Replace select backends with poll backends. selscan() and pollscan()

now call the poll backend.  With this change we implement greater
poll(2) functionality instead of emulating it via the select backend.
Adapted from NetBSD and including some changes from FreeBSD.
Tested by many, deraadt@ OK

1 files changed, 19 insertions, 22 deletions

diff --git a/sys/dev/midi.c b/sys/dev/midi.c
index 0f66c382e8b..710f59d1456 100644
--- a/sys/dev/midi.c
+++ b/sys/dev/midi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: midi.c,v 1.8 2002/03/14 01:26:52 millert Exp $	*/
+/*	$OpenBSD: midi.c,v 1.9 2003/09/23 16:51:12 millert Exp $	*/
 /*	$NetBSD: midi.c,v 1.10 1998/12/20 14:26:44 drochner Exp $	*/
 
 /*
@@ -695,37 +695,34 @@ midiioctl(dev, cmd, addr, flag, p)
 }
 
 int
-midiselect(dev, rw, p)
+midipoll(dev, events, p)
 	dev_t dev;
-	int rw;
+	int events;
 	struct proc *p;
 {
 	int unit = MIDIUNIT(dev);
 	struct midi_softc *sc = midi_cd.cd_devs[unit];
-	int s = splaudio();
+	int revents = 0, s = splaudio();
 
-	DPRINTF(("midiselect: %p rw=0x%x\n", sc, rw));
+	DPRINTF(("midipoll: %p events=0x%x\n", sc, events));
 
-	switch (rw) {
-	case FREAD:
-		if (sc->inbuf.used > 0) {
-			splx(s);
-			return (1);
-		}
-		selrecord(p, &sc->rsel);
-		break;
-
-	case FWRITE:
-		if (sc->outbuf.used < sc->outbuf.usedhigh) {
-			splx(s);
-			return (1);
-		}
-		selrecord(p, &sc->wsel);
-		break;
+	if (events & (POLLIN | POLLRDNORM)) {
+		if (sc->inbuf.used > 0)
+			revents |= events & (POLLIN | POLLRDNORM);
+	}
+	if (events & (POLLOUT | POLLWRNORM)) {
+		if (sc->outbuf.used < sc->outbuf.usedhigh)
+			revents |= events & (POLLOUT | POLLWRNORM);
+	}
+	if (revents == 0) {
+		if (events & (POLLIN | POLLRDNORM))
+			selrecord(p, &sc->rsel);
+		if (events & (POLLOUT | POLLWRNORM))
+			selrecord(p, &sc->wsel);
 	}
 
 	splx(s);
-	return (0);
+	return (revents);
 }
 
 void