Process incoming MIDI data on the fly rather than using an

input fifo; besides being simpler, this way there's no data
to drain when a connection is dropped.

4 files changed, 133 insertions, 145 deletions

diff --git a/usr.bin/sndiod/midi.c b/usr.bin/sndiod/midi.c
index 8e598735f4f..f599d21f94c 100644
--- a/usr.bin/sndiod/midi.c
+++ b/usr.bin/sndiod/midi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: midi.c,v 1.1 2012/11/23 07:03:28 ratchov Exp $	*/
+/*	$OpenBSD: midi.c,v 1.2 2012/11/30 20:30:24 ratchov Exp $	*/
 /*
  * Copyright (c) 2008-2012 Alexandre Ratchov <alex@caoua.org>
  *
@@ -60,7 +60,7 @@ struct port *port_list = NULL;
 unsigned int midi_portnum = 0;
 
 struct midithru {
-	unsigned txmask;
+	unsigned int txmask, rxmask;
 #define MIDITHRU_NMAX 32
 } midithru[MIDITHRU_NMAX];
 
@@ -120,18 +120,16 @@ midi_new(struct midiops *ops, void *arg, int mode)
 	ep->idx = 0;
 	ep->st = 0;
 	ep->txmask = 0;
-	ep->rxmask = 1 << i;
+	ep->self = 1 << i;
+	ep->tickets = 0;
 	ep->mode = mode;
+
 	/*
-	 * client output is our input (ibuf) and our output (obuf) goes
-	 * to client input
+	 * the output buffer is the client intput
 	 */
-	if (ep->mode & MODE_MIDIOUT) {
-		abuf_init(&ep->ibuf, MIDI_BUFSZ);
-	}
-	if (ep->mode & MODE_MIDIIN) {
+	if (ep->mode & MODE_MIDIIN)
 		abuf_init(&ep->obuf, MIDI_BUFSZ);
-	}
+	midi_tickets(ep);
 	return ep;
 }
 
@@ -139,64 +137,82 @@ void
 midi_del(struct midi *ep)
 {
 	int i;
+	struct midi *peer;
 
-	for (i = 0; i < MIDI_NEP; i++)
-		midi_ep[i].txmask &= ~ep->rxmask;
-	for (i = 0; i < MIDITHRU_NMAX; i++)
-		midithru[i].txmask &= ~ep->rxmask;
-
-	/* XXX: drain output */
-	ep->ops = NULL;
-	if (ep->mode & MODE_MIDIOUT) {
-		abuf_done(&ep->ibuf);
+	ep->txmask = 0;
+	for (i = 0; i < MIDI_NEP; i++) {
+		peer = midi_ep + i;
+		if (peer->txmask & ep->self) {
+			peer->txmask &= ~ep->self;
+			midi_tickets(peer);
+		}
 	}
+	for (i = 0; i < MIDITHRU_NMAX; i++) {
+		midithru[i].txmask &= ~ep->self;
+		midithru[i].rxmask &= ~ep->self;
+	}
+	ep->ops = NULL;
 	if (ep->mode & MODE_MIDIIN) {
 		abuf_done(&ep->obuf);
 	}
 }
 
 /*
- * add the midi endpoint in the ``tag'' midi thru box
+ * connect two midi endpoints
  */
 void
-midi_tag(struct midi *ep, unsigned int tag)
+midi_link(struct midi *ep, struct midi *peer)
 {
-	int i;
-	struct midi *m;
-	unsigned members;
-
-	members = midithru[tag].txmask;
-	midithru[tag].txmask |= ep->rxmask;
-
-	for (i = 0, m = midi_ep; i < MIDI_NEP; i++, m++) {
-		if (!(members & (1 << i)))
-			continue;
-		if (ep->mode & MODE_MIDIOUT)
-			ep->txmask |= m->rxmask;
-		if (ep->mode & MODE_MIDIIN)
-			m->txmask |= ep->rxmask;
+	if (ep->mode & MODE_MIDIOUT) {
+		ep->txmask |= peer->self;
+		midi_tickets(ep);
+	}
+	if (ep->mode & MODE_MIDIIN) {
+#ifdef DEBUG
+		if (ep->obuf.used > 0) {
+			midi_log(ep);
+			log_puts(": linked with non-empty buffer\n");
+			panic();
+		}
+#endif
+		/* ep has empry buffer, so no need to call midi_tickets() */
+		peer->txmask |= ep->self;
 	}
 }
 
 /*
- * remove the midi endpoint from the ``tag'' midi thru box
+ * add the midi endpoint in the ``tag'' midi thru box
  */
 void
-midi_untag(struct midi *ep, unsigned int tag)
+midi_tag(struct midi *ep, unsigned int tag)
 {
+	struct midi *peer;
+	struct midithru *t = midithru + tag;
 	int i;
-	struct midi *m;
-	unsigned members;
-
-	members = midithru[tag].txmask;
-	midithru[tag].txmask &= ~ep->rxmask;
 
-	for (i = 0, m = midi_ep;; i++, m++) {
-		if (!(members & (1 << i)))
-			continue;
-		ep->txmask &= ~m->rxmask;
-		m->txmask &= ~ep->rxmask;
+	if (ep->mode & MODE_MIDIOUT) {
+		ep->txmask |= t->txmask;
+		midi_tickets(ep);
+	}
+	if (ep->mode & MODE_MIDIIN) {
+#ifdef DEBUG
+		if (ep->obuf.used > 0) {
+			midi_log(ep);
+			log_puts(": tagged with non-empty buffer\n");
+			panic();
+		}
+#endif
+		for (i = 0; i < MIDI_NEP; i++) {
+			if (!(t->rxmask & (1 << i)))
+				continue;
+			peer = midi_ep + i;
+			peer->txmask |= ep->self;
+		}
 	}
+	if (ep->mode & MODE_MIDIOUT)
+		t->rxmask |= ep->self;
+	if (ep->mode & MODE_MIDIIN)
+		t->txmask |= ep->self;
 }
 
 /*
@@ -241,27 +257,58 @@ midi_send(struct midi *iep, unsigned char *msg, int size)
 }
 
 
+/*
+ * determine if we have gained more input tickets, and if so call the
+ * fill() call-back to notify the i/o layer that it can send more data
+ */
 void
-midi_fill(struct midi *oep)
+midi_tickets(struct midi *iep)
 {
-	int i, count;
-	struct midi *iep;
+	int i, tickets, avail, maxavail;
+	struct midi *oep;
 
+	maxavail = MIDI_BUFSZ;
 	for (i = 0; i < MIDI_NEP ; i++) {
-		if ((oep->rxmask & (1 << i)) == 0)
+		if ((iep->txmask & (1 << i)) == 0)
 			continue;
+		oep = midi_ep + i;
+		avail = oep->obuf.len - oep->obuf.used;
+		if (maxavail > avail)
+			maxavail = avail;
+	}
+
+	/*
+	 * in the worst case output message is twice the 
+	 * input message (2-byte messages with running status)
+	 */
+	tickets = maxavail / 2 - iep->tickets;
+	if (tickets > 0) {
+		iep->tickets += tickets;
+		iep->ops->fill(iep->arg, tickets);
+	}
+}
+
+/*
+ * recalculate tickets of endpoints sending data to this one
+ */
+void
+midi_fill(struct midi *oep)
+{
+	int i;
+	struct midi *iep;
+
+	for (i = 0; i < MIDI_NEP; i++) {
 		iep = midi_ep + i;
-		count = midi_in(iep);
-		if (count)
-			iep->ops->fill(iep->arg, count);
+		if (iep->txmask & oep->self)
+			midi_tickets(iep);
 	}
 }
 
 /*
- * parse the give data chunk, and calling imsg() for each message
+ * parse then give data chunk, and calling imsg() for each message
  */
 void
-midi_parse(struct midi *iep, unsigned char *idata, int icount)
+midi_in(struct midi *iep, unsigned char *idata, int icount)
 {
 	int i;
 	unsigned char c;
@@ -304,60 +351,9 @@ midi_parse(struct midi *iep, unsigned char *idata, int icount)
 			}
 		}
 	}
-}
-
-/*
- * process input data stored in ep->ibuf
- */
-int
-midi_in(struct midi *iep)
-{
-	unsigned char *idata;
-	int i, icount, maxavail, avail, idone;
-	struct midi *oep;
-
-	/*
-	 * calculate the max message size we can process
-	 */
-	maxavail = MIDI_BUFSZ;
-	for (i = 0; i < MIDI_NEP ; i++) {
-		if ((iep->txmask & (1 << i)) == 0)
-			continue;
-		oep = midi_ep + i;
-		avail = oep->obuf.len - oep->obuf.used;
-		if (maxavail > avail)
-			maxavail = avail;
-	}
-	
-	/*
-	 * in the works case output message is twice the 
-	 * input message (2-byte messages with running status)
-	 */
-	maxavail /= 2;
-	idone = 0;
-	for (;;) {
-		idata = abuf_rgetblk(&iep->ibuf, &icount);
-		if (icount > maxavail)
-			icount = maxavail;
-		if (icount == 0)
-			break;
-		maxavail -= icount;
-#ifdef DEBUG
-		if (log_level >= 4) {
-			midi_log(iep);
-			log_puts(":  in:");
-			for (i = 0; i < icount; i++) {
-				log_puts(" ");
-				log_putx(idata[i]);
-			}
-			log_puts("\n");
-		}
-#endif
-		midi_parse(iep, idata, icount);
-		abuf_rdiscard(&iep->ibuf, icount);
-		idone += icount;
-	}
-	return idone;
+	iep->tickets -= icount;
+	if (iep->tickets < 0)
+		iep->tickets = 0;
 }
 
 /*
@@ -377,7 +373,7 @@ midi_out(struct midi *oep, unsigned char *idata, int icount)
 #ifdef DEBUG
 			if (log_level >= 2) {
 				midi_log(oep);
-				log_puts(": overrun, discarding ");
+				log_puts(": too slow, discarding ");
 				log_putu(oep->obuf.used);
 				log_puts(" bytes\n");
 			}
diff --git a/usr.bin/sndiod/midi.h b/usr.bin/sndiod/midi.h
index 60b37a2866a..34ebfa370e5 100644
--- a/usr.bin/sndiod/midi.h
+++ b/usr.bin/sndiod/midi.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: midi.h,v 1.1 2012/11/23 07:03:28 ratchov Exp $	*/
+/*	$OpenBSD: midi.h,v 1.2 2012/11/30 20:30:24 ratchov Exp $	*/
 /*
  * Copyright (c) 2008-2012 Alexandre Ratchov <alex@caoua.org>
  *
@@ -72,8 +72,8 @@ struct midi {
 	unsigned int idx;		/* current ``msg'' size */
 	unsigned int len;		/* expected ``msg'' length */
 	unsigned int txmask;		/* list of ep we send to */
-	unsigned int rxmask;		/* single ep we accept data for */
-	struct abuf ibuf;		/* input buffer */
+	unsigned int self;		/* equal (1 << index) */
+	unsigned int tickets;		/* max bytes we can process */
 	struct abuf obuf;		/* output buffer */
 };
 
@@ -102,12 +102,13 @@ void midi_done(void);
 struct midi *midi_new(struct midiops *, void *, int);
 void midi_del(struct midi *);
 void midi_log(struct midi *);
-int midi_in(struct midi *);
+void midi_tickets(struct midi *);
+void midi_in(struct midi *, unsigned char *, int);
 void midi_out(struct midi *, unsigned char *, int);
 void midi_send(struct midi *, unsigned char *, int);
 void midi_fill(struct midi *);
 void midi_tag(struct midi *, unsigned int);
-void midi_untag(struct midi *, unsigned int);
+void midi_link(struct midi *, struct midi *);
 
 struct port *port_new(char *, unsigned int);
 struct port *port_bynum(int);
diff --git a/usr.bin/sndiod/miofile.c b/usr.bin/sndiod/miofile.c
index 5fee9f9a1ca..ac56d0d0a0a 100644
--- a/usr.bin/sndiod/miofile.c
+++ b/usr.bin/sndiod/miofile.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: miofile.c,v 1.1 2012/11/23 07:03:28 ratchov Exp $	*/
+/*	$OpenBSD: miofile.c,v 1.2 2012/11/30 20:30:24 ratchov Exp $	*/
 /*
  * Copyright (c) 2008-2012 Alexandre Ratchov <alex@caoua.org>
  *
@@ -68,7 +68,7 @@ port_mio_pollfd(void *addr, struct pollfd *pfd)
 	struct midi *ep = p->midi;
 	int events = 0;
 
