#include <Buffer.h>

Inheritance diagram for Buffer< T, allowShortOperation >:

Collaboration diagram for Buffer< T, allowShortOperation >:

Classes
class	ActiveOperation

struct	Segment

Public Member Functions
	Buffer (size_t bufferSize)

size_t	write (const T *buffer, size_t count, bool block=true)

size_t	writeAvailable (const T *buffer, size_t count, bool atomic=false)

size_t	writeAtomic (const T *buffer, size_t count, bool block=true)

bool	tryWrite (const T *buffer, size_t count)

size_t	read (T *buffer, size_t count, bool block=true)

void	disableWrites ()

void	disableReads ()

bool	enableWrites ()

bool	enableReads ()

size_t	getDataSize ()

size_t	getSize ()

bool	canWrite (bool block)

bool	canRead (bool block)

uint64_t	readableGeneration () const

uint64_t	writableGeneration () const

void	wipe ()

void	monitor (Thread pThread, Event pEvent)

void	monitor (Semaphore *pSemaphore)

void	cullMonitorTargets (Thread *pThread)

void	cullMonitorTargets (Semaphore *pSemaphore)

void	cullMonitorTargets (Event *pEvent)

Private Member Functions
	WITHOUT_IMPLICIT_CONSTRUCTORS (Buffer)

bool	beginOperation ()

void	endOperation ()

void	notifyMonitors ()

void	notifyMonitorsLocked ()

size_t	writeLocked (const T *buffer, size_t count)

void	addSegment (const T *buffer, size_t count)

Private Attributes
size_t	m_BufferSize

size_t	m_DataSize

Atomic< uint64_t >	m_ReadableGeneration

Atomic< uint64_t >	m_WritableGeneration

Mutex	m_Lock

ConditionVariable	m_WriteCondition

ConditionVariable	m_ReadCondition

ConditionVariable	m_DrainCondition

List< Segment * >	m_Segments

BufferMonitors	m_Monitors

bool	m_bCanRead

bool	m_bCanWrite

bool	m_bClosing

size_t	m_ActiveOperations

Static Private Attributes
static const size_t	m_SegmentSize = 32768

Friends
class	UnixSocket

Detailed Description

template<class T, bool allowShortOperation = false>
class Buffer< T, allowShortOperation >

Provides a buffer of a specific size and utility functions for integration with e.g. File or other kernel systems.

allowShortOperation defines the action to take on overflow. If true, the buffer's write() operation is permitted to return a size less than requested if the buffer would overflow. Otherwise, the implementation is required to block until bytes are present (unless blocking has been explicitly denied).

Note that an attempt to read when writing is disabled that would block will always return the number of bytes read so far (or zero if none yet). The same is true for an attempt to write when reading is disabled if that would block.

Definition at line 53 of file Buffer.h.

Constructor & Destructor Documentation

◆ Buffer()

template<class T , bool allowShortOperation>

Buffer< T, allowShortOperation >::Buffer ( size_t bufferSize )

Definition at line 41 of file Buffer.cc.

◆ ~Buffer()

template<class T , bool allowShortOperation>

Buffer< T, allowShortOperation >::~Buffer ( )

Definition at line 58 of file Buffer.cc.

Member Function Documentation

◆ addSegment()

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::addSegment	(	const T *	buffer,
		size_t	count
	)

private

Create a new segment with the given data.

Definition at line 727 of file Buffer.cc.

References Buffer< T, allowShortOperation >::Segment::data, and Buffer< T, allowShortOperation >::Segment::size.

◆ beginOperation()

template<class T , bool allowShortOperation>

bool Buffer< T, allowShortOperation >::beginOperation ( )

private

Definition at line 82 of file Buffer.cc.

◆ canRead()

template<class T , bool allowShortOperation>

bool Buffer< T, allowShortOperation >::canRead ( bool block )

Check if the buffer can be read from.

Definition at line 525 of file Buffer.cc.

References LockGuard< T >::disown(), and ConditionVariable::mutexAcquired().

