_p_o_r_t expects an AAAALLLLppppoooorrrrtttt structure. This structure is the returned
value of an aaaallllOOOOppppeeeennnnPPPPoooorrrrtttt((((3333ddddmmmm)))) call.
_f_i_l_l_p_o_i_n_t expects a integer value, the fillpoint, in sample frames.
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
aaaallllGGGGeeeettttFFFFiiiillllllllPPPPooooiiiinnnntttt returns the current fillpoint of a port.
aaaallllSSSSeeeettttFFFFiiiillllllllPPPPooooiiiinnnntttt sets the current fillpoint of a port.
Used with aaaallllGGGGeeeettttFFFFDDDD((((3333ddddmmmm)))) and sssseeeelllleeeecccctttt((((2222)))) or ppppoooollllllll((((2222)))), controlling the
fillpoint lets you block a process until the number of sample frames in
an audio port reaches a given low- or high-water mark.
An input port will trigger the return from a sssseeeelllleeeecccctttt((((2222)))) or ppppoooollllllll((((2222)))) call
when there are at least _f_i_l_l_p_o_i_n_t sample frames available to be read.
For input ports, use the "readfds" fd_set with sssseeeelllleeeecccctttt((((2222)))) or the POLLIN
event flag with ppppoooollllllll((((2222)))).
An output port will trigger the return from a sssseeeelllleeeecccctttt((((2222)))) or ppppoooollllllll((((2222)))) call
when there are more than _f_i_l_l_p_o_i_n_t empty sample frames in the port. For
output ports, use the "writefds" fd_set with sssseeeelllleeeecccctttt((((2222)))) or the POLLOUT
event flag with ppppoooollllllll((((2222)))).
aaaallllSSSSeeeettttFFFFiiiillllllllPPPPooooiiiinnnntttt does not perform any validity checking on the fillpoint;
it is up to the application to pass in a correct value.
The calls aaaallllRRRReeeeaaaaddddFFFFrrrraaaammmmeeeessss((((3333ddddmmmm)))), aaaallllDDDDiiiissssccccaaaarrrrddddFFFFrrrraaaammmmeeeessss((((3333ddddmmmm)))), aaaallllZZZZeeeerrrrooooFFFFrrrraaaammmmeeeessss, and
aaaallllWWWWrrrriiiitttteeeeFFFFrrrraaaammmmeeeessss((((3333ddddmmmm)))) may change the fillpoint so you should set it just
before you call sssseeeelllleeeecccctttt((((2222)))) or ppppoooollllllll((((2222)))).
DDDDIIIIAAAAGGGGNNNNOOOOSSSSTTTTIIIICCCCSSSS
Upon successful completion aaaallllGGGGeeeettttFFFFiiiillllllllPPPPooooiiiinnnntttt returns a non-negative number.
Otherwise, aaaallllGGGGeeeettttFFFFiiiillllllllPPPPooooiiiinnnntttt returns -1 and sets an error number which can
be retrieved with oooosssseeeerrrrrrrroooorrrr((((3333CCCC)))).
aaaallllGGGGeeeettttFFFFiiiillllllllPPPPooooiiiinnnntttt can fail for the following reason: