--- /dev/null
+/*
+ * 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)
+ 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) {
+ pr_debug("ALSA: seq: 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);
+ pr_err("ALSA: seq: 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) {
+ pr_debug("ALSA: seq: 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) {
+ pr_debug("ALSA: seq: 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) {
+ pr_debug("ALSA: seq: 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
+ pr_debug("ALSA: seq: 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;
+ }
+}
+
+
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