Referenced by ConsoleFile::select(), ConsolePhysicalFile::select(), PsAuxFile::select(), UnixSocket::select(), TextIO::select(), InputFile::select(), EvdevFile::select(), and TextIO::writeStr().

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◆ canWrite()

template<class T , bool allowShortOperation>

bool Buffer< T, allowShortOperation >::canWrite ( bool block )

Check if the buffer can be written to.

Note: This does not guarantee the next write() will succeed.

Definition at line 491 of file Buffer.cc.

References LockGuard< T >::disown(), and ConditionVariable::mutexAcquired().

Referenced by ConsoleFile::inputLineDiscipline(), ConsoleFile::select(), PsAuxFile::select(), and TextIO::select().

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◆ cullMonitorTargets() [1/3]

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::cullMonitorTargets ( Event * pEvent )

Remove monitoring targets for the given Event.

Definition at line 646 of file Buffer.cc.

◆ cullMonitorTargets() [2/3]

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::cullMonitorTargets ( Semaphore * pSemaphore )

Remove monitoring targets for the given Semaphore.

Definition at line 633 of file Buffer.cc.

◆ cullMonitorTargets() [3/3]

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::cullMonitorTargets ( Thread * pThread )

Remove monitoring targets for the given thread.

Definition at line 620 of file Buffer.cc.

◆ disableReads()

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::disableReads ( )

Disable further reads from the buffer. This wakes all operations whose wait predicate can no longer succeed.

Definition at line 422 of file Buffer.cc.

◆ disableWrites()

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::disableWrites ( )

Disable further writes to the buffer. This wakes all operations whose wait predicate can no longer succeed.

Definition at line 406 of file Buffer.cc.

Referenced by Ps2Controller::uninitialise().

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◆ enableReads()

template<class T , bool allowShortOperation>

bool Buffer< T, allowShortOperation >::enableReads ( )

Enable reads from the buffer.

Returns: the previous state of reads.

Definition at line 454 of file Buffer.cc.

◆ enableWrites()

template<class T , bool allowShortOperation>

bool Buffer< T, allowShortOperation >::enableWrites ( )

Enable writes to the buffer.

Returns: the previous state of writes.

Definition at line 438 of file Buffer.cc.

Referenced by Ps2Controller::initialise3().

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◆ endOperation()

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::endOperation ( )

private

Definition at line 93 of file Buffer.cc.

◆ getDataSize()

template<class T , bool allowShortOperation>

size_t Buffer< T, allowShortOperation >::getDataSize ( )

Get the number of bytes in the buffer now.

Definition at line 470 of file Buffer.cc.

◆ getSize()

template<class T , bool allowShortOperation>

size_t Buffer< T, allowShortOperation >::getSize ( )

Get the full size of the buffer (potential storage).

Definition at line 481 of file Buffer.cc.

◆ monitor() [1/2]

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::monitor ( Semaphore * pSemaphore )

Add a Semaphore to be signaled when data changes.

Definition at line 607 of file Buffer.cc.

◆ monitor() [2/2]

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::monitor	(	Thread *	pThread,
		Event *	pEvent
	)

Add an event to be sent to the given thread upon a data change.

Note: An event does not guarantee the next operation will succeed.

Definition at line 594 of file Buffer.cc.

◆ notifyMonitors()

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::notifyMonitors ( )

private

Helper function to send events upon completing an action.

Clears all monitors as a side effect.

Definition at line 659 of file Buffer.cc.

◆ notifyMonitorsLocked()

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::notifyMonitorsLocked ( )

private

Sends and retires monitor targets while m_Lock is held.

Definition at line 672 of file Buffer.cc.

◆ read()

template<class T , bool allowShortOperation>

size_t Buffer< T, allowShortOperation >::read	(	T *	buffer,
		size_t	count,
		bool	block = `true`
	)

Read

Parameters

count	values into
buffer,optionally	blocking if no more values are available to be read yet.

Definition at line 296 of file Buffer.cc.

