xentara::utils::lockFree::Queue< Element, Allocator > Class Template Reference

A lock free queue. More...

#include <xentara/utils/lockFree/Queue.hpp>

Public Types
using	value_type = Element
	The element type.
using	allocator_type = Allocator
	The Allocator type.
using	size_type = typename std::allocator_traits< Allocator >::size_type
	The type used for sizes.
using	difference_type = typename std::allocator_traits< Allocator >::difference_type
	The type used for distances.
using	reference = value_type &
	A reference to an element.
using	const_reference = const value_type &
	A const reference to an element.
using	pointer = typename std::allocator_traits< Allocator >::pointer
	A pointer to an element.
using	const_pointer = typename std::allocator_traits< Allocator >::const_pointer
	A const pointer to an element.

Public Member Functions
constexpr	Queue () noexcept(noexcept(Allocator()))=default
	Default constructor.
constexpr	Queue (const Allocator &allocator) noexcept
	Constructor that sets the allocator.
	Queue (size_type capacity)
	Constructor for a queue that can hold a specific number of elements.
	Queue (size_type capacity, const Allocator &allocator)
	Constructor for a queue that can hold a specific number of elements.
template<typename... Arguments>
auto	emplace (Arguments &&...arguments) noexcept(std::is_nothrow_constructible_v< Element, Arguments &&... >) -> bool
	Push an Element onto the queue.
auto	push (const Element &element) noexcept(std::is_nothrow_copy_constructible_v< Element >) -> bool
	Push an element onto the queue without any arguments.
auto	push (Element &&element) noexcept(std::is_nothrow_move_constructible_v< Element >) -> bool
	Move an element onto the queue without any arguments.
auto	pop () noexcept(std::is_nothrow_move_constructible_v< Element >) -> std::optional< Element >
	Pop an element in an optional wrapper from the queue.
auto	clear () -> void
	Clears the queue.
auto	reset (size_type capacity) -> void
	Reset the queue to the given capacity.
constexpr auto	capacity () const noexcept -> size_type
	Gets the maximum number of elements the queue can hold.
constexpr auto	max_size () const noexcept -> size_type
	Gets the maximum possible capacity.

Detailed Description

template<typename Element, typename Allocator = std::allocator<Element>>
class xentara::utils::lockFree::Queue< Element, Allocator >

A lock free queue.

Template Parameters

Element	The element type
Allocator	the allocator for the element type

Member Typedef Documentation

allocator_type

template<typename Element , typename Allocator = std::allocator<Element>>

using xentara::utils::lockFree::Queue< Element, Allocator >::allocator_type = Allocator

The Allocator type.

const_pointer

template<typename Element , typename Allocator = std::allocator<Element>>

using xentara::utils::lockFree::Queue< Element, Allocator >::const_pointer = typename std::allocator_traits<Allocator>::const_pointer

A const pointer to an element.

const_reference

template<typename Element , typename Allocator = std::allocator<Element>>

using xentara::utils::lockFree::Queue< Element, Allocator >::const_reference = const value_type &

A const reference to an element.

difference_type

template<typename Element , typename Allocator = std::allocator<Element>>

using xentara::utils::lockFree::Queue< Element, Allocator >::difference_type = typename std::allocator_traits<Allocator>::difference_type

The type used for distances.

pointer

template<typename Element , typename Allocator = std::allocator<Element>>

using xentara::utils::lockFree::Queue< Element, Allocator >::pointer = typename std::allocator_traits<Allocator>::pointer

A pointer to an element.

reference

template<typename Element , typename Allocator = std::allocator<Element>>

using xentara::utils::lockFree::Queue< Element, Allocator >::reference = value_type &

A reference to an element.

size_type

template<typename Element , typename Allocator = std::allocator<Element>>

using xentara::utils::lockFree::Queue< Element, Allocator >::size_type = typename std::allocator_traits<Allocator>::size_type

The type used for sizes.

value_type

template<typename Element , typename Allocator = std::allocator<Element>>

using xentara::utils::lockFree::Queue< Element, Allocator >::value_type = Element

The element type.

Constructor & Destructor Documentation

Queue() [1/4]

template<typename Element , typename Allocator = std::allocator<Element>>

constexpr xentara::utils::lockFree::Queue< Element, Allocator >::Queue ( )

constexprdefaultnoexcept

Default constructor.

