AZ::RHI::AliasedAttachmentAllocator< Heap > Class Template Reference

#include <AliasedAttachmentAllocator.h>

Inherits AZ::RHI::DeviceObject, and FrameEventBus::Handler.

Classes
struct	Descriptor

Public Member Functions
	AZ_CLASS_ALLOCATOR (AliasedAttachmentAllocator< Heap >, AZ::SystemAllocator)
ResultCode	Init (Device &device, const Descriptor &descriptor)
	Initializes the allocator.
void	Begin (TransientAttachmentPoolCompileFlags compileFlags, const size_t memoryUsageHint=0)
Buffer *	ActivateBuffer (const TransientBufferDescriptor &descriptor, Scope &scope)
void	DeactivateBuffer (const AttachmentId &attachmentId, Scope &scope)
Image *	ActivateImage (const TransientImageDescriptor &descriptor, Scope &scope)
void	DeactivateImage (const AttachmentId &attachmentId, Scope &scope)
void	End ()
	Called when the allocations / deallocations have completed for all scopes.
void	Shutdown () override
	DeviceObject override.
void	GetStatistics (AZStd::vector< TransientAttachmentStatistics::Heap > &heapStatistics) const
const Descriptor &	GetDescriptor () const
	Get allocator descriptor.
Public Member Functions inherited from AZ::RHI::DeviceObject
	AZ_RTTI (DeviceObject, "{17D34F71-944C-4AF5-9823-627474C4C0A6}", Object)
bool	IsInitialized () const
	Returns whether the device object is initialized.
Device &	GetDevice () const
Public Member Functions inherited from AZ::RHI::Object
	AZ_RTTI (Object, "{E43378F1-2331-4173-94B8-990ED20E6003}")
void	SetName (const Name &name)
	Sets the name of the object.
const Name &	GetName () const
	Returns the name set on the object by SetName.
uint32_t	use_count ()
	Returns the current use count of the object.

Static Public Member Functions
static Ptr< AliasedAttachmentAllocator >	Create ()

Additional Inherited Members
Protected Member Functions inherited from AZ::RHI::DeviceObject
void	Init (Device &device)
	The derived class should call this method to assign the device.
void	Shutdown () override
	Clears the current bound device to null.
Protected Member Functions inherited from AZ::RHI::Object
void	add_ref () const
void	release () const
Protected Attributes inherited from AZ::RHI::Object
AZStd::atomic_int	m_useCount = 0

Detailed Description

template<class Heap>
class AZ::RHI::AliasedAttachmentAllocator< Heap >

Utility class that Allocates Aliased Transient Attachments using one or multiple Heaps. The allocator uses pages, where each page corresponds to a Heap that is implemented by the platform. Users must provide a "Heap" class that inherits from the RHI::AliasedHeap class. This allocator use different allocation strategies described by the RHI::HeapAllocationStrategy enum. Depending on the strategy selected, the allocator can grow/shrink by allocating/deallocating heap pages. It can also compact a heap page if it is being underutilized. We also use the template type so we can inherit the AliasedAttachmentAllocator::Descriptor from the Heap::Descriptor to pass implementation specific parameters during the heap initialization.

Member Function Documentation

ActivateBuffer()

template<class Heap >

Buffer * AZ::RHI::AliasedAttachmentAllocator< Heap >::ActivateBuffer	(	const TransientBufferDescriptor &	descriptor,
		Scope &	scope
	)

Called when a buffer is being activated for the first time. This will acquire a buffer from a heap, configured for the provided descriptor. This may trigger a new heap to be allocated.

ActivateImage()

template<class Heap >

Image * AZ::RHI::AliasedAttachmentAllocator< Heap >::ActivateImage	(	const TransientImageDescriptor &	descriptor,
		Scope &	scope
	)

Called when an image is being activated for the first time. This will acquire an image from a heap, configured for the provided descriptor. This may trigger a new heap to be allocated.

Begin()

template<class Heap >

void AZ::RHI::AliasedAttachmentAllocator< Heap >::Begin	(	TransientAttachmentPoolCompileFlags	compileFlags,
		const size_t	memoryUsageHint = 0
	)

This is called at the beginning of the compile phase for the current frame, before any allocations occur.

Parameters

compileFlags	The flags that will be use during the resources activation.
memoryUsageHint	[Optional] The total amount of memory needed by the allocator for allocating resources in the Begin/End cycle. This value is needed when the allocator is using a "MemoryHint" allocation strategy. The amount of memory needed can be calculated by doing a first pass with the flag TransientAttachmentPoolCompileFlags::DontAllocateResources.

DeactivateBuffer()

template<class Heap >

void AZ::RHI::AliasedAttachmentAllocator< Heap >::DeactivateBuffer	(	const AttachmentId &	attachmentId,
		Scope &	scope
	)

Called when a buffer is being de-allocated from the allocator. Called during the last scope the attachment is used, after all allocations for that scope have been processed.

DeactivateImage()

template<class Heap >

void AZ::RHI::AliasedAttachmentAllocator< Heap >::DeactivateImage	(	const AttachmentId &	attachmentId,
		Scope &	scope
	)

Called when a image is being de-allocated from the allocator. Called during the last scope the attachment is used, after all allocations for that scope have been processed.

GetStatistics()

template<class Heap >

void AZ::RHI::AliasedAttachmentAllocator< Heap >::GetStatistics

(

AZStd::vector< TransientAttachmentStatistics::Heap > &

heapStatistics

)

const

Get statistics for the pool (built during End). Statistics will be added at the end of the provided vector.

Shutdown()

template<class Heap >

void AZ::RHI::AliasedAttachmentAllocator< Heap >::Shutdown

overridevirtual

DeviceObject override.

Reimplemented from AZ::RHI::Object.

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

• Gems/Atom/RHI/Code/Include/Atom/RHI/AliasedAttachmentAllocator.h