UE::FPlatformIoDispatcherBase Class Reference

#include <PlatformIoDispatcherBase.h>

Inheritance diagram for UE::FPlatformIoDispatcherBase:

Public Member Functions
virtual	~FPlatformIoDispatcherBase ()
virtual bool	Init () override final
virtual uint32	Run () override final
virtual void	Stop () override final
virtual FIoStatus	Initialize () override final
virtual FIoFileReadRequest	ScatterGather (FIoScatterGatherRequestParams &&Params, FIoFileReadRequestCompleted &&OnCompleted) override
virtual FIoFileReadRequest	ReadDirect (FIoDirectReadRequestParams &&Params, FIoFileReadRequestCompleted &&OnCompleted) override
virtual bool	Tick () override
virtual void	UpdatePriority (FIoFileReadRequest Request, int32 NewPriority) override
virtual void	CancelRequest (FIoFileReadRequest Request) override
virtual void	CancelAllRequests (FIoFileHandle FileHandle) override
virtual void	DeleteRequest (FIoFileReadRequest Request) override
Public Member Functions inherited from FRunnable
virtual void	Exit ()
virtual class FSingleThreadRunnable *	GetSingleThreadInterface ()
virtual	~FRunnable ()
Public Member Functions inherited from UE::IPlatformIoDispatcher
virtual	~IPlatformIoDispatcher ()=default
virtual TIoStatusOr< FIoFileHandle >	OpenFile (const TCHAR *Filename, const FIoFileProperties &FileProperties, FIoFileStat *OutStat=nullptr)=0
virtual FIoStatus	CloseFile (FIoFileHandle FileHandle)=0

Protected Member Functions
	FPlatformIoDispatcherBase (FPlatformIoDispatcherCreateParams &&Params)
virtual FIoStatus	OnInitialize ()
virtual uint32	OnIoThreadEntry ()=0
virtual void	OnWakeUp ()=0
virtual FIoPlatformFileInfo	GetPlatformFileInfo (FIoFileHandle FileHandle)=0
uint32	GetNextFileId ()
void	EnqueueCompletedFileBlock (FIoFileBlockRequest &FileBlockRequest)
void	CompleteFileBlock (FIoFileBlockRequest &FileBlockRequest)
void	EnqueueBlockToDecode (FIoEncodedBlockRequest &EncodedBlockRequest)
void	ProcessDecodedBlock (FIoEncodedBlockRequest &EncodedBlockRequest, FIoChunkBlockDecodeResult &&DecodeResult, FIoChunkBlockDecodeRequest &NextDecodeRequest)
void	ScatterDecodedBlock (FIoEncodedBlockRequest &EncodedBlockRequest)
void	CompleteDecodedBlock (FIoEncodedBlockRequest &EncodedBlockRequest, FIoPlatformReadRequestList &OutCompletedReadRequests)
bool	ProcessCompletedFileBlocks ()
bool	ProcessBlocksToDecode ()
bool	ProcessBlocksToComplete ()
bool	ProcessBlocks ()

Protected Attributes
FPlatformIoDispatcherStats	Stats
TUniquePtr< FRunnableThread >	Thread
TUniquePtr< FIoServiceThread >	SupportThread
FPlatformIoDispatcherRequestMgr	RequestMgr
FIoChunkBlockMemoryPool	ChunkBlockMemoryPool
FIoFileBlockMemoryPool	FileBlockMemoryPool
FIoQueue	IoQueue
FIoFileBlockCache	FileBlockCache
FIoFileBlockRequestList	FileBlocksToComplete
FIoEncodedBlockRequestList	BlocksToDecode
FIoEncodedBlockRequestList	BlocksToComplete
UE::FMutex	FileBlockMutex
UE::FMutex	EncodedBlockMutex
uint32	FileBlockSize = 256 << 10
bool	bMultithreaded = false
std::atomic_bool	bStopRequested {false}

Detailed Description

This is a base class for platform specific I/O dispatcher implementations. There are two kinds of I/O requests when reading data from disk. Direct-read requests for platforms with hardware decompression and scatter-gather requests. Scatter-gather requests are issued by specifying information about how the blocks on disk are encoded, i.e. compressed, encrypted and or signed and forms a set of encoded block request. Encoded block requests can be shared between user requests, i.e. if two user requests are reading the same encoded block, the block is decoded once and then scattered to the destination/targets buffers. The encoded block requests are devided into a set of larger file block requests. The size of the file blocks are configured with GIoDispatcherBufferSizeKB (default=256KiB). The maximum number of concurrent file block requests are constrained by the available memory in the file block memory pool configured with GIoDispatcherBufferMemoryMB (default=8MiB).

