1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
#ifndef foopulseasyncqhfoo
#define foopulseasyncqhfoo
/* $Id$ */
/***
This file is part of PulseAudio.
Copyright 2004-2006 Lennart Poettering
PulseAudio is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
PulseAudio is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with PulseAudio; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.
***/
#include <sys/types.h>
#include <pulse/def.h>
#include <pulsecore/macro.h>
/* A simple, asynchronous, lock-free (if requested also wait-free)
* queue. Not multiple-reader/multiple-writer safe. If that is
* required both sides can be protected by a mutex each. --- Which is
* not a bad thing in most cases, since this queue is intended for
* communication between a normal thread and a single real-time
* thread. Only the real-time side needs to be lock-free/wait-free.
*
* If the queue is full and another entry shall be pushed, or when the
* queue is empty and another entry shall be popped and the "wait"
* argument is non-zero, the queue will block on a UNIX FIFO object --
* that will probably require locking on the kernel side -- which
* however is probably not problematic, because we do it only on
* starvation or overload in which case we have to block anyway. */
typedef struct pa_asyncq pa_asyncq;
pa_asyncq* pa_asyncq_new(unsigned size);
void pa_asyncq_free(pa_asyncq* q, pa_free_cb_t free_cb);
void* pa_asyncq_pop(pa_asyncq *q, pa_bool_t wait);
int pa_asyncq_push(pa_asyncq *q, void *p, pa_bool_t wait);
/* Similar to pa_asyncq_push(), but if the queue is full, postpone it
* locally and delay until pa_asyncq_before_poll_post() */
void pa_asyncq_post(pa_asyncq*l, void *p);
/* For the reading side */
int pa_asyncq_read_fd(pa_asyncq *q);
int pa_asyncq_read_before_poll(pa_asyncq *a);
void pa_asyncq_read_after_poll(pa_asyncq *a);
/* For the writing side */
int pa_asyncq_write_fd(pa_asyncq *q);
void pa_asyncq_write_before_poll(pa_asyncq *a);
void pa_asyncq_write_after_poll(pa_asyncq *a);
#endif
|
