A base class for lock-free queues. More...

#include <lock_free_queue.hpp>

Public Types
using	T = DataType

Public Member Functions
template<bool HasCapacity = has_capacity<LockFreeContainer>::value, typename std::enable_if_t< HasCapacity, int > = 0>
	LockFreeQueueBase ()
	Construct a new LockFreeQueueBase object.

template<bool HasCapacity = has_capacity<LockFreeContainer>::value, typename std::enable_if_t<!HasCapacity, int > = 1>
	LockFreeQueueBase (std::size_t capacity)
	Construct a new LockFreeQueueBase object.

bool	pop (T &data)
	Pop the data from the queue.

template<typename U >
std::enable_if_t< std::is_convertible_v< T, U >, bool >	pop (U &data)
	Pop the data from the queue.

bool	push (const T &data)
	Push the data into the queue.

template<typename U >
std::enable_if_t< std::is_convertible_v< T, U >, bool >	push (const U &data)
	Push the data into the queue.

template<typename U >
std::enable_if_t< std::is_convertible_v< T, U >, bool >	bounded_push (const U &data)
	The bounded_push function pushes the data into the queue and pops the oldest data if the queue is full.

bool	get_latest (T &data)
	Get the latest data from the queue.

bool	empty () const
	Check if the queue is empty.

size_t	capacity () const
	Get the capacity of the queue.

template<bool IsSPSCQueue = is_spsc_queue<LockFreeContainer>::value, typename std::enable_if_t< IsSPSCQueue, int > = 0>
std::size_t	size () const
	Get the size of the queue.

bool	is_lock_free () const
	The method to check if the queue is lock free.

const LockFreeContainer &	get_lockfree_container () const
	Get the lockfree container.

LockFreeContainer &	get_lockfree_container ()
	Get the lockfree container.

Detailed Description

template<typename DataType, typename LockFreeContainer>
class realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >

A base class for lock-free queues.

This class provides a base implementation for lock-free queues with various functionalities such as pushing, popping, and checking the state of the queue. It supports both single-producer single-consumer (SPSC) and multiple-producer multiple-consumer (MPMC) queues.

Template Parameters

DataType	The type of data to be stored in the queue.
LockFreeContainer	The underlying lock-free container type - Typically boost::lockfree::spsc_queue or boost::lockfree::queue with their own template parameters

Constructor & Destructor Documentation

◆ LockFreeQueueBase() [1/2]

template<typename DataType , typename LockFreeContainer >

template<bool HasCapacity = has_capacity<LockFreeContainer>::value, typename std::enable_if_t< HasCapacity, int > = 0>

realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::LockFreeQueueBase ( )

inline

Construct a new LockFreeQueueBase object.

Note: This constructor is enabled only if the LockFreeContainer has a capacity set

◆ LockFreeQueueBase() [2/2]

template<typename DataType , typename LockFreeContainer >

template<bool HasCapacity = has_capacity<LockFreeContainer>::value, typename std::enable_if_t<!HasCapacity, int > = 1>

realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::LockFreeQueueBase ( std::size_t capacity )

inlineexplicit

Construct a new LockFreeQueueBase object.

Parameters

capacity Capacity of the queue

Note: This constructor is enabled only if the LockFreeContainer has no capacity set

Member Function Documentation

◆ bounded_push()

template<typename DataType , typename LockFreeContainer >

template<typename U >

std::enable_if_t< std::is_convertible_v< T, U >, bool > realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::bounded_push ( const U & data )

inline

The bounded_push function pushes the data into the queue and pops the oldest data if the queue is full.

Parameters

data	Data to be pushed

Returns: true If the data is pushed successfully; false If the data could not be pushed

Note: This function is enabled only if the queue is a spsc_queue and only if the data type is convertible to the template type of the queue; For a SPSC Queue, to be used in single-threaded applications

Warning: For a SPSC Queue, this method might not work as expected when used in multi-threaded applications if it is used with two different threads, one doing bounded_push and the other doing pop. In this case, the queue is no longer a single producer single consumer queue. So, the behavior might not be as expected.

◆ capacity()

template<typename DataType , typename LockFreeContainer >

size_t realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::capacity ( ) const

inline

Get the capacity of the queue.

