delete, hash_map

[SimpleCode]

class COsgCar;
class moving_vechicle ;
hash_map<moving _vechicle*, COsgCar*m_hash;

hash_map<moving _vechicle*, COsgCar*>::iter ator iter;
iter = m_hash.find( pMovingVechicle );
if ( iter != m_hash.end() )
{
COsgCar *p = m_hash[pMovingVechicle];
delete p;
}
///////////////////////////////////////
It always run error.
I don't know why.
I just test for some days.

[Ivan Vecerina]

"SimpleCode " <Dr*********@gm ail.comwrote in message
news:11******** **************@ e65g2000hsc.goo glegroups.com.. .
: class COsgCar;
: class moving_vechicle ;
: hash_map<moving _vechicle*, COsgCar*m_hash;
:
: hash_map<moving _vechicle*, COsgCar*>::iter ator iter;
:
:
: iter = m_hash.find( pMovingVechicle );
: if ( iter != m_hash.end() )
: {
: COsgCar *p = m_hash[pMovingVechicle];
: delete p;

Deleting the pointer will not remove it from the hash_map,
so you are leaving in the hash-map a pointer to freed memory.
Try adding, for example:
m_hash.erase(pM ovingVehicle); // remove the hash_map entry

: }
:
:
: ///////////////////////////////////////
: It always run error.
: I don't know why.
: I just test for some days.

hth -Ivan
--
http://ivan.vecerina.com/contact/?subject=NG_POST <- email contact form
Brainbench MVP for C++ <http://www.brainbench.com

[SimpleCode]

Ivan Vecerina дµÀ£º

"SimpleCode " <Dr*********@gm ail.comwrote in message
news:11******** **************@ e65g2000hsc.goo glegroups.com.. .
: class COsgCar;
: class moving_vechicle ;
: hash_map<moving _vechicle*, COsgCar*m_hash;
:
: hash_map<moving _vechicle*, COsgCar*>::iter ator iter;
:
:
: iter = m_hash.find( pMovingVechicle );
: if ( iter != m_hash.end() )
: {
: COsgCar *p = m_hash[pMovingVechicle];
: delete p;

Deleting the pointer will not remove it from the hash_map,
so you are leaving in the hash-map a pointer to freed memory.
Try adding, for example:
m_hash.erase(pM ovingVehicle); // remove the hash_map entry

: }
:
:
: ///////////////////////////////////////
: It always run error.
: I don't know why.
: I just test for some days.

hth -Ivan

yes, I also use it.
The most important, I can't delete the COsgCar object which contains
many memory.
And I don't why I can't do it.

[Ivan Vecerina]

"SimpleCode " <Dr*********@gm ail.comwrote:

The most important, I can't delete the COsgCar object which contains
many memory.
And I don't why I can't do it.

Well, either the object has already been deleted,
or its destructor does an illegal operation (e.g.
maybe a recursion problem?).
It is impossible to tell from the code you've posted.
--
http://ivan.vecerina.com/contact/?subject=NG_POST <- email contact form

[SimpleCode]

Well, either the object has already been deleted,

or its destructor does an illegal operation (e.g.
maybe a recursion problem?).
It is impossible to tell from the code you've posted.

My code:
#include <hash_map>
stdext::hash_ma p<moving_vehicl e*, COsgCar*g_hash; //global
variable
typedef pair<moving_veh icle*, COsgCar*Ptr_Pai r;

void COsgView::setRo otChild(float x, float y, float z, float angle,
int type, moving_vehicle* pMovingVehicle)
{
/**** new, only hear ****/
COsgCar * osgcar = new COsgCar(x, y, z, angle, type);
g_hash.insert(P tr_Pair(pMoving Vehicle, osgcar));
}

vehicle_node* car_list::delet e_car(vehicle_n ode *k)
{
stdext::hash_ma p<moving_vehicl e*, COsgCar*>::iter ator hash_Iter;
hash_Iter = g_hash.find(k->vehicle_p);
if (hash_Iter != g_hash.end())
{
COsgCar *p = g_hash[k->vehicle_p];
g_hash.erase(ha sh_Iter);
delete p; /**** If I comment, there is no problem ***/
p = NULL;
}
}

A puzzle.
----------------
Regards Lung

[Ivan Vecerina]

"SimpleCode " <Dr*********@gm ail.comwrote in message
news:11******** **************@ q75g2000hsh.goo glegroups.com.. .
:Well, either the object has already been deleted,
: or its destructor does an illegal operation (e.g.
: maybe a recursion problem?).
: It is impossible to tell from the code you've posted.
:
: My code:
: #include <hash_map>
: stdext::hash_ma p<moving_vehicl e*, COsgCar*g_hash; //global
: variable
: typedef pair<moving_veh icle*, COsgCar*Ptr_Pai r;
:
: void COsgView::setRo otChild(float x, float y, float z, float angle,
: int type, moving_vehicle* pMovingVehicle)
: {
: /**** new, only hear ****/
: COsgCar * osgcar = new COsgCar(x, y, z, angle, type);
: g_hash.insert(P tr_Pair(pMoving Vehicle, osgcar));
: }
:
: vehicle_node* car_list::delet e_car(vehicle_n ode *k)
: {
: stdext::hash_ma p<moving_vehicl e*, COsgCar*>::iter ator hash_Iter;
: hash_Iter = g_hash.find(k->vehicle_p);
: if (hash_Iter != g_hash.end())
: {
: COsgCar *p = g_hash[k->vehicle_p];
: g_hash.erase(ha sh_Iter);
: delete p; /**** If I comment, there is no problem ***/
: p = NULL;
: }
: }
:
: A puzzle.

Well, it's one of two things:
- the pointer that you are deleting is invalid
You could try to log object addresses in the constructor
and destructor to find out.
- the destructor of COsgCar does something wrong...

Again, the code you've posted seems ok.
--
http://ivan.vecerina.com/contact/?subject=NG_POST <- email contact form

[pmouse]

On May 5, 5:03 am, SimpleCode <DragonXL...@gm ail.comwrote:

Well, either the object has already been deleted,
or its destructor does an illegal operation (e.g.
maybe a recursion problem?).
It is impossible to tell from the code you've posted.

My code:
#include <hash_map>
stdext::hash_ma p<moving_vehicl e*, COsgCar*g_hash; //global
variable
typedef pair<moving_veh icle*, COsgCar*Ptr_Pai r;

void COsgView::setRo otChild(float x, float y, float z, float angle,
int type, moving_vehicle* pMovingVehicle)
{
/**** new, only hear ****/
COsgCar * osgcar = new COsgCar(x, y, z, angle, type);
g_hash.insert(P tr_Pair(pMoving Vehicle, osgcar));

}

vehicle_node* car_list::delet e_car(vehicle_n ode *k)
{
stdext::hash_ma p<moving_vehicl e*, COsgCar*>::iter ator hash_Iter;
hash_Iter = g_hash.find(k->vehicle_p);
if (hash_Iter != g_hash.end())
{
COsgCar *p = g_hash[k->vehicle_p];
g_hash.erase(ha sh_Iter);
delete p; /**** If I comment, there is no problem ***/
p = NULL;
}

}

A puzzle.
----------------
Regards Lung

what exactly is the error message? A double free exception? a memory
corrupted exception? What is the destructor of COsgCar look like?

Regards,

PQ