References Buffer< T, allowShortOperation >::Segment::data, ConditionVariable::mutexAcquired(), Buffer< T, allowShortOperation >::Segment::reader, and Buffer< T, allowShortOperation >::Segment::size.

Referenced by ConsoleFile::inputLineDiscipline(), PsAuxFile::readBytewise(), TextIO::readBytewise(), InputFile::readBytewise(), EvdevFile::readBytewise(), Ps2Controller::readFirstPort(), and Ps2Controller::readSecondPort().

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◆ readableGeneration()

template<class T , bool allowShortOperation>

uint64_t Buffer< T, allowShortOperation >::readableGeneration ( ) const

Rising-edge sequences updated atomically with the protected predicates.

Definition at line 559 of file Buffer.cc.

Referenced by UnixSocket::readinessGenerations().

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◆ tryWrite()

template<class T , bool allowShortOperation>

bool Buffer< T, allowShortOperation >::tryWrite	(	const T *	buffer,
		size_t	count
	)

Writes the complete input without waiting for lock ownership or space. Returns false without changing the buffer when the whole input cannot be accepted immediately. An empty input is a successful no-op.

Definition at line 275 of file Buffer.cc.

◆ wipe()

template<class T , bool allowShortOperation>

void Buffer< T, allowShortOperation >::wipe ( )

Wipes the buffer.

Definition at line 569 of file Buffer.cc.

Referenced by Ps2Controller::initialise3().

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◆ writableGeneration()

template<class T , bool allowShortOperation>

uint64_t Buffer< T, allowShortOperation >::writableGeneration ( ) const

Definition at line 564 of file Buffer.cc.

◆ write()

template<class T , bool allowShortOperation>

size_t Buffer< T, allowShortOperation >::write	(	const T *	buffer,
		size_t	count,
		bool	block = `true`
	)

Write

Parameters

count	values from
buffer,optionally	blocking before writing if there is insufficient space.

Definition at line 103 of file Buffer.cc.

Referenced by ConsoleFile::inputLineDiscipline(), and TextIO::writeStr().

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◆ writeAtomic()

template<class T , bool allowShortOperation>

size_t Buffer< T, allowShortOperation >::writeAtomic	(	const T *	buffer,
		size_t	count,
		bool	block = `true`
	)

Writes the complete input as one indivisible operation. If the input fits in the buffer but there is not enough room yet, a blocking caller waits before publishing any of it.

Definition at line 227 of file Buffer.cc.

◆ writeAvailable()

template<class T , bool allowShortOperation>

size_t Buffer< T, allowShortOperation >::writeAvailable	(	const T *	buffer,
		size_t	count,
		bool	atomic = `false`
	)

Waits for buffer lock ownership, then writes up to the currently available capacity without waiting for a reader. Returns zero if either side closed. When atomic is true, insufficient capacity leaves the buffer unchanged.

Definition at line 201 of file Buffer.cc.

Referenced by ConsoleFile::inputLineDiscipline(), and Ps2Controller::irq().

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◆ writeLocked()

template<class T , bool allowShortOperation>

size_t Buffer< T, allowShortOperation >::writeLocked	(	const T *	buffer,
		size_t	count
	)

private

Appends up to count values while m_Lock is held.

Definition at line 679 of file Buffer.cc.

References Buffer< T, allowShortOperation >::Segment::data, and Buffer< T, allowShortOperation >::Segment::size.

Friends And Related Symbol Documentation

◆ UnixSocket

template<class T , bool allowShortOperation = false>

friend class UnixSocket

friend

Definition at line 54 of file Buffer.h.

Member Data Documentation

◆ m_ActiveOperations

template<class T , bool allowShortOperation = false>

size_t Buffer< T, allowShortOperation >::m_ActiveOperations

private

Definition at line 269 of file Buffer.h.

◆ m_bCanRead

template<class T , bool allowShortOperation = false>

bool Buffer< T, allowShortOperation >::m_bCanRead

private

Definition at line 266 of file Buffer.h.

