1/*
2Copyright (c) 2012, Broadcom Europe Ltd
3All rights reserved.
4
5Redistribution and use in source and binary forms, with or without
6modification, are permitted provided that the following conditions are met:
7 * Redistributions of source code must retain the above copyright
8 notice, this list of conditions and the following disclaimer.
9 * Redistributions in binary form must reproduce the above copyright
10 notice, this list of conditions and the following disclaimer in the
11 documentation and/or other materials provided with the distribution.
12 * Neither the name of the copyright holder nor the
13 names of its contributors may be used to endorse or promote products
14 derived from this software without specific prior written permission.
15
16THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
17ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
20DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26*/
27
28/*=============================================================================
29VideoCore OS Abstraction Layer - mutex public header file
30=============================================================================*/
31
32#ifndef VCOS_MUTEX_H
33#define VCOS_MUTEX_H
34
35#ifdef __cplusplus
36extern "C" {
37#endif
38
39#include "interface/vcos/vcos_types.h"
40#include "vcos.h"
41
42/**
43 * \file vcos_mutex.h
44 *
45 * Mutex API. Mutexes are not re-entrant, as supporting this adds extra code
46 * that slows down clients which have been written sensibly.
47 *
48 * \sa vcos_reentrant_mutex.h
49 *
50 */
51
52/** Create a mutex.
53 *
54 * @param m Filled in with mutex on return
55 * @param name A non-null name for the mutex, used for diagnostics.
56 *
57 * @return VCOS_SUCCESS if mutex was created, or error code.
58 */
59VCOS_INLINE_DECL
60VCOS_STATUS_T vcos_mutex_create(VCOS_MUTEX_T *m, const char *name);
61
62/** Delete the mutex.
63 */
64VCOS_INLINE_DECL
65void vcos_mutex_delete(VCOS_MUTEX_T *m);
66
67/**
68 * \brief Wait to claim the mutex.
69 *
70 * On most platforms this always returns VCOS_SUCCESS, and so would ideally be
71 * a void function, however some platforms allow a wait to be interrupted so
72 * it remains non-void.
73 *
74 * Try to obtain the mutex.
75 * @param m Mutex to wait on
76 * @return VCOS_SUCCESS - mutex was taken.
77 * VCOS_EAGAIN - could not take mutex.
78 */
79#ifndef vcos_mutex_lock
80VCOS_INLINE_DECL
81VCOS_STATUS_T vcos_mutex_lock(VCOS_MUTEX_T *m);
82
83/** Release the mutex.
84 */
85VCOS_INLINE_DECL
86void vcos_mutex_unlock(VCOS_MUTEX_T *m);
87#endif
88
89/** Test if the mutex is already locked.
90 *
91 * @return 1 if mutex is locked, 0 if it is unlocked.
92 */
93VCOS_INLINE_DECL
94int vcos_mutex_is_locked(VCOS_MUTEX_T *m);
95
96/** Obtain the mutex if possible.
97 *
98 * @param m the mutex to try to obtain
99 *
100 * @return VCOS_SUCCESS if mutex is successfully obtained, or VCOS_EAGAIN
101 * if it is already in use by another thread.
102 */
103#ifndef vcos_mutex_trylock
104VCOS_INLINE_DECL
105VCOS_STATUS_T vcos_mutex_trylock(VCOS_MUTEX_T *m);
106#endif
107
108
109#ifdef __cplusplus
110}
111#endif
112#endif
113