Tone Playing Management
This is a tone playing complex that suitable to enforce thread-safe tone-playing tasks like playing rings or musics, recording tones, etc.
It provides a number of patterns to deal with unexpected interventions like ring tones, clock alerts, another tone task or record task, etc.
I did use a prioritized list to manage all kinds of tone tasks.
You'll get a profounding sense of the project by accessing the "charts" & "AppleDoc" directories.