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platform/CircularBuffer.h@172:65be27845400, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 20:53:29 2019 +0000
Revision:
172:65be27845400
Parent:
171:3a7713b1edbc 
mbed library release version 165

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 172:65be27845400 3 * SPDX-License-Identifier: Apache-2.0
AnnaBridge 156:ff21514d8981 4 *
AnnaBridge 156:ff21514d8981 5 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 156:ff21514d8981 6 * you may not use this file except in compliance with the License.
AnnaBridge 156:ff21514d8981 7 * You may obtain a copy of the License at
AnnaBridge 156:ff21514d8981 8 *
AnnaBridge 156:ff21514d8981 9 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 156:ff21514d8981 10 *
AnnaBridge 156:ff21514d8981 11 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 156:ff21514d8981 12 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 156:ff21514d8981 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 156:ff21514d8981 14 * See the License for the specific language governing permissions and
AnnaBridge 156:ff21514d8981 15 * limitations under the License.
AnnaBridge 156:ff21514d8981 16 */
AnnaBridge 156:ff21514d8981 17 #ifndef MBED_CIRCULARBUFFER_H
AnnaBridge 156:ff21514d8981 18 #define MBED_CIRCULARBUFFER_H
AnnaBridge 156:ff21514d8981 19
AnnaBridge 156:ff21514d8981 20 #include "platform/mbed_critical.h"
AnnaBridge 165:d1b4690b3f8b 21 #include "platform/mbed_assert.h"
AnnaBridge 156:ff21514d8981 22
AnnaBridge 156:ff21514d8981 23 namespace mbed {
AnnaBridge 165:d1b4690b3f8b 24
AnnaBridge 165:d1b4690b3f8b 25 namespace internal {
AnnaBridge 165:d1b4690b3f8b 26 /* Detect if CounterType of the Circular buffer is of unsigned type. */
AnnaBridge 165:d1b4690b3f8b 27 template<typename T>
AnnaBridge 170:e95d10626187 28 struct is_unsigned {
AnnaBridge 170:e95d10626187 29 static const bool value = false;
AnnaBridge 170:e95d10626187 30 };
AnnaBridge 165:d1b4690b3f8b 31 template<>
AnnaBridge 170:e95d10626187 32 struct is_unsigned<unsigned char> {
AnnaBridge 170:e95d10626187 33 static const bool value = true;
AnnaBridge 170:e95d10626187 34 };
AnnaBridge 165:d1b4690b3f8b 35 template<>
AnnaBridge 170:e95d10626187 36 struct is_unsigned<unsigned short> {
AnnaBridge 170:e95d10626187 37 static const bool value = true;
AnnaBridge 170:e95d10626187 38 };
AnnaBridge 165:d1b4690b3f8b 39 template<>
AnnaBridge 170:e95d10626187 40 struct is_unsigned<unsigned int> {
AnnaBridge 170:e95d10626187 41 static const bool value = true;
AnnaBridge 170:e95d10626187 42 };
AnnaBridge 165:d1b4690b3f8b 43 template<>
AnnaBridge 170:e95d10626187 44 struct is_unsigned<unsigned long> {
AnnaBridge 170:e95d10626187 45 static const bool value = true;
AnnaBridge 170:e95d10626187 46 };
AnnaBridge 165:d1b4690b3f8b 47 template<>
AnnaBridge 170:e95d10626187 48 struct is_unsigned<unsigned long long> {
AnnaBridge 170:e95d10626187 49 static const bool value = true;
AnnaBridge 170:e95d10626187 50 };
AnnaBridge 165:d1b4690b3f8b 51 };
AnnaBridge 165:d1b4690b3f8b 52
AnnaBridge 156:ff21514d8981 53 /** \addtogroup platform */
AnnaBridge 158:1c57384330a6 54 /** @{*/
AnnaBridge 158:1c57384330a6 55 /**
AnnaBridge 158:1c57384330a6 56 * \defgroup platform_CircularBuffer CircularBuffer functions
AnnaBridge 158:1c57384330a6 57 * @{
AnnaBridge 158:1c57384330a6 58 */
AnnaBridge 156:ff21514d8981 59
AnnaBridge 156:ff21514d8981 60 /** Templated Circular buffer class
AnnaBridge 156:ff21514d8981 61 *
AnnaBridge 156:ff21514d8981 62 * @note Synchronization level: Interrupt safe
AnnaBridge 165:d1b4690b3f8b 63 * @note CounterType must be unsigned and consistent with BufferSize
AnnaBridge 156:ff21514d8981 64 */
