A Lock-free buffer implementation to read and write data of type T in a FIFO way. More...

#include <rtt/base/BufferLockFree.hpp>

Inheritance diagram for RTT::base::BufferLockFree< T >:

Public Types
typedef BufferBase::Options	Options

typedef BufferInterface< T >::reference_t	reference_t

typedef BufferInterface< T >::param_t	param_t

typedef BufferInterface< T >::size_type	size_type

typedef T	value_t

typedef boost::shared_ptr< BufferInterface< T > >	shared_ptr

Public Member Functions
	BufferLockFree (unsigned int bufsize, const Options &options=Options())
	Create an uninitialized lock-free buffer which can store bufsize elements. More...

	BufferLockFree (unsigned int bufsize, param_t initial_value, const Options &options=Options())
	Create a lock-free buffer which can store bufsize elements. More...

	~BufferLockFree ()

virtual bool	data_sample (param_t sample, bool reset=true)
	Initializes this buffer with a data sample, such that for dynamical allocated types T, the buffer can reserve place to hold these elements. More...

virtual value_t	data_sample () const
	Reads back a data sample. More...

size_type	capacity () const
	Returns the maximum number of items that can be stored in the buffer. More...

size_type	size () const
	Returns the actual number of items that are stored in the buffer. More...

bool	empty () const
	Check if this buffer is empty. More...

bool	full () const
	Check if this buffer is full. More...

void	clear ()
	Clears all contents of this buffer. More...

virtual size_type	dropped () const
	Returns the number of dropped samples, because the buffer was full. More...

bool	Push (param_t item)
	Write a single value to the buffer. More...

size_type	Push (const std::vector< value_t > &items)
	Write a sequence of values to the buffer. More...

FlowStatus	Pop (reference_t item)
	Read the oldest value from the buffer. More...

size_type	Pop (std::vector< value_t > &items)
	Read the whole buffer. More...

value_t *	PopWithoutRelease ()
	Returns a pointer to the first element in the buffer. More...

void	Release (value_t *item)
	Releases the pointer. More...

Public Attributes
const unsigned int	MAX_THREADS
	The maximum number of threads. More...

Detailed Description

template<class T>
class RTT::base::BufferLockFree< T >

A Lock-free buffer implementation to read and write data of type T in a FIFO way.

No memory allocation is done during read or write. One thread may read this buffer, unless the multiple_readers flag in the base::BufferBase::Options struct is set. Any number of threads may write this buffer.

Parameters

T	The value type to be stored in the Buffer. Example : BufferLockFree is a buffer which holds values of type A.

Definition at line 70 of file BufferLockFree.hpp.

Member Typedef Documentation

template<class T>

typedef BufferBase::Options RTT::base::BufferLockFree< T >::Options

Definition at line 74 of file BufferLockFree.hpp.

template<class T>

typedef BufferInterface<T>::param_t RTT::base::BufferLockFree< T >::param_t

Definition at line 76 of file BufferLockFree.hpp.

template<class T>

typedef BufferInterface<T>::reference_t RTT::base::BufferLockFree< T >::reference_t

Definition at line 75 of file BufferLockFree.hpp.

template<class T>

typedef boost::shared_ptr< BufferInterface<T> > RTT::base::BufferInterface< T >::shared_ptr

inherited

Definition at line 63 of file BufferInterface.hpp.

template<class T>

typedef BufferInterface<T>::size_type RTT::base::BufferLockFree< T >::size_type

Definition at line 77 of file BufferLockFree.hpp.

template<class T>

typedef T RTT::base::BufferLockFree< T >::value_t

Definition at line 78 of file BufferLockFree.hpp.

Constructor & Destructor Documentation

template<class T>

RTT::base::BufferLockFree< T >::BufferLockFree	(	unsigned int	bufsize,
		const Options &	options = `Options()`
	)

inline

Create an uninitialized lock-free buffer which can store bufsize elements.

Parameters

bufsize the capacity of the buffer. '

Definition at line 100 of file BufferLockFree.hpp.

template<class T>

RTT::base::BufferLockFree< T >::BufferLockFree	(	unsigned int	bufsize,
		param_t	initial_value,
		const Options &	options = `Options()`
	)

inline

Create a lock-free buffer which can store bufsize elements.

Parameters

bufsize	the capacity of the buffer.
initial_value	A data sample with which each preallocated data element is initialized.

Definition at line 116 of file BufferLockFree.hpp.

References RTT::base::BufferLockFree< T >::data_sample().

template<class T>

RTT::base::BufferLockFree< T >::~BufferLockFree ( )

inline

Definition at line 128 of file BufferLockFree.hpp.

References RTT::base::BufferLockFree< T >::clear().

Member Function Documentation

template<class T>

size_type RTT::base::BufferLockFree< T >::capacity ( ) const

inlinevirtual

Returns the maximum number of items that can be stored in the buffer.

Returns: maximum number of items.

Implements RTT::base::BufferBase.

Definition at line 160 of file BufferLockFree.hpp.

References RTT::internal::AtomicQueue< T >::capacity().

Referenced by RTT::base::BufferLockFree< T >::Push().

template<class T>

void RTT::base::BufferLockFree< T >::clear ( )

inlinevirtual

Clears all contents of this buffer.

Implements RTT::base::BufferBase.

Definition at line 180 of file BufferLockFree.hpp.

References RTT::internal::TsPool< T >::deallocate(), and RTT::internal::AtomicQueue< T >::dequeue().

Referenced by RTT::base::BufferLockFree< T >::~BufferLockFree().

template<class T>

virtual bool RTT::base::BufferLockFree< T >::data_sample	(	param_t	sample,
		bool	reset = `true`
	)

inlinevirtual

Initializes this buffer with a data sample, such that for dynamical allocated types T, the buffer can reserve place to hold these elements.

