Multi-tier programming on devices

[Jon Brunson]

Howdy all,

Is it advisable to write Mobile Device applications using multi-tier
methodology? Or as Devices are much more resource-limited, would keeping
the number of tiers help reduce memory and processor usage?

I know apps on Devices can only use a maximum of 32MB of RAM, and
unfortunately our app is approaching, and at a push can be made to
breach that 32MB barrier. It's written in VB.NET, and has 4 tiers:-

1. GUI
2. Business logic
3. SqlCe interface
4. SqlServer interface

If we squished the number of layers from 4 down to 2 (GUI & "Everything
else"), would this help things memory-wise?

 

[Guest]

Pushing it to a single tier would likely gain nothing in memory usage. It's
also not true that you have a 32MB hard limit. The CF does a lot of
allocation from shared space. You have a 32MB virtual space limit per
process.

-Chris

 

[Jon Brunson]

Surely if an app is the first (or perhaps only) .NET app on the device,
the CF would be using that app's memory space for the framework, or does
the CF somehow create it's own process along side your own to run in?

 

[Guest]

The CF runs partly in slot 0, partly in slot 1 and partly in shared memory
space. Read all 3 parts of this, along with Mike Zintel's linked blog
entry:

http://blogs.msdn.com/stevenpr/archive/2005/12/14/503818.aspx

-Chris

 

[Jon Brunson]

Thanks Chris

The CF runs partly in slot 0, partly in slot 1 and partly in shared memory
space. Read all 3 parts of this, along with Mike Zintel's linked blog
entry:

http://blogs.msdn.com/stevenpr/archive/2005/12/14/503818.aspx

-Chris