shm_queue< T, TableType > Class Template Reference

Lock-free circular queue for shared memory IPC. More...

#include <shm_queue.h>

Inheritance diagram for shm_queue< T, TableType >:

Collaboration diagram for shm_queue< T, TableType >:

Public Member Functions
template<typename ShmType >
	shm_queue (ShmType &shm, std::string_view name, size_t capacity=0)
	Create or open a shared memory queue.
bool	enqueue (const T &value) noexcept
	Enqueue an element (lock-free)
std::optional< T >	dequeue () noexcept
	Dequeue an element (lock-free)
bool	dequeue (T &out_value) noexcept
	Try dequeue with output parameter (for compatibility)
bool	empty () const noexcept
bool	full () const noexcept
size_t	size () const noexcept
size_t	capacity () const noexcept
std::string_view	name () const noexcept
Public Member Functions inherited from shm_span< T, ShmType >
	shm_span (ShmType &shm, size_t off, size_t count)
T *	data ()
const T *	data () const
size_t	size () const
T &	operator[] (size_t index)
const T &	operator[] (size_t index) const

Additional Inherited Members
Protected Attributes inherited from shm_span< T, ShmType >
ShmType &	shm
size_t	offset
size_t	num_elem

Detailed Description

template<typename T, typename TableType = shm_table>
requires std::is_trivially_copyable_v<T>
class shm_queue< T, TableType >

Lock-free circular queue for shared memory IPC.

Uses C++20/23 features for modern, efficient implementation:

• std::atomic for lock-free operations
• std::optional for safe dequeue operations
• Concepts for type constraints

Template Parameters

T	The type of elements stored in the queue. Must be trivially copyable.
TableType	The type of shm_table to use (default: shm_table)

Definition at line 24 of file shm_queue.h.

Constructor & Destructor Documentation

shm_queue()

template<typename T , typename TableType = shm_table>

template<typename ShmType >

shm_queue< T, TableType >::shm_queue ( ShmType &  shm, std::string_view  name, size_t  capacity = 0  )

inline

Create or open a shared memory queue.

Definition at line 57 of file shm_queue.h.

References shm_queue< T, TableType >::capacity(), shm_queue< T, TableType >::name(), shm_span< T, ShmType >::num_elem, shm_span< T, ShmType >::offset, and shm_span< T, ShmType >::shm.

Member Function Documentation

capacity()

template<typename T , typename TableType = shm_table>

size_t shm_queue< T, TableType >::capacity ( ) const

inlinenoexcept

Definition at line 184 of file shm_queue.h.

References shm_span< T, ShmType >::num_elem.

Referenced by shm_queue< T, TableType >::shm_queue().

dequeue() [1/2]

template<typename T , typename TableType = shm_table>

std::optional< T > shm_queue< T, TableType >::dequeue ( )

inlinenoexcept

Dequeue an element (lock-free)

Returns

std::optional with value if successful, empty if queue is empty

Definition at line 133 of file shm_queue.h.

Referenced by shm_queue< T, TableType >::dequeue(), and main().

dequeue() [2/2]

template<typename T , typename TableType = shm_table>

bool shm_queue< T, TableType >::dequeue ( T &  out_value )

inlinenoexcept

Try dequeue with output parameter (for compatibility)

Definition at line 151 of file shm_queue.h.

References shm_queue< T, TableType >::dequeue().

empty()

template<typename T , typename TableType = shm_table>

bool shm_queue< T, TableType >::empty ( ) const

inlinenoexcept

Definition at line 159 of file shm_queue.h.

enqueue()

template<typename T , typename TableType = shm_table>

bool shm_queue< T, TableType >::enqueue ( const T &  value )

inlinenoexcept

Enqueue an element (lock-free)

Returns

true if successful, false if queue is full

Definition at line 115 of file shm_queue.h.

Referenced by main().

full()

template<typename T , typename TableType = shm_table>

bool shm_queue< T, TableType >::full ( ) const

inlinenoexcept

Definition at line 165 of file shm_queue.h.

name()

template<typename T , typename TableType = shm_table>

std::string_view shm_queue< T, TableType >::name ( ) const

inlinenoexcept

Definition at line 191 of file shm_queue.h.

Referenced by example_large_simulation(), and shm_queue< T, TableType >::shm_queue().

size()

template<typename T , typename TableType = shm_table>

size_t shm_queue< T, TableType >::size ( ) const

inlinenoexcept

Definition at line 172 of file shm_queue.h.

Referenced by main().

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

• include/shm_queue.h