NewLC - P800 : Is multitasking possible? - Comments

P800 : Is multitasking possible?

amattiuz — Wed, 07 Jul 2004 13:51:38 +0200

Thanx!!
IÂ´ve already had downloaded this example... in fact, I prettry much got inspired by it ;o)

I was thinking that in my case it would be different because there is no UI... I will take a better look at the code of SmallServ

Yes, use the recogniser hack

streetmentioner — Wed, 07 Jul 2004 00:08:16 +0200

If you start your server using the ugly recogniser thing, there's no reason why it should ever exit.

There's an HTTP server at

http://www.symbian.com/developer/techlib/staffapps.html

If you really want to run a server indefinitely, be really careful about memory leaks, polling, and other evil things. Obviously [/url]

P800 : Is multitasking possible?

amattiuz — Tue, 06 Jul 2004 21:55:41 +0200

well, I canÂ´t make my server run at sturt up?

what about using this Recognizer??? is it possible??

P800 : Is multitasking possible?

Anonymous — Tue, 06 Jul 2004 21:45:06 +0200

I don't think you can make your server run forever - of course there are servers that run forever on Symbian devices but they are specified by the device manufacturer and get started at boot up.

P800 : Is multitasking possible?

amattiuz — Tue, 06 Jul 2004 20:50:06 +0200

Thats exactly what I need!
I need a way to make a EXE run "forever" ;o)

My exe is a kind of http server, there is no UI (I am using console for tests, but I intend to remove it) ... but I am not using CServer... what kind of modifications should I do

To write a server...

streetmentioner — Fri, 28 May 2004 23:56:44 +0200

You need to have two MMP files, one for the client and one for the server. The server should be a subclass of CServer. The client should be a subclass of RSessionBase.

To reply to a couple of other things raised in this (old) thread...

1) whoever mentioned 'polling' - don't do it. Symbian shuts down the CPU whenever nothing's happening; that's why the battery lasts so long. Anything polling will destroy that and the battery will be gone in hours.

2) On UIQ (e.g. P800), to stop your *application* being shut down in the background, just override the SaveL of your CQikDocument. That gets called (with EReleaseRam) when the device wants to free up some memory, and is trying to shut you down. The default implementation is Exit(). This is not an issue for servers, since they are .exes not .apps and will not get shut down. Your server will stay running indefinitely.

P800 : Is multitasking possible?

wolfigor — Thu, 27 May 2004 09:11:11 +0200

you need to create 2 apps, or better an application (for the UI) and a server (for the background services).
It's not too complex.

An other possibility (depends on the complexity of the background services) is to put those services inside ActiveObjects (CActive).

BTW UIQ does not shut down background apps!
It makes them run (at lower priority) in background.
Only when RAM is running low, the system starts shutting down background apps.

To set your thread as system yu have a few functions that do the work:
CEikonEnv::SetSystem(TBool aSystem) //sets your app as system
CApaWindowGroupName::SetSystem(TBool aSystem)//set any as system

P800 : Is multitasking possible?

siemensc55 — Wed, 26 May 2004 10:21:57 +0200

Andrea can you tell me the way how do i mark my application "System Task".so that it does not closes when the system runs low in memory .

second how can i make my application to register some part of functionality as a system task and the rest gUI as an app ...so that even if the GUI environment closes the system task continues ........if it is possible

P800 : Is multitasking possible?

Andreas — Mon, 24 May 2004 12:24:11 +0200

It is possible to mark a task as a system task. It is not then closed if apps need to be closed. The apps are closed by the system only when the free memory starts to run out. Otherwise the apps are kept running. It is possible to make the app close if switched to background, but this must be explicitly programmed in the app.

P800 : Is multitasking possible?

siemensc55 — Mon, 24 May 2004 12:15:37 +0200

yea i will also like to know how to write a server application for symbian...

P800 : Is multitasking possible?

sym_pro — Fri, 28 Nov 2003 13:04:00 +0100

ThanX, hope server solves my problem.

My scenario is like :

2 different applications are running and they continuously talking with each other.
1) Status polling
2) Status updating
3) Using status for changing respective GUI's

Since 2 applications run in parallel and require status to be given to each other I am interested in multitasking.
I can not create 2 threads in the same program as user may close the application which is not desired and hence thought of multitasking.

- Sym_Pro

P800 : Is multitasking possible?

DoozerII — Fri, 28 Nov 2003 10:32:17 +0100

Quote from: sym_pro

Actually my problem was to achieve this feature of symbian of multitasking on P800/P900 units.
What documentation of P800 says is that the device closes the running application after new application is launched. Although the device holds the state of closed application it is not useful since the closed application is not in active state.

I am not facing any probelm on series 60 devices but on UIQ.

My query is specific to P800/P900.

I think you misunderstand something. There is no need to have a application running in the background, when you can have the server running. The server is the part of the application wich provides all the services that you wish to keep running.
Why do you need multitasking?

P800 : Is multitasking possible?

sym_pro — Fri, 28 Nov 2003 08:31:52 +0100

Hello,
Actually my problem was to achieve this feature of symbian of multitasking on P800/P900 units.
What documentation of P800 says is that the device closes the running application after new application is launched. Although the device holds the state of closed application it is not useful since the closed application is not in active state.

I am not facing any probelm on series 60 devices but on UIQ.

My query is specific to P800/P900.

Cheers
- Sym_Pro

P800 : Is multitasking possible?

aljaz25 — Thu, 27 Nov 2003 10:48:30 +0100

Hey,

Yeah multitasking is possible in Symbian. For an application to run in the background you'd have to write a server, which then runs in the background and then write a client application that uses services offered by this server. This is the usual way multitasking is implemented on Symbian platform. Check the SDK topic on RThread and CSession for more information on this topic.

Regards, Aljaz

P800 : Is multitasking possible?

sym_pro — Mon, 24 Nov 2003 10:50:09 +0100