#include <KisSafeBlockingQueueConnectionProxy.h>

Public Member Functions
	KisSafeBlockingQueueConnectionProxy (CallbackFunction function)

void	start (T value)

Private Types
using	CallbackFunction = std::function<void (T)>

Private Member Functions
void	fakeSlotTimeout ()

Private Attributes
SignalToFunctionProxy	m_destination

CallbackFunction	m_function

FunctionToSignalProxy	m_source

QQueue< T >	m_value

Detailed Description

template<typename T>
class KisSafeBlockingQueueConnectionProxy< T >

A special class for safe forwarding of blocking-queued signal to the GUI thread.

The class automatically resolves deadlocks when GUI thread blocks on the image. This tie-breaking algorithm is implemented via KisBusyWaitBroker.

Usage:

   \code{.cpp}

   // create the proxy
   KisSafeBlockingQueueConnectionProxy<QTransform> proxy(
       std::bind(&KisShapeLayer::slotTransformShapes, shapeLayer));

   // Q_EMIT synchronous signal with deadlock-avoidance
   proxy.start(QTransform::fromScale(0.5, 0.5));

   \endcode

Definition at line 42 of file KisSafeBlockingQueueConnectionProxy.h.

Member Typedef Documentation

◆ CallbackFunction

template<typename T >

using KisSafeBlockingQueueConnectionProxy< T >::CallbackFunction = std::function<void (T)>

private

Definition at line 44 of file KisSafeBlockingQueueConnectionProxy.h.

Constructor & Destructor Documentation

◆ KisSafeBlockingQueueConnectionProxy()

template<typename T >

KisSafeBlockingQueueConnectionProxy< T >::KisSafeBlockingQueueConnectionProxy ( CallbackFunction function )

inline

Definition at line 46 of file KisSafeBlockingQueueConnectionProxy.h.

        : m_function(function),
          m_destination(std::bind(&KisSafeBlockingQueueConnectionProxy::fakeSlotTimeout, this))
    {
        KisSafeBlockingQueueConnectionProxyPrivate::initProxyObject(&m_source);
        KisSafeBlockingQueueConnectionProxyPrivate::initProxyObject(&m_destination);
 
        QObject::connect(&m_source, SIGNAL(timeout()), &m_destination, SLOT(start()), Qt::BlockingQueuedConnection);
    }

References KisSafeBlockingQueueConnectionProxyPrivate::initProxyObject(), KisSafeBlockingQueueConnectionProxy< T >::m_destination, KisSafeBlockingQueueConnectionProxy< T >::m_source, and KisSafeBlockingQueueConnectionProxy< T >::start().

Member Function Documentation

◆ fakeSlotTimeout()

template<typename T >

void KisSafeBlockingQueueConnectionProxy< T >::fakeSlotTimeout ( )

inlineprivate

Definition at line 66 of file KisSafeBlockingQueueConnectionProxy.h.

                           {
        KIS_SAFE_ASSERT_RECOVER_RETURN(!m_value.isEmpty());
        m_function(m_value.dequeue());
    }

References KIS_SAFE_ASSERT_RECOVER_RETURN, KisSafeBlockingQueueConnectionProxy< T >::m_function, and KisSafeBlockingQueueConnectionProxy< T >::m_value.

◆ start()

template<typename T >

void KisSafeBlockingQueueConnectionProxy< T >::start ( T value )

inline

Definition at line 56 of file KisSafeBlockingQueueConnectionProxy.h.

                        {
        const int sanityQueueSize = m_value.size();
 
        m_value.enqueue(value);
        KisSafeBlockingQueueConnectionProxyPrivate::passBlockingSignalSafely(m_source, m_destination);
 
        KIS_SAFE_ASSERT_RECOVER_NOOP(m_value.size() == sanityQueueSize);
    }