freebsd-dev/sys/dev/sound/midi/midibuf.c

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/*
* Copyright (C) 1999 Seigo Tanimura
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS
* IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*
*/
/*
* This file implements a midi event/message queue. A midi
* event/message queue holds midi events and messages to
* transmit to or received from a midi interface.
*/
#include <dev/sound/midi/midi.h>
/* Some macros to handle the queue. */
#define DATA_AVAIL(dbuf) ((dbuf)->rl)
#define SPACE_AVAIL(dbuf) ((dbuf)->fl)
static void queuerawdata(midi_dbuf *dbuf, char *data, int len);
static void dequeuerawdata(midi_dbuf *dbuf, char *data, int len);
static void copyrawdata(midi_dbuf *dbuf, int offset, char *data, int len);
static void deleterawdata(midi_dbuf *dbuf, int len);
/*
* Here are the functions to interact to the midi device drivers.
* These are called from midi device driver functions under sys/i386/isa/snd.
*/
int
midibuf_init(midi_dbuf *dbuf)
{
if (dbuf->buf == NULL) {
dbuf->buf = malloc(MIDI_BUFFSIZE, M_DEVBUF, M_WAITOK | M_ZERO);
cv_init(&dbuf->cv_in, "midi queue in");
cv_init(&dbuf->cv_out, "midi queue out");
}
return (midibuf_clear(dbuf));
}
int
midibuf_destroy(midi_dbuf *dbuf)
{
if (dbuf->buf != NULL) {
free(dbuf->buf, M_DEVBUF);
cv_destroy(&dbuf->cv_in);
cv_destroy(&dbuf->cv_out);
}
return (0);
}
int
midibuf_clear(midi_dbuf *dbuf)
{
bzero(dbuf->buf, MIDI_BUFFSIZE);
dbuf->bufsize = MIDI_BUFFSIZE;
dbuf->rp = dbuf->fp = 0;
dbuf->dl = 0;
dbuf->rl = 0;
dbuf->fl = dbuf->bufsize;
dbuf->int_count = 0;
dbuf->chan = 0;
/*dbuf->unit_size = 1;*/ /* The drivers are responsible. */
bzero(&dbuf->sel, sizeof(dbuf->sel));
dbuf->total = 0;
dbuf->prev_total = 0;
dbuf->blocksize = dbuf->bufsize / 4;
return (0);
}
/* The sequencer calls this function to queue data. */
int
midibuf_seqwrite(midi_dbuf *dbuf, u_char* data, int len, int *lenw, midi_callback_t *cb, void *d, int reason, struct mtx *m)
{
int i, lwrt;
if (m != NULL)
mtx_assert(m, MA_OWNED);
if (lenw == NULL)
return (EINVAL);
*lenw = 0;
/* Is this a real queue? */
if (dbuf == (midi_dbuf *)NULL)
return (EINVAL);
/* Write down every single byte. */
while (len > 0) {
/* Find out the number of bytes to write. */
lwrt = SPACE_AVAIL(dbuf);
if (lwrt > len)
lwrt = len;
if (lwrt > 0) {
/* We can write some now. Queue the data. */
queuerawdata(dbuf, data, lwrt);
*lenw += lwrt;
len -= lwrt;
data += lwrt;
}
if (cb != NULL)
(*cb)(d, reason);
/* Have we got still more data to write? */
if (len > 0) {
/* Sleep until we have enough space. */
i = cv_wait_sig(&dbuf->cv_out, m);
if (i == EINTR || i == ERESTART)
return (i);
}
}
return (0);
}
int
midibuf_output_intr(midi_dbuf *dbuf, u_char *data, int len, int *leno)
{
if (leno == NULL)
return (EINVAL);
*leno = 0;
/* Is this a real queue? */
if (dbuf == (midi_dbuf *)NULL)
return (EINVAL);
/* Have we got any data in the queue? */
*leno = DATA_AVAIL(dbuf);
if (*leno == 0)
return (EAGAIN);
/* Dequeue the data. */
if (*leno > len)
*leno = len;
dequeuerawdata(dbuf, data, *leno);
return (0);
}
int
midibuf_input_intr(midi_dbuf *dbuf, u_char *data, int len, int *leni)
{
if (leni == NULL)
return (EINVAL);
*leni = 0;
/* Is this a real queue? */
if (dbuf == (midi_dbuf *)NULL)
return (EINVAL);
/* Have we got any data to write? */
if (len == 0)
return (0);
/* Can we write now? */
if (SPACE_AVAIL(dbuf) < len)
return (EAGAIN);
/* We can write some now. Queue the data. */
queuerawdata(dbuf, data, len);
*leni = len;
return (0);
}
/* The sequencer calls this function to dequeue data. */
int
midibuf_seqread(midi_dbuf *dbuf, u_char* data, int len, int *lenr, midi_callback_t *cb, void *d, int reason, struct mtx *m)
{
int i, lrd;
if (m != NULL)
mtx_assert(m, MA_OWNED);
if (lenr == NULL)
return (EINVAL);
*lenr = 0;
/* Is this a real queue? */
if (dbuf == (midi_dbuf *)NULL)
return (EINVAL);
/* Write down every single byte. */
while (len > 0) {
if (cb != NULL)
(*cb)(d, reason);
/* Have we got data to read? */
