summaryrefslogtreecommitdiff
path: root/sound/core/seq/seq_prioq.c
blob: 2bc6759e4adcf6a794efc22e4707b8f228d6b362 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
/*
 *   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, NULL));
	}
	
	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;
}

/* return 1 if the current time >= event timestamp */
static int event_is_ready(struct snd_seq_event *ev, void *current_time)
{
	if ((ev->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK)
		return snd_seq_compare_tick_time(current_time, &ev->time.tick);
	else
		return snd_seq_compare_real_time(current_time, &ev->time.time);
}

/* dequeue cell from prioq */
struct snd_seq_event_cell *snd_seq_prioq_cell_out(struct snd_seq_prioq *f,
						  void *current_time)
{
	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 && current_time && !event_is_ready(&cell->event, current_time))
		cell = NULL;
	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;
}

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;
	}
}