Nicolas Borla / Mbed OS BBR_1Ebene

BBR 1 Ebene

mbed-os/platform/CircularBuffer.h@0:fbdae7e6d805, 2018-05-14 (annotated)

Committer:
borlanic
Date:
Mon May 14 11:29:06 2018 +0000
Revision:
0:fbdae7e6d805
BBR

Who changed what in which revision?

UserRevisionLine numberNew contents of line
borlanic 0:fbdae7e6d805 1 /* mbed Microcontroller Library
borlanic 0:fbdae7e6d805 2 * Copyright (c) 2015 ARM Limited
borlanic 0:fbdae7e6d805 3 *
borlanic 0:fbdae7e6d805 4 * Licensed under the Apache License, Version 2.0 (the "License");
borlanic 0:fbdae7e6d805 5 * you may not use this file except in compliance with the License.
borlanic 0:fbdae7e6d805 6 * You may obtain a copy of the License at
borlanic 0:fbdae7e6d805 7 *
borlanic 0:fbdae7e6d805 8 * http://www.apache.org/licenses/LICENSE-2.0
borlanic 0:fbdae7e6d805 9 *
borlanic 0:fbdae7e6d805 10 * Unless required by applicable law or agreed to in writing, software
borlanic 0:fbdae7e6d805 11 * distributed under the License is distributed on an "AS IS" BASIS,
borlanic 0:fbdae7e6d805 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
borlanic 0:fbdae7e6d805 13 * See the License for the specific language governing permissions and
borlanic 0:fbdae7e6d805 14 * limitations under the License.
borlanic 0:fbdae7e6d805 15 */
borlanic 0:fbdae7e6d805 16 #ifndef MBED_CIRCULARBUFFER_H
borlanic 0:fbdae7e6d805 17 #define MBED_CIRCULARBUFFER_H
borlanic 0:fbdae7e6d805 18
borlanic 0:fbdae7e6d805 19 #include "platform/mbed_critical.h"
borlanic 0:fbdae7e6d805 20 #include "platform/mbed_assert.h"
borlanic 0:fbdae7e6d805 21
borlanic 0:fbdae7e6d805 22 namespace mbed {
borlanic 0:fbdae7e6d805 23
borlanic 0:fbdae7e6d805 24 namespace internal {
borlanic 0:fbdae7e6d805 25 /* Detect if CounterType of the Circular buffer is of unsigned type. */
borlanic 0:fbdae7e6d805 26 template<typename T>
borlanic 0:fbdae7e6d805 27 struct is_unsigned { static const bool value = false; };
borlanic 0:fbdae7e6d805 28 template<>
borlanic 0:fbdae7e6d805 29 struct is_unsigned<unsigned char> { static const bool value = true; };
borlanic 0:fbdae7e6d805 30 template<>
borlanic 0:fbdae7e6d805 31 struct is_unsigned<unsigned short> { static const bool value = true; };
borlanic 0:fbdae7e6d805 32 template<>
borlanic 0:fbdae7e6d805 33 struct is_unsigned<unsigned int> { static const bool value = true; };
borlanic 0:fbdae7e6d805 34 template<>
borlanic 0:fbdae7e6d805 35 struct is_unsigned<unsigned long> { static const bool value = true; };
borlanic 0:fbdae7e6d805 36 template<>
borlanic 0:fbdae7e6d805 37 struct is_unsigned<unsigned long long> { static const bool value = true; };
borlanic 0:fbdae7e6d805 38 };
borlanic 0:fbdae7e6d805 39
borlanic 0:fbdae7e6d805 40 /** \addtogroup platform */
borlanic 0:fbdae7e6d805 41 /** @{*/
borlanic 0:fbdae7e6d805 42 /**
borlanic 0:fbdae7e6d805 43 * \defgroup platform_CircularBuffer CircularBuffer functions
borlanic 0:fbdae7e6d805 44 * @{
borlanic 0:fbdae7e6d805 45 */
borlanic 0:fbdae7e6d805 46
borlanic 0:fbdae7e6d805 47 /** Templated Circular buffer class
borlanic 0:fbdae7e6d805 48 *
borlanic 0:fbdae7e6d805 49 * @note Synchronization level: Interrupt safe
borlanic 0:fbdae7e6d805 50 * @note CounterType must be unsigned and consistent with BufferSize
borlanic 0:fbdae7e6d805 51 */
