1#ifndef foomainloophfoo
2#define foomainloophfoo
3
4/***
5 This file is part of PulseAudio.
6
7 Copyright 2004-2006 Lennart Poettering
8 Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
9
10 PulseAudio is free software; you can redistribute it and/or modify
11 it under the terms of the GNU Lesser General Public License as published
12 by the Free Software Foundation; either version 2.1 of the License,
13 or (at your option) any later version.
14
15 PulseAudio is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 General Public License for more details.
19
20 You should have received a copy of the GNU Lesser General Public License
21 along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
22***/
23
24#include <pulse/mainloop-api.h>
25#include <pulse/cdecl.h>
26
27PA_C_DECL_BEGIN
28
29struct pollfd;
30
31/** \page mainloop Main Loop
32 *
33 * \section overv_sec Overview
34 *
35 * The built-in main loop implementation is based on the poll() system call.
36 * It supports the functions defined in the main loop abstraction and very
37 * little else.
38 *
39 * The main loop is created using pa_mainloop_new() and destroyed using
40 * pa_mainloop_free(). To get access to the main loop abstraction,
41 * pa_mainloop_get_api() is used.
42 *
43 * \section iter_sec Iteration
44 *
45 * The main loop is designed around the concept of iterations. Each iteration
46 * consists of three steps that repeat during the application's entire
47 * lifetime:
48 *
49 * -# Prepare - Build a list of file descriptors
50 * that need to be monitored and calculate the next timeout.
51 * -# Poll - Execute the actual poll() system call.
52 * -# Dispatch - Dispatch any events that have fired.
53 *
54 * When using the main loop, the application can either execute each
55 * iteration, one at a time, using pa_mainloop_iterate(), or let the library
56 * iterate automatically using pa_mainloop_run().
57 *
58 * \section thread_sec Threads
59 *
60 * The main loop functions are designed to be thread safe, but the objects
61 * are not. What this means is that multiple main loops can be used, but only
62 * one object per thread.
63 *
64 */
65
66/** \file
67 *
68 * A minimal main loop implementation based on the C library's poll()
69 * function. Using the routines defined herein you may create a simple
70 * main loop supporting the generic main loop abstraction layer as
71 * defined in \ref mainloop-api.h. This implementation is thread safe
72 * as long as you access the main loop object from a single thread only.
73 *
74 * See also \subpage mainloop
75 */
76
77/** An opaque main loop object */
78typedef struct pa_mainloop pa_mainloop;
79
80/** Allocate a new main loop object. Free with pa_mainloop_free. */
81pa_mainloop *pa_mainloop_new(void);
82
83/** Free a main loop object */
84void pa_mainloop_free(pa_mainloop* m);
85
86/** Prepare for a single iteration of the main loop. Returns a negative value
87on error or exit request. timeout specifies a maximum timeout for the subsequent
88poll, or -1 for blocking behaviour. .*/
89int pa_mainloop_prepare(pa_mainloop *m, int timeout);
90
91/** Execute the previously prepared poll. Returns a negative value on error.*/
92int pa_mainloop_poll(pa_mainloop *m);
93
94/** Dispatch timeout, io and deferred events from the previously executed poll. Returns
95a negative value on error. On success returns the number of source dispatched. */
96int pa_mainloop_dispatch(pa_mainloop *m);
97
98/** Return the return value as specified with the main loop's quit() routine. */
99int pa_mainloop_get_retval(pa_mainloop *m);
100
101/** Run a single iteration of the main loop. This is a convenience function
102for pa_mainloop_prepare(), pa_mainloop_poll() and pa_mainloop_dispatch().
103Returns a negative value on error or exit request. If block is nonzero,
104block for events if none are queued. Optionally return the return value as
105specified with the main loop's quit() routine in the integer variable retval points
106to. On success returns the number of sources dispatched in this iteration. */
107int pa_mainloop_iterate(pa_mainloop *m, int block, int *retval);
108
109/** Run unlimited iterations of the main loop object until the main loop's
110quit() routine is called. Returns a negative value on error. Optionally return
111the return value as specified with the main loop's quit() routine in the integer
112variable retval points to. */
113int pa_mainloop_run(pa_mainloop *m, int *retval);
114
115/** Return the abstract main loop abstraction layer vtable for this
116 main loop. No need to free the API as it is owned by the loop
117 and is destroyed when the loop is freed. */
118pa_mainloop_api* pa_mainloop_get_api(pa_mainloop*m);
119
120/** Shutdown the main loop with the specified return value */
121void pa_mainloop_quit(pa_mainloop *m, int retval);
122
123/** Interrupt a running poll (for threaded systems) */
124void pa_mainloop_wakeup(pa_mainloop *m);
125
126/** Generic prototype of a poll() like function */
127typedef int (*pa_poll_func)(struct pollfd *ufds, unsigned long nfds, int timeout, void*userdata);
128
129/** Change the poll() implementation */
130void pa_mainloop_set_poll_func(pa_mainloop *m, pa_poll_func poll_func, void *userdata);
131
132PA_C_DECL_END
133
134#endif
135