[Nice] API thoughts

[Dafydd Harries]

I've been discussing with my colleagues Olivier and Youness what kind of API
libnice needs to provide so that we can write reasonable GStreamer elements.
Our current idea is to have a new pair of agent methods:

  GMainContext *
  nice_agent_make_recv_context (
      NiceAgent *agent,
      guint stream_id,
      guint component_id,
      NiceAgentRecvFunc func,
      gpointer data);

  GMainContext *
  nice_agent_make_shared_context (
      NiceAgent *agent);

The first would create a GMainContext with a GSource for each of the indicated
stream's candidates, suitable for a GstSource to run in a mainloop. This
provides the ability to stop waiting at any time using g_main_loop_quit ().
The locking should be quite straightforward, I think.

The second would create a context with sources for each of the agent's
timeouts. Code which used nice_agent_make_shared_context () would run a main
loop with that context in a separate thread.

I suspect nice_agent_recv_sock () and nice_agent_poll_read () should be
removed.

-- 
Dafydd