A simple triple buffer for lockfree comunication between a single writer and a single reader. More...

#include <ArmarXCore/util/CPPUtility/TripleBuffer.h>

Public Member Functions
T &	_getNonConstHiddenBuffer ()

T &	_getNonConstReadBuffer ()

void	commitWrite ()

const T &	getReadBuffer () const

const T &	getUpToDateReadBuffer () const

T &	getWriteBuffer ()

const T &	getWriteBuffer () const

template<class U = T>
std::enable_if< std::is_copy_constructible< U >::value >::type	reinitAllBuffers (const T &init)

void	reinitAllBuffers (T &&writeBuff, T &&hiddenBuff, T &&readBuff)

void	setDebugMode (bool mode)

template<class... Ts>
	TripleBuffer (const Ts &...ts)

	TripleBuffer (T &&initR, T &&initH, T &&initW)

bool	updateReadBuffer () const
	Swaps in the hidden buffer if it contains new data. More...

Protected Member Functions
uint_fast8_t	getHiddenBufferIndex () const

uint_fast8_t	getReadBufferIndex () const

uint_fast8_t	getWriteBufferIndex () const

bool	hasNewWrite (uint_fast8_t flags) const

TripleBuffer &	operator= (const TripleBuffer &)=delete

void	swapWriteAndHiddenBuffer ()
	Swap the write buffer with the hidden buffer. More...

	TripleBuffer (const TripleBuffer &)=delete

Static Protected Member Functions
static uint_fast8_t	flagSwapReadWithHidden (uint_fast8_t flags)
	swap read and hidden indexes More...

static uint_fast8_t	flagSwapWriteWithHidden (uint_fast8_t flags)
	swap write and hidden indexes of given flags (set dirty to 1) More...

Protected Attributes
T	buffer [3]

std::atomic_bool	debugMode {false}

std::atomic_uint_fast8_t	flags {initialFlags}

Static Protected Attributes
static const uint_fast8_t	dirtyBitMask = 1 << dirtyBitShift

static const uint_fast8_t	dirtyBitShift = 7

static const uint_fast8_t	hiddenBufferIndexMask = 3 << hiddenBufferIndexShift

static const uint_fast8_t	hiddenBufferIndexShift = 2

static const uint_fast8_t	hiddenToReadShift = hiddenBufferIndexShift - readBufferIndexShift

static const uint_fast8_t	hiddenToWriteShift = writeBufferIndexShift - hiddenBufferIndexShift

static const uint_fast8_t	initialFlags = 2 + (1 << 2)

static const uint_fast8_t	readBufferIndexMask = 3 << readBufferIndexShift

static const uint_fast8_t	readBufferIndexShift = 0

static const uint_fast8_t	writeBufferIndexMask = 3 << writeBufferIndexShift

static const uint_fast8_t	writeBufferIndexShift = 4

Detailed Description

template<typename T>
class armarx::TripleBuffer< T >

A simple triple buffer for lockfree comunication between a single writer and a single reader.

If more than one reader/writer is required, you have to synchronize the access. Writers must not have: writes to the same data cell (except it is an atomic et al) and no writes are allowed during swapping of the buffer. Readers must not read when the buffer is swapped. If a writer only writes parts of the data structure, data loss could occure! (use a WriteBufferedTripleBuffer instead)

Definition at line 71 of file TripleBuffer.h.

Constructor & Destructor Documentation

◆ TripleBuffer() [1/3]

TripleBuffer	(	T &&	initR,
		T &&	initH,
		T &&	initW
	)

inline

Definition at line 78 of file TripleBuffer.h.

◆ TripleBuffer() [2/3]

TripleBuffer ( const Ts &... ts )

inline

Definition at line 85 of file TripleBuffer.h.

◆ TripleBuffer() [3/3]

TripleBuffer ( const TripleBuffer< T > & )

protecteddelete

Member Function Documentation

◆ _getNonConstHiddenBuffer()

T& _getNonConstHiddenBuffer ( )

inline

Returns: the current read buffer (sometimes required for more complex initialization)

Definition at line 121 of file TripleBuffer.h.

◆ _getNonConstReadBuffer()

T& _getNonConstReadBuffer ( )

inline

Returns: the current read buffer (sometimes required for more complex initialization)

Definition at line 115 of file TripleBuffer.h.

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◆ commitWrite()

void commitWrite ( )

inline

Definition at line 146 of file TripleBuffer.h.

◆ flagSwapReadWithHidden()

static uint_fast8_t flagSwapReadWithHidden ( uint_fast8_t flags )

inlinestaticprotected

swap read and hidden indexes

swap read and hidden indexes of given flags (set dirty to 0)

Parameters

flags the current flags

Returns: the new flags

Definition at line 216 of file TripleBuffer.h.

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◆ flagSwapWriteWithHidden()

static uint_fast8_t flagSwapWriteWithHidden ( uint_fast8_t flags )

inlinestaticprotected

swap write and hidden indexes of given flags (set dirty to 1)

Parameters

flags the current flags

Returns: the new flags

Definition at line 229 of file TripleBuffer.h.

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◆ getHiddenBufferIndex()

uint_fast8_t getHiddenBufferIndex ( ) const

inlineprotected

Definition at line 188 of file TripleBuffer.h.

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◆ getReadBuffer()

const T& getReadBuffer ( ) const

inline

Returns: the current read buffer

Definition at line 102 of file TripleBuffer.h.

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◆ getReadBufferIndex()

uint_fast8_t getReadBufferIndex ( ) const

inlineprotected

Definition at line 180 of file TripleBuffer.h.

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◆ getUpToDateReadBuffer()

const T& getUpToDateReadBuffer ( ) const

inline

Returns: the most up to date read buffer

Definition at line 108 of file TripleBuffer.h.

