Re: [linux-audio-dev] sound/gui interaction

[Benno Senoner]

On Thu, 20 Jul 2000, douglas irving repetto wrote:
I heard that older versions of linux have some problems with this call but I am
not sure:

what I usually do is just use sched_setscheduler() at the begin of  the thread's
mainloop before I jump to the endless DSP processing loop.

every thread sets it's own policy, I know it's not nice but it works.

if someone has infos about the pthread_schedparam problems
(or non problems) then let me know please.

Benno.




> 
> 
> i've also (i think) set my dsp thread to the highest priority:
> 
> 
>       /* start our audio thread */
>       printf("going to create audio thread\n");
>       retcode = pthread_create(&th_sound, NULL, ProcessLoop, (void*)this);
>       if (retcode != 0) 
>               fprintf(stderr, "create a failed %d\n", retcode);
>       else
>               printf("thread created\n");
>       
>       sched_param param;
>       memset(&param, 0, sizeof(param));
>       param.sched_priority = sched_get_priority_max(SCHED_FIFO);
>       
>       retcode = pthread_setschedparam(th_sound, SCHED_FIFO, &param);
>       
>       if (retcode != 0)
>               fprintf(stderr, "failed to set sched param%d\n", retcode);
>       
>       retcode = pthread_detach(th_sound);
>       
>       if (retcode != 0) 
>               fprintf(stderr, "failed to detach thread%d\n", retcode);
> 
> 
> this seems to _hurt_ performance quite a bit! i get more glitches than
> ever this way, so i must be doing something dumb. any comments? i've
> pretty much just copied this code from the man pages...
> 
> thanks,
> douglas
> 
> -- 
>                         douglas irving repetto 
>                   http://music.columbia.edu/~douglas 
>                 the music-dsp mailing list and website:
>                   http://shoko.calarts.edu/musicdsp