[sr-dev] Developing kamailio module - Forking issue

[Luis Martin Gil]

Thanks for your response Timo.

I did not find the solution yet since I had to postpone this development for
the future. I am sorry I forgot to reply you. Hopefully I can return to this
in the future and I will let you know my code's situation.

Luis

2011/9/17 Timo Reimann <timo.reimann at 1und1.de>

> Hey Luis,
>
>
> Am 17.09.2011 um 17:44 schrieb Luis Martin Gil:
> > This is Luis Martin. I am developing a new module for Kamailio. This
> module will include some functions which will allow Kamailio to connect to
> another servers and retrieve information. I'm thinking on creating a couple
> of child from my main function, each child will execute a query to an
> specific server. I read this file "doc/modules_init.txt", but I'm having
> some troubles and I would appreciate if you could please help me with this.
> >
> > This is the how the the first draft of the forking code looks like:
> > http://pastebin.com/MLXDN9p9
> > I call the "mod_child" function from my function like this:
> > int myFunction () {
> >   (...)
> >   mod_child(randomNUMBER);
> >   (...)
> > }
> >
> > But nothing happens, neither during the compilation process, nor the
> execution. Nothing is printed on the logs. Can you please point me out any
> suggestion or example?
> > - How I am supposed to call the "mod_child()" function?
>
> You do not call it. It's called automatically by Kamailio for every child
> configured. That is, if you have 16 workers set in your server
> configuration, the function is called 16 times. Place initialization code
> per child (e.g., establishing database connections) in that function, and
> Kamailio will make sure the code will be carried out for each child.
>
>
> > - Which should be the rank_number: PROC_MAIN?
>
> Again, you do not set the rank number, you use (read) it. As the
> documentation states, the child initialization function is called multiple
> times at different steps in the initialization process. By means of
> comparing the rank number to PROC_MAIN and other constants, you can make
> sure that you are doing specific tasks at the right time in the
> initialization life cycle.
>
> The concept is the same as the way you do forking in Linux: fork()'s return
> value of 0 indicates you're in a child process, anything else means you're
> in the parent process. You do the comparison in the very same function, just
> like you do in Kamailio's mod_child(). I noticed you fork off some children
> yourself in your example code; not sure if that is supposed to work within
> Kamailio, I've never done (or needed) it myself. If you're good with having
> as many worker processes as there are configured in the Kamailio
> configuration, you should be fine working with that.
>
>
> > - How I am supposed to cal the "mod_init()" function?
>
> You don't. (I believe you got the idea by now. :) ). Just put your
> non-child-specific initialization code there and let it get called by
> Kamailio.
>
>
> > - Again, could you please provide my any example?
>
> Pick a non-trivial module, many of them require child-based initialization.
> Examples are the dialog or p_usrloc module.
>
>
> HTH,
>
> --Timo
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sip-router.org/pipermail/sr-dev/attachments/20110927/d198a228/attachment-0001.htm>