Constructor & Destructor Documentation

~FPlatformIoDispatcherBase()

UE::FPlatformIoDispatcherBase::~FPlatformIoDispatcherBase ( )

virtual

FPlatformIoDispatcherBase()

UE::FPlatformIoDispatcherBase::FPlatformIoDispatcherBase ( FPlatformIoDispatcherCreateParams &&  Params )

protected

Member Function Documentation

CancelAllRequests()

void UE::FPlatformIoDispatcherBase::CancelAllRequests ( FIoFileHandle  FileHandle )

overridevirtual

Cancel all inflight I/O request for the specified file.

Implements UE::IPlatformIoDispatcher.

CancelRequest()

void UE::FPlatformIoDispatcherBase::CancelRequest ( FIoFileReadRequest  Request )

overridevirtual

Cancel inflight I/O request.

Implements UE::IPlatformIoDispatcher.

CompleteDecodedBlock()

void UE::FPlatformIoDispatcherBase::CompleteDecodedBlock ( FIoEncodedBlockRequest &  EncodedBlockRequest, FIoPlatformReadRequestList &  OutCompletedReadRequests  )

protected

CompleteFileBlock()

void UE::FPlatformIoDispatcherBase::CompleteFileBlock ( FIoFileBlockRequest &  FileBlockRequest )

protected

DeleteRequest()

void UE::FPlatformIoDispatcherBase::DeleteRequest ( FIoFileReadRequest  Request )

overridevirtual

Delete the request. Must be called after the completion callback has been triggered.

Implements UE::IPlatformIoDispatcher.

EnqueueBlockToDecode()

void UE::FPlatformIoDispatcherBase::EnqueueBlockToDecode ( FIoEncodedBlockRequest &  EncodedBlockRequest )

protected

EnqueueCompletedFileBlock()

void UE::FPlatformIoDispatcherBase::EnqueueCompletedFileBlock ( FIoFileBlockRequest &  FileBlockRequest )

protected

GetNextFileId()

uint32 UE::FPlatformIoDispatcherBase::GetNextFileId ( )

protected

GetPlatformFileInfo()

virtual FIoPlatformFileInfo UE::FPlatformIoDispatcherBase::GetPlatformFileInfo ( FIoFileHandle  FileHandle )

protectedpure virtual

Init()

bool UE::FPlatformIoDispatcherBase::Init ( void  )

finaloverridevirtual

Initializes the runnable object.

This method is called in the context of the thread object that aggregates this, not the thread that passes this runnable to a new thread.

Returns

True if initialization was successful, false otherwise

See also

Run, Stop, Exit

Reimplemented from FRunnable.

Initialize()

FIoStatus UE::FPlatformIoDispatcherBase::Initialize ( )

finaloverridevirtual

Initialize the dispatcher. Called after the config system has been initialized.

Implements UE::IPlatformIoDispatcher.

OnInitialize()

FIoStatus UE::FPlatformIoDispatcherBase::OnInitialize ( )

protectedvirtual

OnIoThreadEntry()

virtual uint32 UE::FPlatformIoDispatcherBase::OnIoThreadEntry ( )

protectedpure virtual

OnWakeUp()

virtual void UE::FPlatformIoDispatcherBase::OnWakeUp ( )

protectedpure virtual

ProcessBlocks()

bool UE::FPlatformIoDispatcherBase::ProcessBlocks ( )

protected

ProcessBlocksToComplete()

bool UE::FPlatformIoDispatcherBase::ProcessBlocksToComplete ( )

protected

ProcessBlocksToDecode()

bool UE::FPlatformIoDispatcherBase::ProcessBlocksToDecode ( )

protected

ProcessCompletedFileBlocks()

bool UE::FPlatformIoDispatcherBase::ProcessCompletedFileBlocks ( )

protected

ProcessDecodedBlock()

void UE::FPlatformIoDispatcherBase::ProcessDecodedBlock ( FIoEncodedBlockRequest &  EncodedBlockRequest, FIoChunkBlockDecodeResult &&  DecodeResult, FIoChunkBlockDecodeRequest &  NextDecodeRequest  )

protected

ReadDirect()

FIoFileReadRequest UE::FPlatformIoDispatcherBase::ReadDirect ( FIoDirectReadRequestParams &&  Params, FIoFileReadRequestCompleted &&  OnCompleted  )

overridevirtual

Issue a direct read request. Returns an invalid file handle if direct read is not supported for the specifid file.

