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The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.

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mbed 2

This is the mbed 2 library. If you'd like to learn about Mbed OS please see the mbed-os docs.

platform/CircularBuffer.h@160:5571c4ff569f, 2018-01-17 (annotated)

Committer:
Anna Bridge
Date:
Wed Jan 17 16:13:02 2018 +0000
Revision:
160:5571c4ff569f
Parent:
158:1c57384330a6
Child:
165:d1b4690b3f8b
mbed library. Release version 158

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 156:ff21514d8981 1 /* mbed Microcontroller Library
AnnaBridge 156:ff21514d8981 2 * Copyright (c) 2015 ARM Limited
AnnaBridge 156:ff21514d8981 3 *
AnnaBridge 156:ff21514d8981 4 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 156:ff21514d8981 5 * you may not use this file except in compliance with the License.
AnnaBridge 156:ff21514d8981 6 * You may obtain a copy of the License at
AnnaBridge 156:ff21514d8981 7 *
AnnaBridge 156:ff21514d8981 8 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 156:ff21514d8981 9 *
AnnaBridge 156:ff21514d8981 10 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 156:ff21514d8981 11 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 156:ff21514d8981 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 156:ff21514d8981 13 * See the License for the specific language governing permissions and
AnnaBridge 156:ff21514d8981 14 * limitations under the License.
AnnaBridge 156:ff21514d8981 15 */
AnnaBridge 156:ff21514d8981 16 #ifndef MBED_CIRCULARBUFFER_H
AnnaBridge 156:ff21514d8981 17 #define MBED_CIRCULARBUFFER_H
AnnaBridge 156:ff21514d8981 18
AnnaBridge 156:ff21514d8981 19 #include "platform/mbed_critical.h"
AnnaBridge 156:ff21514d8981 20
AnnaBridge 156:ff21514d8981 21 namespace mbed {
AnnaBridge 156:ff21514d8981 22 /** \addtogroup platform */
AnnaBridge 158:1c57384330a6 23 /** @{*/
AnnaBridge 158:1c57384330a6 24 /**
AnnaBridge 158:1c57384330a6 25 * \defgroup platform_CircularBuffer CircularBuffer functions
AnnaBridge 158:1c57384330a6 26 * @{
AnnaBridge 158:1c57384330a6 27 */
AnnaBridge 156:ff21514d8981 28
AnnaBridge 156:ff21514d8981 29 /** Templated Circular buffer class
AnnaBridge 156:ff21514d8981 30 *
AnnaBridge 156:ff21514d8981 31 * @note Synchronization level: Interrupt safe
AnnaBridge 156:ff21514d8981 32 */
AnnaBridge 156:ff21514d8981 33 template<typename T, uint32_t BufferSize, typename CounterType = uint32_t>
AnnaBridge 156:ff21514d8981 34 class CircularBuffer {
AnnaBridge 156:ff21514d8981 35 public:
AnnaBridge 156:ff21514d8981 36 CircularBuffer() : _head(0), _tail(0), _full(false) {
AnnaBridge 156:ff21514d8981 37 }
AnnaBridge 156:ff21514d8981 38
AnnaBridge 156:ff21514d8981 39 ~CircularBuffer() {
AnnaBridge 156:ff21514d8981 40 }
AnnaBridge 156:ff21514d8981 41
AnnaBridge 156:ff21514d8981 42 /** Push the transaction to the buffer. This overwrites the buffer if it's
AnnaBridge 156:ff21514d8981 43 * full
AnnaBridge 156:ff21514d8981 44 *
AnnaBridge 156:ff21514d8981 45 * @param data Data to be pushed to the buffer
AnnaBridge 156:ff21514d8981 46 */
AnnaBridge 156:ff21514d8981 47 void push(const T& data) {
AnnaBridge 156:ff21514d8981 48 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 49 if (full()) {
AnnaBridge 156:ff21514d8981 50 _tail++;
AnnaBridge 156:ff21514d8981 51 _tail %= BufferSize;
AnnaBridge 156:ff21514d8981 52 }
AnnaBridge 156:ff21514d8981 53 _pool[_head++] = data;
AnnaBridge 156:ff21514d8981 54 _head %= BufferSize;
AnnaBridge 156:ff21514d8981 55 if (_head == _tail) {
AnnaBridge 156:ff21514d8981 56 _full = true;
AnnaBridge 156:ff21514d8981 57 }
AnnaBridge 156:ff21514d8981 58 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 59 }
AnnaBridge 156:ff21514d8981 60
AnnaBridge 156:ff21514d8981 61 /** Pop the transaction from the buffer
AnnaBridge 156:ff21514d8981 62 *
AnnaBridge 156:ff21514d8981 63 * @param data Data to be pushed to the buffer
