Overview

A specialized block used by the BuddyAllocator.

Buddy blocks have outer sizes that are powers of two. When smaller blocks are needed, a block is split into left and right halves of equal size. These half-blocks are "buddies", and when both are freed they are merged back into a single block.

Inheritance diagram for pw::allocator::internal::BuddyBlock:

Public Member Functions
	BuddyBlock (size_t outer_size)

StatusWithSize	CanAlloc (Layout layout) const

BuddyBlock *	Split ()
	Splits a block in half and returns the new block.

Public Member Functions inherited from pw::allocator::BasicBlock< BuddyBlock >
	BasicBlock (const BasicBlock &other)=delete

BasicBlock &	operator= (const BasicBlock &other)=delete

constexpr std::byte *	UsableSpace ()

constexpr const std::byte *	UsableSpace () const

constexpr std::byte *	UsableSpaceUnchecked ()

constexpr const std::byte *	UsableSpaceUnchecked () const

constexpr size_t	OuterSize () const

constexpr size_t	InnerSize () const

constexpr size_t	InnerSizeUnchecked () const

constexpr bool	IsValid () const

constexpr bool	CheckInvariants () const
	Like `IsValid`, but crashes if invalid.

Static Public Member Functions
static BuddyBlock *	Merge (BuddyBlock &&left, BuddyBlock &&right)
	Merges two blocks together.

Static Public Member Functions inherited from pw::allocator::BasicBlock< BuddyBlock >
static constexpr Result< BuddyBlock * >	Init (ByteSpan region)
	Creates the first block for a given memory region.

static constexpr internal::copy_const_ptr_t< Ptr, BuddyBlock * >	FromUsableSpace (Ptr usable_space)

static constexpr size_t	OuterSizeFromInnerSize (size_t inner_size)

static constexpr size_t	InnerSizeFromOuterSize (size_t outer_size)

Additional Inherited Members
Static Public Attributes inherited from pw::allocator::BasicBlock< BuddyBlock >
static constexpr size_t	kAlignment

static constexpr size_t	kBlockOverhead

static constexpr size_t	kMinOuterSize

Protected Member Functions inherited from pw::allocator::BasicBlock< BuddyBlock >
constexpr bool	DoCheckInvariants (bool strict) const

Member Function Documentation

◆ CanAlloc()

StatusWithSize pw::allocator::internal::BuddyBlock::CanAlloc ( Layout layout ) const

Simplified version of Allocatable::CanAlloc, as needed for UnorderedBucket::Remove.

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

pw_allocator/public/pw_allocator/buddy_allocator.h

Overview

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Member Function Documentation

◆ CanAlloc()