borlanic 0:fbdae7e6d805 52 template<typename T, uint32_t BufferSize, typename CounterType = uint32_t>
borlanic 0:fbdae7e6d805 53 class CircularBuffer {
borlanic 0:fbdae7e6d805 54 public:
borlanic 0:fbdae7e6d805 55 CircularBuffer() : _head(0), _tail(0), _full(false) {
borlanic 0:fbdae7e6d805 56 MBED_STATIC_ASSERT(
borlanic 0:fbdae7e6d805 57 internal::is_unsigned<CounterType>::value,
borlanic 0:fbdae7e6d805 58 "CounterType must be unsigned"
borlanic 0:fbdae7e6d805 59 );
borlanic 0:fbdae7e6d805 60
borlanic 0:fbdae7e6d805 61 MBED_STATIC_ASSERT(
borlanic 0:fbdae7e6d805 62 (sizeof(CounterType) >= sizeof(uint32_t)) ||
borlanic 0:fbdae7e6d805 63 (BufferSize < (((uint64_t) 1) << (sizeof(CounterType) * 8))),
borlanic 0:fbdae7e6d805 64 "Invalid BufferSize for the CounterType"
borlanic 0:fbdae7e6d805 65 );
borlanic 0:fbdae7e6d805 66 }
borlanic 0:fbdae7e6d805 67
borlanic 0:fbdae7e6d805 68 ~CircularBuffer() {
borlanic 0:fbdae7e6d805 69 }
borlanic 0:fbdae7e6d805 70
borlanic 0:fbdae7e6d805 71 /** Push the transaction to the buffer. This overwrites the buffer if it's
borlanic 0:fbdae7e6d805 72 * full
borlanic 0:fbdae7e6d805 73 *
borlanic 0:fbdae7e6d805 74 * @param data Data to be pushed to the buffer
borlanic 0:fbdae7e6d805 75 */
borlanic 0:fbdae7e6d805 76 void push(const T& data) {
borlanic 0:fbdae7e6d805 77 core_util_critical_section_enter();
borlanic 0:fbdae7e6d805 78 if (full()) {
borlanic 0:fbdae7e6d805 79 _tail++;
borlanic 0:fbdae7e6d805 80 _tail %= BufferSize;
borlanic 0:fbdae7e6d805 81 }
borlanic 0:fbdae7e6d805 82 _pool[_head++] = data;
borlanic 0:fbdae7e6d805 83 _head %= BufferSize;
borlanic 0:fbdae7e6d805 84 if (_head == _tail) {
borlanic 0:fbdae7e6d805 85 _full = true;
borlanic 0:fbdae7e6d805 86 }
borlanic 0:fbdae7e6d805 87 core_util_critical_section_exit();
borlanic 0:fbdae7e6d805 88 }
borlanic 0:fbdae7e6d805 89
borlanic 0:fbdae7e6d805 90 /** Pop the transaction from the buffer
borlanic 0:fbdae7e6d805 91 *
borlanic 0:fbdae7e6d805 92 * @param data Data to be popped from the buffer
borlanic 0:fbdae7e6d805 93 * @return True if the buffer is not empty and data contains a transaction, false otherwise
borlanic 0:fbdae7e6d805 94 */
borlanic 0:fbdae7e6d805 95 bool pop(T& data) {
borlanic 0:fbdae7e6d805 96 bool data_popped = false;
borlanic 0:fbdae7e6d805 97 core_util_critical_section_enter();
borlanic 0:fbdae7e6d805 98 if (!empty()) {
borlanic 0:fbdae7e6d805 99 data = _pool[_tail++];
borlanic 0:fbdae7e6d805 100 _tail %= BufferSize;
borlanic 0:fbdae7e6d805 101 _full = false;
borlanic 0:fbdae7e6d805 102 data_popped = true;
borlanic 0:fbdae7e6d805 103 }
borlanic 0:fbdae7e6d805 104 core_util_critical_section_exit();
borlanic 0:fbdae7e6d805 105 return data_popped;
borlanic 0:fbdae7e6d805 106 }
borlanic 0:fbdae7e6d805 107
borlanic 0:fbdae7e6d805 108 /** Check if the buffer is empty
borlanic 0:fbdae7e6d805 109 *
borlanic 0:fbdae7e6d805 110 * @return True if the buffer is empty, false if not
borlanic 0:fbdae7e6d805 111 */
borlanic 0:fbdae7e6d805 112 bool empty() const {
borlanic 0:fbdae7e6d805 113 core_util_critical_section_enter();
borlanic 0:fbdae7e6d805 114 bool is_empty = (_head == _tail) && !_full;
borlanic 0:fbdae7e6d805 115 core_util_critical_section_exit();
borlanic 0:fbdae7e6d805 116 return is_empty;