AnnaBridge 156:ff21514d8981 64 * @return True if the buffer is not empty and data contains a transaction, false otherwise
AnnaBridge 156:ff21514d8981 65 */
AnnaBridge 156:ff21514d8981 66 bool pop(T& data) {
AnnaBridge 156:ff21514d8981 67 bool data_popped = false;
AnnaBridge 156:ff21514d8981 68 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 69 if (!empty()) {
AnnaBridge 156:ff21514d8981 70 data = _pool[_tail++];
AnnaBridge 156:ff21514d8981 71 _tail %= BufferSize;
AnnaBridge 156:ff21514d8981 72 _full = false;
AnnaBridge 156:ff21514d8981 73 data_popped = true;
AnnaBridge 156:ff21514d8981 74 }
AnnaBridge 156:ff21514d8981 75 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 76 return data_popped;
AnnaBridge 156:ff21514d8981 77 }
AnnaBridge 156:ff21514d8981 78
AnnaBridge 156:ff21514d8981 79 /** Check if the buffer is empty
AnnaBridge 156:ff21514d8981 80 *
AnnaBridge 156:ff21514d8981 81 * @return True if the buffer is empty, false if not
AnnaBridge 156:ff21514d8981 82 */
AnnaBridge 156:ff21514d8981 83 bool empty() const {
AnnaBridge 156:ff21514d8981 84 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 85 bool is_empty = (_head == _tail) && !_full;
AnnaBridge 156:ff21514d8981 86 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 87 return is_empty;
AnnaBridge 156:ff21514d8981 88 }
AnnaBridge 156:ff21514d8981 89
AnnaBridge 156:ff21514d8981 90 /** Check if the buffer is full
AnnaBridge 156:ff21514d8981 91 *
AnnaBridge 156:ff21514d8981 92 * @return True if the buffer is full, false if not
AnnaBridge 156:ff21514d8981 93 */
AnnaBridge 156:ff21514d8981 94 bool full() const {
AnnaBridge 156:ff21514d8981 95 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 96 bool full = _full;
AnnaBridge 156:ff21514d8981 97 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 98 return full;
AnnaBridge 156:ff21514d8981 99 }
AnnaBridge 156:ff21514d8981 100
AnnaBridge 156:ff21514d8981 101 /** Reset the buffer
AnnaBridge 156:ff21514d8981 102 *
AnnaBridge 156:ff21514d8981 103 */
AnnaBridge 156:ff21514d8981 104 void reset() {
AnnaBridge 156:ff21514d8981 105 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 106 _head = 0;
AnnaBridge 156:ff21514d8981 107 _tail = 0;
AnnaBridge 156:ff21514d8981 108 _full = false;
AnnaBridge 156:ff21514d8981 109 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 110 }
AnnaBridge 156:ff21514d8981 111
Anna Bridge 160:5571c4ff569f 112 /** Get the number of elements currently stored in the circular_buffer */
Anna Bridge 160:5571c4ff569f 113 CounterType size() const {
Anna Bridge 160:5571c4ff569f 114 core_util_critical_section_enter();
Anna Bridge 160:5571c4ff569f 115 CounterType elements;
Anna Bridge 160:5571c4ff569f 116 if (!_full) {
Anna Bridge 160:5571c4ff569f 117 if (_head < _tail) {
Anna Bridge 160:5571c4ff569f 118 elements = BufferSize + _head - _tail;
Anna Bridge 160:5571c4ff569f 119 } else {
Anna Bridge 160:5571c4ff569f 120 elements = _head - _tail;
Anna Bridge 160:5571c4ff569f 121 }
Anna Bridge 160:5571c4ff569f 122 } else {
Anna Bridge 160:5571c4ff569f 123 elements = BufferSize;
Anna Bridge 160:5571c4ff569f 124 }
Anna Bridge 160:5571c4ff569f 125 core_util_critical_section_exit();
Anna Bridge 160:5571c4ff569f 126 return elements;
Anna Bridge 160:5571c4ff569f 127 }
Anna Bridge 160:5571c4ff569f 128
AnnaBridge 156:ff21514d8981 129 private:
AnnaBridge 156:ff21514d8981 130 T _pool[BufferSize];
AnnaBridge 156:ff21514d8981 131 volatile CounterType _head;
AnnaBridge 156:ff21514d8981 132 volatile CounterType _tail;
AnnaBridge 156:ff21514d8981 133 volatile bool _full;
AnnaBridge 156:ff21514d8981 134 };
AnnaBridge 156:ff21514d8981 135
AnnaBridge 158:1c57384330a6 136 /**@}*/
AnnaBridge 158:1c57384330a6 137
AnnaBridge 158:1c57384330a6 138 /**@}*/
AnnaBridge 158:1c57384330a6 139
AnnaBridge 156:ff21514d8981 140 }
AnnaBridge 156:ff21514d8981 141
AnnaBridge 156:ff21514d8981 142 #endif
AnnaBridge 156:ff21514d8981 143