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mbed 2

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platform/CircularBuffer.h@170:e95d10626187, 2018-09-06 (annotated)

Committer:
AnnaBridge
Date:
Thu Sep 06 13:39:34 2018 +0100
Revision:
170:e95d10626187
Parent:
169:a7c7b631e539
Child:
171:3a7713b1edbc
mbed library. Release version 163

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 165:d1b4690b3f8b 20 #include "platform/mbed_assert.h"
AnnaBridge 156:ff21514d8981 21
AnnaBridge 156:ff21514d8981 22 namespace mbed {
AnnaBridge 165:d1b4690b3f8b 23
AnnaBridge 165:d1b4690b3f8b 24 namespace internal {
AnnaBridge 165:d1b4690b3f8b 25 /* Detect if CounterType of the Circular buffer is of unsigned type. */
AnnaBridge 165:d1b4690b3f8b 26 template<typename T>
AnnaBridge 170:e95d10626187 27 struct is_unsigned {
AnnaBridge 170:e95d10626187 28 static const bool value = false;
AnnaBridge 170:e95d10626187 29 };
AnnaBridge 165:d1b4690b3f8b 30 template<>
AnnaBridge 170:e95d10626187 31 struct is_unsigned<unsigned char> {
AnnaBridge 170:e95d10626187 32 static const bool value = true;
AnnaBridge 170:e95d10626187 33 };
AnnaBridge 165:d1b4690b3f8b 34 template<>
AnnaBridge 170:e95d10626187 35 struct is_unsigned<unsigned short> {
AnnaBridge 170:e95d10626187 36 static const bool value = true;
AnnaBridge 170:e95d10626187 37 };
AnnaBridge 165:d1b4690b3f8b 38 template<>
AnnaBridge 170:e95d10626187 39 struct is_unsigned<unsigned int> {
AnnaBridge 170:e95d10626187 40 static const bool value = true;
AnnaBridge 170:e95d10626187 41 };
AnnaBridge 165:d1b4690b3f8b 42 template<>
AnnaBridge 170:e95d10626187 43 struct is_unsigned<unsigned long> {
AnnaBridge 170:e95d10626187 44 static const bool value = true;
AnnaBridge 170:e95d10626187 45 };
AnnaBridge 165:d1b4690b3f8b 46 template<>
AnnaBridge 170:e95d10626187 47 struct is_unsigned<unsigned long long> {
AnnaBridge 170:e95d10626187 48 static const bool value = true;
AnnaBridge 170:e95d10626187 49 };
AnnaBridge 165:d1b4690b3f8b 50 };
AnnaBridge 165:d1b4690b3f8b 51
AnnaBridge 156:ff21514d8981 52 /** \addtogroup platform */
AnnaBridge 158:1c57384330a6 53 /** @{*/
AnnaBridge 158:1c57384330a6 54 /**
AnnaBridge 158:1c57384330a6 55 * \defgroup platform_CircularBuffer CircularBuffer functions
AnnaBridge 158:1c57384330a6 56 * @{
AnnaBridge 158:1c57384330a6 57 */
AnnaBridge 156:ff21514d8981 58
AnnaBridge 156:ff21514d8981 59 /** Templated Circular buffer class
AnnaBridge 156:ff21514d8981 60 *
AnnaBridge 156:ff21514d8981 61 * @note Synchronization level: Interrupt safe
AnnaBridge 165:d1b4690b3f8b 62 * @note CounterType must be unsigned and consistent with BufferSize
AnnaBridge 156:ff21514d8981 63 */
AnnaBridge 156:ff21514d8981 64 template<typename T, uint32_t BufferSize, typename CounterType = uint32_t>
AnnaBridge 156:ff21514d8981 65 class CircularBuffer {
AnnaBridge 156:ff21514d8981 66 public:
AnnaBridge 170:e95d10626187 67 CircularBuffer() : _head(0), _tail(0), _full(false)
AnnaBridge 170:e95d10626187 68 {
AnnaBridge 165:d1b4690b3f8b 69 MBED_STATIC_ASSERT(
AnnaBridge 165:d1b4690b3f8b 70 internal::is_unsigned<CounterType>::value,
AnnaBridge 165:d1b4690b3f8b 71 "CounterType must be unsigned"
AnnaBridge 165:d1b4690b3f8b 72 );
AnnaBridge 165:d1b4690b3f8b 73
AnnaBridge 165:d1b4690b3f8b 74 MBED_STATIC_ASSERT(
