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 <linux/time.h>
  23 #include <linux/slab.h>
  24 #include <sound/core.h>
  25 #include "seq_timer.h"
  26 #include "seq_prioq.h"
  27
  28
  29 /* Implementation is a simple linked list for now...
  30
  31    This priority queue orders the events on timestamp. For events with an
  32    equeal timestamp the queue behaves as a FIFO.
  33
  34    *
  35    *           +-------+
  36    *  Head --> | first |
  37    *           +-------+
  38    *                 |next
  39    *           +-----v-+
  40    *           |       |
  41    *           +-------+
  42    *                 |
  43    *           +-----v-+
  44    *           |       |
  45    *           +-------+
  46    *                 |
  47    *           +-----v-+
  48    *  Tail --> | last  |
  49    *           +-------+
  50    *
  51
  52  */
  53
  54
  55
  56 /* create new prioq (constructor) */
  57 struct snd_seq_prioq *snd_seq_prioq_new(void)
  58 {
  59         struct snd_seq_prioq *f;
  60
  61         f = kzalloc(sizeof(*f), GFP_KERNEL);
  62         if (f == NULL) {
  63                 snd_printd("oops: malloc failed for snd_seq_prioq_new()\n");
  64                 return NULL;
  65         }
  66
  67         spin_lock_init(&f->lock);
  68         f->head = NULL;
  69         f->tail = NULL;
  70         f->cells = 0;
  71
  72         return f;
  73 }
  74
  75 /* delete prioq (destructor) */
  76 void snd_seq_prioq_delete(struct snd_seq_prioq **fifo)
  77 {
  78         struct snd_seq_prioq *f = *fifo;
  79         *fifo = NULL;
  80
  81         if (f == NULL) {
  82                 snd_printd("oops: snd_seq_prioq_delete() called with NULL prioq\n");
  83                 return;
  84         }
  85
  86         /* release resources...*/
  87         /*....................*/
  88
  89         if (f->cells > 0) {
  90                 /* drain prioQ */
  91                 while (f->cells > 0)
  92                         snd_seq_cell_free(snd_seq_prioq_cell_out(f));
  93         }
  94
  95         kfree(f);
  96 }
  97
  98
  99
 100
 101 /* compare timestamp between events */
 102 /* return 1 if a >= b; 0 */
 103 static inline int compare_timestamp(struct snd_seq_event *a,
 104                                     struct snd_seq_event *b)
 105 {
 106         if ((a->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK) {
 107                 /* compare ticks */
 108                 return (snd_seq_compare_tick_time(&a->time.tick, &b->time.tick));
 109         } else {
 110                 /* compare real time */
 111                 return (snd_seq_compare_real_time(&a->time.time, &b->time.time));
 112         }
 113 }
 114
 115 /* compare timestamp between events */
 116 /* return negative if a < b;
 117  *        zero     if a = b;
 118  *        positive if a > b;
 119  */
 120 static inline int compare_timestamp_rel(struct snd_seq_event *a,
 121                                         struct snd_seq_event *b)
 122 {
 123         if ((a->flags & SNDRV_SEQ_TIME_STAMP_MASK) == SNDRV_SEQ_TIME_STAMP_TICK) {
 124                 /* compare ticks */
 125                 if (a->time.tick > b->time.tick)
 126                         return 1;
 127                 else if (a->time.tick == b->time.tick)
 128                         return 0;
 129                 else
 130                         return -1;
 131         } else {
 132                 /* compare real time */
 133                 if (a->time.time.tv_sec > b->time.time.tv_sec)
 134                         return 1;
 135                 else if (a->time.time.tv_sec == b->time.time.tv_sec) {
 136                         if (a->time.time.tv_nsec > b->time.time.tv_nsec)
 137                                 return 1;
 138                         else if (a->time.time.tv_nsec == b->time.time.tv_nsec)
 139                                 return 0;
 140                         else
 141                                 return -1;
 142                 } else
 143                         return -1;
 144         }
 145 }
 146
 147 /* enqueue cell to prioq */
 148 int snd_seq_prioq_cell_in(struct snd_seq_prioq * f,
 149                           struct snd_seq_event_cell * cell)
 150 {
 151         struct snd_seq_event_cell *cur, *prev;
 152         unsigned long flags;
 153         int count;
 154         int prior;
 155
 156         if (snd_BUG_ON(!f || !cell))
 157                 return -EINVAL;
 158
 159         /* check flags */
 160         prior = (cell->event.flags & SNDRV_SEQ_PRIORITY_MASK);
 161
 162         spin_lock_irqsave(&f->lock, flags);
 163
 164         /* check if this element needs to inserted at the end (ie. ordered
 165            data is inserted) This will be very likeley if a sequencer
 166            application or midi file player is feeding us (sequential) data */
 167         if (f->tail && !prior) {
 168                 if (compare_timestamp(&cell->event, &f->tail->event)) {
 169                         /* add new cell to tail of the fifo */
 170                         f->tail->next = cell;
 171                         f->tail = cell;
 172                         cell->next = NULL;
 173                         f->cells++;
 174                         spin_unlock_irqrestore(&f->lock, flags);
 175                         return 0;
 176                 }
 177         }
 178         /* traverse list of elements to find the place where the new cell is
 179            to be inserted... Note that this is a order n process ! */
 180
 181         prev = NULL;            /* previous cell */
