D3D12MA::VirtualBlock Class Reference

Represents pure allocation algorithm and a data structure with allocations in some memory block, without actually allocating any GPU memory. More...

#include <D3D12MemAlloc.h>

Inherits IUnknownImpl.

Public Member Functions
BOOL	IsEmpty () const
	Returns true if the block is empty - contains 0 allocations.
void	GetAllocationInfo (VirtualAllocation allocation, VIRTUAL_ALLOCATION_INFO *pInfo) const
	Returns information about an allocation - its offset, size and custom pointer.
HRESULT	Allocate (const VIRTUAL_ALLOCATION_DESC *pDesc, VirtualAllocation *pAllocation, UINT64 *pOffset)
	Creates new allocation.
void	FreeAllocation (VirtualAllocation allocation)
	Frees the allocation.
void	Clear ()
	Frees all the allocations.
void	SetAllocationPrivateData (VirtualAllocation allocation, void *pPrivateData)
	Changes custom pointer for an allocation to a new value.
void	GetStatistics (Statistics *pStats) const
	Retrieves basic statistics of the virtual block that are fast to calculate.
void	CalculateStatistics (DetailedStatistics *pStats) const
	Retrieves detailed statistics of the virtual block that are slower to calculate.
void	BuildStatsString (WCHAR **ppStatsString) const
	Builds and returns statistics as a string in JSON format, including the list of allocations with their parameters.
void	FreeStatsString (WCHAR *pStatsString) const
	Frees memory of a string returned from VirtualBlock::BuildStatsString.

Protected Member Functions
void	ReleaseThis () override

Friends
D3D12MA_API HRESULT	CreateVirtualBlock (const VIRTUAL_BLOCK_DESC *, VirtualBlock **)
	Creates new D3D12MA::VirtualBlock object and returns it through ppVirtualBlock.
template<typename T >
void	D3D12MA_DELETE (const ALLOCATION_CALLBACKS &, T *)

Detailed Description

Represents pure allocation algorithm and a data structure with allocations in some memory block, without actually allocating any GPU memory.

This class allows to use the core algorithm of the library custom allocations e.g. CPU memory or sub-allocation regions inside a single GPU buffer.

To create this object, fill in D3D12MA::VIRTUAL_BLOCK_DESC and call CreateVirtualBlock(). To destroy it, call its method VirtualBlock::Release(). You need to free all the allocations within this block or call Clear() before destroying it.

This object is not thread-safe - should not be used from multiple threads simultaneously, must be synchronized externally.

Member Function Documentation

Allocate()

HRESULT D3D12MA::VirtualBlock::Allocate	(	const VIRTUAL_ALLOCATION_DESC *	pDesc,
		VirtualAllocation *	pAllocation,
		UINT64 *	pOffset
	)

Creates new allocation.

Parameters

	pDesc
[out]	pAllocation	Unique indentifier of the new allocation within single block.
[out]	pOffset	Returned offset of the new allocation. Optional, can be null.

Returns

S_OK if allocation succeeded, E_OUTOFMEMORY if it failed.

If the allocation failed, pAllocation->AllocHandle is set to 0 and pOffset, if not null, is set to UINT64_MAX.

BuildStatsString()

void D3D12MA::VirtualBlock::BuildStatsString

(

WCHAR **

ppStatsString

)

const

Builds and returns statistics as a string in JSON format, including the list of allocations with their parameters.

Parameters

[out]

ppStatsString

Must be freed using VirtualBlock::FreeStatsString.

CalculateStatistics()

void D3D12MA::VirtualBlock::CalculateStatistics

(

DetailedStatistics *

pStats

)

const

Retrieves detailed statistics of the virtual block that are slower to calculate.

Parameters

[out]

pStats

Statistics of the virtual block.

FreeAllocation()

void D3D12MA::VirtualBlock::FreeAllocation

(

VirtualAllocation

allocation

)

Frees the allocation.

Calling this function with allocation.AllocHandle == 0 is correct and does nothing.

GetStatistics()

void D3D12MA::VirtualBlock::GetStatistics

(

Statistics *

pStats

)

const

Retrieves basic statistics of the virtual block that are fast to calculate.

Parameters

[out]

pStats

Statistics of the virtual block.

Friends And Related Function Documentation

CreateVirtualBlock

D3D12MA_API HRESULT CreateVirtualBlock ( const VIRTUAL_BLOCK_DESC *  , VirtualBlock **    )

friend

Creates new D3D12MA::VirtualBlock object and returns it through ppVirtualBlock.

Note you don't need to create D3D12MA::Allocator to use virtual blocks.

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

• Gems/Atom/RHI/DX12/External/AMD_D3D12MemoryAllocator/v2.0.1/dx12ma/D3D12MemAlloc.h