init

Dependencies:   mbed

Committer:
Nathan Yonkee
Date:
Fri Mar 02 07:12:37 2018 -0700
Revision:
9:d58e77ebd769
add mbed-os library

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Nathan Yonkee 9:d58e77ebd769 1 /* mbed Microcontroller Library
Nathan Yonkee 9:d58e77ebd769 2 * Copyright (c) 2015 ARM Limited
Nathan Yonkee 9:d58e77ebd769 3 *
Nathan Yonkee 9:d58e77ebd769 4 * Licensed under the Apache License, Version 2.0 (the "License");
Nathan Yonkee 9:d58e77ebd769 5 * you may not use this file except in compliance with the License.
Nathan Yonkee 9:d58e77ebd769 6 * You may obtain a copy of the License at
Nathan Yonkee 9:d58e77ebd769 7 *
Nathan Yonkee 9:d58e77ebd769 8 * http://www.apache.org/licenses/LICENSE-2.0
Nathan Yonkee 9:d58e77ebd769 9 *
Nathan Yonkee 9:d58e77ebd769 10 * Unless required by applicable law or agreed to in writing, software
Nathan Yonkee 9:d58e77ebd769 11 * distributed under the License is distributed on an "AS IS" BASIS,
Nathan Yonkee 9:d58e77ebd769 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
Nathan Yonkee 9:d58e77ebd769 13 * See the License for the specific language governing permissions and
Nathan Yonkee 9:d58e77ebd769 14 * limitations under the License.
Nathan Yonkee 9:d58e77ebd769 15 */
Nathan Yonkee 9:d58e77ebd769 16 #ifndef MBED_CIRCULARBUFFER_H
Nathan Yonkee 9:d58e77ebd769 17 #define MBED_CIRCULARBUFFER_H
Nathan Yonkee 9:d58e77ebd769 18
Nathan Yonkee 9:d58e77ebd769 19 #include "platform/mbed_critical.h"
Nathan Yonkee 9:d58e77ebd769 20 #include "platform/mbed_assert.h"
Nathan Yonkee 9:d58e77ebd769 21
Nathan Yonkee 9:d58e77ebd769 22 namespace mbed {
Nathan Yonkee 9:d58e77ebd769 23
Nathan Yonkee 9:d58e77ebd769 24 namespace internal {
Nathan Yonkee 9:d58e77ebd769 25 /* Detect if CounterType of the Circular buffer is of unsigned type. */
Nathan Yonkee 9:d58e77ebd769 26 template<typename T>
Nathan Yonkee 9:d58e77ebd769 27 struct is_unsigned { static const bool value = false; };
Nathan Yonkee 9:d58e77ebd769 28 template<>
Nathan Yonkee 9:d58e77ebd769 29 struct is_unsigned<unsigned char> { static const bool value = true; };
Nathan Yonkee 9:d58e77ebd769 30 template<>
Nathan Yonkee 9:d58e77ebd769 31 struct is_unsigned<unsigned short> { static const bool value = true; };
Nathan Yonkee 9:d58e77ebd769 32 template<>
Nathan Yonkee 9:d58e77ebd769 33 struct is_unsigned<unsigned int> { static const bool value = true; };
Nathan Yonkee 9:d58e77ebd769 34 template<>
Nathan Yonkee 9:d58e77ebd769 35 struct is_unsigned<unsigned long> { static const bool value = true; };
Nathan Yonkee 9:d58e77ebd769 36 template<>
Nathan Yonkee 9:d58e77ebd769 37 struct is_unsigned<unsigned long long> { static const bool value = true; };
Nathan Yonkee 9:d58e77ebd769 38 };
Nathan Yonkee 9:d58e77ebd769 39
Nathan Yonkee 9:d58e77ebd769 40 /** \addtogroup platform */
Nathan Yonkee 9:d58e77ebd769 41 /** @{*/
Nathan Yonkee 9:d58e77ebd769 42 /**
Nathan Yonkee 9:d58e77ebd769 43 * \defgroup platform_CircularBuffer CircularBuffer functions
Nathan Yonkee 9:d58e77ebd769 44 * @{
Nathan Yonkee 9:d58e77ebd769 45 */
Nathan Yonkee 9:d58e77ebd769 46
Nathan Yonkee 9:d58e77ebd769 47 /** Templated Circular buffer class
Nathan Yonkee 9:d58e77ebd769 48 *
