Move underrun/overrun recovery code from the sun-api back-end to

the the generic code, so it can be used by other back-ends as well.
No behavior change (hopefully).

3 files changed, 138 insertions, 144 deletions

diff --git a/lib/libsndio/sio.c b/lib/libsndio/sio.c
index a3ebdc102e2..d8ccf0c666c 100644
--- a/lib/libsndio/sio.c
+++ b/lib/libsndio/sio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sio.c,v 1.13 2013/04/03 03:13:32 guenther Exp $	*/
+/*	$OpenBSD: sio.c,v 1.14 2013/08/24 12:32:34 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -98,6 +98,10 @@ sio_close(struct sio_hdl *hdl)
 int
 sio_start(struct sio_hdl *hdl)
 {
+#ifdef DEBUG
+	struct timespec ts;
+#endif
+
 	if (hdl->eof) {
 		DPRINTF("sio_start: eof\n");
 		return 0;
@@ -110,9 +114,11 @@ sio_start(struct sio_hdl *hdl)
 #ifdef DEBUG
 	if (!sio_getpar(hdl, &hdl->par))
 		return 0;
-	hdl->pollcnt = hdl->wcnt = hdl->rcnt = hdl->realpos = 0;
-	clock_gettime(CLOCK_MONOTONIC, &hdl->ts);
+	hdl->pollcnt = hdl->wcnt = hdl->rcnt = hdl->cpos = 0;
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	hdl->start_nsec = 1000000000LL * ts.tv_sec + ts.tv_nsec;
 #endif
+	hdl->rdrop = hdl->wsil = 0;
 	if (!hdl->ops->start(hdl))
 		return 0;
 	hdl->started = 1;
@@ -236,6 +242,46 @@ sio_psleep(struct sio_hdl *hdl, int event)
 	return 1;
 }
 
+static int
+sio_rdrop(struct sio_hdl *hdl)
+{
+#define DROP_NMAX 0x1000
+	static char dummy[DROP_NMAX];
+	ssize_t n, todo;
+
+	while (hdl->rdrop > 0) {
+		todo = hdl->rdrop;
+		if (todo > DROP_NMAX)
+			todo = DROP_NMAX;
+		n = hdl->ops->read(hdl, dummy, todo);
+		if (n == 0)
+			return 0;
+		hdl->rdrop -= n;
+		DPRINTF("sio_rdrop: dropped %zu bytes\n", n);
+	}
+	return 1;
+}
+
+static int
+sio_wsil(struct sio_hdl *hdl)
+{
+#define ZERO_NMAX 0x1000
+	static char zero[ZERO_NMAX];
+	ssize_t n, todo;
+
+	while (hdl->wsil > 0) {
+		todo = hdl->wsil;
+		if (todo > ZERO_NMAX)
+			todo = ZERO_NMAX;
+		n = hdl->ops->write(hdl, zero, todo);
+		if (n == 0)
+			return 0;
+		hdl->wsil -= n;
+		DPRINTF("sio_wsil: inserted %zu bytes\n", n);
+	}
+	return 1;
+}
+
 size_t
 sio_read(struct sio_hdl *hdl, void *buf, size_t len)
 {
@@ -256,6 +302,8 @@ sio_read(struct sio_hdl *hdl, void *buf, size_t len)
 		DPRINTF("sio_read: zero length read ignored\n");
 		return 0;
 	}
+	if (!sio_rdrop(hdl))
+		return 0;
 	while (todo > 0) {
 		n = hdl->ops->read(hdl, data, todo);
 		if (n == 0) {
@@ -280,13 +328,6 @@ sio_write(struct sio_hdl *hdl, const void *buf, size_t len)
 	unsigned int n;
 	const unsigned char *data = buf;
 	size_t todo = len;
-#ifdef DEBUG
-	struct timespec ts0, ts1, dts;
-	unsigned int us;
-
-	if (sndio_debug >= 2)
-		clock_gettime(CLOCK_MONOTONIC, &ts0);
-#endif
 