Parameters

sample	the data sample
reset	enforce reinitialization even if this operation clears all data.

Returns: true if the buffer was successfully (re)initialized.

Postcondition: Calling this function causes all data in the buffer to be lost and the size being reset to zero.

Implements RTT::base::BufferInterface< T >.

Definition at line 136 of file BufferLockFree.hpp.

References RTT::internal::TsPool< T >::data_sample().

template<class T>

virtual value_t RTT::base::BufferLockFree< T >::data_sample ( ) const

inlinevirtual

Reads back a data sample.

Implements RTT::base::BufferInterface< T >.

Definition at line 148 of file BufferLockFree.hpp.

References RTT::internal::TsPool< T >::allocate(), and RTT::internal::TsPool< T >::deallocate().

Referenced by RTT::base::BufferLockFree< T >::BufferLockFree().

template<class T>

virtual size_type RTT::base::BufferLockFree< T >::dropped ( ) const

inlinevirtual

Returns the number of dropped samples, because the buffer was full.

Implements RTT::base::BufferBase.

Definition at line 187 of file BufferLockFree.hpp.

References RTT::os::AtomicInt::read().

template<class T>

bool RTT::base::BufferLockFree< T >::empty ( ) const

inlinevirtual

Check if this buffer is empty.

Returns: true if size() == 0

Implements RTT::base::BufferBase.

Definition at line 170 of file BufferLockFree.hpp.

References RTT::internal::AtomicQueue< T >::isEmpty().

template<class T>

bool RTT::base::BufferLockFree< T >::full ( ) const

inlinevirtual

Check if this buffer is full.

Returns: true if size() == capacity()

Implements RTT::base::BufferBase.

Definition at line 175 of file BufferLockFree.hpp.

References RTT::internal::AtomicQueue< T >::isFull().

template<class T>

FlowStatus RTT::base::BufferLockFree< T >::Pop ( reference_t item )

inlinevirtual

Read the oldest value from the buffer.

Parameters

item	is to be set with a value from the buffer.

Returns: true if something was read.

Implements RTT::base::BufferInterface< T >.

Definition at line 261 of file BufferLockFree.hpp.

References RTT::internal::TsPool< T >::deallocate(), RTT::internal::AtomicQueue< T >::dequeue(), RTT::NewData, and RTT::NoData.

template<class T>

size_type RTT::base::BufferLockFree< T >::Pop ( std::vector< value_t > & items )

inlinevirtual

Read the whole buffer.

Parameters

items is to be filled with all values in the buffer, with items.begin() the oldest value.

Returns: the number of items read.

Implements RTT::base::BufferInterface< T >.

Definition at line 272 of file BufferLockFree.hpp.

References RTT::internal::TsPool< T >::deallocate(), and RTT::internal::AtomicQueue< T >::dequeue().

template<class T>

value_t* RTT::base::BufferLockFree< T >::PopWithoutRelease ( )

inlinevirtual

Returns a pointer to the first element in the buffer.

The pointer is only garanteed to stay valid until the next pop operation.

Note the pointer needs the be released by calling Release on the buffer.

Returns: a pointer to a sample or Zero if buffer is empty

Implements RTT::base::BufferInterface< T >.

Definition at line 284 of file BufferLockFree.hpp.

References RTT::internal::AtomicQueue< T >::dequeue().

template<class T>

bool RTT::base::BufferLockFree< T >::Push ( param_t item )

inlinevirtual

Write a single value to the buffer.

Parameters

item	the value to write

Returns: false if the buffer is full.

Implements RTT::base::BufferInterface< T >.

Definition at line 192 of file BufferLockFree.hpp.

References RTT::internal::TsPool< T >::allocate(), RTT::base::BufferLockFree< T >::capacity(), RTT::internal::TsPool< T >::deallocate(), RTT::internal::AtomicQueue< T >::dequeue(), RTT::internal::AtomicQueue< T >::enqueue(), RTT::os::AtomicInt::inc(), and RTT::internal::AtomicQueue< T >::size().

Referenced by RTT::base::BufferLockFree< T >::Push().

template<class T>

size_type RTT::base::BufferLockFree< T >::Push ( const std::vector< value_t > & items )

inlinevirtual

Write a sequence of values to the buffer.

Parameters

items the values to write

Returns: the number of values written (may be less than items.size())

Implements RTT::base::BufferInterface< T >.

Definition at line 244 of file BufferLockFree.hpp.

References RTT::os::AtomicInt::add(), and RTT::base::BufferLockFree< T >::Push().

template<class T>

void RTT::base::BufferLockFree< T >::Release ( value_t * item )

inlinevirtual

Releases the pointer.

Parameters

item	pointer aquired using PopWithoutRelease()

Implements RTT::base::BufferInterface< T >.

Definition at line 292 of file BufferLockFree.hpp.

References RTT::internal::TsPool< T >::deallocate().

template<class T>

size_type RTT::base::BufferLockFree< T >::size ( ) const

inlinevirtual

Returns the actual number of items that are stored in the buffer.

Returns: number of items.

Implements RTT::base::BufferBase.

Definition at line 165 of file BufferLockFree.hpp.

References RTT::internal::AtomicQueue< T >::size().

Member Data Documentation

template<class T>

const unsigned int RTT::base::BufferLockFree< T >::MAX_THREADS

The maximum number of threads.

Definition at line 83 of file BufferLockFree.hpp.

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

rtt/base/BufferLockFree.hpp

Public Types

Public Member Functions

Public Attributes

Detailed Description

template<class T> class RTT::base::BufferLockFree< T >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<class T>
class RTT::base::BufferLockFree< T >