borlanic 0:fbdae7e6d805 117 }
borlanic 0:fbdae7e6d805 118
borlanic 0:fbdae7e6d805 119 /** Check if the buffer is full
borlanic 0:fbdae7e6d805 120 *
borlanic 0:fbdae7e6d805 121 * @return True if the buffer is full, false if not
borlanic 0:fbdae7e6d805 122 */
borlanic 0:fbdae7e6d805 123 bool full() const {
borlanic 0:fbdae7e6d805 124 core_util_critical_section_enter();
borlanic 0:fbdae7e6d805 125 bool full = _full;
borlanic 0:fbdae7e6d805 126 core_util_critical_section_exit();
borlanic 0:fbdae7e6d805 127 return full;
borlanic 0:fbdae7e6d805 128 }
borlanic 0:fbdae7e6d805 129
borlanic 0:fbdae7e6d805 130 /** Reset the buffer
borlanic 0:fbdae7e6d805 131 *
borlanic 0:fbdae7e6d805 132 */
borlanic 0:fbdae7e6d805 133 void reset() {
borlanic 0:fbdae7e6d805 134 core_util_critical_section_enter();
borlanic 0:fbdae7e6d805 135 _head = 0;
borlanic 0:fbdae7e6d805 136 _tail = 0;
borlanic 0:fbdae7e6d805 137 _full = false;
borlanic 0:fbdae7e6d805 138 core_util_critical_section_exit();
borlanic 0:fbdae7e6d805 139 }
borlanic 0:fbdae7e6d805 140
borlanic 0:fbdae7e6d805 141 /** Get the number of elements currently stored in the circular_buffer */
borlanic 0:fbdae7e6d805 142 CounterType size() const {
borlanic 0:fbdae7e6d805 143 core_util_critical_section_enter();
borlanic 0:fbdae7e6d805 144 CounterType elements;
borlanic 0:fbdae7e6d805 145 if (!_full) {
borlanic 0:fbdae7e6d805 146 if (_head < _tail) {
borlanic 0:fbdae7e6d805 147 elements = BufferSize + _head - _tail;
borlanic 0:fbdae7e6d805 148 } else {
borlanic 0:fbdae7e6d805 149 elements = _head - _tail;
borlanic 0:fbdae7e6d805 150 }
borlanic 0:fbdae7e6d805 151 } else {
borlanic 0:fbdae7e6d805 152 elements = BufferSize;
borlanic 0:fbdae7e6d805 153 }
borlanic 0:fbdae7e6d805 154 core_util_critical_section_exit();
borlanic 0:fbdae7e6d805 155 return elements;
borlanic 0:fbdae7e6d805 156 }
borlanic 0:fbdae7e6d805 157
borlanic 0:fbdae7e6d805 158 /** Peek into circular buffer without popping
borlanic 0:fbdae7e6d805 159 *
borlanic 0:fbdae7e6d805 160 * @param data Data to be peeked from the buffer
borlanic 0:fbdae7e6d805 161 * @return True if the buffer is not empty and data contains a transaction, false otherwise
borlanic 0:fbdae7e6d805 162 */
borlanic 0:fbdae7e6d805 163 bool peek(T& data) const {
borlanic 0:fbdae7e6d805 164 bool data_updated = false;
borlanic 0:fbdae7e6d805 165 core_util_critical_section_enter();
borlanic 0:fbdae7e6d805 166 if (!empty()) {
borlanic 0:fbdae7e6d805 167 data = _pool[_tail];
borlanic 0:fbdae7e6d805 168 data_updated = true;
borlanic 0:fbdae7e6d805 169 }
borlanic 0:fbdae7e6d805 170 core_util_critical_section_exit();
borlanic 0:fbdae7e6d805 171 return data_updated;
borlanic 0:fbdae7e6d805 172 }
borlanic 0:fbdae7e6d805 173
borlanic 0:fbdae7e6d805 174 private:
borlanic 0:fbdae7e6d805 175 T _pool[BufferSize];
borlanic 0:fbdae7e6d805 176 volatile CounterType _head;
borlanic 0:fbdae7e6d805 177 volatile CounterType _tail;
borlanic 0:fbdae7e6d805 178 volatile bool _full;
borlanic 0:fbdae7e6d805 179 };
borlanic 0:fbdae7e6d805 180
borlanic 0:fbdae7e6d805 181 /**@}*/
borlanic 0:fbdae7e6d805 182
borlanic 0:fbdae7e6d805 183 /**@}*/
borlanic 0:fbdae7e6d805 184
borlanic 0:fbdae7e6d805 185 }
borlanic 0:fbdae7e6d805 186
borlanic 0:fbdae7e6d805 187 #endif