Nathan Yonkee 9:d58e77ebd769 49 * @note Synchronization level: Interrupt safe
Nathan Yonkee 9:d58e77ebd769 50 * @note CounterType must be unsigned and consistent with BufferSize
Nathan Yonkee 9:d58e77ebd769 51 */
Nathan Yonkee 9:d58e77ebd769 52 template<typename T, uint32_t BufferSize, typename CounterType = uint32_t>
Nathan Yonkee 9:d58e77ebd769 53 class CircularBuffer {
Nathan Yonkee 9:d58e77ebd769 54 public:
Nathan Yonkee 9:d58e77ebd769 55 CircularBuffer() : _head(0), _tail(0), _full(false) {
Nathan Yonkee 9:d58e77ebd769 56 MBED_STATIC_ASSERT(
Nathan Yonkee 9:d58e77ebd769 57 internal::is_unsigned<CounterType>::value,
Nathan Yonkee 9:d58e77ebd769 58 "CounterType must be unsigned"
Nathan Yonkee 9:d58e77ebd769 59 );
Nathan Yonkee 9:d58e77ebd769 60
Nathan Yonkee 9:d58e77ebd769 61 MBED_STATIC_ASSERT(
Nathan Yonkee 9:d58e77ebd769 62 (sizeof(CounterType) >= sizeof(uint32_t)) ||
Nathan Yonkee 9:d58e77ebd769 63 (BufferSize < (((uint64_t) 1) << (sizeof(CounterType) * 8))),
Nathan Yonkee 9:d58e77ebd769 64 "Invalid BufferSize for the CounterType"
Nathan Yonkee 9:d58e77ebd769 65 );
Nathan Yonkee 9:d58e77ebd769 66 }
Nathan Yonkee 9:d58e77ebd769 67
Nathan Yonkee 9:d58e77ebd769 68 ~CircularBuffer() {
Nathan Yonkee 9:d58e77ebd769 69 }
Nathan Yonkee 9:d58e77ebd769 70
Nathan Yonkee 9:d58e77ebd769 71 /** Push the transaction to the buffer. This overwrites the buffer if it's
Nathan Yonkee 9:d58e77ebd769 72 * full
Nathan Yonkee 9:d58e77ebd769 73 *
Nathan Yonkee 9:d58e77ebd769 74 * @param data Data to be pushed to the buffer
Nathan Yonkee 9:d58e77ebd769 75 */
Nathan Yonkee 9:d58e77ebd769 76 void push(const T& data) {
Nathan Yonkee 9:d58e77ebd769 77 core_util_critical_section_enter();
Nathan Yonkee 9:d58e77ebd769 78 if (full()) {
Nathan Yonkee 9:d58e77ebd769 79 _tail++;
Nathan Yonkee 9:d58e77ebd769 80 _tail %= BufferSize;
Nathan Yonkee 9:d58e77ebd769 81 }
Nathan Yonkee 9:d58e77ebd769 82 _pool[_head++] = data;
Nathan Yonkee 9:d58e77ebd769 83 _head %= BufferSize;
Nathan Yonkee 9:d58e77ebd769 84 if (_head == _tail) {
Nathan Yonkee 9:d58e77ebd769 85 _full = true;
Nathan Yonkee 9:d58e77ebd769 86 }
Nathan Yonkee 9:d58e77ebd769 87 core_util_critical_section_exit();
Nathan Yonkee 9:d58e77ebd769 88 }
Nathan Yonkee 9:d58e77ebd769 89
Nathan Yonkee 9:d58e77ebd769 90 /** Pop the transaction from the buffer
Nathan Yonkee 9:d58e77ebd769 91 *
Nathan Yonkee 9:d58e77ebd769 92 * @param data Data to be pushed to the buffer
Nathan Yonkee 9:d58e77ebd769 93 * @return True if the buffer is not empty and data contains a transaction, false otherwise
Nathan Yonkee 9:d58e77ebd769 94 */
Nathan Yonkee 9:d58e77ebd769 95 bool pop(T& data) {
Nathan Yonkee 9:d58e77ebd769 96 bool data_popped = false;
Nathan Yonkee 9:d58e77ebd769 97 core_util_critical_section_enter();
Nathan Yonkee 9:d58e77ebd769 98 if (!empty()) {
Nathan Yonkee 9:d58e77ebd769 99 data = _pool[_tail++];
Nathan Yonkee 9:d58e77ebd769 100 _tail %= BufferSize;
Nathan Yonkee 9:d58e77ebd769 101 _full = false;
Nathan Yonkee 9:d58e77ebd769 102 data_popped = true;
Nathan Yonkee 9:d58e77ebd769 103 }
Nathan Yonkee 9:d58e77ebd769 104 core_util_critical_section_exit();
Nathan Yonkee 9:d58e77ebd769 105 return data_popped;
Nathan Yonkee 9:d58e77ebd769 106 }
Nathan Yonkee 9:d58e77ebd769 107
