ph::MemoryArena Class Reference

A general purpose bump allocator. More...

#include <MemoryArena.h>

Inheritance diagram for ph::MemoryArena:

Public Member Functions
	MemoryArena ()
	Empty arena without any allocation performed yet.
	MemoryArena (std::size_t blockSizeHintInBytes, std::size_t numDefaultBlocks)
	~MemoryArena ()
std::byte *	allocRaw (std::size_t numBytes, std::size_t alignmentInBytes=alignof(std::max_align_t))
	Allocate raw memory. Generally speaking, the memory returned contains no object–placement new is required before any use of the memory content for most object types, otherwise it is UB by C++ standard. An exception is implicit-lifetime types. This method implicitly create objects of implicit-lifetime type in the memory returned.
void	clear ()
	Reset the usage of the arena. All memory handed out are effectively deallocated/deleted after this call. The arena then transitions to its initial state and is ready for allocation again. Destructors are called if required.
std::size_t	numUsedBytes () const
std::size_t	numAllocatedBytes () const
std::size_t	getBlockSizeInBytes () const
std::size_t	numAllocatedBlocks () const
template<typename T >
T *	alloc ()
	Allocate raw memory for type T. Convenient method for allocating raw memory for object of type T. Alignment is handled automatically. See allocRaw(std::size_t, std::size_t) for details.
template<typename T >
TSpan< T >	allocArray (const std::size_t arraySize)
	Allocate raw memory for array of type T. Convenient method for allocating raw memory for array of type T. Alignment is handled automatically. See allocRaw(std::size_t, std::size_t) for details.
template<typename T , typename... Args>
T *	make (Args &&... args)
	Make an object of type T. Convenient method for creating an object without needing a placement new later. Equivalent to allocate then placement new for an object of type T. Alignment is handled automatically. Additionally, destructors will be automatically called (if needed) when clearing the arena.
	MemoryArena (MemoryArena &&other)=default
	Move another arena into this one. The moved-from arena cannot be used unless:
MemoryArena &	operator= (MemoryArena &&rhs)=default

Detailed Description

A general purpose bump allocator.

Constructor & Destructor Documentation

MemoryArena() [1/3]

ph::MemoryArena::MemoryArena

(

)

Empty arena without any allocation performed yet.

MemoryArena() [2/3]

ph::MemoryArena::MemoryArena	(	std::size_t	blockSizeHintInBytes,
		std::size_t	numDefaultBlocks )

Parameters

blockSizeHintInBytes	Size of each memory block in the arena. This imposed a limit on the maximum size of a single allocation. The parameter is only a hint, actual size may be larger for performance reasons.
numDefaultBlocks	Number of pre-allocated blocks.

MemoryArena() [3/3]

ph::MemoryArena::MemoryArena ( MemoryArena && other )

inlinedefault

Move another arena into this one. The moved-from arena cannot be used unless:

1. yet another arena has moved into it
2. clear() has been called.

~MemoryArena()

ph::MemoryArena::~MemoryArena

(

)

Member Function Documentation

alloc()

template<typename T >

T * ph::MemoryArena::alloc ( )

inline

Allocate raw memory for type T. Convenient method for allocating raw memory for object of type T. Alignment is handled automatically. See allocRaw(std::size_t, std::size_t) for details.

Template Parameters

T	Type for the raw memory allocated, must be trivially destructible.

Note

Provides storage only. Placement new is required before any use of the memory content. For const types, laundering is needed to access the created object via the returned pointer ([basic.life] section 8.3).

allocArray()

template<typename T >

TSpan< T > ph::MemoryArena::allocArray ( const std::size_t arraySize )

inline

Allocate raw memory for array of type T. Convenient method for allocating raw memory for array of type T. Alignment is handled automatically. See allocRaw(std::size_t, std::size_t) for details.

Template Parameters

T	Type for the raw array memory allocated, must be trivially destructible.

Note

Provides storage only. Placement new is required before any use of the memory content. For const types, laundering is needed to access the created object via the returned pointer ([basic.life] section 8.3).

allocRaw()

std::byte * ph::MemoryArena::allocRaw	(	std::size_t	numBytes,
		std::size_t	alignmentInBytes = alignof(std::max_align_t) )

Allocate raw memory. Generally speaking, the memory returned contains no object–placement new is required before any use of the memory content for most object types, otherwise it is UB by C++ standard. An exception is implicit-lifetime types. This method implicitly create objects of implicit-lifetime type in the memory returned.

Parameters

numBytes	Number of bytes to allocate.
alignmentInBytes	Alignment requirement of the allocation, in bytes.

Returns

Allocated memory, never nullptr.

Exceptions

std::bad_alloc

If the allocation failed.

clear()

void ph::MemoryArena::clear

(

)

Reset the usage of the arena. All memory handed out are effectively deallocated/deleted after this call. The arena then transitions to its initial state and is ready for allocation again. Destructors are called if required.

getBlockSizeInBytes()

std::size_t ph::MemoryArena::getBlockSizeInBytes ( ) const

inline

make()

template<typename T , typename... Args>

T * ph::MemoryArena::make ( Args &&... args )

inline

Make an object of type T. Convenient method for creating an object without needing a placement new later. Equivalent to allocate then placement new for an object of type T. Alignment is handled automatically. Additionally, destructors will be automatically called (if needed) when clearing the arena.

Template Parameters

T	Type for the object created.

Parameters

args	Arguments for calling the constructor of T.

numAllocatedBlocks()

std::size_t ph::MemoryArena::numAllocatedBlocks ( ) const

inline

numAllocatedBytes()

std::size_t ph::MemoryArena::numAllocatedBytes ( ) const

inline

numUsedBytes()

std::size_t ph::MemoryArena::numUsedBytes ( ) const

inline

operator=()

MemoryArena & ph::MemoryArena::operator= ( MemoryArena && rhs )

inlinedefault

---

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

• Source/Utility/MemoryArena.h
• Source/Utility/MemoryArena.cpp
• Source/Utility/MemoryArena.ipp