Re: [linux-audio-dev] Daemon mode

Lars Luthman wrote:
> On Sat, 2006-12-16 at 12:14 +0100, Lars Luthman wrote:
>> On Sat, 2006-12-16 at 17:56 +0700, Patrick Shirkey wrote:
>>> Hi,
>>>
>>> I am adding a Daemon mode to jackEQ and have most of the code in place now.
>>>
>>> I am stuck at the point where the daemon starts up and keeps going.
>>>
>>> Essentially I need the daemon mode equivalent of gtk_main() that keeps
>>> ticking over until the app is told to stop or otherwise shutdown.
>>>
>>> I have not threaded the app at this point so hopefully there is a very
>>> simple solution.
>> So the only thread that needs to do anything is the JACK thread? In that
>> case you can just add something like
>>
>> ... init code ...
>>
>> bool run = true;
>> while (run) sleep(10000);
>>
>> ... cleanup code ...
>>
>> in the main thread, after setting up JACK. If you want to be nice you
>> can add signal handlers for SIGHUP and SIGINT that set 'run' to false.
>
> Ehm, and in that case you better change the sleep time to 1 or use
> usleep() and specify microseconds instead. You wouldn't want to wait for
> hours after trying to stop the program.
>
> Or is sleep() interrupted by signals even if there are signal handlers
> for them?
>

Thanks for the pointer Lars.

However I'm using c so this code doesn't work. I have modified it like so:

                    int run = TRUE;

                    while (run)
                           sleep(10000);
                
but that just gives a segv. It runs for about a second then gives up.

I'm also looking at the code for jackd and have spotted this function:

                sigwait (&signals, &sig);
                        

so I added some new bits and pieces like so:

static sigset_t signals;

int main(int argc, char *argv[])
{

     int run;
     int sig;
     sigset_t allsignals;
        
        sigemptyset (&signals);
        sigaddset(&signals, SIGHUP);
        sigaddset(&signals, SIGINT);
        sigaddset(&signals, SIGQUIT);
        sigaddset(&signals, SIGPIPE);
        sigaddset(&signals, SIGTERM);
        sigfillset (&allsignals);

        process_init();

        run = TRUE;

        while (run)
                sigwait (&signals, &sig);

        return 0;

}

                        
but that also returns segv at sigwait(). If I put a printf after sigwait
it doesn't print. Before is ok.

I'm not sure how to proceed from here.

Cheers.

-- 
Patrick Shirkey - Boost Hardware Ltd.
http://www.boosthardware.com
http://lau.linuxaudio.org - The Linux Audio Users guide
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