1 files changed, 453 insertions, 0 deletions

diff --git a/sound/core/seq/seq_prioq.c b/sound/core/seq/seq_prioq.c
new file mode 100644
index 00000000..29896ab2
--- /dev/null
+++ b/sound/core/seq/seq_prioq.c
@@ -0,0 +1,453 @@
+/*
+ *   ALSA sequencer Priority Queue
+ *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
+ *
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/time.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include "seq_timer.h"
+#include "seq_prioq.h"
+
+
+/* Implementation is a simple linked list for now...
+
+   This priority queue orders the events on timestamp. For events with an
+   equeal timestamp the queue behaves as a FIFO. 
+
+   *
+   *           +-------+
+   *  Head --> | first |
+   *           +-------+
+   *                 |next
+   *           +-----v-+
+   *           |       |
+   *           +-------+
+   *                 |
+   *           +-----v-+
+   *           |       |
+   *           +-------+
+   *                 |
+   *           +-----v-+
+   *  Tail --> | last  |
+   *           +-------+
+   *
+
+ */
+
+
+
+/* create new prioq (constructor) */
+struct snd_seq_prioq *snd_seq_prioq_new(void)
+{
+	struct snd_seq_prioq *f;
+
+	f = kzalloc(sizeof(*f), GFP_KERNEL);
+	if (f == NULL) {
+		snd_printd("oops: malloc failed for snd_seq_prioq_new()\n");
+		return NULL;
+	}
+	
+	spin_lock_init(&f->lock);
+	f->head = NULL;
+	f->tail = NULL;
+	f->cells = 0;
+	
+	return f;
+}
+
+/* delete prioq (destructor) */
+void snd_seq_prioq_delete(struct snd_seq_prioq **fifo)
+{
+	struct snd_seq_prioq *f = *fifo;
+	*fifo = NULL;
+
+	if (f == NULL) {
+		snd_printd("oops: snd_seq_prioq_delete() called with NULL prioq\n");
+		return;
+	}
+
+	/* release resources...*/
+	/*....................*/
+	
+	if (f->cells > 0) {
+		/* drain prioQ */
+		while (f->cells > 0)
+			snd_seq_cell_free(snd_seq_prioq_cell_out(f));
+	}
+	
+	kfree(f);
+}
+
+
+
+
+/* compare timestamp between events */
+/* return 1 if a >= b; 0 */
+static inline int compare_timestamp(struct snd_seq_event *a,
+				    struct snd_seq_event *b)
+{
+	if ((a->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK) {
+		/* compare ticks */
+		return (snd_seq_compare_tick_time(&a->time.tick, &b->time.tick));
+	} else {
+		/* compare real time */
+		return (snd_seq_compare_real_time(&a->time.time, &b->time.time));
+	}
+}
+
+/* compare timestamp between events */
+/* return negative if a < b;
+ *        zero     if a = b;
+ *        positive if a > b;
+ */
+static inline int compare_timestamp_rel(struct snd_seq_event *a,
+					struct snd_seq_event *b)
+{
+	if ((a->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK) {
+		/* compare ticks */
+		if (a->time.tick > b->time.tick)
+			return 1;
+		else if (a->time.tick == b->time.tick)
+			return 0;
+		else
+			return -1;
+	} else {
+		/* compare real time */
+		if (a->time.time.tv_sec > b->time.time.tv_sec)
+			return 1;
+		else if (a->time.time.tv_sec == b->time.time.tv_sec) {
+			if (a->time.time.tv_nsec > b->time.time.tv_nsec)
+				return 1;
+			else if (a->time.time.tv_nsec == b->time.time.tv_nsec)
+				return 0;
+			else
+				return -1;
+		} else
+			return -1;
+	}
+}
+
+/* enqueue cell to prioq */
+int snd_seq_prioq_cell_in(struct snd_seq_prioq * f,
+			  struct snd_seq_event_cell * cell)
+{
+	struct snd_seq_event_cell *cur, *prev;
+	unsigned long flags;
+	int count;
+	int prior;
+
+	if (snd_BUG_ON(!f || !cell))
+		return -EINVAL;
+	
+	/* check flags */
+	prior = (cell->event.flags & SNDRV_SEQ_PRIORITY_MASK);
+
+	spin_lock_irqsave(&f->lock, flags);
+
+	/* check if this element needs to inserted at the end (ie. ordered 