AnnaBridge 165:d1b4690b3f8b 75 (sizeof(CounterType) >= sizeof(uint32_t)) ||
AnnaBridge 165:d1b4690b3f8b 76 (BufferSize < (((uint64_t) 1) << (sizeof(CounterType) * 8))),
AnnaBridge 165:d1b4690b3f8b 77 "Invalid BufferSize for the CounterType"
AnnaBridge 165:d1b4690b3f8b 78 );
AnnaBridge 156:ff21514d8981 79 }
AnnaBridge 156:ff21514d8981 80
AnnaBridge 170:e95d10626187 81 ~CircularBuffer()
AnnaBridge 170:e95d10626187 82 {
AnnaBridge 156:ff21514d8981 83 }
AnnaBridge 156:ff21514d8981 84
AnnaBridge 156:ff21514d8981 85 /** Push the transaction to the buffer. This overwrites the buffer if it's
AnnaBridge 156:ff21514d8981 86 * full
AnnaBridge 156:ff21514d8981 87 *
AnnaBridge 156:ff21514d8981 88 * @param data Data to be pushed to the buffer
AnnaBridge 156:ff21514d8981 89 */
AnnaBridge 170:e95d10626187 90 void push(const T &data)
AnnaBridge 170:e95d10626187 91 {
AnnaBridge 156:ff21514d8981 92 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 93 if (full()) {
AnnaBridge 156:ff21514d8981 94 _tail++;
AnnaBridge 156:ff21514d8981 95 _tail %= BufferSize;
AnnaBridge 156:ff21514d8981 96 }
AnnaBridge 156:ff21514d8981 97 _pool[_head++] = data;
AnnaBridge 156:ff21514d8981 98 _head %= BufferSize;
AnnaBridge 156:ff21514d8981 99 if (_head == _tail) {
AnnaBridge 156:ff21514d8981 100 _full = true;
AnnaBridge 156:ff21514d8981 101 }
AnnaBridge 156:ff21514d8981 102 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 103 }
AnnaBridge 156:ff21514d8981 104
AnnaBridge 156:ff21514d8981 105 /** Pop the transaction from the buffer
AnnaBridge 156:ff21514d8981 106 *
Anna Bridge 169:a7c7b631e539 107 * @param data Data to be popped from the buffer
AnnaBridge 156:ff21514d8981 108 * @return True if the buffer is not empty and data contains a transaction, false otherwise
AnnaBridge 156:ff21514d8981 109 */
AnnaBridge 170:e95d10626187 110 bool pop(T &data)
AnnaBridge 170:e95d10626187 111 {
AnnaBridge 156:ff21514d8981 112 bool data_popped = false;
AnnaBridge 156:ff21514d8981 113 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 114 if (!empty()) {
AnnaBridge 156:ff21514d8981 115 data = _pool[_tail++];
AnnaBridge 156:ff21514d8981 116 _tail %= BufferSize;
AnnaBridge 156:ff21514d8981 117 _full = false;
AnnaBridge 156:ff21514d8981 118 data_popped = true;
AnnaBridge 156:ff21514d8981 119 }
AnnaBridge 156:ff21514d8981 120 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 121 return data_popped;
AnnaBridge 156:ff21514d8981 122 }
AnnaBridge 156:ff21514d8981 123
AnnaBridge 156:ff21514d8981 124 /** Check if the buffer is empty
AnnaBridge 156:ff21514d8981 125 *
AnnaBridge 156:ff21514d8981 126 * @return True if the buffer is empty, false if not
AnnaBridge 156:ff21514d8981 127 */
AnnaBridge 170:e95d10626187 128 bool empty() const
AnnaBridge 170:e95d10626187 129 {
AnnaBridge 156:ff21514d8981 130 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 131 bool is_empty = (_head == _tail) && !_full;
AnnaBridge 156:ff21514d8981 132 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 133 return is_empty;
AnnaBridge 156:ff21514d8981 134 }
AnnaBridge 156:ff21514d8981 135
AnnaBridge 156:ff21514d8981 136 /** Check if the buffer is full
AnnaBridge 156:ff21514d8981 137 *
AnnaBridge 156:ff21514d8981 138 * @return True if the buffer is full, false if not
AnnaBridge 156:ff21514d8981 139 */
AnnaBridge 170:e95d10626187 140 bool full() const
