Allocating Memory in CMyApplication

[mlepage]

If I take the minimal application (GapiDraw 2.05eval), and add one line to CMyApplication to allocate an array:

int array[240 * 240];

then when I launch the application, it locks the device before the splash screen is displayed.

If I drop it down to this amount:

char array[240 * 240];

then I get an actual dialogue which says illegal exception, and the device does not hang.

If I drop it down to this amount:

char array[240 * 210];

Then it works fine.

If I increase it to this amount:

char array[240 * 225];

Then I get the spinning wait cursor, for half a minute before I lose patience and reset the device.

So I assume I'm running out of memory. Yet 240 * 240 * 1 byte is only 56KB, which doesn't seem like a lot. Wouldn't surfaces take up 240 * 320 * 2 bytes which is even more?

Does anyone else see this behaviour? Can they allocate a 240x240 array of chars? ints? I'm using a release build for iPAQ 3970.

[ppcStudios]

[mlepage]

[Pam]

[mlepage]

[Layre5150]

I believe you are taxing the stack. If for example you have:

char cMyArray[128];
char cMyArray[128*100];

Which is allocated from the stack and is totally different than:

char* pMyArray = (char*)malloc( 128 * 100 * sizeof(char) );

Which comes from the heap.

[Layre5150]

I took a look at the date on that post which was posted about a month ago - sorry. I guess you probably would have solved it by now.

[mlepage]

Yup it was on the stack and I didn't really notice it was. :-)

In my older project I also allocated in CMyApplication, but I actually created the application instance on the heap so it was fine.

In my newer project, however, the instance is created on the stack just like the Minimal sample applicaiton.

[Layre5150]

[mlepage]

Well, I only allocate this at the beginning of the program run. So it's not a problem allocating and deallocating.

Further, if you allocate statically, apparently that would be a problem if you port to devices like Symbian.

The correct way to approach memory problems is to only write your own allocators once you've shown allocation to actually be a problem.

Right now it's not a problem for me, my app runs quite well.