Dev (#6) - API changes (#19) - Message List

Here are my current ideas for the the libwiimote API, addressing interface modes, thread complexity, and configuration:

1. Drop the event queue, use a pipe instead.
2. Provide three interfaces to that pipe (a and b are mutually exclusive)
   1. Blocking: int wiimote_get_mesg(wiimote_t *wiimote, int *mesg_count, union wiimote_mesg **mesg[]), blocks on the pipe, and fills in *mesg_count and *mesg
   2. Callback: remove the callback parameter from wiimote_connect, add a wiimote_set_callback function that, when called, sets up a thread (much like the current dispatch thread) that issues the callbacks.
   3. Polling: add a flags parameter to wiimote_connect, or a separate function that enables state tracking. State is retrieved through int wiimote_get_state(wiimote_t *wiimote, wiimote_state *state).
3. wiimote_read and wiimote_write duplicate the pipe, and wait for their own responses from the wiimote (currently, int_listen receives the response and signals wiimote_read or wiimote_write) - this will significantly reduce the complexity of the thread model and make disconnect and cleanup easier.
4. Add flags to wiimote_connect (e.g. continuous output, repeat identical buttons, various). Add wiimote_enable, wiimote_disable to change flags after connect.
5. Drop the int *id from wiimote_connect, add another function to get it. Move the id parameter to the callback to the end, effectively making it optional (is this portable?). This removes all multiple wiimote considerations from apps using a single wiimote.
6. Drop stdint types from externally visible flag parameters to ease future backward compatibility.

So the API would look something like this (not all functions listed):

/* Connection */
int wiimote_connect(bdaddr_t *bdaddr, int flags);
int wiimote_disconnect(wiimote_t *wiimote);
int wiimote_get_id(wiimote_t *wiimote);
int wiimote_enable(int flags);
int wiimote_disable(int flags);
/* Operations */
int wiimote_command(wiimote_t *, enum wiimote_command command, int flags);
int wiimote_read(wiimote_t *wiimote, int flags, uint32_t offset, uint16_t len, void *data);
int wiimote_write(wiimote_t *wiimote, int flags, uint32_t offset, uint16_t len, const void *data);
/* Blocking Interface */
int wiimote_get_mesg(wiimote_t *wiimote, int *mesg_count, union wiimote_mesg **mesg[]);
/* Callback Interface */
int wiimote_set_callback(wiimote_t *wiimote, wiimote_mesg_callback_t *callback);
/* State/Polling Interface */
int wiimote_get_state(wiimote_t *wiimote, wiimote_state *state);

Comments? Suggestions?