1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * ALSA sequencer FIFO
4 * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
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
15 struct 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) */
28 struct snd_seq_fifo *snd_seq_fifo_new(int poolsize);
29
30 /* delete fifo (destructor) */
31 void snd_seq_fifo_delete(struct snd_seq_fifo **f);
32
33
34 /* enqueue event to fifo */
35 int 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)
40
41 /* get a cell from fifo - fifo should be locked */
42 int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, struct snd_seq_event_cell **cellp, int nonblock);
43
44 /* free dequeued cell - fifo should be locked */
45 void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, struct snd_seq_event_cell *cell);
46
47 /* clean up queue */
48 void snd_seq_fifo_clear(struct snd_seq_fifo *f);
49
50 /* polling */
51 int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, poll_table *wait);
52
53 /* resize pool in fifo */
54 int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize);
55
56 /* get the number of unused cells safely */
57 int snd_seq_fifo_unused_cells(struct snd_seq_fifo *f);
58
59 #endif
60
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