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 | |