Problem with de-allocating memory

[Christov]

Hi guys,
I'm totally new to C++ and trying to program something using the Marmalade API (www.madewithmarmalade.com. The problem I'm facing is de-allocating the memory I've used at the end of the code doesn't seem to work... and no matter what I read/try I can't get it to work sadly :(

My code looks something like this:

// Marmalade headers
#include "s3e.h"
#include "Iw2D.h"
#include "IwGx.h"
#include "vector"


int main()
{
	// Initialise Marmalade graphics system and Iw2D module
	Iw2DInit();

	//create array
	std::vector<CIw2DImage*> images;

	// Create an image for the app to use
	//CIw2DImage* image1 = Iw2DCreateImage("lol1.png");
	//CIw2DImage* image2 = Iw2DCreateImage("lol2.png");
	//CIw2DImage* image3 = Iw2DCreateImage("lol3.png");

	//Add actual images to the array 'images'
	images.push_back(Iw2DCreateImage("lol1.png"));
	images.push_back(Iw2DCreateImage("lol2.png"));
	images.push_back(Iw2DCreateImage("lol3.png"));

	// Main Game Loop
	while (!s3eDeviceCheckQuitRequest())
	{	
		//Clear the Screen
		Iw2DSurfaceClear(0xff000000);

		//Draw an image
		Iw2DDrawImage(images[IwRandMinMax(0, images.size())], CIwSVec2(10,10));

		// Show the surface
		Iw2DSurfaceShow();

		//yield to the system
		s3eDeviceYield(1);
	}

	//de-allocate pointers from vector array
	for(int i = 0; i < images.size(); ++i)
	delete images[i];

	// Shut down Marmalade graphics system and the Iw2D module
	Iw2DTerminate();
	
    return 0;
}

The Iw2D and s3e calls are in ref to the marmalade system.

Problem I'm facing is I'm getting this error:

IwAssert failure (MEMORY, 2356).
Message: Bucket 0(System) is still in use (first allocation ID=185); deleting it is dangerous

Callstack:
IwUtilTerminate
IwGxTerminate
Iw2DTerminate
_IwGxInitPipeline

From what I read this is a 'still in use' memory error and I haven't de-allocated properly so I suspect this is a general c++ coding error rather than a marmalade specific error.

So my question is... how am I supposed to properly remove the points from a vector array if not how I've done above? Any help would be greatly appreciated as I am absolutely a complete c++ noob... but I would like to learn more!

[Jikax]

you use delete, but you never used new to allocate space...

[Christov]

@ Jikax
Thanks! Ok so when I call this:

std::vector<CIw2DImage*> images;

This doesn't automatically create the space it needs? I have to allocate space manually?

How much is needed for a vector, obviously images are being put 'into' this array so it's not a straight forward integer right?

[Jikax]

obviously images are being put 'into' this array

actually, no... pointers to images are put into the array...and pointers take 4 bytes;)... But you don't have to worry about that...
The iwd2createimage allocated the space for you... Maybe there is a iwd2deleteimage or something...

[Chervil]

The example on this page seems to pair 'Iw2DCreateImage' with 'delete'.

I think that's more or less what you do too, so it doesn't help much.

http://docs.madewithmarmalade.com/native/api_reference/api/ExampleIw2DImages.html

[Jikax]

Hmmm... Indeed... It looks like your doing the right thing...

[Jikax]

I found this: https://www.madewithmarmalade.com/devnet/forum/memory-issue-when-using-stl-vector-3

It looks like vectors and marmalade don't go well together...

[Christov]

Hmm.. this does not bode well.
delete does work when it's just a regular display image command but not with the array it seems.
Thanks for the replies guys...

Any suggestions as to what I could use otherwise?
My end result is to create something that will display a random image from a list of images.
I thought a vector array would be the best way to do this but perhaps not....

[Chervil]

The previous post seems to contain the solution:
http://docs.madewithmarmalade.com/native/api_reference/iwutilapidocumentation/iwutilapioverview/array.html

[Athar]

Unless the documentation specifically mentions that Iw2DDrawImage keeps pointers to the images that you pass and that you may not delete them before calling Iw2DTerminate(), this looks like a bug in that library. You probably should file a bug report.

[Christov]

@Chevril
That's awesome! Ok so I use CIwArray instead of vector, no problem. However I can no longer use Iw2DCreateImage with this it seems... how do I put images into the CIwArray?

[Chervil]

I can no longer use Iw2DCreateImage

- is this from your experience, or something you read? I didn't notice it mentioned.

[Christov]

This was from my experience, I was getting errors until I changed to

CIwArray<void> images;

and now IW2D works, however I still get this error:

IwAssert failure (MEMORY, 2356).
Message: Bucket 0(System) is still in use (first allocation ID=185); deleting it is dangerous

Callstack:
IwUtilTerminate
IwGxTerminate
Iw2DTerminate
_IwGxInitPipeline

This is what my code looks like now that I've changed to CIwArray:

// Marmalade headers
#include "s3e.h"
#include "Iw2D.h"
#include "IwGx.h"
#include "vector"


int main()
{
	// Initialise Marmalade graphics system and Iw2D module
	Iw2DInit();

	//create array
	CIwArray<void> images;

	// Create an image for the app to use
	//CIw2DImage* image1 = Iw2DCreateImage("lol1.png");
	//CIw2DImage* image2 = Iw2DCreateImage("lol2.png");
	//CIw2DImage* image3 = Iw2DCreateImage("lol3.png");

	//Add actual images to the array 'images'
	images.push_back(Iw2DCreateImage("lol1.png"));
	images.push_back(Iw2DCreateImage("lol2.png"));
	images.push_back(Iw2DCreateImage("lol3.png"));

	// Main Game Loop
	while (!s3eDeviceCheckQuitRequest())
	{	
		//Clear the Screen
		Iw2DSurfaceClear(0xff000000);

		//Draw an image
		Iw2DDrawImage(images[IwRandMinMax(0, images.size())], CIwSVec2(10,10));

		// Show the surface
		Iw2DSurfaceShow();

		//yield to the system
		s3eDeviceYield(1);
	}
	
	images.clear();

	// Shut down Marmalade graphics system and the Iw2D module
	Iw2DTerminate();
	
    return 0;
}

[Chervil]

I noticed this comment on one of the pages: "Try to move the vector operations (push_back etc.) before Iw2DInit() or IwGxInit() functions."
http://www.madewithmarmalade.com/devnet/forum/memory-issue-when-using-stl-vector-3

I'm wondering whether you could first create the array, and add three (or however many you need) null pointers to it.

Then after calling Iw2DInit(); you could create your images. Copy your proper image pointers to replace the null values already in the array.

I'm guessing of course, as I don't have the files to test this myself.