Discussion :

[zenux]

Bonjour,

J'ai ce code source:

Code :

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	/**
        * Constructor
        * @param pos Position of the octree
        * @param size Size of the octree
        * @param depth Level of the octree (0 = leaf of the octree)
        * @param parent Parent of the octree
        */
	Octree::Octree(const Point3<float> &position, const Vector3<float> &size, int depth, Octree *parent) :
		parent(parent),
		position(position),
		size(size),
		depth(depth)
	{
		//create 8 children
		if(depth > 0)
		{
			const Vector3<float> &sizeChild = size / 2.0f;
 
			//child 1
			Point3<float> posChild = position;
			children.push_back(new Octree(posChild, sizeChild, depth-1, this));
 
			//child 2
			posChild = position;
			posChild.X = posChild.X + sizeChild.X;
			children.push_back(new Octree(posChild, sizeChild, depth-1, this));
 
			//child 3
			posChild = position;
			posChild.Z = posChild.Z + sizeChild.Z;
			children.push_back(new Octree(posChild, sizeChild, depth-1, this));
 
			//child 4, 5, 6, 7, 8
			//...idem child 1, 2, 3
		}
	}
 
	/**
        * Destructor
        */
	Octree::~Octree()
	{	
		//delete children
		for(vector<Octree *>::iterator it=children.begin(); it!=children.end(); ++it)
		{
			delete (*it); //line 96
		}
	}

J'ai lancé Valgrind pour détecter les erreurs à l'éxécution et voici ce que j'obtiens quand je fait un delete de l'Octree:

==10229== Invalid read of size 4
==10229== at 0x40C96A4: __gnu_cxx::__normal_iterator<Cortex::Octreeable**, std::vector<Cortex::Octreeable*, std::allocator<Cortex::Octreeable*> > >::__normal_iterator(Cortex::Octreeable** const&) (stl_iterator.h:686)
==10229== by 0x40C8A99: std::vector<Cortex::Octreeable*, std::allocator<Cortex::Octreeable*> >::end() (stl_vector.h:444)
==10229== by 0x40C7038: Cortex::Octree::deleteOctreeable(Cortex::Octreeable const*) (Octree.cpp:168)
==10229== by 0x40D136F: Cortex::OctreeManager::deleteOctreeable(Cortex::Octreeable*) (OctreeManager.cpp:148)
==10229== by 0x40D1497: Cortex::OctreeManager::resetOctreeables() (OctreeManager.cpp:196)
==10229== by 0x40D13AE: Cortex::OctreeManager::getVisibleOctreeablesInFrustum() (OctreeManager.cpp:159)
==10229== by 0x40DBB24: Cortex::Renderer3d::display() (Renderer3d.cpp:320)
==10229== by 0x40DD758: Cortex::SceneManager::display() (SceneManager.cpp:233)
==10229== by 0x804DE51: GLWidget::paintGL() (GLWidget.cpp:99)
==10229== by 0x41750FA: QGLWidget::glDraw() (in /usr/lib/libQtOpenGL.so.4.7.0)
==10229== by 0x4173C1D: QGLWidget::paintEvent(QPaintEvent*) (in /usr/lib/libQtOpenGL.so.4.7.0)
==10229== by 0x43C3CC5: QWidget::event(QEvent*) (in /usr/lib/libQtGui.so.4.7.0)
==10229== Address 0x9561dd4 is 20 bytes inside a block of size 60 free'd
==10229== at 0x4025504: operator delete(void*) (vg_replace_malloc.c:387)
==10229== by 0x40C6CEC: Cortex::Octree::~Octree() (Octree.cpp:96)
==10229== by 0x40C6CE4: Cortex::Octree::~Octree() (Octree.cpp:96)
==10229== by 0x40C6CE4: Cortex::Octree::~Octree() (Octree.cpp:96)
==10229== by 0x40D1221: Cortex::OctreeManager::buildOctree(std::set<Cortex::Octreeable*, std::less<Cortex::Octreeable*>, std::allocator<Cortex::Octreeable*> >&) (OctreeManager.cpp:117)
==10229== by 0x40D1757: Cortex::OctreeManager::resizeOctree(Cortex::Octreeable*) (OctreeManager.cpp:235)
==10229== by 0x40D130F: Cortex::OctreeManager::addOctreeable(Cortex::Octreeable*) (OctreeManager.cpp:133)
==10229== by 0x40D14B3: Cortex::OctreeManager::resetOctreeables() (OctreeManager.cpp:197)
==10229== by 0x40D13AE: Cortex::OctreeManager::getVisibleOctreeablesInFrustum() (OctreeManager.cpp:159)
==10229== by 0x40DBB24: Cortex::Renderer3d::display() (Renderer3d.cpp:320)
==10229== by 0x40DD758: Cortex::SceneManager::display() (SceneManager.cpp:233)
==10229== by 0x804DE51: GLWidget::paintGL() (GLWidget.cpp:99)

Savez-vous pourquoi Valgrind me génére cette erreur ?

Merci d'avance.

[abarral]

Salut;

As tu essayé de remplacer la boucle dans ton destructeur par :

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children.clear();

C'est la méthode la plus sure d'appeler le destructeur de tous les objets contenus dans un vecteur (ou une liste)...


Cordialement,

-----------------
Adrien BARRAL
REETI's development team
http://www.reeti.fr

[abarral]

ERRRATUM ::

J'avais pas vu que c'est des pointeurs vers Octree que tu met dans le vecteur, du coups mon message précedent est une énorme erreur...


Adrien

[Nydhu]

Bonjour,

Essaye de résoudre ce problème:
==10229== by 0x40C7038: Cortex::Octree::deleteOctreeable(Cortex::Octreeable const*) (Octree.cpp:168)

Fait attention avec Valgrind, les premières erreurs causent souvent d'autres erreurs par la suite.

[zenux]

Merci, je viens de comprendre comment interpréter l'erreur de Valgrind.

L'erreur se trouve en effet dans la méthode "Cortex::Octree::deleteOctreeable()" qui essaye d'accèder à une zone mémoire deleté dans le destructeur de la classe "Octree".

Plus d'info ici: http://people.gnome.org/~newren/tuto...l/ch03s03.html

Merci.