference

Allocates virtual memory using the memory server. More...

#include <PageAllocator.h>

Inheritance diagram for PageAllocator:

Public Member Functions
	PageAllocator (const Range range)
	Class constructor. More...
virtual Size	available () const
	Get memory available. More...
virtual Result	allocate (Range &args)
	Allocate memory. More...
virtual Result	release (const Address addr)
	Release memory. More...
Public Member Functions inherited from Allocator
	Allocator ()
	Default class constructor. More...
	Allocator (const Range range)
	Class constructor with Range input. More...
virtual	~Allocator ()
	Class destructor. More...
void	setParent (Allocator *parent)
	Set parent allocator. More...
Allocator *	parent ()
	Get parent Allocator. More...
Address	base () const
	Get memory base address for allocations. More...
Size	alignment () const
	Get memory alignment in bytes for allocations. More...
virtual Size	size () const
	Get memory size. More...

Private Attributes
Size	m_allocated
	Total number of bytes allocated. More...

Static Private Attributes
static const Size	MinimumAllocationSize = PAGESIZE * 32U
	Minimum size required for allocations. More...

Additional Inherited Members
Public Types inherited from Allocator
enum	Result {   Success = 0, InvalidAddress, InvalidSize, InvalidAlignment,   OutOfMemory }
	Allocation results. More...
typedef struct Allocator::Range	Range
	Describes a range of memory. More...
Static Public Member Functions inherited from Allocator
static void	setDefault (Allocator *alloc)
	Makes the given Allocator the default. More...
static Allocator *	getDefault ()
	Retrieve the currently default Allocator. More...
Protected Member Functions inherited from Allocator
Address	aligned (const Address addr, const Size boundary) const
	Align memory address. More...

Detailed Description

Allocates virtual memory using the memory server.

Definition at line 36 of file PageAllocator.h.

Constructor & Destructor Documentation

PageAllocator()

PageAllocator::PageAllocator

(

const Range

range

)

Class constructor.

Parameters

range

Block of continguous memory to be managed.

Definition at line 21 of file PageAllocator.cpp.

Member Function Documentation

allocate()

Allocator::Result PageAllocator::allocate ( Allocator::Range &  args )

virtual

Allocate memory.

Parameters

args	Contains the requested size and alignment on input. On output, contains the actual allocated address.

Returns

Result value.

Reimplemented from Allocator.

Definition at line 32 of file PageAllocator.cpp.

References Memory::Range::access, Allocator::Range::address, Allocator::aligned(), Allocator::base(), ERROR, m_allocated, MapSparse, MinimumAllocationSize, Allocator::OutOfMemory, PAGESIZE, Memory::Range::phys, MemoryMap::range(), Memory::Readable, SELF, Memory::Range::size, Allocator::Range::size, Allocator::Success, API::Success, Memory::User, MemoryMap::UserHeap, Memory::Range::virt, VMCtl(), Memory::Writable, and ZERO.

available()

Size PageAllocator::available ( ) const

virtual

Get memory available.

Returns

Size of memory available by the Allocator.

Reimplemented from Allocator.

Definition at line 27 of file PageAllocator.cpp.

References m_allocated, and Allocator::size().

release()

Allocator::Result PageAllocator::release ( const Address  addr )

virtual

Release memory.

Parameters

addr	Points to memory previously returned by allocate().

Returns

Result value.

See also

allocate

Todo:

Currently this function does not actually release memory back to the system. A potential problem with the current implementation is that releasing memory may result in fragmented virtual memory that may break higher-level allocators.

Reimplemented from Allocator.

Definition at line 73 of file PageAllocator.cpp.

References Allocator::InvalidAddress.

Field Documentation

m_allocated

Size PageAllocator::m_allocated

private

Total number of bytes allocated.

Definition at line 87 of file PageAllocator.h.

Referenced by allocate(), and available().

MinimumAllocationSize

const Size PageAllocator::MinimumAllocationSize = PAGESIZE * 32U

staticprivate

Minimum size required for allocations.

Definition at line 41 of file PageAllocator.h.

Referenced by allocate().

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

• lib/libruntime/PageAllocator.h
• lib/libruntime/PageAllocator.cpp