 	if (hdl->eof) {
 		DPRINTF("sio_write: eof\n");
@@ -301,6 +342,8 @@ sio_write(struct sio_hdl *hdl, const void *buf, size_t len)
 		DPRINTF("sio_write: zero length write ignored\n");
 		return 0;
 	}
+	if (!sio_wsil(hdl))
+		return 0;
 	while (todo > 0) {
 		n = hdl->ops->write(hdl, data, todo);
 		if (n == 0) {
@@ -316,19 +359,6 @@ sio_write(struct sio_hdl *hdl, const void *buf, size_t len)
 		hdl->wcnt += n;
 #endif
 	}
-#ifdef DEBUG
-	if (sndio_debug >= 2) {
-		clock_gettime(CLOCK_MONOTONIC, &ts1);
-		timespecsub(&ts0, &hdl->ts, &dts);
-		DPRINTF("%lld.%09ld: ", (long long)dts.tv_sec, dts.tv_nsec);
-
-		timespecsub(&ts1, &ts0, &dts);
-		us = dts.tv_sec * 1000000 + dts.tv_nsec/1000;
-		DPRINTF(
-		    "sio_write: wrote %d bytes of %d in %uus\n",
-		    (int)(len - todo), (int)len, us);
-	}
-#endif
 	return len - todo;
 }
 
@@ -353,8 +383,7 @@ sio_revents(struct sio_hdl *hdl, struct pollfd *pfd)
 {
 	int revents;
 #ifdef DEBUG
-	struct timespec ts0, ts1, dts;
-	unsigned int us;
+	struct timespec ts0, ts1;
 
 	if (sndio_debug >= 2)
 		clock_gettime(CLOCK_MONOTONIC, &ts0);
@@ -368,17 +397,20 @@ sio_revents(struct sio_hdl *hdl, struct pollfd *pfd)
 	if (!hdl->started)
 		return revents & POLLHUP;
 #ifdef DEBUG
-	if (sndio_debug >= 2) {
+	if (sndio_debug >= 3) {
 		clock_gettime(CLOCK_MONOTONIC, &ts1);
-		timespecsub(&ts0, &hdl->ts, &dts);
-		DPRINTF("%lld.%09ld: ", (long long)dts.tv_sec, dts.tv_nsec);
-
-		timespecsub(&ts1, &ts0, &dts);
-		us = dts.tv_sec * 1000000 + dts.tv_nsec/1000;
-		DPRINTF("sio_revents: revents = 0x%x, complete in %uus\n",
-		    revents, us);
+		DPRINTF("%09lld: sio_revents: revents = 0x%x, took %lldns\n",
+		    1000000000LL * ts0.tv_sec +
+		    ts0.tv_nsec - hdl->start_nsec,
+		    revents,
+		    1000000000LL * (ts1.tv_sec - ts0.tv_sec) +
+		    ts1.tv_nsec - ts0.tv_nsec);
 	}
 #endif
+	if ((hdl->mode & SIO_PLAY) && !sio_wsil(hdl))
+		revents &= ~POLLOUT;
+	if ((hdl->mode & SIO_REC) && !sio_rdrop(hdl))
+		revents &= ~POLLIN;
 	return revents;
 }
 
@@ -400,28 +432,54 @@ sio_onmove(struct sio_hdl *hdl, void (*cb)(void *, int), void *addr)
 	hdl->move_addr = addr;
 }
 