-	if ((ep->mode & MODE_MIDIIN) && ep->ibuf.used < ep->ibuf.len)
+	if (ep->mode & MODE_MIDIIN)
 		events |= POLLIN;
 	if ((ep->mode & MODE_MIDIOUT) && ep->obuf.used > 0)
 		events |= POLLOUT;
@@ -86,22 +86,16 @@ port_mio_revents(void *addr, struct pollfd *pfd)
 void
 port_mio_in(void *arg)
 {
+	unsigned char data[MIDI_BUFSZ];
 	struct port *p = arg;
 	struct midi *ep = p->midi;
-	unsigned char *data;
-	int n, count;
+	int n;
 
 	for (;;) {
-		data = abuf_wgetblk(&ep->ibuf, &count);
-		if (count == 0)
-			break;
-		n = mio_read(p->mio.hdl, data, count);
+		n = mio_read(p->mio.hdl, data, MIDI_BUFSZ);
 		if (n == 0)
 			break;
-		abuf_wcommit(&ep->ibuf, n);
-		midi_in(ep);
-		if (n < count)
-			break;
+		midi_in(ep, data, n);
 	}
 }
 
@@ -123,8 +117,8 @@ port_mio_out(void *arg)
 		abuf_rdiscard(&ep->obuf, n);
 		if (n < count)
 			break;
-		midi_fill(ep);
 	}
+	midi_fill(ep);
 }
 
 void
diff --git a/usr.bin/sndiod/sock.c b/usr.bin/sndiod/sock.c
index 93122aae8a5..e7e9b6678ae 100644
--- a/usr.bin/sndiod/sock.c
+++ b/usr.bin/sndiod/sock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sock.c,v 1.1 2012/11/23 07:03:28 ratchov Exp $	*/
+/*	$OpenBSD: sock.c,v 1.2 2012/11/30 20:30:24 ratchov Exp $	*/
 /*
  * Copyright (c) 2008-2012 Alexandre Ratchov <alex@caoua.org>
  *
@@ -505,7 +505,7 @@ sock_wmsg(struct sock *f)
 int
 sock_rdata(struct sock *f)
 {
-	struct abuf *buf;
+	unsigned char midibuf[MIDI_BUFSZ];
 	unsigned char *data;
 	int n, count;
 
@@ -516,19 +516,23 @@ sock_rdata(struct sock *f)
 		panic();
 	}
 #endif
-	if (f->slot)
-		buf = &f->slot->mix.buf;
-	else
-		buf = &f->midi->ibuf;
 	while (f->rtodo > 0) {
-		data = abuf_wgetblk(buf, &count);
+		if (f->slot)
+			data = abuf_wgetblk(&f->slot->mix.buf, &count);
+		else {
+			data = midibuf;
+			count = MIDI_BUFSZ;
+		}
 		if (count > f->rtodo)
 			count = f->rtodo;
 		n = sock_fdread(f, data, count);
 		if (n == 0)
 			return 0;
 		f->rtodo -= n;
-		abuf_wcommit(buf, n);
+		if (f->slot)
+			abuf_wcommit(&f->slot->mix.buf, n);
+		else
+			midi_in(f->midi, midibuf, n);
 	}
 #ifdef DEBUG
 	if (log_level >= 4) {
@@ -538,8 +542,6 @@ sock_rdata(struct sock *f)
 #endif
 	if (f->slot)
 		slot_write(f->slot);
-	if (f->midi)
-		f->fillpending += midi_in(f->midi);
 	return 1;
 }
 
@@ -864,14 +866,9 @@ sock_hello(struct sock *f)
 			c = port_bynum(p->devnum - 32);
 			if (c == NULL)
 				return 0;
-			if (mode & MODE_MIDIOUT)
-				f->midi->txmask |= c->midi->rxmask;
-			if (mode & MODE_MIDIIN)
-				c->midi->txmask |= f->midi->rxmask;
+			midi_link(f->midi, c->midi);
 		} else
 			return 0;
-		if (mode & MODE_MIDIOUT)
-			f->fillpending = MIDI_BUFSZ;
 		return 1;
 	}
 	f->opt = opt_byname(p->opt, p->devnum);