Hi Bruno,
On 03.06.2011 20:00, Bruno Bresciani wrote: > Actually I'm migrating my call routing module of version 1.5.0 of > kamailio to version 3.1.2. I want to understand why the tm module > registers an event callback after the INVITE message is processed by my > routing module. > When I use the dispatcher module for routing, no event callback is > registered by the tm module. I am certain that the tm module isn't doing any callback registrations itself -- at least not by calling register_tmcb() which is used by other modules exclusively. Some grep'ing and cscope'ing acknowledges that. It seems to me that some other, intermediary module registers a callback instead. If it's not a problem for you, run SR in gdb and post a backtrace from the instance the callback you are wondering about is allegedly registered. That way, we can take a look at the call flow and figure out how things work. Cheers, --Timo > 2011/6/3 Timo Reimann <timo.reim...@1und1.de <mailto:timo.reim...@1und1.de>> > > Hey Bruno, > > > On 03.06.2011 16:21, Bruno Bresciani wrote: > > In file t_hook.c line 386 "*cbp->callback( trans, cbp->types, > params )*" > > calls the function to record register_tmcb when I received a > INVITE. I'd > > like to now how register_tmcb function is call by the function > callback. > > register_tmcb() isn't called by a callback function, it rather works the > other way around. For clarity, here's the call flow: > > (1) A user is interested in being called back on a particular tm event, > e.g., TMCB_DESTROY. To be notified of such events, he calls > tmcb_register() and passes the set of events (callback types) he is > interested in (e.g., TMCB_DESTROY and possibly others) together with the > desired callback function and a few other parameters. > (2) In tmcb_register(), a few sanity checks are done first (e.g., > callback type is valid, callback function is not NULL, transaction > exists, etc.). If they pass, the callback function and the parameters > are stored in a list of callbacks (called cb_list in register_tmcb()). > (3) When a particular tm event occurs, the tm module checks if any > callbacks were registered for that specific event. If so, it executes > each registered callback function in sequence, with each function being > passed the callback type and callback-specific parameter. The call of > the callback is exactly what > > cbp->callback( trans, type, params ) > > does, at least for call types other than TMCB_REQUEST_IN. > > For TMCB_REQUEST_IN, the handling is slightly different because > callbacks for new SIP requests cannot be associated with an already > existing transaction (after all, they are new). With regards to how > TMCB_REQUEST_IN-typed callback functions are called, the only difference > is that the callback function is being passed the set of all callback > types the registering user was interested in, and not just > TMCB_REQUEST_IN: > > cbp->callback( trans, cbp->types, params ) > > (This is line 386.) Actually, I am not quite sure why the extent of > returned callback types differs here. I'm using tm callbacks myself but > never had to take advantage of that. > > > Anyways, if all you want to do is use tm callbacks from a module of > yours, just call register_tmcb() passing > > - a callback function, > - a transaction cell (unless you're registering for TMCB_REQUEST_IN), > - a void pointer to something you want to be passed back on callback > execution, and > - an optional release function for cleanup purposes. > > Implement your callback-specific logic in the callback function, and > that's it. Naturally, your callback function must fit the callback > signature defined in t_hooks.h. > > > I hope this answers your question. If not, let us know what you > specifically have in mind, i.e., whether you would like to use tm > callbacks, change the framework, or whatever. > > > Cheers, > > --Timo > > > > > 2011/6/3 Timo Reimann <timo.reim...@1und1.de > <mailto:timo.reim...@1und1.de> <mailto:timo.reim...@1und1.de > <mailto:timo.reim...@1und1.de>>> > > > > Hi Bruno, > > > > > > On 03.06.2011 00:07, Bruno Bresciani wrote: > > > I'm having doubts in the implementation of the callback function > > module > > > tm. As she calls the function to record register_tmcb ()? > > > Can someome help me? > > > > Could you be more specific on which part of the tm module you > are having > > trouble with? > > > > If you need an example on how to use tm's callbacks you may > take a look > > at the dialog module, specifically the files dialog.c and > > dlg_handlers.c. > > > > > > Cheers, > > > > --Timo _______________________________________________ SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users@lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