Implements UE::IPlatformIoDispatcher.

Run()

uint32 UE::FPlatformIoDispatcherBase::Run ( )

finaloverridevirtual

Runs the runnable object.

This is where all per object thread work is done. This is only called if the initialization was successful.

Returns

The exit code of the runnable object

See also

Init, Stop, Exit

Implements FRunnable.

ScatterDecodedBlock()

void UE::FPlatformIoDispatcherBase::ScatterDecodedBlock ( FIoEncodedBlockRequest &  EncodedBlockRequest )

protected

ScatterGather()

FIoFileReadRequest UE::FPlatformIoDispatcherBase::ScatterGather ( FIoScatterGatherRequestParams &&  Params, FIoFileReadRequestCompleted &&  OnCompleted  )

overridevirtual

Issue a scatter-gather request.

Implements UE::IPlatformIoDispatcher.

Stop()

void UE::FPlatformIoDispatcherBase::Stop ( void  )

finaloverridevirtual

Stops the runnable object.

This is called if a thread is requested to terminate early.

See also

Init, Run, Exit

Reimplemented from FRunnable.

Tick()

virtual bool UE::FPlatformIoDispatcherBase::Tick ( )

inlineoverridevirtual

Tick the dispatcher. Only used when multithreading is disabled.

Implements UE::IPlatformIoDispatcher.

UpdatePriority()

void UE::FPlatformIoDispatcherBase::UpdatePriority ( FIoFileReadRequest  Request, int32  NewPriority  )

overridevirtual

Update priority for an inflight I/O request.

Implements UE::IPlatformIoDispatcher.

Member Data Documentation

BlocksToComplete

FIoEncodedBlockRequestList UE::FPlatformIoDispatcherBase::BlocksToComplete

protected

BlocksToDecode

FIoEncodedBlockRequestList UE::FPlatformIoDispatcherBase::BlocksToDecode

protected

bMultithreaded

bool UE::FPlatformIoDispatcherBase::bMultithreaded = false

protected

bStopRequested

std::atomic_bool UE::FPlatformIoDispatcherBase::bStopRequested {false}

protected

ChunkBlockMemoryPool

FIoChunkBlockMemoryPool UE::FPlatformIoDispatcherBase::ChunkBlockMemoryPool

protected

EncodedBlockMutex

UE::FMutex UE::FPlatformIoDispatcherBase::EncodedBlockMutex

protected

FileBlockCache

FIoFileBlockCache UE::FPlatformIoDispatcherBase::FileBlockCache

protected

FileBlockMemoryPool

FIoFileBlockMemoryPool UE::FPlatformIoDispatcherBase::FileBlockMemoryPool

protected

FileBlockMutex

UE::FMutex UE::FPlatformIoDispatcherBase::FileBlockMutex

protected

FileBlockSize

uint32 UE::FPlatformIoDispatcherBase::FileBlockSize = 256 << 10

protected

FileBlocksToComplete

FIoFileBlockRequestList UE::FPlatformIoDispatcherBase::FileBlocksToComplete

protected

IoQueue

FIoQueue UE::FPlatformIoDispatcherBase::IoQueue

protected

RequestMgr

FPlatformIoDispatcherRequestMgr UE::FPlatformIoDispatcherBase::RequestMgr

protected

Stats

FPlatformIoDispatcherStats UE::FPlatformIoDispatcherBase::Stats

protected

SupportThread

TUniquePtr<FIoServiceThread> UE::FPlatformIoDispatcherBase::SupportThread

protected

Thread

TUniquePtr<FRunnableThread> UE::FPlatformIoDispatcherBase::Thread

protected

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

• Engine/Source/Runtime/Core/Internal/IO/PlatformIoDispatcherBase.h
• Engine/Source/Runtime/Core/Internal/IO/PlatformIoDispatcherBase.cpp