AZ::RHI::Allocator Class Reference

#include <Allocator.h>

Inherited by AZ::RHI::FreeListAllocator, AZ::RHI::LinearAllocator, and AZ::RHI::PoolAllocator.

Classes
struct	Descriptor

Public Member Functions
virtual void	Shutdown ()=0
virtual VirtualAddress	Allocate (size_t byteCount, size_t byteAlignment)=0
virtual void	DeAllocate (VirtualAddress offset)=0
virtual void	GarbageCollect ()=0
virtual void	GarbageCollectForce ()=0
	Forces garbage collection of all allocations, regardless of the GC latency.
virtual size_t	GetAllocationCount () const
virtual size_t	GetAllocatedByteCount () const
virtual const Descriptor &	GetDescriptor () const =0
	Returns the descriptor used to initialize the allocator.
virtual float	ComputeFragmentation () const
virtual void	Clone (RHI::Allocator *newAllocator)
	Clone the current allocator to the new allocator passed in.
template<typename T >
T *	AllocateAs (size_t byteCount, size_t byteAlignment)

Detailed Description

An allocator interface used for external GPU allocations. The allocator does not manage the host memory. Instead, the user specifies a base address (which may be 0, in order to allocate offsets from a base resource). The allocator interface also provides an API for garbage collection. If used to manage GPU resources, these are often deferred-released after N frames. The user may provide a garbage collection latency, which controls the number of GarbageCollect calls that must occur before an allocation is actually reclaimed. The intended use case is to garbage collect at the end of each frame.

Member Function Documentation

Allocate()

virtual VirtualAddress AZ::RHI::Allocator::Allocate ( size_t  byteCount, size_t  byteAlignment  )

pure virtual

Allocates a virtual address relative to the base address provided at initialization time.

Parameters

byteCount	The number of bytes to allocate.
byteAlignement	The alignment used to align the allocation.

Implemented in AZ::RHI::FreeListAllocator, AZ::RHI::LinearAllocator, and AZ::RHI::PoolAllocator.

AllocateAs()

template<typename T >

T * AZ::RHI::Allocator::AllocateAs ( size_t  byteCount, size_t  byteAlignment  )

inline

Helper for converting agnostic VirtualAddress type to pointer type. Will convert VirtualAddress::Null to nullptr.

Clone()

virtual void AZ::RHI::Allocator::Clone ( RHI::Allocator *  newAllocator )

inlinevirtual

Clone the current allocator to the new allocator passed in.

Reimplemented in AZ::RHI::FreeListAllocator.

ComputeFragmentation()

virtual float AZ::RHI::Allocator::ComputeFragmentation ( ) const

inlinevirtual

Compute the fragmentation present in the allocator (possibly an estimate). The returned value is expected to be a measure between 0.f and 1.f inclusive, with 0.f indicating zero fragmentation.

Reimplemented in AZ::RHI::FreeListAllocator.

DeAllocate()

virtual void AZ::RHI::Allocator::DeAllocate ( VirtualAddress  offset )

pure virtual

Deallocates an allocation. The memory is not reclaimed until garbage collect is called. Depending on the garbage collection latency, it may take several garbage collection cycles before the memory is reclaimed.

Implemented in AZ::RHI::FreeListAllocator, AZ::RHI::LinearAllocator, and AZ::RHI::PoolAllocator.

GarbageCollect()

virtual void AZ::RHI::Allocator::GarbageCollect ( )

pure virtual

Allocations are deferred-released until a specific number of GC cycles have occurred. This is useful for allocations actively being consumed by the GPU.

Implemented in AZ::RHI::FreeListAllocator, AZ::RHI::LinearAllocator, and AZ::RHI::PoolAllocator.

GarbageCollectForce()

virtual void AZ::RHI::Allocator::GarbageCollectForce ( )

pure virtual

Forces garbage collection of all allocations, regardless of the GC latency.

Implemented in AZ::RHI::FreeListAllocator, AZ::RHI::LinearAllocator, and AZ::RHI::PoolAllocator.

GetAllocatedByteCount()

virtual size_t AZ::RHI::Allocator::GetAllocatedByteCount ( ) const

inlinevirtual

Returns the number of bytes used by the allocator. This includes allocations that are pending garbage collection.

Reimplemented in AZ::RHI::FreeListAllocator, AZ::RHI::LinearAllocator, and AZ::RHI::PoolAllocator.

GetAllocationCount()

virtual size_t AZ::RHI::Allocator::GetAllocationCount ( ) const

inlinevirtual

Returns the number of allocations active for this allocator. This includes allocations that are pending garbage collection.

Reimplemented in AZ::RHI::FreeListAllocator, and AZ::RHI::PoolAllocator.

GetDescriptor()

virtual const Descriptor & AZ::RHI::Allocator::GetDescriptor ( ) const

pure virtual

Returns the descriptor used to initialize the allocator.

Implemented in AZ::RHI::FreeListAllocator, AZ::RHI::LinearAllocator, and AZ::RHI::PoolAllocator.

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

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