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 QUEUE_H
17 #define QUEUE_H
18 
19 #include <atomic>
20 
21 #include "protocol/retcode_inner/aie_retcode_inner.h"
22 #include "utils/aie_macros.h"
23 
24 namespace OHOS {
25 namespace AI {
26 template<class TYPE>
27 class Queue {
28     FORBID_COPY_AND_ASSIGN(Queue);
29 public:
30     explicit Queue(size_t maxQueueSize);
31 
32     virtual ~Queue();
33 
34 public:
35     /**
36      * Check if the queue is empty.
37      *
38      * @return true if empty or false if not empty.
39      */
40     bool IsEmpty() const;
41 
42     /**
43      * Check if the queue is full.
44      *
45      * @return true if full or false if not full.
46      */
47     bool IsFull() const;
48 
49     /**
50      * Push a message at the rear.
51      *
52      * @param [in] msgBlock message to push.
53      * @return 1011 if the queue is full or 0 if success.
54      */
55     int PushBack(TYPE &msgBlock);
56 
57     /**
58      * Pop a message from the head.
59      *
60      * @param [out] msgBlock message from the head.
61      * @return 1012 if the queue is empty or 0 if success.
62      */
63     int PopFront(TYPE &msgBlock);
64 
65     /**
66      * Query the number of elements in the queue.
67      *
68      * @return the number of elements in the queue.
69      */
70     size_t Count() const;
71 
72     /**
73      * Reset the queue.
74      */
75     void Reset();
76 
77 private:
78     /**
79      * Next position to push elements to.
80      */
81     std::atomic<size_t> pushPos_;
82 
83     /**
84      * Next position to pop message from.
85      */
86     std::atomic<size_t> popPos_;
87 
88     /**
89      * Maximum message of the queue.
90      */
91     size_t totalNum_;
92 
93     /**
94      * Writable message number.
95      */
96     std::atomic<size_t> writeAbleCount_;
97 
98     /**
99      * Readable message number.
100      */
101     std::atomic<size_t> readAbleCount_;
102 
103     struct QueueNode {
104         bool empty = true;
105         TYPE node;
106     };
107 
108     QueueNode *queue_;
109 };
110 } // namespace AI
111 } // namespace OHOS
112 
113 #include "platform/queuepool/queue.inl"
114 
115 #endif // QUEUE_H