sound/core/seq/seq_prioq.c

   1 /*
   2  *   ALSA sequencer Priority Queue
   3  *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <sound/driver.h>
  23 #include <linux/time.h>
  24 #include <linux/slab.h>
  25 #include <sound/core.h>
  26 #include "seq_timer.h"
  27 #include "seq_prioq.h"
  28
  29
  30 /* Implementation is a simple linked list for now...
  31
  32    This priority queue orders the events on timestamp. For events with an
  33    equeal timestamp the queue behaves as a FIFO.
  34
  35    *
  36    *           +-------+
  37    *  Head --> | first |
  38    *           +-------+
  39    *                 |next
  40    *           +-----v-+
  41    *           |       |
  42    *           +-------+
  43    *                 |
  44    *           +-----v-+
  45    *           |       |
  46    *           +-------+
  47    *                 |
  48    *           +-----v-+
  49    *  Tail --> | last  |
  50    *           +-------+
  51    *
  52
  53  */
  54
  55
  56
  57 /* create new prioq (constructor) */
  58 struct snd_seq_prioq *snd_seq_prioq_new(void)
  59 {
  60         struct snd_seq_prioq *f;
  61
  62         f = kzalloc(sizeof(*f), GFP_KERNEL);
  63         if (f == NULL) {
  64                 snd_printd("oops: malloc failed for snd_seq_prioq_new()\n");
  65                 return NULL;
  66         }
  67
  68         spin_lock_init(&f->lock);
  69         f->head = NULL;
  70         f->tail = NULL;
  71         f->cells = 0;
  72
  73         return f;
  74 }
  75
  76 /* delete prioq (destructor) */
  77 void snd_seq_prioq_delete(struct snd_seq_prioq **fifo)
  78 {
  79         struct snd_seq_prioq *f = *fifo;
  80         *fifo = NULL;
  81
  82         if (f == NULL) {
  83                 snd_printd("oops: snd_seq_prioq_delete() called with NULL prioq\n");
  84                 return;
  85         }
  86
  87         /* release resources...*/
  88         /*....................*/
  89
  90         if (f->cells > 0) {
  91                 /* drain prioQ */
  92                 while (f->cells > 0)
  93                         snd_seq_cell_free(snd_seq_prioq_cell_out(f));
  94         }
  95
  96         kfree(f);
  97 }
  98
  99
 100
 101
 102 /* compare timestamp between events */
 103 /* return 1 if a >= b; 0 */
 104 static inline int compare_timestamp(struct snd_seq_event *a,
 105                                     struct snd_seq_event *b)
 106 {
 107         if ((a->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK) {
 108                 /* compare ticks */
 109                 return (snd_seq_compare_tick_time(&a->time.tick, &b->time.tick));
 110         } else {
 111                 /* compare real time */
 112                 return (snd_seq_compare_real_time(&a->time.time, &b->time.time));
 113         }
 114 }
 115
 116 /* compare timestamp between events */
 117 /* return negative if a < b;
 118  *        zero     if a = b;
 119  *        positive if a > b;
 120  */
 121 static inline int compare_timestamp_rel(struct snd_seq_event *a,
 122                                         struct snd_seq_event *b)
 123 {
 124         if ((a->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK) {
 125                 /* compare ticks */
 126                 if (a->time.tick > b->time.tick)
 127                         return 1;
 128                 else if (a->time.tick == b->time.tick)
 129                         return 0;
 130                 else
 131                         return -1;
 132         } else {
 133                 /* compare real time */
 134                 if (a->time.time.tv_sec > b->time.time.tv_sec)
 135                         return 1;
 136                 else if (a->time.time.tv_sec == b->time.time.tv_sec) {
 137                         if (a->time.time.tv_nsec > b->time.time.tv_nsec)
 138                                 return 1;
 139                         else if (a->time.time.tv_nsec == b->time.time.tv_nsec)
 140                                 return 0;
 141                         else
 142                                 return -1;
 143                 } else
 144                         return -1;
 145         }
 146 }
 147
 148 /* enqueue cell to prioq */
 149 int snd_seq_prioq_cell_in(struct snd_seq_prioq * f,
 150                           struct snd_seq_event_cell * cell)
 151 {
 152         struct snd_seq_event_cell *cur, *prev;
 153         unsigned long flags;
 154         int count;
 155         int prior;
 156
 157         snd_assert(f, return -EINVAL);
 158         snd_assert(cell, return -EINVAL);
 159
 160         /* check flags */
 161         prior = (cell->event.flags & SNDRV_SEQ_PRIORITY_MASK);
 162
 163         spin_lock_irqsave(&f->lock, flags);
 164
 165         /* check if this element needs to inserted at the end (ie. ordered
 166            data is inserted) This will be very likeley if a sequencer
 167            application or midi file player is feeding us (sequential) data */
 168         if (f->tail && !prior) {
 169                 if (compare_timestamp(&cell->event, &f->tail->event)) {
 170                         /* add new cell to tail of the fifo */
 171                         f->tail->next = cell;
 172                         f->tail = cell;
 173                         cell->next = NULL;
 174                         f->cells++;
 175                         spin_unlock_irqrestore(&f->lock, flags);
 176                         return 0;
 177                 }
 178         }
