diff options
Diffstat (limited to 'sound/core/seq/seq_prioq.c')
-rw-r--r-- | sound/core/seq/seq_prioq.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/sound/core/seq/seq_prioq.c b/sound/core/seq/seq_prioq.c new file mode 100644 index 00000000000..a519732ed83 --- /dev/null +++ b/sound/core/seq/seq_prioq.c @@ -0,0 +1,449 @@ +/* + * 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 <sound/driver.h> +#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) */ +prioq_t *snd_seq_prioq_new(void) +{ + prioq_t *f; + + f = kcalloc(1, 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(prioq_t **fifo) +{ + prioq_t *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(snd_seq_event_t * a, snd_seq_event_t * 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(snd_seq_event_t *a, snd_seq_event_t *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(prioq_t * f, snd_seq_event_cell_t * cell) +{ + snd_seq_event_cell_t *cur, *prev; + unsigned long flags; + int count; + int prior; + + snd_assert(f, return -EINVAL); + snd_assert(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 */ +snd_seq_event_cell_t *snd_seq_prioq_cell_out(prioq_t * f) +{ + snd_seq_event_cell_t *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(prioq_t * 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 */ +snd_seq_event_cell_t *snd_seq_prioq_cell_peek(prioq_t * 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(snd_seq_event_cell_t *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(prioq_t * f, int client, int timestamp) +{ + register snd_seq_event_cell_t *cell, *next; + unsigned long flags; + snd_seq_event_cell_t *prev = NULL; + snd_seq_event_cell_t *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("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(snd_seq_remove_events_t *info, + snd_seq_event_t *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(prioq_t * f, int client, + snd_seq_remove_events_t *info) +{ + register snd_seq_event_cell_t *cell, *next; + unsigned long flags; + snd_seq_event_cell_t *prev = NULL; + snd_seq_event_cell_t *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; + } +} + + |