Making progress on bidirectional communication

hdjd.c

@@ -71,6 +71,30 @@ usb_xfer_done(struct libusb_transfer *transfer)
 	midi_send(data, datalen);
 }
 
+void
+handle_alsa()
+{
+	snd_midi_event_t *midi_event_parser;
+	snd_seq_event_t *ev;
+	int ret = 1;
+
+	for (ret = 1; ret > 0; ) {
+		char buf[512];
+		long converted;
+		int i;
+		
+		ret = snd_seq_event_input(handle, &ev);
+		snd_midi_event_new(512, &midi_event_parser);
+		converted = snd_midi_event_decode(midi_event_parser, buf, 512, ev);
+		printf(" << ");
+		for (i = 0; i < converted; i += 1) {
+			printf("%02x ", buf[i]);
+		}
+		printf("\n");
+		snd_midi_event_free(midi_event_parser);
+	}	
+}
+
 int
 main(int argc, char **argv)
 {
@@ -147,11 +171,36 @@ main(int argc, char **argv)
 		// Select on our file descriptors
 		{
 			const struct libusb_pollfd **usb_fds = libusb_get_pollfds(NULL);
+			struct pollfd *pfd;
+			int npfd;
 			struct timeval tv;
 			struct timeval *timeout;
 			fd_set rfds, wfds;
 			int nfds = 0;
 			
+			FD_ZERO(&rfds);
+			FD_ZERO(&wfds);
+			
+			// ALSA shit
+			{
+				
+				npfd = snd_seq_poll_descriptors_count(handle, POLLIN);
+				pfd = (struct pollfd *)alloca(npfd * sizeof(struct pollfd));
+				snd_seq_poll_descriptors(handle, pfd, npfd, POLLIN);
+				
+				for (i = 0; i < npfd; i += 1) {
+					if (pfd[i].fd > nfds) {
+						nfds = pfd[i].fd;
+					}
+					if (pfd[i].events & POLLIN) {
+						FD_SET(pfd[i].fd, &rfds);
+					}
+				}
+			}
+			
+			// USB shit
+			{
+	
 				ret = libusb_get_next_timeout(NULL, &tv);
 				if (0 == ret) {
 					timeout = NULL;
@@ -159,8 +208,6 @@ main(int argc, char **argv)
 					timeout = &tv;
 				}
 				
-			FD_ZERO(&rfds);
-			FD_ZERO(&wfds);
 				for (i = 0; usb_fds[i]; i += 1) {
 					const struct libusb_pollfd *ufd = usb_fds[i];
 		
@@ -174,6 +221,7 @@ main(int argc, char **argv)
 						FD_SET(ufd->fd, &wfds);
 					}
 				}
+			}
 			
 			ret = select(nfds + 1, &rfds, &wfds, NULL, timeout);
 			
@@ -184,6 +232,14 @@ main(int argc, char **argv)
 					libusb_handle_events(NULL);
 				}
 			}
+			
+			for (i = 0; i < npfd; i += 1) {
+				int fd = pfd[i].fd;
+				
+				if (FD_ISSET(fd, &rfds)) {
+					handle_alsa();
+				}
+			}
 		}
 		
 		libusb_free_transfer(xfer);