1 /*
2  * Copyright (C) 2021 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef SEMAPHORE_H
17 #define SEMAPHORE_H
18 
19 #include <stdint.h>
20 
21 #ifdef __cplusplus
22 extern "C" {
23 #endif
24 
25 typedef struct Semaphore Semaphore;
26 
27 /**
28  * @brief Perform instantiation of the Semaphore.
29  *
30  * @param val set Semaphore initial val.
31  * @return Semaphore* Succeed return Semaphore pointer, failed return NULL.
32  * @since 6
33  */
34 Semaphore *SemaphoreCreate(uint32_t val);
35 
36 /**
37  * @brief Delete an instantiation of the Semaphore.
38  *
39  * @param sem Semaphore pointer.
40  * @since 6
41  */
42 void SemaphoreDelete(Semaphore *sem);
43 
44 /**
45  * @brief Block reduce Semaphore val by 1.
46  *
47  * @param sem Semaphore pointer.
48  * @since 6
49  */
50 void SemaphoreWait(const Semaphore *sem);
51 
52 /**
53  * @brief NonBlock reduce Semaphore val by 1.
54  *
55  * @param sem Semaphore pointer.
56  * @return Succeed return 0, failed return -1.
57  * @since 6
58  */
59 int32_t SemaphoreTryWait(Semaphore *sem);
60 
61 /**
62  * @brief Block increase Semaphore val by 1.
63  *
64  * @param sem Semaphore pointer.
65  * @since 6
66  */
67 void SemaphorePost(const Semaphore *sem);
68 
69 /**
70  * @brief Try Increase Semaphore val by 1.
71  *
72  * @param sem Semaphore pointer.
73  * @return Succeed return 0, failed return -1.
74  * @since 6
75  */
76 int32_t SemaphoreTryPost(Semaphore *sem);
77 
78 /**
79  * @brief Get Semaphore instantiation fd.
80  *
81  * @param sem Semaphore pointer.
82  * @return Succeed return fd, failed return -1.
83  * @since 6
84  */
85 int32_t SemaphoreGetfd(const Semaphore *sem);
86 
87 #ifdef __cplusplus
88 }
89 #endif
90 
91 #endif  // SEMAPHORE_H