#238 DPFUIImageView Memory Leak

[Diego]

Hi Babak:

Long time without talking!

I think I have found a memory problem with TDPFUIImageView.

Each time you assign a new bitmap to it, the RAM memory is decreased and it is never released, even if you do a DisposeOf().

So, eventually, you get a crash (tested in real devices) with the out of memory error.

I prepared a sample where you can see it.

It has 3 forms, the main is a selector with the Firemonkey and the DPF options. With the firemonkey component TImage you can assign a new bitmap anytime, however, with DPF the memory leak appears with 15-20 assignments.

Greetings!

Just press the "Fill Chart" button in both forms (the firemonkey and the dpf one) and you can see it by yourself.

[Babak Yaghoobi]

Hi Diego

How did you compile this example with TChart on iOS !?
So that I know the iOS not have a chart component.

Please tell me more about it.

Regards

[Diego]

Hi Babak, they are the Steema Charting components included in Firemonkey plattform for XE4 and XE5. I don´t know if they are included in all RAD Studio versions.

Since they are not native... I managed to capture their frame with Makescreenshot and then load the image into a native UIImage. (The posted source shows how to do this)

I tried to load the images in several ways (with SetImage, Bitmap directly, etc)...

[Babak Yaghoobi]

Hi Diego

Can you reproduce this bug with another sample without chart ?

Thanks.

Regards

[Diego]

Sure Babak.

I have removed the chart.

The bigger and complex the bitmap is, the sooner it will crash the application.
With this sample in an iPad 2 takes about 35-40 taps to crash. If you have a device with more RAM, it will take longer.

In simulator it doesn´t crash (I guess it is because it has much more RAM than a real device)

You can use instruments to check how fast the RAM is decreased with TDPFUIImageView bitmat assignment, while with Firemonkey TImage it works OK.

If you have cydia installed, I recommend you to install the free tool: StatusModifier, which allows you to see the free ram in status bar. This way you can see it directly in your device.

Thanks for your support!

[Babak Yaghoobi]

Hi Diego

Fixed.
Please download last source [code]
Thank you for your feedback.

Regards

[Diego]

Hi Babak:

Thanks for the help!

Anyways, it seems there is still a problem when you do a "DisposeOf" in a TDPFUIImageView.

I have prepared the same demo, but this time, the TDPFImageView is created and destroyed in runtime.

With this situation, the memory leak appears again. Maybe I am not freeing the component correctly...

I tried to clearimage before destroying it, but it didn´t help.

Thanks in advance!

[Diego]

Hi again Babak:

I think I have found the solution.

As you already did in the procedure DoBitmapChanged, I added the line

if FUIImageView.image <> nil then FUIImageView.image.release;

to the destructor TDPFImageView.Destroy

like this:

destructor TDPFImageView.Destroy;
begin
  if FUIImageView.image <> nil then FUIImageView.image.release;
  FBitmap.DisposeOf;
  FImageList.DisposeOf;
.
.
.

There is still a small memory leak if you create a lot of images (12 or so) with big bitmaps assigned to them. Anyways, I think it won´t be a problem and I'll try to find the solution on my own.

Thanks again Babak!

[Babak Yaghoobi]

Hi Diego

Don't add this line inside Destroy section, this work for you only if you set BitMap image in others this cause crash your app!

I changed some codes for fix leak,
Download last source code and test it again please.

Regards

[Diego]

Hi Babak:

It is working perfectly.

Thanks a lot!

By the way, you forgot the {IFDEF IOS} in var declaration of DoBitmapChanged.

Greetings!