dart::collision::CollisionGroup::ShapeFrameObserver Class Reference

This class watches when ShapeFrames get deleted so that they can be safely removes from the CollisionGroup. More...

Inheritance diagram for dart::collision::CollisionGroup::ShapeFrameObserver:

Public Member Functions
void	addShapeFrame (const dynamics::ShapeFrame *shapeFrame)
	Add a shape frame to this observer. More...
void	removeShapeFrame (const dynamics::ShapeFrame *shapeFrame)
	Remove a shape frame from this observer. More...
void	removeAllShapeFrames ()
	Remove all shape frames from this observer. More...

Public Attributes
std::unordered_set< const dynamics::ShapeFrame * >	mDeletedFrames
	Whenever an observed shape frame gets deleted, its pointer will be added to this set. More...

Protected Member Functions
void	handleDestructionNotification (const common::Subject *subject) override
	This will be called each time an observed shape frame is deleted. More...
void	receiveDestructionNotification (const Subject *_subject)
	Called whenever a Subject is destroyed (or sends out a destruction notification). More...
void	addSubject (const Subject *_subject)
	Add a Subject for this Observer. More...
void	removeSubject (const Subject *_subject)
	Remove a Subject from this Observer. More...
void	removeAllSubjects ()
	Remove all Subjects from this Observer. More...

Protected Attributes
std::set< const Subject * >	mSubjects
	List of current Subjects for this Observer. More...

Private Attributes
std::unordered_map< const common::Subject *, const dynamics::ShapeFrame * >	mMap
	A map from a subject pointer to its corresponding ShapeFrame pointer. More...

Detailed Description

This class watches when ShapeFrames get deleted so that they can be safely removes from the CollisionGroup.

We cannot have a weak_ptr to a ShapeFrame because some are managed by std::shared_ptr while others are managed by NodePtr.

If we don't carefully track when each ShapeFrame gets destructed, then we can land in a situation where a ShapeFrame gets removed from a BodyNode, deallocated, and then a new ShapeFrame is allocated in the memory address of the old one. This can lead to invalid memory accesses if we neglect to correctly clean up our references to deleted ShapeFrames.

Member Function Documentation

addShapeFrame()

void dart::collision::CollisionGroup::ShapeFrameObserver::addShapeFrame

(

const dynamics::ShapeFrame *

shapeFrame

)

Add a shape frame to this observer.

addSubject()

void dart::common::Observer::addSubject ( const Subject *  _subject )

protectedinherited

Add a Subject for this Observer.

handleDestructionNotification()

void dart::collision::CollisionGroup::ShapeFrameObserver::handleDestructionNotification ( const common::Subject *  subject )

overrideprotectedvirtual

This will be called each time an observed shape frame is deleted.

Reimplemented from dart::common::Observer.

receiveDestructionNotification()

void dart::common::Observer::receiveDestructionNotification ( const Subject *  _subject )

protectedinherited

Called whenever a Subject is destroyed (or sends out a destruction notification).

Override handleDestructionNotification() in order to customize your class's response to destruction notifications.

removeAllShapeFrames()

void dart::collision::CollisionGroup::ShapeFrameObserver::removeAllShapeFrames

(

)

Remove all shape frames from this observer.

removeAllSubjects()

void dart::common::Observer::removeAllSubjects ( )

protectedinherited

Remove all Subjects from this Observer.

removeShapeFrame()

void dart::collision::CollisionGroup::ShapeFrameObserver::removeShapeFrame

(

const dynamics::ShapeFrame *

shapeFrame

)

Remove a shape frame from this observer.

removeSubject()

void dart::common::Observer::removeSubject ( const Subject *  _subject )

protectedinherited

Remove a Subject from this Observer.

Member Data Documentation

mDeletedFrames

std::unordered_set<const dynamics::ShapeFrame*> dart::collision::CollisionGroup::ShapeFrameObserver::mDeletedFrames

Whenever an observed shape frame gets deleted, its pointer will be added to this set.

The next time the collision group updates, it will check this set and wipe away any references to the pointers in this set.

mMap

std::unordered_map<const common::Subject*, const dynamics::ShapeFrame*> dart::collision::CollisionGroup::ShapeFrameObserver::mMap

private

A map from a subject pointer to its corresponding ShapeFrame pointer.

This needs to be stored because by the time a Subject is being destructed, it can no longer be cast back to its ShapeFrame.

mSubjects

std::set<const Subject*> dart::common::Observer::mSubjects

protectedinherited

List of current Subjects for this Observer.