projects/linux·blob master · refs

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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * ALSA sequencer FIFO
4 * Copyright (c) 1998 by Frank van de Pol <[email protected]>
5 */
6#ifndef __SND_SEQ_FIFO_H
7#define __SND_SEQ_FIFO_H
8
9#include "seq_memory.h"
10#include "seq_lock.h"
11
12
13/* === FIFO === */
14
15struct snd_seq_fifo {
16 struct snd_seq_pool *pool; /* FIFO pool */
17 struct snd_seq_event_cell *head; /* pointer to head of fifo */
18 struct snd_seq_event_cell *tail; /* pointer to tail of fifo */
19 int cells;
20 spinlock_t lock;
21 snd_use_lock_t use_lock;
22 wait_queue_head_t input_sleep;
23 atomic_t overflow;
24
25};
26
27/* create new fifo (constructor) */
28struct snd_seq_fifo *snd_seq_fifo_new(int poolsize);
29
30/* delete fifo (destructor) */
31void snd_seq_fifo_delete(struct snd_seq_fifo **f);
32
33
34/* enqueue event to fifo */
35int snd_seq_fifo_event_in(struct snd_seq_fifo *f, struct snd_seq_event *event);
36
37/* lock fifo from release */
38#define snd_seq_fifo_lock(fifo) snd_use_lock_use(&(fifo)->use_lock)
39#define snd_seq_fifo_unlock(fifo) snd_use_lock_free(&(fifo)->use_lock)
40DEFINE_GUARD(snd_seq_fifo, struct snd_seq_fifo *, snd_seq_fifo_lock(_T), snd_seq_fifo_unlock(_T))
41
42/* get a cell from fifo - fifo should be locked */
43int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, struct snd_seq_event_cell **cellp, int nonblock);
44
45/* free dequeued cell - fifo should be locked */
46void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, struct snd_seq_event_cell *cell);
47
48/* clean up queue */
49void snd_seq_fifo_clear(struct snd_seq_fifo *f);
50
51/* polling */
52int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, poll_table *wait);
53
54/* resize pool in fifo */
55int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize);
56
57/* get the number of unused cells safely */
58int snd_seq_fifo_unused_cells(struct snd_seq_fifo *f);
59
60#endif