[Kamailio-Devel] [SR-Dev] register_timer versus register_timer_process

[Ovidiu Sas]

So what is the outcome of this discussion?
Are we going to port the 'register_timer_process' from kamailio into
the sip-router?
This is a blocker for porting certain modules from kamailio to sip-router.

Regards,
Ovidiu Sas

On Fri, Mar 6, 2009 at 10:31 AM, Andrei Pelinescu-Onciul
<andrei at iptel.org> wrote:
> On Mar 06, 2009 at 14:53, Jan Janak <jan at iptel.org> wrote:
>> On 06-03 15:44, Daniel-Constantin Mierla wrote:
>> > Hello,
>> >
>> > On 03/06/2009 03:16 PM, Jan Janak wrote:
>> >> Hello,
>> >>
>> >> There are two functions in the implementation of timers in kamailio,
>> >> register_timer and register_timer_process. What is the different between those
>> >> two functions and which should be used when?
>> > the first one is to register a function to be executed by the main timer
>> > process. Second is to create a new time process dedicated to run a
>> > specific function.
>> >
>> >>  I noticed that, for example, the
>> >> htable module seems to be using them interchangeably, there is a modparam
>> >> which controls which function is gonna be used.
>> >>
>> >> Can we replace register_timer_process with register_timer function from the
>> >> sip-router core?
>> >>
>> > Doesn't ser support to create a new timer process? How is it in the
>> > timer module? Is the route executed by the main timer process?
>> >
>> > Idea behind dedicated timer process is to be able to execute timely
>> > operations there without affecting the main timer which deals with
>> > retransmissions, etc.
>>
>> I see, we have the concept of slow and fast timers, so in that case the stuff
>> that needs its own timer process should probably be executed from within the
>> slow timer handler.
>
> It depends, if it's very slow (e.g. can block for long periods of time
> in the timer handle), it will be better to run in its own process.
>
> After a quick look at what register_timer_process(f, p, i, f) does, it seems
> it's equivalent with:
>
> if (fork()==0) { sleep(interval); function(param); }
>
> (meaning one can have only 1 timer in one timer process, I haven't seen
> a way to register more)
>
> If you only need 1 timer in your extra timer process, this can be done
> in sr like above, but replacing fork() with fork_process(...).
> If you need several timers and you want to be able to register/delete
> them dynamically, you should use local_timer (local_timer is a
> generalized very efficient timer, designed to be run "by hand" in a
> single process).
>
> #include "local_timer.h"
>
> struct local_timer lt;
>
> if (fork_process(...,"my timer", ...)==0){
>    /* init */
>    init_local_timer(&lt, get_ticks_raw());
>    /* add timers */
>    local_timer_init(t1, handler1, param, 0);
>    local_timer_add(&lt, t1, S_TO_TICKS(10) /* 10 s*/, get_ticks_raw());
>    /* as many times as needed */
>    while(..){
>        /* do something, e.g. poll some fds, read or even sleep(..) */
>        /* periodically call local_timer_run  which checks if any timer
>           has expired and is so runs it */
>        local_timer_run(&lt, get_ticks_raw());
>        /* add more timers or delete some of them */
>        local_timer_del(&tl, t3);
>       ...
>    }
> }
>
>
> Andrei
>
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