osg::DeleteHandler Class Reference

Class for overriding the default delete behaviour so that users can implement their own object deletion schemes. More...

Public Types
typedef std::pair< unsigned int, const osg::Referenced * >	FrameNumberObjectPair
typedef std::list< FrameNumberObjectPair >	ObjectsToDeleteList

Public Member Functions
	DeleteHandler (int numberOfFramesToRetainObjects=0)
virtual	~DeleteHandler ()
void	setNumFramesToRetainObjects (unsigned int numberOfFramesToRetainObjects)
	Set the number of frames to retain objects that have been requested for deletion. More...
unsigned int	getNumFramesToRetainObjects () const
void	setFrameNumber (unsigned int frameNumber)
	Set the current frame number so that subsequent deletes get tagged as associated with this frame. More...
unsigned int	getFrameNumber () const
	Get the current frame number. More...
void	doDelete (const Referenced *object)
virtual void	flush ()
	Flush objects that are ready to be fully deleted. More...
virtual void	flushAll ()
	Flush all objects that the DeleteHandler holds. More...
virtual void	requestDelete (const osg::Referenced *object)
	Request the deletion of an object. More...

Protected Member Functions
	DeleteHandler (const DeleteHandler &)
DeleteHandler	operator= (const DeleteHandler &)

Protected Attributes
unsigned int	_numFramesToRetainObjects
unsigned int	_currentFrameNumber
OpenThreads::Mutex	_mutex
ObjectsToDeleteList	_objectsToDelete

Detailed Description

Class for overriding the default delete behaviour so that users can implement their own object deletion schemes.

This might be used to implement a protection scheme that avoids multiple threads deleting objects unintentionally. Note, the DeleteHandler cannot itself be reference counted, otherwise it would be responsible for deleting itself! A static auto_ptr<> is used internally in Referenced.cpp to manage the DeleteHandler's memory.

Member Typedef Documentation

typedef std::pair<unsigned int, const osg::Referenced*> osg::DeleteHandler::FrameNumberObjectPair

typedef std::list<FrameNumberObjectPair> osg::DeleteHandler::ObjectsToDeleteList

Constructor & Destructor Documentation

osg::DeleteHandler::DeleteHandler

(

int

numberOfFramesToRetainObjects = 0

)

virtual osg::DeleteHandler::~DeleteHandler ( )

virtual

osg::DeleteHandler::DeleteHandler ( const DeleteHandler &  )

inlineprotected

Member Function Documentation

void osg::DeleteHandler::doDelete ( const Referenced *  object )

inline

virtual void osg::DeleteHandler::flush ( )

virtual

Flush objects that are ready to be fully deleted.

virtual void osg::DeleteHandler::flushAll ( )

virtual

Flush all objects that the DeleteHandler holds.

Note, this should only be called if there are no threads running with non ref_ptr<> pointers, such as graphics threads.

unsigned int osg::DeleteHandler::getFrameNumber ( ) const

inline

Get the current frame number.

unsigned int osg::DeleteHandler::getNumFramesToRetainObjects ( ) const

inline

DeleteHandler osg::DeleteHandler::operator= ( const DeleteHandler &  )

inlineprotected

virtual void osg::DeleteHandler::requestDelete ( const osg::Referenced *  object )

virtual

Request the deletion of an object.

Depending on users implementation of DeleteHandler, the delete of the object may occur straight away or be delayed until doDelete is called. The default implementation does a delete straight away.

void osg::DeleteHandler::setFrameNumber ( unsigned int  frameNumber )

inline

Set the current frame number so that subsequent deletes get tagged as associated with this frame.

void osg::DeleteHandler::setNumFramesToRetainObjects ( unsigned int  numberOfFramesToRetainObjects )

inline

Set the number of frames to retain objects that have been requested for deletion.

When set to zero objects are deleted immediately, by setting to 1 they are kept around for an extra frame etc. The ability to retain objects for several frames is useful to prevent premature deletion when objects are still being used by graphics threads that use double buffering of rendering data structures with non ref_ptr<> pointers to scene graph elements.

Member Data Documentation

unsigned int osg::DeleteHandler::_currentFrameNumber

protected

OpenThreads::Mutex osg::DeleteHandler::_mutex

protected

unsigned int osg::DeleteHandler::_numFramesToRetainObjects

protected

ObjectsToDeleteList osg::DeleteHandler::_objectsToDelete

protected

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

• osg/DeleteHandler