Nathan Yonkee 9:d58e77ebd769 108 /** Check if the buffer is empty
Nathan Yonkee 9:d58e77ebd769 109 *
Nathan Yonkee 9:d58e77ebd769 110 * @return True if the buffer is empty, false if not
Nathan Yonkee 9:d58e77ebd769 111 */
Nathan Yonkee 9:d58e77ebd769 112 bool empty() const {
Nathan Yonkee 9:d58e77ebd769 113 core_util_critical_section_enter();
Nathan Yonkee 9:d58e77ebd769 114 bool is_empty = (_head == _tail) && !_full;
Nathan Yonkee 9:d58e77ebd769 115 core_util_critical_section_exit();
Nathan Yonkee 9:d58e77ebd769 116 return is_empty;
Nathan Yonkee 9:d58e77ebd769 117 }
Nathan Yonkee 9:d58e77ebd769 118
Nathan Yonkee 9:d58e77ebd769 119 /** Check if the buffer is full
Nathan Yonkee 9:d58e77ebd769 120 *
Nathan Yonkee 9:d58e77ebd769 121 * @return True if the buffer is full, false if not
Nathan Yonkee 9:d58e77ebd769 122 */
Nathan Yonkee 9:d58e77ebd769 123 bool full() const {
Nathan Yonkee 9:d58e77ebd769 124 core_util_critical_section_enter();
Nathan Yonkee 9:d58e77ebd769 125 bool full = _full;
Nathan Yonkee 9:d58e77ebd769 126 core_util_critical_section_exit();
Nathan Yonkee 9:d58e77ebd769 127 return full;
Nathan Yonkee 9:d58e77ebd769 128 }
Nathan Yonkee 9:d58e77ebd769 129
Nathan Yonkee 9:d58e77ebd769 130 /** Reset the buffer
Nathan Yonkee 9:d58e77ebd769 131 *
Nathan Yonkee 9:d58e77ebd769 132 */
Nathan Yonkee 9:d58e77ebd769 133 void reset() {
Nathan Yonkee 9:d58e77ebd769 134 core_util_critical_section_enter();
Nathan Yonkee 9:d58e77ebd769 135 _head = 0;
Nathan Yonkee 9:d58e77ebd769 136 _tail = 0;
Nathan Yonkee 9:d58e77ebd769 137 _full = false;
Nathan Yonkee 9:d58e77ebd769 138 core_util_critical_section_exit();
Nathan Yonkee 9:d58e77ebd769 139 }
Nathan Yonkee 9:d58e77ebd769 140
Nathan Yonkee 9:d58e77ebd769 141 /** Get the number of elements currently stored in the circular_buffer */
Nathan Yonkee 9:d58e77ebd769 142 CounterType size() const {
Nathan Yonkee 9:d58e77ebd769 143 core_util_critical_section_enter();
Nathan Yonkee 9:d58e77ebd769 144 CounterType elements;
Nathan Yonkee 9:d58e77ebd769 145 if (!_full) {
Nathan Yonkee 9:d58e77ebd769 146 if (_head < _tail) {
Nathan Yonkee 9:d58e77ebd769 147 elements = BufferSize + _head - _tail;
Nathan Yonkee 9:d58e77ebd769 148 } else {
Nathan Yonkee 9:d58e77ebd769 149 elements = _head - _tail;
Nathan Yonkee 9:d58e77ebd769 150 }
Nathan Yonkee 9:d58e77ebd769 151 } else {
Nathan Yonkee 9:d58e77ebd769 152 elements = BufferSize;
Nathan Yonkee 9:d58e77ebd769 153 }
Nathan Yonkee 9:d58e77ebd769 154 core_util_critical_section_exit();
Nathan Yonkee 9:d58e77ebd769 155 return elements;
Nathan Yonkee 9:d58e77ebd769 156 }
Nathan Yonkee 9:d58e77ebd769 157
Nathan Yonkee 9:d58e77ebd769 158 private:
Nathan Yonkee 9:d58e77ebd769 159 T _pool[BufferSize];
Nathan Yonkee 9:d58e77ebd769 160 volatile CounterType _head;
Nathan Yonkee 9:d58e77ebd769 161 volatile CounterType _tail;
Nathan Yonkee 9:d58e77ebd769 162 volatile bool _full;
Nathan Yonkee 9:d58e77ebd769 163 };
Nathan Yonkee 9:d58e77ebd769 164
Nathan Yonkee 9:d58e77ebd769 165 /**@}*/
Nathan Yonkee 9:d58e77ebd769 166
Nathan Yonkee 9:d58e77ebd769 167 /**@}*/
Nathan Yonkee 9:d58e77ebd769 168
Nathan Yonkee 9:d58e77ebd769 169 }
Nathan Yonkee 9:d58e77ebd769 170
Nathan Yonkee 9:d58e77ebd769 171 #endif