Re: [NTLK] A heaping of heap questions

From: Victor Rehorst (victor_at_newtontalk.net)
Date: Fri Nov 08 2002 - 09:41:21 EST


Scott Clitheroe wrote:
> Hi,
>
> I'm into the second week of using my Newton 120, and still loving it. The
> Palm is begining to gather dust :) Anyways, I was curious about heap
> usage, as I understand it can be an issue on Newtons. I've learned that
> applications can be "frozen" to minimize or remove their heap allocations,
> and that leads me to a few questions:
>

> - what actually (technically) happens when you freeze an app?

The app is uninstalled, but not deleted from the storage space. It basicially
lies dormant. When a Newton application is installed, it is registered with
the system so that other applications can access it, and it can also run its
InstallScript to do various tasks before it is run. When you delete an
application, it is unregistered, its RemoveScript is run (which typically
undoes whatever the InstallScript did), and it is deleted from flash.
Freezing does the first two but not the third.

> - I installed an app called BatterBuddy, from Tactile systems, which allows
> me to freeze apps. Do all app freezers work the same? Is one better than
> another, in terms of stability, features, whatever?

Freezing is done by the system - it merely has to be enabled (it's a hidden
preference). If you just wanted to turn on/off freezing, there's a myriad of
apps to do it for you. I even wrote one:

http://www.chuma.org/code/newton/freezeit/

> - I check my free RAM before and after freezing a few small apps, and saw
> no difference. Are heap allocations counted against available RAM? If
> not, are there third party apps that can tell me how much heap is
> used/available?

If you want to talk in-depth about the Newton's memory model, there's a great
technical explanation of it in the FAQ:

http://www.chuma.org/newton/faq/newton-faq-nos.html#IIID3b

-- 
Victor Rehorst - victor_at_newtontalk.net - chuma_at_chuma.org
NewtonTalk list administrator - http://www.newtontalk.net
Will help you with your list problems - as long as you're nice.

-- This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries List FAQ/Etiquette/Terms: http://www.newtontalk.net/faq.html Official Newton FAQ: http://www.chuma.org/newton/faq/



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