LXR linux/sound/core/seq/seq

   1/*
   2 *   ALSA sequencer FIFO
   3 *   Copyright (c) 1998 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#ifndef __SND_SEQ_FIFO_H
  22#define __SND_SEQ_FIFO_H
  23
  24#include "seq_memory.h"
  25#include "seq_lock.h"
  26
  27
  28/* === FIFO === */
  29
  30struct snd_seq_fifo {
  31        struct snd_seq_pool *pool;              /* FIFO pool */
  32        struct snd_seq_event_cell *head;        /* pointer to head of fifo */
  33        struct snd_seq_event_cell *tail;        /* pointer to tail of fifo */
  34        int cells;
  35        spinlock_t lock;
  36        snd_use_lock_t use_lock;
  37        wait_queue_head_t input_sleep;
  38        atomic_t overflow;
  39
  40};
  41
  42/* create new fifo (constructor) */
  43struct snd_seq_fifo *snd_seq_fifo_new(int poolsize);
  44
  45/* delete fifo (destructor) */
  46void snd_seq_fifo_delete(struct snd_seq_fifo **f);
  47
  48
  49/* enqueue event to fifo */
  50int snd_seq_fifo_event_in(struct snd_seq_fifo *f, struct snd_seq_event *event);
  51
  52/* lock fifo from release */
  53#define snd_seq_fifo_lock(fifo)         snd_use_lock_use(&(fifo)->use_lock)
  54#define snd_seq_fifo_unlock(fifo)       snd_use_lock_free(&(fifo)->use_lock)
  55
  56/* get a cell from fifo - fifo should be locked */
  57int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, struct snd_seq_event_cell **cellp, int nonblock);
  58
  59/* free dequeued cell - fifo should be locked */
  60void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, struct snd_seq_event_cell *cell);
  61
  62/* clean up queue */
  63void snd_seq_fifo_clear(struct snd_seq_fifo *f);
  64
  65/* polling */
  66int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, poll_table *wait);
  67
  68/* resize pool in fifo */
  69int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize);
  70
  71
  72#endif
  73