+	   data is inserted) This will be very likeley if a sequencer 
+	   application or midi file player is feeding us (sequential) data */
+	if (f->tail && !prior) {
+		if (compare_timestamp(&cell->event, &f->tail->event)) {
+			/* add new cell to tail of the fifo */
+			f->tail->next = cell;
+			f->tail = cell;
+			cell->next = NULL;
+			f->cells++;
+			spin_unlock_irqrestore(&f->lock, flags);
+			return 0;
+		}
+	}
+	/* traverse list of elements to find the place where the new cell is
+	   to be inserted... Note that this is a order n process ! */
+
+	prev = NULL;		/* previous cell */
+	cur = f->head;		/* cursor */
+
+	count = 10000; /* FIXME: enough big, isn't it? */
+	while (cur != NULL) {
+		/* compare timestamps */
+		int rel = compare_timestamp_rel(&cell->event, &cur->event);
+		if (rel < 0)
+			/* new cell has earlier schedule time, */
+			break;
+		else if (rel == 0 && prior)
+			/* equal schedule time and prior to others */
+			break;
+		/* new cell has equal or larger schedule time, */
+		/* move cursor to next cell */
+		prev = cur;
+		cur = cur->next;
+		if (! --count) {
+			spin_unlock_irqrestore(&f->lock, flags);
+			snd_printk(KERN_ERR "cannot find a pointer.. infinite loop?\n");
+			return -EINVAL;
+		}
+	}
+
+	/* insert it before cursor */
+	if (prev != NULL)
+		prev->next = cell;
+	cell->next = cur;
+
+	if (f->head == cur) /* this is the first cell, set head to it */
+		f->head = cell;
+	if (cur == NULL) /* reached end of the list */
+		f->tail = cell;
+	f->cells++;
+	spin_unlock_irqrestore(&f->lock, flags);
+	return 0;
+}
+
+/* dequeue cell from prioq */
+struct snd_seq_event_cell *snd_seq_prioq_cell_out(struct snd_seq_prioq *f)
+{
+	struct snd_seq_event_cell *cell;
+	unsigned long flags;
+
+	if (f == NULL) {
+		snd_printd("oops: snd_seq_prioq_cell_in() called with NULL prioq\n");
+		return NULL;
+	}
+	spin_lock_irqsave(&f->lock, flags);
+
+	cell = f->head;
+	if (cell) {
+		f->head = cell->next;
+
+		/* reset tail if this was the last element */
+		if (f->tail == cell)
+			f->tail = NULL;
+
+		cell->next = NULL;
+		f->cells--;
+	}
+
+	spin_unlock_irqrestore(&f->lock, flags);
+	return cell;
+}
+
+/* return number of events available in prioq */
+int snd_seq_prioq_avail(struct snd_seq_prioq * f)
+{
+	if (f == NULL) {
+		snd_printd("oops: snd_seq_prioq_cell_in() called with NULL prioq\n");
+		return 0;
+	}
+	return f->cells;
+}
+
+
+/* peek at cell at the head of the prioq */
+struct snd_seq_event_cell *snd_seq_prioq_cell_peek(struct snd_seq_prioq * f)
+{
+	if (f == NULL) {
+		snd_printd("oops: snd_seq_prioq_cell_in() called with NULL prioq\n");
+		return NULL;
+	}
+	return f->head;
+}
+
+
+static inline int prioq_match(struct snd_seq_event_cell *cell,
+			      int client, int timestamp)
+{
+	if (cell->event.source.client == client ||
+	    cell->event.dest.client == client)
+		return 1;
+	if (!timestamp)
+		return 0;
+	switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
+	case SNDRV_SEQ_TIME_STAMP_TICK:
+		if (cell->event.time.tick)
+			return 1;
+		break;
+	case SNDRV_SEQ_TIME_STAMP_REAL:
+		if (cell->event.time.time.tv_sec ||
+		    cell->event.time.time.tv_nsec)
+			return 1;
+		break;
+	}
+	return 0;
+}
+
+/* remove cells for left client */
+void snd_seq_prioq_leave(struct snd_seq_prioq * f, int client, int timestamp)
+{
+	register struct snd_seq_event_cell *cell, *next;
+	unsigned long flags;
+	struct snd_seq_event_cell *prev = NULL;
+	struct snd_seq_event_cell *freefirst = NULL, *freeprev = NULL, *freenext;
+
+	/* collect all removed cells */
+	spin_lock_irqsave(&f->lock, flags);
+	cell = f->head;
+	while (cell) {
+		next = cell->next;
+		if (prioq_match(cell, client, timestamp)) {