AnnaBridge 156:ff21514d8981 65 template<typename T, uint32_t BufferSize, typename CounterType = uint32_t>
AnnaBridge 156:ff21514d8981 66 class CircularBuffer {
AnnaBridge 156:ff21514d8981 67 public:
AnnaBridge 170:e95d10626187 68 CircularBuffer() : _head(0), _tail(0), _full(false)
AnnaBridge 170:e95d10626187 69 {
AnnaBridge 165:d1b4690b3f8b 70 MBED_STATIC_ASSERT(
AnnaBridge 165:d1b4690b3f8b 71 internal::is_unsigned<CounterType>::value,
AnnaBridge 165:d1b4690b3f8b 72 "CounterType must be unsigned"
AnnaBridge 165:d1b4690b3f8b 73 );
AnnaBridge 165:d1b4690b3f8b 74
AnnaBridge 165:d1b4690b3f8b 75 MBED_STATIC_ASSERT(
AnnaBridge 165:d1b4690b3f8b 76 (sizeof(CounterType) >= sizeof(uint32_t)) ||
AnnaBridge 165:d1b4690b3f8b 77 (BufferSize < (((uint64_t) 1) << (sizeof(CounterType) * 8))),
AnnaBridge 165:d1b4690b3f8b 78 "Invalid BufferSize for the CounterType"
AnnaBridge 165:d1b4690b3f8b 79 );
AnnaBridge 156:ff21514d8981 80 }
AnnaBridge 156:ff21514d8981 81
AnnaBridge 170:e95d10626187 82 ~CircularBuffer()
AnnaBridge 170:e95d10626187 83 {
AnnaBridge 156:ff21514d8981 84 }
AnnaBridge 156:ff21514d8981 85
AnnaBridge 156:ff21514d8981 86 /** Push the transaction to the buffer. This overwrites the buffer if it's
AnnaBridge 156:ff21514d8981 87 * full
AnnaBridge 156:ff21514d8981 88 *
AnnaBridge 156:ff21514d8981 89 * @param data Data to be pushed to the buffer
AnnaBridge 156:ff21514d8981 90 */
AnnaBridge 170:e95d10626187 91 void push(const T &data)
AnnaBridge 170:e95d10626187 92 {
AnnaBridge 156:ff21514d8981 93 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 94 if (full()) {
AnnaBridge 156:ff21514d8981 95 _tail++;
AnnaBridge 171:3a7713b1edbc 96 if (_tail == BufferSize) {
AnnaBridge 171:3a7713b1edbc 97 _tail = 0;
AnnaBridge 171:3a7713b1edbc 98 }
AnnaBridge 156:ff21514d8981 99 }
AnnaBridge 156:ff21514d8981 100 _pool[_head++] = data;
AnnaBridge 171:3a7713b1edbc 101 if (_head == BufferSize) {
AnnaBridge 172:65be27845400 102 _head = 0;
AnnaBridge 171:3a7713b1edbc 103 }
AnnaBridge 156:ff21514d8981 104 if (_head == _tail) {
AnnaBridge 156:ff21514d8981 105 _full = true;
AnnaBridge 156:ff21514d8981 106 }
AnnaBridge 156:ff21514d8981 107 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 108 }
AnnaBridge 156:ff21514d8981 109
AnnaBridge 156:ff21514d8981 110 /** Pop the transaction from the buffer
AnnaBridge 156:ff21514d8981 111 *
Anna Bridge 169:a7c7b631e539 112 * @param data Data to be popped from the buffer
AnnaBridge 156:ff21514d8981 113 * @return True if the buffer is not empty and data contains a transaction, false otherwise
AnnaBridge 156:ff21514d8981 114 */
AnnaBridge 170:e95d10626187 115 bool pop(T &data)
AnnaBridge 170:e95d10626187 116 {
AnnaBridge 156:ff21514d8981 117 bool data_popped = false;
AnnaBridge 156:ff21514d8981 118 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 119 if (!empty()) {
AnnaBridge 156:ff21514d8981 120 data = _pool[_tail++];
AnnaBridge 171:3a7713b1edbc 121 if (_tail == BufferSize) {
AnnaBridge 171:3a7713b1edbc 122 _tail = 0;
AnnaBridge 171:3a7713b1edbc 123 }
AnnaBridge 156:ff21514d8981 124 _full = false;
AnnaBridge 156:ff21514d8981 125 data_popped = true;
AnnaBridge 156:ff21514d8981 126 }
AnnaBridge 156:ff21514d8981 127 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 128 return data_popped;
AnnaBridge 156:ff21514d8981 129 }
AnnaBridge 156:ff21514d8981 130
AnnaBridge 156:ff21514d8981 131 /** Check if the buffer is empty
AnnaBridge 156:ff21514d8981 132 *
AnnaBridge 156:ff21514d8981 133 * @return True if the buffer is empty, false if not
AnnaBridge 156:ff21514d8981 134 */
AnnaBridge 170:e95d10626187 135 bool empty() const
AnnaBridge 170:e95d10626187 136 {
AnnaBridge 156:ff21514d8981 137 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 138 bool is_empty = (_head == _tail) && !_full;
