6 Jun
2008
6 Jun
'08
4:47 p.m.
On Fri, Jun 06, 2008 at 20:22:44 +0200
Fons Adriaensen <fons(a)kokkinizita.net> wrote:
On Fri, Jun 06, 2008 at 07:30:49PM +0200,
rdxesy(a)yahoo.de wrote:
Ciao,
sorry for being unprecise.
let me show you :)
...
pthread_create (&midi_listener, NULL, midi_listen, NULL);
...
static void
*midi_listen(void *ptr)
{
int seq_nfds, i;
struct pollfd *pfds;
seq_nfds = snd_seq_poll_descriptors_count(seq, POLLIN);
pfds = (struct pollfd *)alloca(sizeof(struct pollfd) * (seq_nfds));
snd_seq_poll_descriptors(seq, pfds, seq_nfds, POLLIN);
while (1)
{
if (poll (pfds, seq_nfds, 1000) > 0)
{
pmesg(100, "poll\n");
for (i = 0; i < seq_nfds; i++)
if (pfds[i].revents > 0)
midi_callback ();
}
}
}
static void
midi_callback(void)
{
pmesg(100, "midi midi_callback() ENTERING\n");
snd_seq_event_t *ev;
unsigned char *data = NULL;
int param, value, err;
do
{
err = snd_seq_event_input(seq, &ev);
if (err < 0)
return;
if (ev->type == SND_SEQ_EVENT_SYSEX)
{
data = ev->data.ext.ptr;
... set sliders and stuff eg:
if (param == VOLUME || param == PAN)
{
gdk_threads_enter ();
set_slider(param, value);
gdk_threads_leave ();
}
...
}
while (snd_seq_event_input_pending(seq, 0) > 0);
}
I guess this makes things clearer :)
While this thread is running i am requesting the parameters
as shown earlier.
Cheers,
Jan
now there are two things i dont understand:
first: why is the midi_callback() thread being called once
...
1. call the midi_callback() thread more often
...
I try to understand what's happening, but your terminology
is somewhat confusing...
Threads are run, or can be running or waiting, but they
are never 'called'. Functions are called.
So what is this 'midi callback' thing exactly ?
Is it a thread doing a blocking read() on a midi port,
and waking up when there is data for it ? If so what
does this trhead do with the data it receives ?
Or is it a function you call periodically ?
Or something else ?
Ciao,