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 - named semaphores
30=============================================================================*/
31
32#ifndef VCOS_GENERIC_NAMED_SEM_H
33#define VCOS_GENERIC_NAMED_SEM_H
34
35#ifdef __cplusplus
36extern "C" {
37#endif
38
39#include "interface/vcos/vcos_types.h"
40
41/**
42 * \file
43 *
44 * Generic support for named semaphores, using regular ones. This is only
45 * suitable for emulating them on an embedded MMUless system, since there is
46 * no support for opening semaphores across process boundaries.
47 *
48 */
49
50#define VCOS_NAMED_SEMAPHORE_NAMELEN 64
51
52/* In theory we could use the name facility provided within Nucleus. However, this
53 * is hard to do as semaphores are constantly being created and destroyed; we
54 * would need to stop everything while allocating the memory for the semaphore
55 * list and then walking it. So keep our own list.
56 */
57typedef struct VCOS_NAMED_SEMAPHORE_T
58{
59 struct VCOS_NAMED_SEMAPHORE_IMPL_T *actual; /**< There are 'n' named semaphores per 1 actual semaphore */
60 VCOS_SEMAPHORE_T *sem; /**< Pointer to actual underlying semaphore */
61} VCOS_NAMED_SEMAPHORE_T;
62
63VCOSPRE_ VCOS_STATUS_T VCOSPOST_
64vcos_generic_named_semaphore_create(VCOS_NAMED_SEMAPHORE_T *sem, const char *name, VCOS_UNSIGNED count);
65
66VCOSPRE_ void VCOSPOST_ vcos_named_semaphore_delete(VCOS_NAMED_SEMAPHORE_T *sem);
67
68VCOSPRE_ VCOS_STATUS_T VCOSPOST_ _vcos_named_semaphore_init(void);
69VCOSPRE_ void VCOSPOST_ _vcos_named_semaphore_deinit(void);
70
71#if defined(VCOS_INLINE_BODIES)
72
73VCOS_INLINE_IMPL
74VCOS_STATUS_T vcos_named_semaphore_create(VCOS_NAMED_SEMAPHORE_T *sem, const char *name, VCOS_UNSIGNED count) {
75 return vcos_generic_named_semaphore_create(sem, name, count);
76}
77
78VCOS_INLINE_IMPL
79void vcos_named_semaphore_wait(VCOS_NAMED_SEMAPHORE_T *sem) {
80 vcos_semaphore_wait(sem->sem);
81}
82
83VCOS_INLINE_IMPL
84VCOS_STATUS_T vcos_named_semaphore_trywait(VCOS_NAMED_SEMAPHORE_T *sem) {
85 return vcos_semaphore_trywait(sem->sem);
86}
87
88VCOS_INLINE_IMPL
89void vcos_named_semaphore_post(VCOS_NAMED_SEMAPHORE_T *sem) {
90 vcos_semaphore_post(sem->sem);
91}
92
93
94#endif
95
96#ifdef __cplusplus
97}
98#endif
99#endif
100
101
102