 179         /* traverse list of elements to find the place where the new cell is
 180            to be inserted... Note that this is a order n process ! */
 181
 182         prev = NULL;            /* previous cell */
 183         cur = f->head;          /* cursor */
 184
 185         count = 10000; /* FIXME: enough big, isn't it? */
 186         while (cur != NULL) {
 187                 /* compare timestamps */
 188                 int rel = compare_timestamp_rel(&cell->event, &cur->event);
 189                 if (rel < 0)
 190                         /* new cell has earlier schedule time, */
 191                         break;
 192                 else if (rel == 0 && prior)
 193                         /* equal schedule time and prior to others */
 194                         break;
 195                 /* new cell has equal or larger schedule time, */
 196                 /* move cursor to next cell */
 197                 prev = cur;
 198                 cur = cur->next;
 199                 if (! --count) {
 200                         spin_unlock_irqrestore(&f->lock, flags);
 201                         snd_printk(KERN_ERR "cannot find a pointer.. infinite loop?\n");
 202                         return -EINVAL;
 203                 }
 204         }
 205
 206         /* insert it before cursor */
 207         if (prev != NULL)
 208                 prev->next = cell;
 209         cell->next = cur;
 210
 211         if (f->head == cur) /* this is the first cell, set head to it */
 212                 f->head = cell;
 213         if (cur == NULL) /* reached end of the list */
 214                 f->tail = cell;
 215         f->cells++;
 216         spin_unlock_irqrestore(&f->lock, flags);
 217         return 0;
 218 }
 219
 220 /* dequeue cell from prioq */
 221 struct snd_seq_event_cell *snd_seq_prioq_cell_out(struct snd_seq_prioq *f)
 222 {
 223         struct snd_seq_event_cell *cell;
 224         unsigned long flags;
 225
 226         if (f == NULL) {
 227                 snd_printd("oops: snd_seq_prioq_cell_in() called with NULL prioq\n");
 228                 return NULL;
 229         }
 230         spin_lock_irqsave(&f->lock, flags);
 231
 232         cell = f->head;
 233         if (cell) {
 234                 f->head = cell->next;
 235
 236                 /* reset tail if this was the last element */
 237                 if (f->tail == cell)
 238                         f->tail = NULL;
 239
 240                 cell->next = NULL;
 241                 f->cells--;
 242         }
 243
 244         spin_unlock_irqrestore(&f->lock, flags);
 245         return cell;
 246 }
 247
 248 /* return number of events available in prioq */
 249 int snd_seq_prioq_avail(struct snd_seq_prioq * f)
 250 {
 251         if (f == NULL) {
 252                 snd_printd("oops: snd_seq_prioq_cell_in() called with NULL prioq\n");
 253                 return 0;
 254         }
 255         return f->cells;
 256 }
 257
 258
 259 /* peek at cell at the head of the prioq */
 260 struct snd_seq_event_cell *snd_seq_prioq_cell_peek(struct snd_seq_prioq * f)
 261 {
 262         if (f == NULL) {
 263                 snd_printd("oops: snd_seq_prioq_cell_in() called with NULL prioq\n");
 264                 return NULL;
 265         }
 266         return f->head;
 267 }
 268
 269
 270 static inline int prioq_match(struct snd_seq_event_cell *cell,
 271                               int client, int timestamp)
 272 {
 273         if (cell->event.source.client == client ||
 274             cell->event.dest.client == client)
 275                 return 1;
 276         if (!timestamp)
 277                 return 0;
 278         switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
 279         case SNDRV_SEQ_TIME_STAMP_TICK:
 280                 if (cell->event.time.tick)
 281                         return 1;
 282                 break;
 283         case SNDRV_SEQ_TIME_STAMP_REAL:
 284                 if (cell->event.time.time.tv_sec ||
 285                     cell->event.time.time.tv_nsec)
 286                         return 1;
 287                 break;
 288         }
 289         return 0;
 290 }
 291
 292 /* remove cells for left client */
 293 void snd_seq_prioq_leave(struct snd_seq_prioq * f, int client, int timestamp)
 294 {
 295         register struct snd_seq_event_cell *cell, *next;
 296         unsigned long flags;
 297         struct snd_seq_event_cell *prev = NULL;
 298         struct snd_seq_event_cell *freefirst = NULL, *freeprev = NULL, *freenext;
 299
 300         /* collect all removed cells */
 301         spin_lock_irqsave(&f->lock, flags);
 302         cell = f->head;
 303         while (cell) {
 304                 next = cell->next;
 305                 if (prioq_match(cell, client, timestamp)) {
 306                         /* remove cell from prioq */
 307                         if (cell == f->head) {
 308                                 f->head = cell->next;
 309                         } else {
 310                                 prev->next = cell->next;
 311                         }
 312                         if (cell == f->tail)
 313                                 f->tail = cell->next;
 314                         f->cells--;
 315                         /* add cell to free list */
 316                         cell->next = NULL;
 317                         if (freefirst == NULL) {
 318                                 freefirst = cell;
 319                         } else {
