mirror of https://gitee.com/openkylin/linux.git
73 lines
2.1 KiB
C
73 lines
2.1 KiB
C
/*
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* ALSA sequencer FIFO
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* Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#ifndef __SND_SEQ_FIFO_H
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#define __SND_SEQ_FIFO_H
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#include "seq_memory.h"
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#include "seq_lock.h"
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/* === FIFO === */
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typedef struct {
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pool_t *pool; /* FIFO pool */
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snd_seq_event_cell_t* head; /* pointer to head of fifo */
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snd_seq_event_cell_t* tail; /* pointer to tail of fifo */
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int cells;
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spinlock_t lock;
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snd_use_lock_t use_lock;
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wait_queue_head_t input_sleep;
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atomic_t overflow;
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} fifo_t;
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/* create new fifo (constructor) */
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extern fifo_t *snd_seq_fifo_new(int poolsize);
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/* delete fifo (destructor) */
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extern void snd_seq_fifo_delete(fifo_t **f);
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/* enqueue event to fifo */
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extern int snd_seq_fifo_event_in(fifo_t *f, snd_seq_event_t *event);
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/* lock fifo from release */
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#define snd_seq_fifo_lock(fifo) snd_use_lock_use(&(fifo)->use_lock)
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#define snd_seq_fifo_unlock(fifo) snd_use_lock_free(&(fifo)->use_lock)
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/* get a cell from fifo - fifo should be locked */
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int snd_seq_fifo_cell_out(fifo_t *f, snd_seq_event_cell_t **cellp, int nonblock);
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/* free dequeued cell - fifo should be locked */
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extern void snd_seq_fifo_cell_putback(fifo_t *f, snd_seq_event_cell_t *cell);
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/* clean up queue */
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extern void snd_seq_fifo_clear(fifo_t *f);
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/* polling */
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extern int snd_seq_fifo_poll_wait(fifo_t *f, struct file *file, poll_table *wait);
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/* resize pool in fifo */
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int snd_seq_fifo_resize(fifo_t *f, int poolsize);
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#endif
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