+#ifdef DEBUG
+void
+sio_printpos(struct sio_hdl *hdl)
+{	
+	struct timespec ts;
+	long long rpos, rdiff;
+	long long cpos, cdiff;
+	long long wpos, wdiff;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+
+	rpos = (hdl->mode & SIO_REC) ? 
+	    hdl->rcnt / (hdl->par.bps * hdl->par.rchan) : 0;
+	wpos = (hdl->mode & SIO_PLAY) ?
+	    hdl->wcnt / (hdl->par.bps * hdl->par.pchan) : 0;
+
+	cdiff = hdl->cpos % hdl->par.round;
+	cpos  = hdl->cpos / hdl->par.round;
+	if (cdiff > hdl->par.round / 2) {
+		cpos++;
+		cdiff = cdiff - hdl->par.round;
+	}
+	rdiff = rpos % hdl->par.round;
+	rpos  = rpos / hdl->par.round;
+	if (rdiff > hdl->par.round / 2) {
+		rpos++;
+		rdiff = rdiff - hdl->par.round;
+	}
+	wdiff = wpos % hdl->par.round;
+	wpos  = wpos / hdl->par.round;
+	if (wdiff > hdl->par.round / 2) {
+		wpos++;
+		wdiff = wdiff - hdl->par.round;
+	}
+	DPRINTF("%011lld: "
+	    "clk %+5lld%+5lld, wr %+5lld%+5lld rd: %+5lld%+5lld\n",
+	    1000000000LL * ts.tv_sec + ts.tv_nsec - hdl->start_nsec,
+	    cpos, cdiff, wpos, wdiff, rpos, rdiff);
+}
+#endif
+
 void
 sio_onmove_cb(struct sio_hdl *hdl, int delta)
 {
 #ifdef DEBUG
-	struct timespec ts0, dts;
-	long long playpos;
-
-	if (sndio_debug >= 3 && (hdl->mode & SIO_PLAY)) {
-		clock_gettime(CLOCK_MONOTONIC, &ts0);
-		timespecsub(&ts0, &hdl->ts, &dts);
-		DPRINTF("%lld.%09ld: ", (long long)dts.tv_sec, dts.tv_nsec);
-		hdl->realpos += delta;
-		playpos = hdl->wcnt / (hdl->par.bps * hdl->par.pchan);
-		DPRINTF("sio_onmove_cb: delta = %+7d, "
-		    "plat = %+7lld, "
-		    "realpos = %+7lld, "
-		    "bufused = %+7lld\n",
-		    delta,
-		    playpos - hdl->realpos,
-		    hdl->realpos,
-		    hdl->realpos < 0 ? playpos : playpos - hdl->realpos);
-	}
+	hdl->cpos += delta;
+	if (sndio_debug >= 2)
+		sio_printpos(hdl);
 #endif
 	if (hdl->move_cb)
 		hdl->move_cb(hdl->move_addr, delta);
diff --git a/lib/libsndio/sio_priv.h b/lib/libsndio/sio_priv.h
index f95885d2aa9..b8792ffcc46 100644
--- a/lib/libsndio/sio_priv.h
+++ b/lib/libsndio/sio_priv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sio_priv.h,v 1.5 2013/04/03 03:13:32 guenther Exp $	*/
+/*	$OpenBSD: sio_priv.h,v 1.6 2013/08/24 12:32:35 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -35,12 +35,14 @@ struct sio_hdl {
 	int started;			/* true if started */
 	int nbio;			/* true if non-blocking io */
 	int eof;			/* true if error occured */
+	int rdrop;			/* recorded bytes to drop */
+	int wsil;			/* silence to play */
 #ifdef DEBUG
 	unsigned long long pollcnt;	/* times sio_revents was called */
-	unsigned long long wcnt;	/* bytes written with sio_write() */
-	unsigned long long rcnt;	/* bytes read with sio_read() */
-	long long realpos;
-	struct timespec ts;
+	long long wcnt;			/* bytes written with sio_write() */
+	long long rcnt;			/* bytes read with sio_read() */
+	long long cpos;
+	long long start_nsec;
 	struct sio_par par;
 #endif
 };
@@ -70,5 +72,8 @@ void sio_create(struct sio_hdl *, struct sio_ops *, unsigned, int);
 void sio_destroy(struct sio_hdl *);
 void sio_onmove_cb(struct sio_hdl *, int);
 void sio_onvol_cb(struct sio_hdl *, unsigned);
+#ifdef DEBUG
+void sio_printpos(struct sio_hdl *);
+#endif
 