 182         cur = f->head;          /* cursor */
 183
 184         count = 10000; /* FIXME: enough big, isn't it? */
 185         while (cur != NULL) {
 186                 /* compare timestamps */
 187                 int rel = compare_timestamp_rel(&cell->event, &cur->event);
 188                 if (rel < 0)
 189                         /* new cell has earlier schedule time, */
 190                         break;
 191                 else if (rel == 0 && prior)
 192                         /* equal schedule time and prior to others */
 193                         break;
 194                 /* new cell has equal or larger schedule time, */
 195                 /* move cursor to next cell */
 196                 prev = cur;
 197                 cur = cur->next;
 198                 if (! --count) {
 199                         spin_unlock_irqrestore(&f->lock, flags);
 200                         snd_printk(KERN_ERR "cannot find a pointer.. infinite loop?\n");
 201                         return -EINVAL;
 202                 }
 203         }
 204
 205         /* insert it before cursor */
 206         if (prev != NULL)
 207                 prev->next = cell;
 208         cell->next = cur;
 209
 210         if (f->head == cur) /* this is the first cell, set head to it */
 211                 f->head = cell;
 212         if (cur == NULL) /* reached end of the list */
 213                 f->tail = cell;
 214         f->cells++;
 215         spin_unlock_irqrestore(&f->lock, flags);
 216         return 0;
 217 }
 218
 219 /* dequeue cell from prioq */
 220 struct snd_seq_event_cell *snd_seq_prioq_cell_out(struct snd_seq_prioq *f)
 221 {
 222         struct snd_seq_event_cell *cell;
 223         unsigned long flags;
 224
 225         if (f == NULL) {
 226                 snd_printd("oops: snd_seq_prioq_cell_in() called with NULL prioq\n");
 227                 return NULL;
 228         }
 229         spin_lock_irqsave(&f->lock, flags);
 230
 231         cell = f->head;
 232         if (cell) {
 233                 f->head = cell->next;
 234
 235                 /* reset tail if this was the last element */
 236                 if (f->tail == cell)
 237                         f->tail = NULL;
 238
 239                 cell->next = NULL;
 240                 f->cells--;
 241         }
 242
 243         spin_unlock_irqrestore(&f->lock, flags);
 244         return cell;
 245 }
 246
 247 /* return number of events available in prioq */
 248 int snd_seq_prioq_avail(struct snd_seq_prioq * f)
 249 {
 250         if (f == NULL) {
 251                 snd_printd("oops: snd_seq_prioq_cell_in() called with NULL prioq\n");
 252                 return 0;
 253         }
 254         return f->cells;
 255 }
 256
 257
 258 /* peek at cell at the head of the prioq */
 259 struct snd_seq_event_cell *snd_seq_prioq_cell_peek(struct snd_seq_prioq * f)
 260 {
 261         if (f == NULL) {
 262                 snd_printd("oops: snd_seq_prioq_cell_in() called with NULL prioq\n");
 263                 return NULL;
 264         }
 265         return f->head;
 266 }
 267
 268
 269 static inline int prioq_match(struct snd_seq_event_cell *cell,
 270                               int client, int timestamp)
 271 {
 272         if (cell->event.source.client == client ||
 273             cell->event.dest.client == client)
 274                 return 1;
 275         if (!timestamp)
 276                 return 0;
 277         switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
 278         case SNDRV_SEQ_TIME_STAMP_TICK:
 279                 if (cell->event.time.tick)
 280                         return 1;
 281                 break;
 282         case SNDRV_SEQ_TIME_STAMP_REAL:
 283                 if (cell->event.time.time.tv_sec ||
 284                     cell->event.time.time.tv_nsec)
 285                         return 1;
 286                 break;
 287         }
 288         return 0;
 289 }
 290
 291 /* remove cells for left client */
 292 void snd_seq_prioq_leave(struct snd_seq_prioq * f, int client, int timestamp)
 293 {
 294         register struct snd_seq_event_cell *cell, *next;
 295         unsigned long flags;
 296         struct snd_seq_event_cell *prev = NULL;
 297         struct snd_seq_event_cell *freefirst = NULL, *freeprev = NULL, *freenext;
 298
 299         /* collect all removed cells */
 300         spin_lock_irqsave(&f->lock, flags);
 301         cell = f->head;
 302         while (cell) {
 303                 next = cell->next;
 304                 if (prioq_match(cell, client, timestamp)) {
 305                         /* remove cell from prioq */
 306                         if (cell == f->head) {
 307                                 f->head = cell->next;
 308                         } else {
 309                                 prev->next = cell->next;
 310                         }
 311                         if (cell == f->tail)
 312                                 f->tail = cell->next;
 313                         f->cells--;
 314                         /* add cell to free list */
 315                         cell->next = NULL;
 316                         if (freefirst == NULL) {
 317                                 freefirst = cell;
 318                         } else {
 319                                 freeprev->next = cell;
 320                         }
 321                         freeprev = cell;
 322                 } else {
 323 #if 0
 324                         printk(KERN_DEBUG "type = %i, source = %i, dest = %i, "
 325                                "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