+			/* remove cell from prioq */
+			if (cell == f->head) {
+				f->head = cell->next;
+			} else {
+				prev->next = cell->next;
+			}
+			if (cell == f->tail)
+				f->tail = cell->next;
+			f->cells--;
+			/* add cell to free list */
+			cell->next = NULL;
+			if (freefirst == NULL) {
+				freefirst = cell;
+			} else {
+				freeprev->next = cell;
+			}
+			freeprev = cell;
+		} else {
+#if 0
+			printk(KERN_DEBUG "type = %i, source = %i, dest = %i, "
+			       "client = %i\n",
+				cell->event.type,
+				cell->event.source.client,
+				cell->event.dest.client,
+				client);
+#endif
+			prev = cell;
+		}
+		cell = next;		
+	}
+	spin_unlock_irqrestore(&f->lock, flags);	
+
+	/* remove selected cells */
+	while (freefirst) {
+		freenext = freefirst->next;
+		snd_seq_cell_free(freefirst);
+		freefirst = freenext;
+	}
+}
+
+static int prioq_remove_match(struct snd_seq_remove_events *info,
+			      struct snd_seq_event *ev)
+{
+	int res;
+
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_DEST) {
+		if (ev->dest.client != info->dest.client ||
+				ev->dest.port != info->dest.port)
+			return 0;
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_DEST_CHANNEL) {
+		if (! snd_seq_ev_is_channel_type(ev))
+			return 0;
+		/* data.note.channel and data.control.channel are identical */
+		if (ev->data.note.channel != info->channel)
+			return 0;
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_AFTER) {
+		if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_TICK)
+			res = snd_seq_compare_tick_time(&ev->time.tick, &info->time.tick);
+		else
+			res = snd_seq_compare_real_time(&ev->time.time, &info->time.time);
+		if (!res)
+			return 0;
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_BEFORE) {
+		if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_TICK)
+			res = snd_seq_compare_tick_time(&ev->time.tick, &info->time.tick);
+		else
+			res = snd_seq_compare_real_time(&ev->time.time, &info->time.time);
+		if (res)
+			return 0;
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_EVENT_TYPE) {
+		if (ev->type != info->type)
+			return 0;
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_IGNORE_OFF) {
+		/* Do not remove off events */
+		switch (ev->type) {
+		case SNDRV_SEQ_EVENT_NOTEOFF:
+		/* case SNDRV_SEQ_EVENT_SAMPLE_STOP: */
+			return 0;
+		default:
+			break;
+		}
+	}
+	if (info->remove_mode & SNDRV_SEQ_REMOVE_TAG_MATCH) {
+		if (info->tag != ev->tag)
+			return 0;
+	}
+
+	return 1;
+}
+
+/* remove cells matching remove criteria */
+void snd_seq_prioq_remove_events(struct snd_seq_prioq * f, int client,
+				 struct snd_seq_remove_events *info)
+{
+	struct snd_seq_event_cell *cell, *next;
+	unsigned long flags;
+	struct snd_seq_event_cell *prev = NULL;
+	struct snd_seq_event_cell *freefirst = NULL, *freeprev = NULL, *freenext;
+
+	/* collect all removed cells */
+	spin_lock_irqsave(&f->lock, flags);
+	cell = f->head;
+
+	while (cell) {
+		next = cell->next;
+		if (cell->event.source.client == client &&
+			prioq_remove_match(info, &cell->event)) {
+
+			/* remove cell from prioq */
+			if (cell == f->head) {
+				f->head = cell->next;
+			} else {
+				prev->next = cell->next;
+			}
+
+			if (cell == f->tail)
+				f->tail = cell->next;
+			f->cells--;
+
+			/* add cell to free list */
+			cell->next = NULL;
+			if (freefirst == NULL) {
+				freefirst = cell;
+			} else {
+				freeprev->next = cell;
+			}
+
+			freeprev = cell;
+		} else {
+			prev = cell;
+		}
+		cell = next;		
+	}
+	spin_unlock_irqrestore(&f->lock, flags);	
+
+	/* remove selected cells */
+	while (freefirst) {
+		freenext = freefirst->next;
+		snd_seq_cell_free(freefirst);
+		freefirst = freenext;
+	}
+}
+
+