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

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 86 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 132 of file TripleBuffer.h.

◆ _getNonConstReadBuffer()

T& _getNonConstReadBuffer ( )

inline

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

Definition at line 124 of file TripleBuffer.h.

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◆ commitWrite()

void commitWrite ( )

inline

Definition at line 163 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 255 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 271 of file TripleBuffer.h.

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◆ getHiddenBufferIndex()

uint_fast8_t getHiddenBufferIndex ( ) const

inlineprotected

Definition at line 217 of file TripleBuffer.h.

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◆ getReadBuffer()

const T& getReadBuffer ( ) const

inline

Returns: the current read buffer

Definition at line 108 of file TripleBuffer.h.

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◆ getReadBufferIndex()

uint_fast8_t getReadBufferIndex ( ) const

inlineprotected

Definition at line 203 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 116 of file TripleBuffer.h.

◆ getWriteBuffer() [1/2]

T& getWriteBuffer ( )

inline

Returns: the write buffer

Definition at line 92 of file TripleBuffer.h.

◆ getWriteBuffer() [2/2]

const T& getWriteBuffer ( ) const

inline

Returns: the write buffer

Definition at line 100 of file TripleBuffer.h.

◆ getWriteBufferIndex()

uint_fast8_t getWriteBufferIndex ( ) const

inlineprotected

Definition at line 210 of file TripleBuffer.h.

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◆ hasNewWrite()

bool hasNewWrite ( uint_fast8_t flags ) const

inlineprotected

Definition at line 243 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 171 of file TripleBuffer.h.

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◆ reinitAllBuffers() [2/2]

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

inline

Definition at line 179 of file TripleBuffer.h.

◆ setDebugMode()

void setDebugMode ( bool mode )

inline

Definition at line 187 of file TripleBuffer.h.

◆ swapWriteAndHiddenBuffer()

void swapWriteAndHiddenBuffer ( )

inlineprotected

Swap the write buffer with the hidden buffer.

Definition at line 227 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 143 of file TripleBuffer.h.

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Member Data Documentation

◆ buffer

T buffer[3]

protected

Definition at line 302 of file TripleBuffer.h.

◆ debugMode

std::atomic_bool debugMode {false}

protected

Definition at line 303 of file TripleBuffer.h.

◆ dirtyBitMask

const uint_fast8_t dirtyBitMask = 1 << dirtyBitShift

staticprotected

Definition at line 295 of file TripleBuffer.h.

◆ dirtyBitShift

const uint_fast8_t dirtyBitShift = 7

staticprotected

Definition at line 286 of file TripleBuffer.h.

◆ flags

std::atomic_uint_fast8_t flags {initialFlags}

mutableprotected

Definition at line 301 of file TripleBuffer.h.

◆ hiddenBufferIndexMask

const uint_fast8_t hiddenBufferIndexMask = 3 << hiddenBufferIndexShift

staticprotected

Definition at line 293 of file TripleBuffer.h.

◆ hiddenBufferIndexShift

const uint_fast8_t hiddenBufferIndexShift = 2

staticprotected

Definition at line 284 of file TripleBuffer.h.

◆ hiddenToReadShift

const uint_fast8_t hiddenToReadShift = hiddenBufferIndexShift - readBufferIndexShift

staticprotected

Definition at line 288 of file TripleBuffer.h.

◆ hiddenToWriteShift

const uint_fast8_t hiddenToWriteShift

staticprotected

Initial value:

=

writeBufferIndexShift - hiddenBufferIndexShift

Definition at line 289 of file TripleBuffer.h.

◆ initialFlags

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

staticprotected

Definition at line 297 of file TripleBuffer.h.

◆ readBufferIndexMask

const uint_fast8_t readBufferIndexMask = 3 << readBufferIndexShift

staticprotected

Definition at line 292 of file TripleBuffer.h.

◆ readBufferIndexShift

const uint_fast8_t readBufferIndexShift = 0

staticprotected

Definition at line 283 of file TripleBuffer.h.

◆ writeBufferIndexMask

const uint_fast8_t writeBufferIndexMask = 3 << writeBufferIndexShift

staticprotected

Definition at line 294 of file TripleBuffer.h.

◆ writeBufferIndexShift

const uint_fast8_t writeBufferIndexShift = 4

staticprotected

Definition at line 285 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 >