osmscout::ProcessingQueue< T > Class Template Reference

A ProcessingQueue is a special multi-threaded safe implementation of a queue. More...

#include <ProcessingQueue.h>

Public Member Functions
bool	Finished ()
	Return true, if the queue is stopped and empty, else false.
ProcessingQueue &	operator= (const ProcessingQueue &)=delete
std::optional< T >	PopTask ()
	Move one data entry out of the queue (FIFO semantics).
	ProcessingQueue ()
	Initialize a unbounded queue.
	ProcessingQueue (const ProcessingQueue &)=delete
	ProcessingQueue (size_t queueLimit)
	Initialize a bounded queue.
void	PushTask (const T &task)
	Push a copy of the given data into the queue.
void	PushTask (T &&task)
	Push a copy or move the given data into the queue.
void	Stop ()
	Signal that all data has been pushed into the queue.
void	StopAndDiscard ()
	Stop the queue and drop the data that has not been popped yet, in one step, so that a consumer returning from its current item cannot pick up one of the dropped items.
virtual	~ProcessingQueue ()=default

Detailed Description

template<typename T>
class osmscout::ProcessingQueue< T >

A ProcessingQueue is a special multi-threaded safe implementation of a queue.

The goal is to use this queues as a asynchronous pipeline between individual agents or worker threads.

The queue has FIFO semantics.

A queue can have multiple producers and consumers. There is currently no Peek() method data that has been taken has either to be consumed, pushed back or dropped.

The queue data should be movable but can be copyable also. If the content is not movable additional CPU overhead for copying data is to be expected.

Note that even is the content is moveable is should be assumed that moving data through the queue has it own cost.

Template Parameters

T	Type of the queue content

Constructor & Destructor Documentation

ProcessingQueue() [1/3]

template<class T>

osmscout::ProcessingQueue< T >::ProcessingQueue ( )

default

Initialize a unbounded queue.

Template Parameters

T

ProcessingQueue() [2/3]

template<class T>

osmscout::ProcessingQueue< T >::ProcessingQueue ( size_t queueLimit )

explicit

Initialize a bounded queue.

The queue is guaranteed to hold no more than the given amount of data entries. Producer will be blocked until the queue shrinks below its limit before data can be pushed.

Template Parameters

T

Parameters

queueLimit

Queue size limit

ProcessingQueue() [3/3]

template<typename T>

osmscout::ProcessingQueue< T >::ProcessingQueue ( const ProcessingQueue< T > & )

delete

~ProcessingQueue()

template<typename T>

virtual osmscout::ProcessingQueue< T >::~ProcessingQueue ( )

virtualdefault

Member Function Documentation

Finished()

template<class R>

bool osmscout::ProcessingQueue< R >::Finished

(

)

Return true, if the queue is stopped and empty, else false.

Template Parameters

R

Returns

true, if stopped and empty, else false

operator=()

template<typename T>

ProcessingQueue & osmscout::ProcessingQueue< T >::operator= ( const ProcessingQueue< T > & )

delete

PopTask()

template<class T>

std::optional< T > osmscout::ProcessingQueue< T >::PopTask

(

)

Move one data entry out of the queue (FIFO semantics).

No data will be returned if the queue is stopped and empty.

Template Parameters

T

Returns

PushTask() [1/2]

template<class T>

void osmscout::ProcessingQueue< T >::PushTask

(

const T &

task

)

Push a copy of the given data into the queue.

Pushing data will be blocked until queue size is below limit.

Template Parameters

T

Parameters

task

PushTask() [2/2]

template<class T>

void osmscout::ProcessingQueue< T >::PushTask

(

T &&

task

)

Push a copy or move the given data into the queue.

Pushing data will be blocked until queue size is below limit.

Template Parameters

T

Parameters

task

Stop()

template<class R>

void osmscout::ProcessingQueue< R >::Stop

(

)

Signal that all data has been pushed into the queue.

Template Parameters

R

StopAndDiscard()

template<class R>

void osmscout::ProcessingQueue< R >::StopAndDiscard

(

)

Stop the queue and drop the data that has not been popped yet, in one step, so that a consumer returning from its current item cannot pick up one of the dropped items.

Discard all data that has not been popped yet, so that work that did not start does not run.

Meant for shutdown; Stop() alone keeps the data that is already queued.

Meant for shutdown, next to Stop().

Template Parameters

R

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

• ProcessingQueue.h