When g_timeout_add doesn't seem to be enough

[RafaÅ MuÅyÅo <galtgendo o2 pl>]

I'm trying to modify an app that's using callback-based sound system to
one that does not use callbacks.
I need a way to execute a group of commands genarating sound in an
endless loop while allowing rest of the app to work.
Now I'm executing those comands in a function that I give to
g_timeout_add, but I'm getting short gaps of silence.
Even g_timeout_add_full with interval=0 and
priority=G_PRIORITY_DEFAULT_IDLE is not enough (with g_timeout_add
interval=0 resultls in a full stop). What would be a good way to do it ?
Threads ? If so, how ? Can anybody give me a simple example ?