 320                                 freeprev->next = cell;
 321                         }
 322                         freeprev = cell;
 323                 } else {
 324 #if 0
 325                         printk("type = %i, source = %i, dest = %i, client = %i\n",
 326                                 cell->event.type,
 327                                 cell->event.source.client,
 328                                 cell->event.dest.client,
 329                                 client);
 330 #endif
 331                         prev = cell;
 332                 }
 333                 cell = next;
 334         }
 335         spin_unlock_irqrestore(&f->lock, flags);
 336
 337         /* remove selected cells */
 338         while (freefirst) {
 339                 freenext = freefirst->next;
 340                 snd_seq_cell_free(freefirst);
 341                 freefirst = freenext;
 342         }
 343 }
 344
 345 static int prioq_remove_match(struct snd_seq_remove_events *info,
 346                               struct snd_seq_event *ev)
 347 {
 348         int res;
 349
 350         if (info->remove_mode & SNDRV_SEQ_REMOVE_DEST) {
 351                 if (ev->dest.client != info->dest.client ||
 352                                 ev->dest.port != info->dest.port)
 353                         return 0;
 354         }
 355         if (info->remove_mode & SNDRV_SEQ_REMOVE_DEST_CHANNEL) {
 356                 if (! snd_seq_ev_is_channel_type(ev))
 357                         return 0;
 358                 /* data.note.channel and data.control.channel are identical */
 359                 if (ev->data.note.channel != info->channel)
 360                         return 0;
 361         }
 362         if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_AFTER) {
 363                 if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_TICK)
 364                         res = snd_seq_compare_tick_time(&ev->time.tick, &info->time.tick);
 365                 else
 366                         res = snd_seq_compare_real_time(&ev->time.time, &info->time.time);
 367                 if (!res)
 368                         return 0;
 369         }
 370         if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_BEFORE) {
 371                 if (info->remove_mode & SNDRV_SEQ_REMOVE_TIME_TICK)
 372                         res = snd_seq_compare_tick_time(&ev->time.tick, &info->time.tick);
 373                 else
 374                         res = snd_seq_compare_real_time(&ev->time.time, &info->time.time);
 375                 if (res)
 376                         return 0;
 377         }
 378         if (info->remove_mode & SNDRV_SEQ_REMOVE_EVENT_TYPE) {
 379                 if (ev->type != info->type)
 380                         return 0;
 381         }
 382         if (info->remove_mode & SNDRV_SEQ_REMOVE_IGNORE_OFF) {
 383                 /* Do not remove off events */
 384                 switch (ev->type) {
 385                 case SNDRV_SEQ_EVENT_NOTEOFF:
 386                 /* case SNDRV_SEQ_EVENT_SAMPLE_STOP: */
 387                         return 0;
 388                 default:
 389                         break;
 390                 }
 391         }
 392         if (info->remove_mode & SNDRV_SEQ_REMOVE_TAG_MATCH) {
 393                 if (info->tag != ev->tag)
 394                         return 0;
 395         }
 396
 397         return 1;
 398 }
 399
 400 /* remove cells matching remove criteria */
 401 void snd_seq_prioq_remove_events(struct snd_seq_prioq * f, int client,
 402                                  struct snd_seq_remove_events *info)
 403 {
 404         struct snd_seq_event_cell *cell, *next;
 405         unsigned long flags;
 406         struct snd_seq_event_cell *prev = NULL;
 407         struct snd_seq_event_cell *freefirst = NULL, *freeprev = NULL, *freenext;
 408
 409         /* collect all removed cells */
 410         spin_lock_irqsave(&f->lock, flags);
 411         cell = f->head;
 412
 413         while (cell) {
 414                 next = cell->next;
 415                 if (cell->event.source.client == client &&
 416                         prioq_remove_match(info, &cell->event)) {
 417
 418                         /* remove cell from prioq */
 419                         if (cell == f->head) {
 420                                 f->head = cell->next;
 421                         } else {
 422                                 prev->next = cell->next;
 423                         }
 424
 425                         if (cell == f->tail)
 426                                 f->tail = cell->next;
 427                         f->cells--;
 428
 429                         /* add cell to free list */
 430                         cell->next = NULL;
 431                         if (freefirst == NULL) {
 432                                 freefirst = cell;
 433                         } else {
 434                                 freeprev->next = cell;
 435                         }
 436
 437                         freeprev = cell;
 438                 } else {
 439                         prev = cell;
 440                 }
 441                 cell = next;
 442         }
 443         spin_unlock_irqrestore(&f->lock, flags);
 444
 445         /* remove selected cells */
 446         while (freefirst) {
 447                 freenext = freefirst->next;
 448                 snd_seq_cell_free(freefirst);
 449                 freefirst = freenext;
 450         }
 451 }
 452
 453