Re: [alsa-devel] XRUN happens too often.

I found that there will be a thread generated after calling snd_pcm_open(). I use command 'ps' to check it. Due to this I guess snd_pcm_writei() only put the data into the buffer of

the

thread 'pcm'.

This thread then schedules of mixes the audio data, and put it into the

buffer

of ALSA driver. ALSA ringbuffer only belongs to ALSA library, and ALSA driver uses anoother buffer in kernel. Thus, there must be a thread that can put the data in ALSA ringbuffer into

the

buffer of ALSA driver.

I found that snd_pcm_direct_server_create() in ALSA library will create a thread. This resolves my problem that why ALSA library needn't use a daemon to mixing audio like other mixing server.