text: /*
   *   ALSA sequencer FIFO
   *   Copyright (c) 1998 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
   *
   */
  #ifndef __SND_SEQ_FIFO_H
  #define __SND_SEQ_FIFO_H
  
  #include "seq_memory.h"
  #include "seq_lock.h"
  
  
  /* === FIFO === */
  
  struct snd_seq_fifo {
  	struct snd_seq_pool *pool;		/* FIFO pool */
  	struct snd_seq_event_cell *head;    	/* pointer to head of fifo */
  	struct snd_seq_event_cell *tail;    	/* pointer to tail of fifo */
  	int cells;
  	spinlock_t lock;
  	snd_use_lock_t use_lock;
  	wait_queue_head_t input_sleep;
  	atomic_t overflow;
  
  };
  
  /* create new fifo (constructor) */
  struct snd_seq_fifo *snd_seq_fifo_new(int poolsize);
  
  /* delete fifo (destructor) */
  void snd_seq_fifo_delete(struct snd_seq_fifo **f);
  
  
  /* enqueue event to fifo */
  int snd_seq_fifo_event_in(struct snd_seq_fifo *f, struct snd_seq_event *event);
  
  /* lock fifo from release */
  #define snd_seq_fifo_lock(fifo)		snd_use_lock_use(&(fifo)->use_lock)
  #define snd_seq_fifo_unlock(fifo)	snd_use_lock_free(&(fifo)->use_lock)
  
  /* get a cell from fifo - fifo should be locked */
  int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, struct snd_seq_event_cell **cellp, int nonblock);
  
  /* free dequeued cell - fifo should be locked */
  void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, struct snd_seq_event_cell *cell);
  
  /* clean up queue */
  void snd_seq_fifo_clear(struct snd_seq_fifo *f);
  
  /* polling */
  int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, poll_table *wait);
  
  /* resize pool in fifo */
  int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize);
  
  
  #endif
  