Subject: Re: Strange error when trying to intercept sysNotifyVolumeMountedEvent
From: "Dr. Vesselin Bontchev" <[EMAIL PROTECTED]>
Date: Wed, 4 May 2005 14:02:19 -0000
> Again, you fail to understand what's going on and are trying to
> use your background in disk-based OS to understand Palm OS (and
> therefore mis-undertand)
I understand it very well - and I insist that what I said is right and what you said is wrong. In PalmOS "all programs" DO NOT "run in the background all the time".
Yes they do. But apparently no one can tell you anything.
Note: This statement only covers programs located in RAM.
> This are a lot more powerful as you receive these in background > mode and can service them regardless of what the foreground > program is doing.
They are most definitely *not* "more powerful. At best, they could be just as powerful, because they allow you to do essentially the same things. In practice, they are less powerful, because your "background" program cannot receive them until the "foreground" program allows it to; there is absolutely no support from the OS in that aspect.
Foreground programs run using the event loop, and every time they pass around the event loop the OS gets control and can send launch codes and notifications to the other programs on the unit, all of which are running in background mode all the time. Note: This statement only covers programs located in RAM.
In Palm OS, the vast majority of foreground programs are truly GUI based, and therefore have to keep the event loop going in order to service the GUI. While it is possible for a program to ignore the event loop, the reality of the need to service the GUI ensures that the vast majority of programs are actually well behaved in this respect.
If you (or anyone else) are going to have a process that runs for any significant time (say more than 0.5 sec) you should either use the Progress Manager or build your own using a dialog screen, and either way cycle through the event loop on a frequent basis to maintain the GUI and let the OS handle whatever else it needs to handle.
Roger Stringer Marietta Systems, Inc., P.O. Box 71506, Marietta, Georgia 30007, USA 770-565-1560 PDE, RF-TP and piDB are trademarks of Marietta Systems, Inc. http://www.rf-tp.com
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