Memory Leak in Qt 4.10.0

[J.Hilk]

@ndiwan should actually not be necessary , m_SelectedPath is, despite its name, a local (scoped) variable:

void CSkateRetarder::paintEvent(QPaintEvent * )
{
   QPainter painter(this);
   painter.setRenderHint(QPainter::Antialiasing);
   QPainterPath m_SelectedPath = QPainterPath();
   m_SelectedPath.addRect(0,0, getRectWidth()+10, getRectHeight()+10);
...

so it should get cleaned up when the function returns

[jsulm]

@J-Hilk Ah, you're right, didn't notice this.

[ndiwan]

I am drawing a rectangular widget. That's why addign rectangle. Did you still see any memory leakage related issue in paintEvent ?

Thanks

[jsulm]

@ndiwan said in Memory Leak in Qt 4.10.0:

Did you still see any memory leakage related issue in paintEvent ?

No
Did you run Valgrind as suggested to find memory leaks?

[ndiwan]

Sorry, But I am not sure how to use that in Window Qt. I know ho to use valgrind in Linux

Actually my application runs with a login dialog. Do I need to provided user id and passoword in arguments here ?
Also kit drop down is diable.

Thanks

[jsulm]

@ndiwan said in Memory Leak in Qt 4.10.0:

Do I need to provided user id and passoword in arguments here ?

No

"Also kit drop down is diable" - what do you mean?

[ndiwan]

Kit dropdown is disable.

Thansks

[jsulm]

@ndiwan said in Memory Leak in Qt 4.10.0:

Kit dropdown is disable

This is the same what I asked about. Can you please explain what dropdown you mean? Maybe a screen-shot?

[ndiwan]

In the above screenshot Kit combo dropdown is disable. If I click manage , I can see this:

[jsulm]

@ndiwan Do you have Valgrind? Check in Analyzer/Valgrind. You need to set the path to Valgrind executable.

[Christian Ehrlicher]

@jsulm Since when does valgrind run on windows?

[jsulm]

@Christian-Ehrlicher Ah, Windows. Well, since never :-)

[ndiwan]

So How I can check memory leakage in Qt Creator running on Windows 10 ?

Thanks

[JonB]

@Christian-Ehrlicher said in Memory Leak in Qt 4.10.0:

Since when does valgrind run on windows?

I am the person who originally replied to @ndiwan 's "Could you please help me with how I can detect memory leak." with "Use valgrind to detect memory leakages."

I read the question carefully and nowhere did it mention using Windows. One of my pet bug-bears is if questioners cannot tell you what OS they are on for a question of this kind, why should I guess they are under Windows? Other OS people tell you what they are on, why do Windows users think people ought know they are on Windows...?

[JonB]

@ndiwan said in Memory Leak in Qt 4.10.0:

So How I can check memory leakage in Qt Creator running on Windows 10 ?

I would imagine it would depend on what compiler you have chosen to use, which we don't know....

[jsulm]

@JonB According to Kits it's MinGW

[Christian Ehrlicher]

@JonB said in Memory Leak in Qt 4.10.0:

why do Windows users think people ought know they are on Windows...?

I don't know.
And yes - my answer would also be - use valgrind or any other proper leak checker tool and how to you know that there is a memleak at all?

[JoeCFD]

On Windows, it may be a good idea to use Visual Studio + Qt plugin. Visual Studio is a powerful tool and has memory check functions for C++ code.
https://docs.microsoft.com/en-us/visualstudio/debugger/finding-memory-leaks-using-the-crt-library?view=vs-2019

[JoeCFD]

https://www.albertgao.xyz/2016/09/28/how-to-use-valgrind-on-windows/
I came across this, but never tried it by myself. Strongly recommend to use VS.

[Christian Ehrlicher]

@JoeCFD said in Memory Leak in Qt 4.10.0:

Visual Studio is a powerful tool

powerful? Nice try...