[Asterisk-Dev] Changing Asterisk's module invocation

[Juan Jose Comellas]

But if I do what you propose, each Java module would be created and destroyed 
when each channel is created and destroyed. I want to have Java modules that 
last as long as C modules do and that are not tied to specific channels. 

The problem I'm facing is that I need to map the C callback for each 
application to multiple Java classes in order to have only one instance of 
the JVM for all the Java modules. The configuration file would look like 
this:

--- java.conf 
[commands]
JavaTransfer = org.asterisk.JavaTransferModule
JavaConference = org.asterisk.JavaConferenceModule
JavaDirectory = org.asterisk.JavaDirectoryModule

So, whenever the any of the commands is found in the dialplan and Asterisk 
invokes the C callback for my bridge module I would like to invoke a method 
of the corresponding Java class.

The reason for doing it this way is that I want to be able to dynamically set 
the Java applications without having to write different C entry points for 
the different Java Asterisk applications. Do you think this is feasible with 
the current functionality in Asterisk?

BTW, how can I set up some kind of hook to be notified when Asterisk creates 
and destroys a channel?

Thanks for your help.


On Tuesday 14 September 2004 19:34, David Pollak wrote:
> Juan Jose,
>
> You don't need to change Asterisk.  In your glue layer between SWIG and
> Asterisk, you can determine the unique identifier of the channel.  Based
> on this unique ID, you can look up the void * data structure in your own
> store.  Put another way, you manage your own cookies and use the
> channel's unique ID as the lookup for the cookie.  The only additional
> bit of work is that you'll have to monitor to see when a channel is
> destroyed so you can free the cookie entry for the destroyed channel.
>
> Depending on exactly what you're using Java for, you might want to take
> a look at a patch I made (enclosed) to Asterisk.  This patch merges AGI
> with the Manager API.  It's useful to have a single socket open between
> a Java app server and Asterisk and control all the Asterisk channels
> through that socket.
>
> If you've got more questions, please feel free to ping me.
>
> Thanks,
>
> David
>
> Juan Jose Comellas wrote:
> >I am writing Java bindings for the Asterisk API using SWIG
> >(http://www.swig.org) so that I can create Asterisk modules written in
> > Java. The main problem I'm having is that in order to make this process
> > efficient I need to have more than one application per module (I load
> > only one instance of the JVM). To be able to build a generic solution
> > (where I don't have to add one entry point in C per Java application), I
> > need to make a slight change to the ast_register_application() function
> > and to the code that invokes each application's callback function.
> > Currently all application callbacks follow the following prototype:
> >
> >int (*execute)(struct ast_channel *, void *data);
> >
> >The problem is that when building Java modules this function acts as a
> > bridge to the Java invocation and I need extra data to be able to map the
> > call into a Java class/method. To solve this problem I need to make the
> > following changes to Asterisk's public interface:
> >
> >1) Add one argument to the application callback to be able to pass the
> >"cookie" that will let me map to the Java class/method:
> >
> >int (*execute)(struct ast_channel *, void *data, void *cookie);
> >
> >2) Change the ast_app struct to be able to store the "cookie". With my
> > changes it looks like this:
> >
> >struct ast_app {
> > char name[AST_MAX_APP];   /* Name of the application */
> > int (*execute)(struct ast_channel *chan, void *data, void *cookie);
> > char *synopsis;    /* Synopsis text for 'show applications' */
> > char *description;   /* Description (help text) for 'show application
> > <name>' */
> > void *cookie;    /* Data used to map the call when using Java modules */
> > struct ast_app *next;   /* Next app in list */
> >};
> >
> >3) Change the ast_register_application() function to pass the cookie to
> > the ast_app struct:
> >
> >int ast_register_application(char *app, int (*execute)(struct ast_channel
> > *, void *data, void *cookie), char *synopsis, char *description, void
> > *cookie);
> >
> >Do these modifications have any chance of being accepted into Asterisk?

-- 
Juan Jose Comellas
(juanjo at comellas.com.ar)