 #endif /* !defined(SNDIO_PRIV_H) */
diff --git a/lib/libsndio/sio_sun.c b/lib/libsndio/sio_sun.c
index 880017566be..779e864f9ce 100644
--- a/lib/libsndio/sio_sun.c
+++ b/lib/libsndio/sio_sun.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sio_sun.c,v 1.7 2012/09/14 22:50:26 ratchov Exp $	*/
+/*	$OpenBSD: sio_sun.c,v 1.8 2013/08/24 12:32:35 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -50,9 +50,7 @@ struct sio_sun_hdl {
 	unsigned int ibpf, obpf;	/* bytes per frame */
 	unsigned int ibytes, obytes;	/* bytes the hw transferred */
 	unsigned int ierr, oerr;	/* frames the hw dropped */
-	int offset;			/* frames play is ahead of record */
 	int idelta, odelta;		/* position reported to client */
-	int mix_fd, mix_index;		/* /dev/mixerN stuff */
 };
 
 static void sio_sun_close(struct sio_hdl *);
@@ -450,7 +448,6 @@ sio_sun_start(struct sio_hdl *sh)
 	hdl->obytes = 0;
 	hdl->ierr = 0;
 	hdl->oerr = 0;
-	hdl->offset = 0;
 	hdl->idelta = 0;
 	hdl->odelta = 0;
 
@@ -726,48 +723,12 @@ sio_sun_getpar(struct sio_hdl *sh, struct sio_par *par)
 	return 1;
 }
 
-/*
- * drop recorded samples to compensate xruns
- */
-static int
-sio_sun_rdrop(struct sio_sun_hdl *hdl)
-{
-#define DROP_NMAX 0x1000
-	static char dropbuf[DROP_NMAX];
-	ssize_t n, todo;
-
-	while (hdl->offset > 0) {
-		todo = hdl->offset * hdl->ibpf;
-		if (todo > DROP_NMAX)
-			todo = DROP_NMAX - DROP_NMAX % hdl->ibpf;
-		while ((n = read(hdl->fd, dropbuf, todo)) < 0) {
-			if (errno == EINTR)
-				continue;
-			if (errno != EAGAIN) {
-				DPERROR("sio_sun_rdrop: read");
-				hdl->sio.eof = 1;
-			}
-			return 0;
-		}
-		if (n == 0) {
-			DPRINTF("sio_sun_rdrop: eof\n");
-			hdl->sio.eof = 1;
-			return 0;
-		}
-		hdl->offset -= (int)n / (int)hdl->ibpf;
-		DPRINTF("sio_sun_rdrop: dropped %ld/%ld bytes\n", n, todo);
-	}
-	return 1;
-}
-
 static size_t
 sio_sun_read(struct sio_hdl *sh, void *buf, size_t len)
 {
 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
 	ssize_t n;
 
-	if (!sio_sun_rdrop(hdl))
-		return 0;
 	while ((n = read(hdl->fd, buf, len)) < 0) {
 		if (errno == EINTR)
 			continue;
@@ -817,37 +778,6 @@ sio_sun_autostart(struct sio_sun_hdl *hdl)
 	return 1;
 }
 