◆ getWriteBuffer() [1/2]

T& getWriteBuffer ( )

inline

Returns: the write buffer

Definition at line 90 of file TripleBuffer.h.

◆ getWriteBuffer() [2/2]

const T& getWriteBuffer ( ) const

inline

Returns: the write buffer

Definition at line 96 of file TripleBuffer.h.

◆ getWriteBufferIndex()

uint_fast8_t getWriteBufferIndex ( ) const

inlineprotected

Definition at line 184 of file TripleBuffer.h.

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◆ hasNewWrite()

bool hasNewWrite ( uint_fast8_t flags ) const

inlineprotected

Definition at line 206 of file TripleBuffer.h.

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◆ operator=()

TripleBuffer& operator= ( const TripleBuffer< T > & )

protecteddelete

◆ reinitAllBuffers() [1/2]

std::enable_if<std::is_copy_constructible<U>::value>::type reinitAllBuffers ( const T & init )

inline

Definition at line 153 of file TripleBuffer.h.

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◆ reinitAllBuffers() [2/2]

void reinitAllBuffers	(	T &&	writeBuff,
		T &&	hiddenBuff,
		T &&	readBuff
	)

inline

Definition at line 159 of file TripleBuffer.h.

◆ setDebugMode()

void setDebugMode ( bool mode )

inline

Definition at line 165 of file TripleBuffer.h.

◆ swapWriteAndHiddenBuffer()

void swapWriteAndHiddenBuffer ( )

inlineprotected

Swap the write buffer with the hidden buffer.

Definition at line 196 of file TripleBuffer.h.

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◆ updateReadBuffer()

bool updateReadBuffer ( ) const

inline

Swaps in the hidden buffer if it contains new data.

Returns: True if new data is available

Definition at line 131 of file TripleBuffer.h.

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Member Data Documentation

◆ buffer

T buffer[3]

protected

Definition at line 257 of file TripleBuffer.h.

◆ debugMode

std::atomic_bool debugMode {false}

protected

Definition at line 258 of file TripleBuffer.h.

◆ dirtyBitMask

const uint_fast8_t dirtyBitMask = 1 << dirtyBitShift

staticprotected

Definition at line 250 of file TripleBuffer.h.

◆ dirtyBitShift

const uint_fast8_t dirtyBitShift = 7

staticprotected

Definition at line 242 of file TripleBuffer.h.

◆ flags

std::atomic_uint_fast8_t flags {initialFlags}

mutableprotected

Definition at line 256 of file TripleBuffer.h.

◆ hiddenBufferIndexMask

const uint_fast8_t hiddenBufferIndexMask = 3 << hiddenBufferIndexShift

staticprotected

Definition at line 248 of file TripleBuffer.h.

◆ hiddenBufferIndexShift

const uint_fast8_t hiddenBufferIndexShift = 2

staticprotected

Definition at line 240 of file TripleBuffer.h.

◆ hiddenToReadShift

const uint_fast8_t hiddenToReadShift = hiddenBufferIndexShift - readBufferIndexShift

staticprotected

Definition at line 244 of file TripleBuffer.h.

◆ hiddenToWriteShift

const uint_fast8_t hiddenToWriteShift = writeBufferIndexShift - hiddenBufferIndexShift

staticprotected

Definition at line 245 of file TripleBuffer.h.

◆ initialFlags

const uint_fast8_t initialFlags = 2 + (1 << 2)

staticprotected

Definition at line 252 of file TripleBuffer.h.

◆ readBufferIndexMask

const uint_fast8_t readBufferIndexMask = 3 << readBufferIndexShift

staticprotected

Definition at line 247 of file TripleBuffer.h.

◆ readBufferIndexShift

const uint_fast8_t readBufferIndexShift = 0

staticprotected

Definition at line 239 of file TripleBuffer.h.

◆ writeBufferIndexMask

const uint_fast8_t writeBufferIndexMask = 3 << writeBufferIndexShift

staticprotected

Definition at line 249 of file TripleBuffer.h.

◆ writeBufferIndexShift

const uint_fast8_t writeBufferIndexShift = 4

staticprotected

Definition at line 241 of file TripleBuffer.h.

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

ArmarXCore/util/CPPUtility/TripleBuffer.h

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

template<typename T> class armarx::TripleBuffer< T >

Constructor & Destructor Documentation

◆ TripleBuffer() [1/3]

◆ TripleBuffer() [2/3]

◆ TripleBuffer() [3/3]

Member Function Documentation

◆ _getNonConstHiddenBuffer()

◆ _getNonConstReadBuffer()

◆ commitWrite()

◆ flagSwapReadWithHidden()

◆ flagSwapWriteWithHidden()

◆ getHiddenBufferIndex()

◆ getReadBuffer()

◆ getReadBufferIndex()

◆ getUpToDateReadBuffer()

◆ getWriteBuffer() [1/2]

◆ getWriteBuffer() [2/2]

◆ getWriteBufferIndex()

◆ hasNewWrite()

◆ operator=()

◆ reinitAllBuffers() [1/2]

◆ reinitAllBuffers() [2/2]

◆ setDebugMode()

◆ swapWriteAndHiddenBuffer()

◆ updateReadBuffer()

Member Data Documentation

◆ buffer

◆ debugMode

◆ dirtyBitMask

◆ dirtyBitShift

◆ flags

◆ hiddenBufferIndexMask

◆ hiddenBufferIndexShift

◆ hiddenToReadShift

◆ hiddenToWriteShift

◆ initialFlags

◆ readBufferIndexMask

◆ readBufferIndexShift

◆ writeBufferIndexMask

◆ writeBufferIndexShift

template<typename T>
class armarx::TripleBuffer< T >