# Trying to delete object with non-zero reference count.
**URL:** https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807
**Category:** Engineering
**Tags:** registration
**Created:** [March 16, 2023, 9:59am UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807 "2023-03-16T09:59:23Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@ma1282029525](https://discourse.itk.org/u/ma1282029525)
#### Post date: [March 16, 2023, 9:59am UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807/1 "2023-03-16T09:59:23Z")
When my program exits, the title appears. Does it represent my memory leak？
---
### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [March 16, 2023, 2:35pm UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807/2 "2023-03-16T14:35:37Z")
Probably. It is hard to tell without more information.
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### Author:  [@ma1282029525](https://discourse.itk.org/u/ma1282029525)
#### Post date: [March 17, 2023, 1:21am UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807/3 "2023-03-17T01:21:40Z")
do you have any method about checkthe itk memory lack ?
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### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [March 17, 2023, 12:56pm UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807/4 "2023-03-17T12:56:06Z")
I remember that VTK can bring up a dialog with a message similar to “Trying to delete object with non-zero reference count”. But I don’t think ITK does that. @blowekamp @mihail.isakov Do you agree?
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### Author:  [@mihail.isakov](https://discourse.itk.org/u/mihail.isakov)
#### Post date: [March 17, 2023, 2:40pm UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807/5 "2023-03-17T14:40:02Z")
ITK has the warning [here](https://github.com/InsightSoftwareConsortium/ITK/blob/0afd0ddf4bbe1ded5ce6af06af2cd3babffcb086/Modules/Core/Common/src/itkLightObject.cxx#L182)
```auto
LightObject::~LightObject()
{
/**
* warn user if reference counting is on and the object is being referenced
* by another object.
*/
if (m_ReferenceCount > 0)
{
// A general exception safety rule is that destructors should
// never throw. Something is wrong with a program that reaches
// this point anyway. Also this is the least-derived class so the
// whole object has been destroyed by this point anyway. Just
// issue a warning, do not call `itkExceptionMacro`.
itkWarningMacro("Trying to delete object with non-zero reference count.");
}
}
```
I have the warning at one point, seems to be harmless, _Valgrind_ doesn’t detect leak at this point, so far nothing happens. Probably it is my mistake somewhere, not sure. I shall look again little later.
Edit:
Also see this [post](https://github.com/InsightSoftwareConsortium/ITK/pull/2744#issuecomment-922542576). There is a minimal example.
---
### Author:  [@mihail.isakov](https://discourse.itk.org/u/mihail.isakov)
#### Post date: [March 17, 2023, 10:07pm UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807/6 "2023-03-17T22:07:35Z")
> Probably it is my mistake somewhere, not sure. I shall look again little later.
I have found my mistake. I used _itk::MapContainer_ on a stack.
```cpp
#include
int main(int, char**)
{
itk::MapContainer map;
return 0;
}
```
```auto
r@deb2:~/tmp/test5/build$ ./test
WARNING: In /home/r/itk/ITK/Modules/Core/Common/src/itkLightObject.cxx, line 182
LightObject (0x7ffc902d3020): Trying to delete object with non-zero reference count.
```
It should be:
```cpp
#include
int main(int, char**)
{
itk::MapContainer::Pointer map = itk::MapContainer::New();
return 0;
}
```
```auto
r@deb2:~/tmp/test5/build$ ./test
r@deb2:~/tmp/test5/build$
```
---
### Author:  [@ma1282029525](https://discourse.itk.org/u/ma1282029525)
#### Post date: [March 22, 2023, 1:40am UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807/7 "2023-03-22T01:40:08Z")
thank you,I resolved an error that is the same as yours, but I still have a warning, and when I debug a breakpoint, the system already prints that warning the first time I enter the destructor.
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### Author:  [@blowekamp](https://discourse.itk.org/u/blowekamp)
#### Post date: [March 22, 2023, 11:47am UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807/8 "2023-03-22T11:47:59Z")
> [@mihail.isakov](#):
>
> I have found my mistake. I used _itk::MapContainer_ on a stack.
@Niels_Dekker Is this a bug? I thought we had a mechanism to prevent these object from being constructed on the stack?
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### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [March 22, 2023, 5:16pm UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807/9 "2023-03-22T17:16:56Z")
There is a [mechanism via a macro](https://github.com/InsightSoftwareConsortium/ITK/blob/v5.3.0/Modules/Core/Common/include/itkMacro.h#L399-L411) which is usually applied to filters. Maybe it was forgotten for `MapContainer`?
---
### Author:  [@Niels\_Dekker](https://discourse.itk.org/u/Niels_Dekker)
#### Post date: [March 22, 2023, 6:06pm UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807/10 "2023-03-22T18:06:23Z")
Apparently the `MapContainer()` default-constructor was originally declared `protected`:
>
It was then afterwards declared `public` instead, on November 30, 2001, commit [ENH:Unified documentation style. · InsightSoftwareConsortium/ITK@e9c0020 · GitHub](https://github.com/InsightSoftwareConsortium/ITK/commit/e9c002026368eee503bc39d363b9c9344d587385)
Here:
[ITK/itkMapContainer.h at e9c002026368eee503bc39d363b9c9344d587385 · InsightSoftwareConsortium/ITK · GitHub](https://github.com/InsightSoftwareConsortium/ITK/blob/e9c002026368eee503bc39d363b9c9344d587385/Code/Common/itkMapContainer.h#L98-L102)
HTH, Niels
---
### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [March 22, 2023, 6:10pm UTC](https://discourse.itk.org/t/trying-to-delete-object-with-non-zero-reference-count/5807/11 "2023-03-22T18:10:40Z")
Since it has a `New` macro and `Pointer` type, it should probably use constructor disallow macro. Anyone willing to submit a PR?