-/*
- * insert silence to play to compensate xruns
- */
-static int
-sio_sun_wsil(struct sio_sun_hdl *hdl)
-{
-#define ZERO_NMAX 0x1000
-	static char zero[ZERO_NMAX];
-	ssize_t n, todo;
-
-	while (hdl->offset < 0) {
-		todo = (int)-hdl->offset * (int)hdl->obpf;
-		if (todo > ZERO_NMAX)
-			todo = ZERO_NMAX - ZERO_NMAX % hdl->obpf;
-		while ((n = write(hdl->fd, zero, todo)) < 0) {
-			if (errno == EINTR)
-				continue;
-			if (errno != EAGAIN) {
-				DPERROR("sio_sun_wsil: write");
-				hdl->sio.eof = 1;
-				return 0;
-			}
-			return 0;
-		}
-		hdl->offset += (int)n / (int)hdl->obpf;
-		DPRINTF("sio_sun_wsil: inserted %ld/%ld bytes\n", n, todo);
-	}
-	return 1;
-}
-
-
 static size_t
 sio_sun_write(struct sio_hdl *sh, const void *buf, size_t len)
 {
@@ -855,8 +785,6 @@ sio_sun_write(struct sio_hdl *sh, const void *buf, size_t len)
 	const unsigned char *data = buf;
 	ssize_t n, todo;
 
-	if (!sio_sun_wsil(hdl))
-		return 0;
 	todo = len;
 	while ((n = write(hdl->fd, data, todo)) < 0) {
 		if (errno == EINTR)
@@ -895,7 +823,7 @@ sio_sun_revents(struct sio_hdl *sh, struct pollfd *pfd)
 {
 	struct sio_sun_hdl *hdl = (struct sio_sun_hdl *)sh;
 	struct audio_offset ao;
-	int xrun, dmove, dierr = 0, doerr = 0, delta;
+	int xrun, dierr = 0, doerr = 0, offset, delta;
 	int revents = pfd->revents;
 
 	if (!hdl->sio.started)
@@ -934,6 +862,8 @@ sio_sun_revents(struct sio_hdl *sh, struct pollfd *pfd)
 		hdl->oerr = xrun;
 		if (!(hdl->sio.mode & SIO_REC))
 			dierr = doerr;
+		if (doerr > 0)
+			DPRINTF("play xrun %d\n", doerr);
 	}
 	if (hdl->sio.mode & SIO_REC) {
 		if (ioctl(hdl->fd, AUDIO_RERROR, &xrun) < 0) {
@@ -945,11 +875,21 @@ sio_sun_revents(struct sio_hdl *sh, struct pollfd *pfd)
 		hdl->ierr = xrun;
 		if (!(hdl->sio.mode & SIO_PLAY))
 			doerr = dierr;
+		if (dierr > 0)
+			DPRINTF("rec xrun %d\n", dierr);
+	}
+	offset = doerr - dierr;
+	if (offset > 0) {
+		hdl->sio.rdrop += offset * hdl->ibpf;
+		hdl->idelta -= doerr;
+		hdl->odelta -= doerr;
+		DPRINTF("will drop %d and pause %d\n", offset, doerr);
+	} else if (offset < 0) {
+		hdl->sio.wsil += -offset * hdl->obpf;
+		hdl->idelta -= dierr;
+		hdl->odelta -= dierr;
+		DPRINTF("will insert %d and pause %d\n", -offset, dierr);
 	}
-	hdl->offset += doerr - dierr;
-	dmove = dierr > doerr ? dierr : doerr;
-	hdl->idelta -= dmove;
-	hdl->odelta -= dmove;
 
 	delta = (hdl->idelta > hdl->odelta) ? hdl->idelta : hdl->odelta;
 	if (delta > 0) {
@@ -958,16 +898,7 @@ sio_sun_revents(struct sio_hdl *sh, struct pollfd *pfd)
 		hdl->odelta -= delta;
 	}
 
-	/*
-	 * drop recorded samples or insert silence to play
-	 * right now to adjust revents, and avoid busy loops
-	 * programs
-	 */
 	if (hdl->filling)
-		revents |= POLLOUT;
-	if ((hdl->sio.mode & SIO_PLAY) && !sio_sun_wsil(hdl))
-		revents &= ~POLLOUT;
-	if ((hdl->sio.mode & SIO_REC) && !sio_sun_rdrop(hdl))
-		revents &= ~POLLIN;
+		revents |= POLLOUT; /* XXX: is this necessary ? */
 	return revents;
 }