OpenAL - Playing a cyclic buffer

Hi,

I'd like to create a basic audio tracker using OpenAL.
My problem is that I don't understand how I can put data in a audio buffer and then loop playing... I mean: I'm look for a mechanism such the double buffer used by basic DSP: subdivide the buffer by two, while the sound card is playing one half, you put "next" audio data in the other half, and so on...
I think/hope this is possible with OpenAL!

Thank you.

P.S.:
Sorry for my English :-/