BOUNCE rtl@rtlinux.org: Approval required: Non-member submissionfrom [David Olofson <david.olofson@reologica.se>] (fwd)

[Der Herr Hofrat <der.herr@hofr.at>]

>From owner-rtl Wed May 30 02:29:58 2001
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From: David Olofson <david.olofson@reologica.se>
Reply-To: david.olofson@reologica.se
Organization: Reologica Instruments AB
To: rtl@fsmlabs.com
Subject: Re: [rtl] RTLinux: C++ static members != good ?
Date: Wed, 30 May 2001 10:25:06 +0200
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References: <F26QABZTW5k1Ed28kIN00002f30@hotmail.com> <009b01c0e7dc$16f76fb0$ba7fd13f@baby> <20010529145523.A11694@audi.fzi.de>
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On Tuesday 29 May 2001 14:55, Jan Albiez wrote:
> On Mon, May 28, 2001 at 09:10:00PM -0400, Heinz Haeberle wrote:
> > well the only clue I have is that there must be some initialisation code,
> > which is not executed. Like the static objects have to be initialized
> > too. I remember from VxWorks, that there was something which called those
> > init code when you loaded the code. It has to be done only for cpp code.
> > If you make the initialisation in the init code. What's gonna happen
> > then?
>
> The point is: Where is this Init code, why it is not executed, and what do
> I do to get it executed. My knowledege about the internals of the c++
> compiler is not that big ... 8[

Kernel modules aren't "applications", and thus lack the standard C++ (or C, 
for that matter) intit/exit code - and consequently, there's nowhere to hook 
in the application dependent init code generated by the compiler.

In your main C++ module, you need to do something like

	extern "C" {
		#include <linux/module.h>
 
		int init_module(void);
		void cleanup_module(void);
		__do_global_ctors_aux();
		__do_global_dtors_aux();
	};   

and then call __do_global_ctors_aux() from init_module(), and 
__do_global_dtors_aux() from cleanup_module(). That way, your global 
variables and object instances will be initialized and destroyed properly 
when the module is loaded and removed, respectively.


//David Olofson --- Programmer, Reologica Instruments AB

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