ProducerConsumerQueue< T > Class Template Reference

#include "PCQueue.h"

Public Member Functions
	ProducerConsumerQueue ()
void	Push (const T &value)
bool	Empty ()
std::size_t	Size () const
bool	Pop (T &value)
void	WaitAndPop (T &value)
void	Cancel ()

Private Member Functions
template<typename E = T>
std::enable_if< std::is_pointer< E >::value >::type	DeleteQueuedObject (E &obj)
template<typename E = T>
std::enable_if<!std::is_pointer< E >::value >::type	DeleteQueuedObject (E const &)

Private Attributes
std::mutex	_queueLock
std::queue< T >	_queue
std::condition_variable	_condition
std::atomic< bool >	_shutdown

Detailed Description

template<typename T>
class ProducerConsumerQueue< T >

Constructor & Destructor Documentation

ProducerConsumerQueue()

template<typename T >

ProducerConsumerQueue< T >::ProducerConsumerQueue ( )

inline

: _shutdown(false) { }

Member Function Documentation

Cancel()

template<typename T >

void ProducerConsumerQueue< T >::Cancel ( )

inline

    {
        std::unique_lock<std::mutex> lock(_queueLock);
 
        while (!_queue.empty())
        {
            T& value = _queue.front();
 
            DeleteQueuedObject(value);
 
            _queue.pop();
        }
 
        _shutdown = true;
 
        _condition.notify_all();
    }

References ProducerConsumerQueue< T >::_condition, ProducerConsumerQueue< T >::_queue, ProducerConsumerQueue< T >::_queueLock, ProducerConsumerQueue< T >::_shutdown, and ProducerConsumerQueue< T >::DeleteQueuedObject().

Referenced by MapUpdater::deactivate(), and DatabaseWorker::~DatabaseWorker().

DeleteQueuedObject() [1/2]

template<typename T >

template<typename E = T>

std::enable_if< std::is_pointer< E >::value >::type ProducerConsumerQueue< T >::DeleteQueuedObject ( E &  obj )

inlineprivate

{ delete obj; }

Referenced by ProducerConsumerQueue< T >::Cancel().

DeleteQueuedObject() [2/2]

template<typename T >

template<typename E = T>

std::enable_if<!std::is_pointer< E >::value >::type ProducerConsumerQueue< T >::DeleteQueuedObject ( E const &  )

inlineprivate

{ }

Empty()

template<typename T >

bool ProducerConsumerQueue< T >::Empty ( )

inline

    {
        std::lock_guard<std::mutex> lock(_queueLock);
 
        return _queue.empty();
    }

References ProducerConsumerQueue< T >::_queue, and ProducerConsumerQueue< T >::_queueLock.

Pop()

template<typename T >

bool ProducerConsumerQueue< T >::Pop ( T &  value )

inline

    {
        std::lock_guard<std::mutex> lock(_queueLock);
 
        if (_queue.empty() || _shutdown)
        {
            return false;
        }
 
        value = _queue.front();
 
        _queue.pop();
 
        return true;
    }

References ProducerConsumerQueue< T >::_queue, ProducerConsumerQueue< T >::_queueLock, and ProducerConsumerQueue< T >::_shutdown.

Push()

template<typename T >

void ProducerConsumerQueue< T >::Push ( const T &  value )

inline

    {
        std::lock_guard<std::mutex> lock(_queueLock);
        _queue.push(std::move(value));
 
        _condition.notify_one();
    }

References ProducerConsumerQueue< T >::_condition, ProducerConsumerQueue< T >::_queue, and ProducerConsumerQueue< T >::_queueLock.

Referenced by MapUpdater::schedule_lfg_update(), and MapUpdater::schedule_update().

Size()

template<typename T >

std::size_t ProducerConsumerQueue< T >::Size ( ) const

inline

    {
        return _queue.size();
    }

References ProducerConsumerQueue< T >::_queue.

WaitAndPop()

template<typename T >

void ProducerConsumerQueue< T >::WaitAndPop ( T &  value )

inline

    {
        std::unique_lock<std::mutex> lock(_queueLock);
 
        // we could be using .wait(lock, predicate) overload here but it is broken
        // https://connect.microsoft.com/VisualStudio/feedback/details/1098841
        while (_queue.empty() && !_shutdown)
        {
            _condition.wait(lock);
        }
 
        if (_queue.empty() || _shutdown)
        {
            return;
        }
 
        value = _queue.front();
 
        _queue.pop();
    }

References ProducerConsumerQueue< T >::_condition, ProducerConsumerQueue< T >::_queue, ProducerConsumerQueue< T >::_queueLock, and ProducerConsumerQueue< T >::_shutdown.

Referenced by DatabaseWorker::WorkerThread(), and MapUpdater::WorkerThread().

Member Data Documentation

_condition

template<typename T >

std::condition_variable ProducerConsumerQueue< T >::_condition

private

Referenced by ProducerConsumerQueue< T >::Cancel(), ProducerConsumerQueue< T >::Push(), and ProducerConsumerQueue< T >::WaitAndPop().

_queue

template<typename T >

std::queue<T> ProducerConsumerQueue< T >::_queue

private

Referenced by ProducerConsumerQueue< T >::Cancel(), ProducerConsumerQueue< T >::Empty(), ProducerConsumerQueue< T >::Pop(), ProducerConsumerQueue< T >::Push(), ProducerConsumerQueue< T >::Size(), and ProducerConsumerQueue< T >::WaitAndPop().

_queueLock

template<typename T >

std::mutex ProducerConsumerQueue< T >::_queueLock

private

Referenced by ProducerConsumerQueue< T >::Cancel(), ProducerConsumerQueue< T >::Empty(), ProducerConsumerQueue< T >::Pop(), ProducerConsumerQueue< T >::Push(), and ProducerConsumerQueue< T >::WaitAndPop().

_shutdown

template<typename T >

std::atomic<bool> ProducerConsumerQueue< T >::_shutdown

private

Referenced by ProducerConsumerQueue< T >::Cancel(), ProducerConsumerQueue< T >::Pop(), and ProducerConsumerQueue< T >::WaitAndPop().