AnnaBridge 156:ff21514d8981 139 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 140 return is_empty;
AnnaBridge 156:ff21514d8981 141 }
AnnaBridge 156:ff21514d8981 142
AnnaBridge 156:ff21514d8981 143 /** Check if the buffer is full
AnnaBridge 156:ff21514d8981 144 *
AnnaBridge 156:ff21514d8981 145 * @return True if the buffer is full, false if not
AnnaBridge 156:ff21514d8981 146 */
AnnaBridge 170:e95d10626187 147 bool full() const
AnnaBridge 170:e95d10626187 148 {
AnnaBridge 156:ff21514d8981 149 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 150 bool full = _full;
AnnaBridge 156:ff21514d8981 151 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 152 return full;
AnnaBridge 156:ff21514d8981 153 }
AnnaBridge 156:ff21514d8981 154
AnnaBridge 156:ff21514d8981 155 /** Reset the buffer
AnnaBridge 156:ff21514d8981 156 *
AnnaBridge 156:ff21514d8981 157 */
AnnaBridge 170:e95d10626187 158 void reset()
AnnaBridge 170:e95d10626187 159 {
AnnaBridge 156:ff21514d8981 160 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 161 _head = 0;
AnnaBridge 156:ff21514d8981 162 _tail = 0;
AnnaBridge 156:ff21514d8981 163 _full = false;
AnnaBridge 156:ff21514d8981 164 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 165 }
AnnaBridge 156:ff21514d8981 166
Anna Bridge 160:5571c4ff569f 167 /** Get the number of elements currently stored in the circular_buffer */
AnnaBridge 170:e95d10626187 168 CounterType size() const
AnnaBridge 170:e95d10626187 169 {
Anna Bridge 160:5571c4ff569f 170 core_util_critical_section_enter();
Anna Bridge 160:5571c4ff569f 171 CounterType elements;
Anna Bridge 160:5571c4ff569f 172 if (!_full) {
Anna Bridge 160:5571c4ff569f 173 if (_head < _tail) {
Anna Bridge 160:5571c4ff569f 174 elements = BufferSize + _head - _tail;
Anna Bridge 160:5571c4ff569f 175 } else {
Anna Bridge 160:5571c4ff569f 176 elements = _head - _tail;
Anna Bridge 160:5571c4ff569f 177 }
Anna Bridge 160:5571c4ff569f 178 } else {
Anna Bridge 160:5571c4ff569f 179 elements = BufferSize;
Anna Bridge 160:5571c4ff569f 180 }
Anna Bridge 160:5571c4ff569f 181 core_util_critical_section_exit();
Anna Bridge 160:5571c4ff569f 182 return elements;
Anna Bridge 160:5571c4ff569f 183 }
Anna Bridge 169:a7c7b631e539 184
Anna Bridge 169:a7c7b631e539 185 /** Peek into circular buffer without popping
Anna Bridge 169:a7c7b631e539 186 *
Anna Bridge 169:a7c7b631e539 187 * @param data Data to be peeked from the buffer
Anna Bridge 169:a7c7b631e539 188 * @return True if the buffer is not empty and data contains a transaction, false otherwise
Anna Bridge 169:a7c7b631e539 189 */
AnnaBridge 170:e95d10626187 190 bool peek(T &data) const
AnnaBridge 170:e95d10626187 191 {
Anna Bridge 169:a7c7b631e539 192 bool data_updated = false;
Anna Bridge 169:a7c7b631e539 193 core_util_critical_section_enter();
Anna Bridge 169:a7c7b631e539 194 if (!empty()) {
Anna Bridge 169:a7c7b631e539 195 data = _pool[_tail];
Anna Bridge 169:a7c7b631e539 196 data_updated = true;
Anna Bridge 169:a7c7b631e539 197 }
Anna Bridge 169:a7c7b631e539 198 core_util_critical_section_exit();
Anna Bridge 169:a7c7b631e539 199 return data_updated;
Anna Bridge 169:a7c7b631e539 200 }
AnnaBridge 170:e95d10626187 201
AnnaBridge 156:ff21514d8981 202 private:
AnnaBridge 156:ff21514d8981 203 T _pool[BufferSize];
AnnaBridge 171:3a7713b1edbc 204 CounterType _head;
AnnaBridge 171:3a7713b1edbc 205 CounterType _tail;
AnnaBridge 171:3a7713b1edbc 206 bool _full;
AnnaBridge 156:ff21514d8981 207 };
AnnaBridge 156:ff21514d8981 208
AnnaBridge 158:1c57384330a6 209 /**@}*/
AnnaBridge 158:1c57384330a6 210
AnnaBridge 158:1c57384330a6 211 /**@}*/
AnnaBridge 158:1c57384330a6 212
AnnaBridge 156:ff21514d8981 213 }
AnnaBridge 156:ff21514d8981 214
AnnaBridge 156:ff21514d8981 215 #endif