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 - event flags implemented via a semaphore
30=============================================================================*/
31
32#ifndef VCOS_GENERIC_EVENT_FLAGS_H
33#define VCOS_GENERIC_EVENT_FLAGS_H
34
35#ifdef __cplusplus
36extern "C" {
37#endif
38
39#include "interface/vcos/vcos_types.h"
40
41/**
42 * \file
43 *
44 * This provides event flags (as per Nucleus Event Groups) based on a
45 * mutex, a semaphore (per waiting thread) and a timer (per waiting
46 * thread).
47 *
48 * The data structure is a 32 bit unsigned int (the current set of
49 * flags) and a linked list of clients waiting to be 'satisfied'.
50 *
51 * The mutex merely locks access to the data structure. If a client
52 * calls vcos_event_flags_get() and the requested bits are not already
53 * present, it then sleeps on its per-thread semaphore after adding
54 * this semaphore to the queue waiting. It also sets up a timer.
55 *
56 * The per-thread semaphore and timer are actually stored in the
57 * thread context (joinable thread). In future it may become necessary
58 * to support non-VCOS threads by using thread local storage to
59 * create these objects and associate them with the thread.
60 */
61
62struct VCOS_EVENT_WAITER_T;
63
64typedef struct VCOS_EVENT_FLAGS_T
65{
66 VCOS_UNSIGNED events; /**< Events currently set */
67 VCOS_MUTEX_T lock; /**< Serialize access */
68 struct
69 {
70 struct VCOS_EVENT_WAITER_T *head; /**< List of threads waiting */
71 struct VCOS_EVENT_WAITER_T *tail; /**< List of threads waiting */
72 } waiters;
73} VCOS_EVENT_FLAGS_T;
74
75#define VCOS_OR 1
76#define VCOS_AND 2
77#define VCOS_CONSUME 4
78#define VCOS_OR_CONSUME (VCOS_OR | VCOS_CONSUME)
79#define VCOS_AND_CONSUME (VCOS_AND | VCOS_CONSUME)
80#define VCOS_EVENT_FLAG_OP_MASK (VCOS_OR|VCOS_AND)
81
82VCOSPRE_ VCOS_STATUS_T VCOSPOST_ vcos_generic_event_flags_create(VCOS_EVENT_FLAGS_T *flags, const char *name);
83VCOSPRE_ void VCOSPOST_ vcos_generic_event_flags_set(VCOS_EVENT_FLAGS_T *flags,
84 VCOS_UNSIGNED events,
85 VCOS_OPTION op);
86VCOSPRE_ void VCOSPOST_ vcos_generic_event_flags_delete(VCOS_EVENT_FLAGS_T *);
87VCOSPRE_ VCOS_STATUS_T VCOSPOST_ vcos_generic_event_flags_get(VCOS_EVENT_FLAGS_T *flags,
88 VCOS_UNSIGNED requested_events,
89 VCOS_OPTION op,
90 VCOS_UNSIGNED suspend,
91 VCOS_UNSIGNED *retrieved_events);
92
93#ifdef VCOS_INLINE_BODIES
94
95VCOS_INLINE_IMPL
96VCOS_STATUS_T vcos_event_flags_create(VCOS_EVENT_FLAGS_T *flags, const char *name) {
97 return vcos_generic_event_flags_create(flags, name);
98}
99
100VCOS_INLINE_IMPL
101void vcos_event_flags_set(VCOS_EVENT_FLAGS_T *flags,
102 VCOS_UNSIGNED events,
103 VCOS_OPTION op) {
104 vcos_generic_event_flags_set(flags, events, op);
105}
106
107VCOS_INLINE_IMPL
108void vcos_event_flags_delete(VCOS_EVENT_FLAGS_T *f) {
109 vcos_generic_event_flags_delete(f);
110}
111
112VCOS_INLINE_IMPL
113VCOS_STATUS_T vcos_event_flags_get(VCOS_EVENT_FLAGS_T *flags,
114 VCOS_UNSIGNED requested_events,
115 VCOS_OPTION op,
116 VCOS_UNSIGNED suspend,
117 VCOS_UNSIGNED *retrieved_events) {
118 return vcos_generic_event_flags_get(flags, requested_events, op, suspend, retrieved_events);
119}
120
121#endif /* VCOS_INLINE_BODIES */
122
123#ifdef __cplusplus
124}
125#endif
126#endif
127
128