◆ m_bCanWrite

template<class T , bool allowShortOperation = false>

bool Buffer< T, allowShortOperation >::m_bCanWrite

private

Definition at line 267 of file Buffer.h.

◆ m_bClosing

template<class T , bool allowShortOperation = false>

bool Buffer< T, allowShortOperation >::m_bClosing

private

Definition at line 268 of file Buffer.h.

◆ m_BufferSize

template<class T , bool allowShortOperation = false>

size_t Buffer< T, allowShortOperation >::m_BufferSize

private

Definition at line 252 of file Buffer.h.

◆ m_DataSize

template<class T , bool allowShortOperation = false>

size_t Buffer< T, allowShortOperation >::m_DataSize

private

Definition at line 253 of file Buffer.h.

◆ m_DrainCondition

template<class T , bool allowShortOperation = false>

ConditionVariable Buffer< T, allowShortOperation >::m_DrainCondition

private

Definition at line 261 of file Buffer.h.

◆ m_Lock

template<class T , bool allowShortOperation = false>

Mutex Buffer< T, allowShortOperation >::m_Lock

private

Definition at line 257 of file Buffer.h.

◆ m_Monitors

template<class T , bool allowShortOperation = false>

BufferMonitors Buffer< T, allowShortOperation >::m_Monitors

private

Definition at line 264 of file Buffer.h.

◆ m_ReadableGeneration

template<class T , bool allowShortOperation = false>

Atomic<uint64_t> Buffer< T, allowShortOperation >::m_ReadableGeneration

private

Definition at line 254 of file Buffer.h.

◆ m_ReadCondition

template<class T , bool allowShortOperation = false>

ConditionVariable Buffer< T, allowShortOperation >::m_ReadCondition

private

Definition at line 260 of file Buffer.h.

◆ m_Segments

template<class T , bool allowShortOperation = false>

List<Segment*> Buffer< T, allowShortOperation >::m_Segments

private

Definition at line 263 of file Buffer.h.

◆ m_SegmentSize

template<class T , bool allowShortOperation = false>

const size_t Buffer< T, allowShortOperation >::m_SegmentSize = 32768

staticprivate

Controls the size of each segment.

Definition at line 233 of file Buffer.h.

◆ m_WritableGeneration

template<class T , bool allowShortOperation = false>

Atomic<uint64_t> Buffer< T, allowShortOperation >::m_WritableGeneration

private

Definition at line 255 of file Buffer.h.

◆ m_WriteCondition

template<class T , bool allowShortOperation = false>

ConditionVariable Buffer< T, allowShortOperation >::m_WriteCondition

private

Definition at line 259 of file Buffer.h.

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

Classes

Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ Buffer()

◆ ~Buffer()

Member Function Documentation

◆ addSegment()

◆ beginOperation()

◆ canRead()

◆ canWrite()

◆ cullMonitorTargets() [1/3]

◆ cullMonitorTargets() [2/3]

◆ cullMonitorTargets() [3/3]

◆ disableReads()

◆ disableWrites()

◆ enableReads()

◆ enableWrites()

◆ endOperation()

◆ getDataSize()

◆ getSize()

◆ monitor() [1/2]

◆ monitor() [2/2]

◆ notifyMonitors()

◆ notifyMonitorsLocked()

◆ read()

◆ readableGeneration()

◆ tryWrite()

◆ wipe()

◆ writableGeneration()

◆ write()

◆ writeAtomic()

◆ writeAvailable()

◆ writeLocked()

Friends And Related Symbol Documentation

◆ UnixSocket

Member Data Documentation

◆ m_ActiveOperations

◆ m_bCanRead

◆ m_bCanWrite

◆ m_bClosing

◆ m_BufferSize

◆ m_DataSize

◆ m_DrainCondition

◆ m_Lock

◆ m_Monitors

◆ m_ReadableGeneration

◆ m_ReadCondition

◆ m_Segments

◆ m_SegmentSize

◆ m_WritableGeneration

◆ m_WriteCondition