Memory diagnosis on emulator, my app is using a lot! Why?

[nhammond]

Im using the memory diagnosis tool on the emulator. When I start my app it goes from about 1/5 usage to 4/5. I take it this is a bad thing! Is this anything to with with the fact that I have changed to heap size in the mmp file?

Any suggests?

[stichbury]

What did you change the heap size to? And if you did make it significantly larger than the default, why did you need to to this?

[nhammond]

Hi, thanks for your reply.

I changed it to 5 MB. Because I want to handle files (in heap buffer form) of around 3 or 4 MB. Do I need to change the heap size in this case?

[stichbury]

If you want to read in 4MB from a file, you do most definitely need to do it in a heap buffer. I guess the question is, do you need to read the entire file in at once, or can you process it in sections? And, if you do need to read the entire file, does it need to be that big, or can you work with a smaller format (lower resolution graphic for example)?

It depends what devices you're targetting for your application, but some have fairly limited amount of memory. For example, N71 has 10MB (http://www.forum.nokia.com/devices/N71). So, if your app consumes 5MB, you run the risk of not being able to run it if a couple of other applications are already consuming memory. If you can cut back on what you need, it would be advisable to do so.

[nhammond]

I have written a HTTP app for upload files, I just wanted to be able to send bigger files, perhaps music files. In reality Im not tho because it takes a while. Would just be nice tho.

[ltomuta]

Big files can be read and sent (or received and writen) in small chunks, e.g. 4K at a time. Even if you need e.g. a 4MB buffer there is no need to alocate that memory for the entire life time of your app.