1 /*
2  *   ALSA sequencer FIFO
3  *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 #ifndef __SND_SEQ_FIFO_H
22 #define __SND_SEQ_FIFO_H
23 
24 #include "seq_memory.h"
25 #include "seq_lock.h"
26 
27 
28 /* === FIFO === */
29 
30 struct snd_seq_fifo {
31 	struct snd_seq_pool *pool;		/* FIFO pool */
32 	struct snd_seq_event_cell *head;    	/* pointer to head of fifo */
33 	struct snd_seq_event_cell *tail;    	/* pointer to tail of fifo */
34 	int cells;
35 	spinlock_t lock;
36 	snd_use_lock_t use_lock;
37 	wait_queue_head_t input_sleep;
38 	atomic_t overflow;
39 
40 };
41 
42 /* create new fifo (constructor) */
43 struct snd_seq_fifo *snd_seq_fifo_new(int poolsize);
44 
45 /* delete fifo (destructor) */
46 void snd_seq_fifo_delete(struct snd_seq_fifo **f);
47 
48 
49 /* enqueue event to fifo */
50 int snd_seq_fifo_event_in(struct snd_seq_fifo *f, struct snd_seq_event *event);
51 
52 /* lock fifo from release */
53 #define snd_seq_fifo_lock(fifo)		snd_use_lock_use(&(fifo)->use_lock)
54 #define snd_seq_fifo_unlock(fifo)	snd_use_lock_free(&(fifo)->use_lock)
55 
56 /* get a cell from fifo - fifo should be locked */
57 int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, struct snd_seq_event_cell **cellp, int nonblock);
58 
59 /* free dequeued cell - fifo should be locked */
60 void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, struct snd_seq_event_cell *cell);
61 
62 /* clean up queue */
63 void snd_seq_fifo_clear(struct snd_seq_fifo *f);
64 
65 /* polling */
66 int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, poll_table *wait);
67 
68 /* resize pool in fifo */
69 int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize);
70 
71 
72 #endif
73