shaka::media::ProducerConsumerQueue< T > Class Template Reference

#include <producer_consumer_queue.h>

Public Member Functions
	ProducerConsumerQueue (size_t capacity)
	ProducerConsumerQueue (size_t capacity, size_t starting_pos)
Status	Push (const T &element, int64_t timeout_ms)
Status	Pop (T *element, int64_t timeout_ms)
Status	Peek (size_t pos, T *element, int64_t timeout_ms)
void	Stop ()
bool	Empty () const
size_t	Size () const
size_t	HeadPos () const
size_t	TailPos () const
bool	Stopped () const

Detailed Description

template<class T>
class shaka::media::ProducerConsumerQueue< T >

A thread safe producer consumer queue implementation. It allows the standard push and pop operations. It also maintains a monotonically-increasing element position and allows peeking at the element at certain position.

Definition at line 28 of file producer_consumer_queue.h.

Constructor & Destructor Documentation

template<class T >

shaka::media::ProducerConsumerQueue< T >::ProducerConsumerQueue ( size_t  capacity )

explicit

Create a ProducerConsumerQueue starting from position 0.

Parameters

capacity

is the maximum number of elements that the queue can hold at once. A value of zero means unlimited capacity.

Definition at line 138 of file producer_consumer_queue.h.

template<class T >

shaka::media::ProducerConsumerQueue< T >::ProducerConsumerQueue	(	size_t	capacity,
		size_t	starting_pos
	)

Create a ProducerConsumerQueue starting from indicated position.

Parameters

capacity	is the maximum number of elements that the queue can hold at once. A value of zero means unlimited capacity.
starting_pos	is the starting head position.

Definition at line 147 of file producer_consumer_queue.h.

Member Function Documentation

template<class T >

bool shaka::media::ProducerConsumerQueue< T >::Empty ( ) const

inline

Returns

true if there are no elements in the queue.

Definition at line 88 of file producer_consumer_queue.h.

template<class T >

size_t shaka::media::ProducerConsumerQueue< T >::HeadPos ( ) const

inline

Returns

The position of the head element in the queue. Note that the returned value may be meaningless if the queue is empty.

Definition at line 101 of file producer_consumer_queue.h.

template<class T >

Status shaka::media::ProducerConsumerQueue< T >::Peek	(	size_t	pos,
		T *	element,
		int64_t	timeout_ms
	)

Peek at the element at the specified position from the queue. If the element is not available yet, block until it to be available or time out or stopped. NOTE: Elements before (pos - capacity/2) will be removed from the queue after Peek operation.

Parameters

	pos	refers to the element position.
[out]	element	receives the peeked element.
	timeout_ms	indicates timeout in milliseconds. A value of zero means return immediately. A negative value means waiting indefinitely.

Returns

STOPPED if Stop has been called and pos is out of range, INVALID_ARGUMENT if the pos < Head(), TIME_OUT if times out, OK otherwise.

Definition at line 252 of file producer_consumer_queue.h.

template<class T >

Status shaka::media::ProducerConsumerQueue< T >::Pop	(	T *	element,
		int64_t	timeout_ms
	)

Pop an element from the front of the queue. If the queue is empty, block for an element to be available to be consumed or time out or stopped.

Parameters

[out]	element	receives the popped element.
	timeout_ms	indicates timeout in milliseconds. A value of zero means return immediately. A negative value means waiting indefinitely.

Returns

STOPPED if Stop has been called and the queue is completely empty, TIME_OUT if times out, OK otherwise.

Definition at line 210 of file producer_consumer_queue.h.

template<class T >

Status shaka::media::ProducerConsumerQueue< T >::Push	(	const T &	element,
		int64_t	timeout_ms
	)

Push an element to the back of the queue. If the queue has reached its capacity limit, block until spare capacity is available or time out or stopped.

Parameters

element	refers the element to be pushed.
timeout_ms	indicates timeout in milliseconds. A value of zero means return immediately. A negative value means waiting indefinitely.

Returns

OK if the element was pushed successfully, STOPPED if Stop has has been called, TIME_OUT if times out.

Definition at line 161 of file producer_consumer_queue.h.

template<class T >

size_t shaka::media::ProducerConsumerQueue< T >::Size ( ) const

inline

Returns

The number of elements in the queue.

Definition at line 94 of file producer_consumer_queue.h.

template<class T >

void shaka::media::ProducerConsumerQueue< T >::Stop ( )

inline

Terminate Pop and Peek requests once the queue drains entirely. Also terminate all waiting and future Push requests immediately. Stop cannot stall.

Definition at line 79 of file producer_consumer_queue.h.

template<class T >

bool shaka::media::ProducerConsumerQueue< T >::Stopped ( ) const

inline

Returns

true if the queue has been stopped using Stop(). This allows producers to check if they can add new elements to the queue.

Definition at line 115 of file producer_consumer_queue.h.

template<class T >

size_t shaka::media::ProducerConsumerQueue< T >::TailPos ( ) const

inline

Returns

The position of the tail element in the queue. Note that the returned value may be meaningless if the queue is empty.

Definition at line 108 of file producer_consumer_queue.h.

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

• media/base/producer_consumer_queue.h