AnnaBridge 170:e95d10626187 141 {
AnnaBridge 156:ff21514d8981 142 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 143 bool full = _full;
AnnaBridge 156:ff21514d8981 144 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 145 return full;
AnnaBridge 156:ff21514d8981 146 }
AnnaBridge 156:ff21514d8981 147
AnnaBridge 156:ff21514d8981 148 /** Reset the buffer
AnnaBridge 156:ff21514d8981 149 *
AnnaBridge 156:ff21514d8981 150 */
AnnaBridge 170:e95d10626187 151 void reset()
AnnaBridge 170:e95d10626187 152 {
AnnaBridge 156:ff21514d8981 153 core_util_critical_section_enter();
AnnaBridge 156:ff21514d8981 154 _head = 0;
AnnaBridge 156:ff21514d8981 155 _tail = 0;
AnnaBridge 156:ff21514d8981 156 _full = false;
AnnaBridge 156:ff21514d8981 157 core_util_critical_section_exit();
AnnaBridge 156:ff21514d8981 158 }
AnnaBridge 156:ff21514d8981 159
Anna Bridge 160:5571c4ff569f 160 /** Get the number of elements currently stored in the circular_buffer */
AnnaBridge 170:e95d10626187 161 CounterType size() const
AnnaBridge 170:e95d10626187 162 {
Anna Bridge 160:5571c4ff569f 163 core_util_critical_section_enter();
Anna Bridge 160:5571c4ff569f 164 CounterType elements;
Anna Bridge 160:5571c4ff569f 165 if (!_full) {
Anna Bridge 160:5571c4ff569f 166 if (_head < _tail) {
Anna Bridge 160:5571c4ff569f 167 elements = BufferSize + _head - _tail;
Anna Bridge 160:5571c4ff569f 168 } else {
Anna Bridge 160:5571c4ff569f 169 elements = _head - _tail;
Anna Bridge 160:5571c4ff569f 170 }
Anna Bridge 160:5571c4ff569f 171 } else {
Anna Bridge 160:5571c4ff569f 172 elements = BufferSize;
Anna Bridge 160:5571c4ff569f 173 }
Anna Bridge 160:5571c4ff569f 174 core_util_critical_section_exit();
Anna Bridge 160:5571c4ff569f 175 return elements;
Anna Bridge 160:5571c4ff569f 176 }
Anna Bridge 169:a7c7b631e539 177
Anna Bridge 169:a7c7b631e539 178 /** Peek into circular buffer without popping
Anna Bridge 169:a7c7b631e539 179 *
Anna Bridge 169:a7c7b631e539 180 * @param data Data to be peeked from the buffer
Anna Bridge 169:a7c7b631e539 181 * @return True if the buffer is not empty and data contains a transaction, false otherwise
Anna Bridge 169:a7c7b631e539 182 */
AnnaBridge 170:e95d10626187 183 bool peek(T &data) const
AnnaBridge 170:e95d10626187 184 {
Anna Bridge 169:a7c7b631e539 185 bool data_updated = false;
Anna Bridge 169:a7c7b631e539 186 core_util_critical_section_enter();
Anna Bridge 169:a7c7b631e539 187 if (!empty()) {
Anna Bridge 169:a7c7b631e539 188 data = _pool[_tail];
Anna Bridge 169:a7c7b631e539 189 data_updated = true;
Anna Bridge 169:a7c7b631e539 190 }
Anna Bridge 169:a7c7b631e539 191 core_util_critical_section_exit();
Anna Bridge 169:a7c7b631e539 192 return data_updated;
Anna Bridge 169:a7c7b631e539 193 }
AnnaBridge 170:e95d10626187 194
AnnaBridge 156:ff21514d8981 195 private:
AnnaBridge 156:ff21514d8981 196 T _pool[BufferSize];
AnnaBridge 156:ff21514d8981 197 volatile CounterType _head;
AnnaBridge 156:ff21514d8981 198 volatile CounterType _tail;
AnnaBridge 156:ff21514d8981 199 volatile bool _full;
AnnaBridge 156:ff21514d8981 200 };
AnnaBridge 156:ff21514d8981 201
AnnaBridge 158:1c57384330a6 202 /**@}*/
AnnaBridge 158:1c57384330a6 203
AnnaBridge 158:1c57384330a6 204 /**@}*/
AnnaBridge 158:1c57384330a6 205
AnnaBridge 156:ff21514d8981 206 }
AnnaBridge 156:ff21514d8981 207
AnnaBridge 156:ff21514d8981 208 #endif