Constructs an empty queue with a default constructed allocator.

A queue created with this constructor has a capacity of 0 and cannot hold any elements. You must make room for the elements using reset() before inserting any elements.

Queue() [2/4]

template<typename Element , typename Allocator = std::allocator<Element>>

constexpr xentara::utils::lockFree::Queue< Element, Allocator >::Queue ( const Allocator &  allocator )

explicitconstexprnoexcept

Constructor that sets the allocator.

A queue created with this constructor has a capacity of 0 and cannot hold any elements. You must make room for the elements using reset() before inserting any elements.

Parameters

allocator

The allocator

Queue() [3/4]

template<typename Element , typename Allocator = std::allocator<Element>>

xentara::utils::lockFree::Queue< Element, Allocator >::Queue ( size_type  capacity )

explicit

Constructor for a queue that can hold a specific number of elements.

Parameters

capacity

The number of entries to create room for

Queue() [4/4]

template<typename Element , typename Allocator = std::allocator<Element>>

xentara::utils::lockFree::Queue< Element, Allocator >::Queue ( size_type  capacity, const Allocator &  allocator  )

explicit

Constructor for a queue that can hold a specific number of elements.

Parameters

capacity	The number of entries to create room for
allocator	The allocator

Member Function Documentation

capacity()

template<typename Element , typename Allocator = std::allocator<Element>>

constexpr auto xentara::utils::lockFree::Queue< Element, Allocator >::capacity ( ) const -> size_type

constexprnoexcept

Gets the maximum number of elements the queue can hold.

Returns

the capacity of the queue

clear()

template<typename Element , typename Allocator = std::allocator<Element>>

auto xentara::utils::lockFree::Queue< Element, Allocator >::clear

(

)

-> void

Clears the queue.

Any current elements in the queue are deleted

Attention

This function is unsynchronized and must not be called while other threads are accessing the queue

emplace()

template<typename Element , typename Allocator = std::allocator<Element>>

template<typename... Arguments>

auto xentara::utils::lockFree::Queue< Element, Allocator >::emplace ( Arguments &&...  arguments ) -> bool

noexcept

Push an Element onto the queue.

Parameters

arguments

the arguments to use to construct the element

Returns

returns true if element pushed on queue and false if it failed due to queue being full

max_size()

template<typename Element , typename Allocator = std::allocator<Element>>

constexpr auto xentara::utils::lockFree::Queue< Element, Allocator >::max_size ( ) const -> size_type

constexprnoexcept

Gets the maximum possible capacity.

Returns

The maximum capacity that can be specified

pop()

template<typename Element , typename Allocator = std::allocator<Element>>

auto xentara::utils::lockFree::Queue< Element, Allocator >::pop ( ) -> std::optional<Element>

noexcept

Pop an element in an optional wrapper from the queue.

Note

If the move constructor of the object throws an exception, the object is removed from the queue and destroyed silently. The exception is then rethrown.

Returns

returns the popped element in the optional wrapper or std::nullopt if the queue was empty

push() [1/2]

template<typename Element , typename Allocator = std::allocator<Element>>

auto xentara::utils::lockFree::Queue< Element, Allocator >::push ( const Element &  element ) -> bool

noexcept

Push an element onto the queue without any arguments.

Parameters

element

the element to push onto the queue

Returns

returns true if element pushed on queue and false if it failed due to queue being full

push() [2/2]

template<typename Element , typename Allocator = std::allocator<Element>>

auto xentara::utils::lockFree::Queue< Element, Allocator >::push ( Element &&  element ) -> bool

noexcept

Move an element onto the queue without any arguments.

Parameters

element

the element to move onto the queue

Returns

returns true if element pushed on queue and false if it failed due to queue being full

reset()

template<typename Element , typename Allocator = std::allocator<Element>>

auto xentara::utils::lockFree::Queue< Element, Allocator >::reset

(

size_type

capacity

)

-> void

Reset the queue to the given capacity.

Any current elements in the queue are deleted

Attention

This function is unsynchronized and must not be called while other threads are accessing the queue

Parameters

capacity

The number of entries to create room for