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> Unreal Engine API Reference > Runtime > Core > Containers > TCircularQueue

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TCircularQueue

Implements a lock-free first-in first-out queue using a circular array.

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MacOS

Linux

References

Module	Core
Header	/Engine/Source/Runtime/Core/Public/Containers/CircularQueue.h
Include	#include "Containers/CircularQueue.h"

Syntax

template<typename ElementType>
class TCircularQueue

Remarks

Implements a lock-free first-in first-out queue using a circular array.

This class is thread safe only in single-producer single-consumer scenarios.

The number of items that can be enqueued is one less than the queue's capacity, because one item will be used for detecting full and empty states.

There is some room for optimization via using fine grained memory fences, but the implications for all of our target platforms need further analysis, so we're using the simpler sequentially consistent model for now.

Constructors

	Name	Description
	TCircularQueue ( uint32 CapacityPlusOne )	Constructor.

Functions

	Name	Description
uint32	Count()	Gets the number of elements in the queue.
bool	Dequeue()	Removes an item from the front of the queue. To be called only from consumer thread.
bool	Dequeue ( ElementType& OutElement )	Removes an item from the front of the queue. To be called only from consumer thread.
void	Empty()	Empties the queue. To be called only from consumer thread.
bool	Enqueue ( const ElementType& Element )	Adds an item to the end of the queue. To be called only from producer thread.
bool	Enqueue ( ElementType&& Element )	Adds an item to the end of the queue. To be called only from producer thread.
bool	IsEmpty()	Checks whether the queue is empty.
bool	IsFull()	Checks whether the queue is full.
const Elemen...	Peek()	Returns the oldest item in the queue without removing it.
bool	Peek ( ElementType& OutItem )	Returns the oldest item in the queue without removing it.

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