if ((lrd = DATA_AVAIL(dbuf)) == 0) {
/* Sleep until we have data ready to read. */
i = cv_wait_sig(&dbuf->cv_in, m);
if (i == EINTR || i == ERESTART)
return (i);
/* Find out the number of bytes to read. */
lrd = DATA_AVAIL(dbuf);
}
if (lrd > len)
lrd = len;
if (lrd > 0) {
/* We can read some data now. Dequeue the data. */
dequeuerawdata(dbuf, data, lrd);
*lenr += lrd;
len -= lrd;
data += lrd;
}
}
return (0);
}
/* The sequencer calls this function to copy data without dequeueing. */
int
midibuf_seqcopy(midi_dbuf *dbuf, u_char* data, int len, int *lenc, midi_callback_t *cb, void *d, int reason, struct mtx *m)
{
int i, lrd;
if (m != NULL)
mtx_assert(m, MA_OWNED);
if (lenc == NULL)
return (EINVAL);
*lenc = 0;
/* Is this a real queue? */
if (dbuf == (midi_dbuf *)NULL)
return (EINVAL);
/* Write down every single byte. */
while (len > 0) {
if (cb != NULL)
(*cb)(d, reason);
/* Have we got data to read? */
if ((lrd = DATA_AVAIL(dbuf)) == 0) {
/* Sleep until we have data ready to read. */
i = cv_wait_sig(&dbuf->cv_in, m);
if (i == EINTR || i == ERESTART)
return (i);
/* Find out the number of bytes to read. */
lrd = DATA_AVAIL(dbuf);
}
if (lrd > len)
lrd = len;
if (lrd > 0) {
/* We can read some data now. Copy the data. */
copyrawdata(dbuf, *lenc, data, lrd);
*lenc += lrd;
len -= lrd;
data += lrd;
}
}
return (0);
}
/*
* The sequencer calls this function to delete the data
* that the sequencer has already read.
*/
int
midibuf_seqdelete(midi_dbuf *dbuf, int len, int *lenr, midi_callback_t *cb, void *d, int reason, struct mtx *m)
{
int i, lrd;
if (m != NULL)
mtx_assert(m, MA_OWNED);
if (lenr == NULL)
return (EINVAL);
*lenr = 0;
/* Is this a real queue? */
if (dbuf == (midi_dbuf *)NULL)
return (EINVAL);
/* Write down every single byte. */
while (len > 0) {
if (cb != NULL)
(*cb)(d, reason);
/* Have we got data to read? */
if ((lrd = DATA_AVAIL(dbuf)) == 0) {
/* Sleep until we have data ready to read. */
i = cv_wait_sig(&dbuf->cv_in, m);
if (i == EINTR || i == ERESTART)
return (i);
/* Find out the number of bytes to read. */
lrd = DATA_AVAIL(dbuf);
}
if (lrd > len)
lrd = len;
if (lrd > 0) {
/* We can read some data now. Delete the data. */
deleterawdata(dbuf, lrd);
*lenr += lrd;
len -= lrd;
}
}
return (0);
}
/*
* The functions below here are the libraries for the above ones.
*/
static void
queuerawdata(midi_dbuf *dbuf, char *data, int len)
{
/* dbuf->fp might wrap around dbuf->bufsize. */
if (dbuf->bufsize - dbuf->fp < len) {
/* The new data wraps, copy them twice. */
bcopy(data, dbuf->buf + dbuf->fp, dbuf->bufsize - dbuf->fp);
bcopy(data + dbuf->bufsize - dbuf->fp, dbuf->buf, len - (dbuf->bufsize - dbuf->fp));
} else
/* The new data do not wrap, once is enough. */
bcopy(data, dbuf->buf + dbuf->fp, len);
/* Adjust the pointer and the length counters. */
dbuf->fp = (dbuf->fp + len) % dbuf->bufsize;
dbuf->fl -= len;
dbuf->rl += len;
/* Wake up the processes sleeping on input data. */
cv_broadcast(&dbuf->cv_in);
if (dbuf->sel.si_pid && dbuf->rl >= dbuf->blocksize)
selwakeup(&dbuf->sel);
}
static void
dequeuerawdata(midi_dbuf *dbuf, char *data, int len)
{
/* Copy the data. */
copyrawdata(dbuf, 0, data, len);
/* Delete the data. */
deleterawdata(dbuf, len);
}
static void
copyrawdata(midi_dbuf *dbuf, int offset, char *data, int len)
{
int rp;
rp = (dbuf->rp + offset) % dbuf->bufsize;
/* dbuf->rp might wrap around dbuf->bufsize. */
if (dbuf->bufsize - rp < len) {
/* The data to be read wraps, copy them twice. */
bcopy(dbuf->buf + rp, data, dbuf->bufsize - rp);
bcopy(dbuf->buf, data + dbuf->bufsize - rp, len - (dbuf->bufsize - rp));
} else
/* The new data do not wrap, once is enough. */
bcopy(dbuf->buf + rp, data, len);
}
static void
deleterawdata(midi_dbuf *dbuf, int len)
{
/* Adjust the pointer and the length counters. */
dbuf->rp = (dbuf->rp + len) % dbuf->bufsize;
dbuf->rl -= len;
dbuf->fl += len;
/* Wake up the processes sleeping on queueing. */
cv_broadcast(&dbuf->cv_out);
if (dbuf->sel.si_pid && dbuf->fl >= dbuf->blocksize)
selwakeup(&dbuf->sel);
}