Returns: std::size_t Capacity of the queue

◆ empty()

template<typename DataType , typename LockFreeContainer >

bool realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::empty ( ) const

inline

Check if the queue is empty.

Returns: true If the queue is empty; false If the queue is not empty

Note: The result is only accurate, if no other thread modifies the queue. Therefore, it is rarely practical to use this value in program logic.; For a SPSC Queue, it should only be called from the consumer thread where pop is called. If need to be called from producer thread, use write_available() instead.

◆ get_latest()

template<typename DataType , typename LockFreeContainer >

bool realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::get_latest ( T & data )

inline

Get the latest data from the queue.

Parameters

data	Data to be filled with the latest data

Returns: true If the data is filled with the latest data, false otherwise; false If the queue is empty

Note: This function consumes all the data in the queue until the last data and returns the last element of the queue

◆ get_lockfree_container() [1/2]

template<typename DataType , typename LockFreeContainer >

LockFreeContainer & realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::get_lockfree_container ( )

inline

Get the lockfree container.

Returns: LockFreeContainer& Reference to the lockfree container

◆ get_lockfree_container() [2/2]

template<typename DataType , typename LockFreeContainer >

const LockFreeContainer & realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::get_lockfree_container ( ) const

inline

Get the lockfree container.

Returns: const LockFreeContainer& Reference to the lockfree container

◆ is_lock_free()

template<typename DataType , typename LockFreeContainer >

bool realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::is_lock_free ( ) const

inline

The method to check if the queue is lock free.

Returns: true If the queue is lock free, false otherwise

Warning: It only checks, if the queue head and tail nodes and the freelist can be modified in a lock-free manner. On most platforms, the whole implementation is lock-free, if this is true. Using c++0x-style atomics, there is no possibility to provide a completely accurate implementation, because one would need to test every internal node, which is impossible if further nodes will be allocated from the operating system. https://www.boost.org/doc/libs/1_74_0/doc/html/boost/lockfree/queue.html

◆ pop() [1/2]

template<typename DataType , typename LockFreeContainer >

bool realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::pop ( T & data )

inline

Pop the data from the queue.

Parameters

data	Data to be popped

Returns: true If the data is popped successfully; false If the queue is empty or the data could not be popped

◆ pop() [2/2]

template<typename DataType , typename LockFreeContainer >

template<typename U >

std::enable_if_t< std::is_convertible_v< T, U >, bool > realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::pop ( U & data )

inline

Pop the data from the queue.

Parameters

data	Data to be popped

Returns: true If the data is popped successfully; false If the queue is empty or the data could not be popped

Note: This function is enabled only if the data type is convertible to the template type of the queue

◆ push() [1/2]

template<typename DataType , typename LockFreeContainer >

bool realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::push ( const T & data )

inline

Push the data into the queue.

Parameters

data	Data to be pushed

Returns: true If the data is pushed successfully; false If the queue is full or the data could not be pushed

◆ push() [2/2]

template<typename DataType , typename LockFreeContainer >

template<typename U >

std::enable_if_t< std::is_convertible_v< T, U >, bool > realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::push ( const U & data )

inline

Push the data into the queue.

Parameters

data	Data to be pushed

Returns: true If the data is pushed successfully; false If the queue is full or the data could not be pushed

Note: This function is enabled only if the data type is convertible to the template type of the queue

◆ size()

template<typename DataType , typename LockFreeContainer >

template<bool IsSPSCQueue = is_spsc_queue<LockFreeContainer>::value, typename std::enable_if_t< IsSPSCQueue, int > = 0>

std::size_t realtime_tools::LockFreeQueueBase< DataType, LockFreeContainer >::size ( ) const

inline

Get the size of the queue.

Returns: std::size_t Size of the queue

Note: This function is enabled only if the queue is a spsc_queue

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

realtime_tools/realtime_tools/include/realtime_tools/lock_free_queue.hpp

Public Types

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ LockFreeQueueBase() [1/2]

◆ LockFreeQueueBase() [2/2]

Member Function Documentation

◆ bounded_push()

◆ capacity()

◆ empty()

◆ get_latest()

◆ get_lockfree_container() [1/2]

◆ get_lockfree_container() [2/2]

◆ is_lock_free()

◆ pop() [1/2]

◆ pop() [2/2]

◆ push() [1/2]

◆ push() [2/2]

◆ size()