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Dependents: TYBLE16_simple_data_logger TYBLE16_MP3_Air
CircularBuffer.h
00001 /* mbed Microcontroller Library 00002 * Copyright (c) 2015-2019 ARM Limited 00003 * SPDX-License-Identifier: Apache-2.0 00004 * 00005 * Licensed under the Apache License, Version 2.0 (the "License"); 00006 * you may not use this file except in compliance with the License. 00007 * You may obtain a copy of the License at 00008 * 00009 * http://www.apache.org/licenses/LICENSE-2.0 00010 * 00011 * Unless required by applicable law or agreed to in writing, software 00012 * distributed under the License is distributed on an "AS IS" BASIS, 00013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 00014 * See the License for the specific language governing permissions and 00015 * limitations under the License. 00016 */ 00017 #ifndef MBED_CIRCULARBUFFER_H 00018 #define MBED_CIRCULARBUFFER_H 00019 00020 #include <stdint.h> 00021 #include "platform/mbed_critical.h" 00022 #include "platform/mbed_assert.h" 00023 00024 namespace mbed { 00025 00026 namespace internal { 00027 /* Detect if CounterType of the Circular buffer is of unsigned type. */ 00028 template<typename T> 00029 struct is_unsigned { 00030 static const bool value = false; 00031 }; 00032 template<> 00033 struct is_unsigned<unsigned char> { 00034 static const bool value = true; 00035 }; 00036 template<> 00037 struct is_unsigned<unsigned short> { 00038 static const bool value = true; 00039 }; 00040 template<> 00041 struct is_unsigned<unsigned int> { 00042 static const bool value = true; 00043 }; 00044 template<> 00045 struct is_unsigned<unsigned long> { 00046 static const bool value = true; 00047 }; 00048 template<> 00049 struct is_unsigned<unsigned long long> { 00050 static const bool value = true; 00051 }; 00052 }; 00053 00054 /** \addtogroup platform-public-api */ 00055 /** @{*/ 00056 /** 00057 * \defgroup platform_CircularBuffer CircularBuffer functions 00058 * @{ 00059 */ 00060 00061 /** Templated Circular buffer class 00062 * 00063 * @note Synchronization level: Interrupt safe 00064 * @note CounterType must be unsigned and consistent with BufferSize 00065 */ 00066 template<typename T, uint32_t BufferSize, typename CounterType = uint32_t> 00067 class CircularBuffer { 00068 public: 00069 CircularBuffer() : _head(0), _tail(0), _full(false) 00070 { 00071 MBED_STATIC_ASSERT( 00072 internal::is_unsigned<CounterType>::value, 00073 "CounterType must be unsigned" 00074 ); 00075 00076 MBED_STATIC_ASSERT( 00077 (sizeof(CounterType) >= sizeof(uint32_t)) || 00078 (BufferSize < (((uint64_t) 1) << (sizeof(CounterType) * 8))), 00079 "Invalid BufferSize for the CounterType" 00080 ); 00081 } 00082 00083 ~CircularBuffer() 00084 { 00085 } 00086 00087 /** Push the transaction to the buffer. This overwrites the buffer if it's 00088 * full 00089 * 00090 * @param data Data to be pushed to the buffer 00091 */ 00092 void push(const T &data) 00093 { 00094 core_util_critical_section_enter(); 00095 if (full()) { 00096 _tail++; 00097 if (_tail == BufferSize) { 00098 _tail = 0; 00099 } 00100 } 00101 _pool[_head++] = data; 00102 if (_head == BufferSize) { 00103 _head = 0; 00104 } 00105 if (_head == _tail) { 00106 _full = true; 00107 } 00108 core_util_critical_section_exit(); 00109 } 00110 00111 /** Pop the transaction from the buffer 00112 * 00113 * @param data Data to be popped from the buffer 00114 * @return True if the buffer is not empty and data contains a transaction, false otherwise 00115 */ 00116 bool pop(T &data) 00117 { 00118 bool data_popped = false; 00119 core_util_critical_section_enter(); 00120 if (!empty()) { 00121 data = _pool[_tail++]; 00122 if (_tail == BufferSize) { 00123 _tail = 0; 00124 } 00125 _full = false; 00126 data_popped = true; 00127 } 00128 core_util_critical_section_exit(); 00129 return data_popped; 00130 } 00131 00132 /** Check if the buffer is empty 00133 * 00134 * @return True if the buffer is empty, false if not 00135 */ 00136 bool empty() const 00137 { 00138 core_util_critical_section_enter(); 00139 bool is_empty = (_head == _tail) && !_full; 00140 core_util_critical_section_exit(); 00141 return is_empty; 00142 } 00143 00144 /** Check if the buffer is full 00145 * 00146 * @return True if the buffer is full, false if not 00147 */ 00148 bool full() const 00149 { 00150 core_util_critical_section_enter(); 00151 bool full = _full; 00152 core_util_critical_section_exit(); 00153 return full; 00154 } 00155 00156 /** Reset the buffer 00157 * 00158 */ 00159 void reset() 00160 { 00161 core_util_critical_section_enter(); 00162 _head = 0; 00163 _tail = 0; 00164 _full = false; 00165 core_util_critical_section_exit(); 00166 } 00167 00168 /** Get the number of elements currently stored in the circular_buffer */ 00169 CounterType size() const 00170 { 00171 core_util_critical_section_enter(); 00172 CounterType elements; 00173 if (!_full) { 00174 if (_head < _tail) { 00175 elements = BufferSize + _head - _tail; 00176 } else { 00177 elements = _head - _tail; 00178 } 00179 } else { 00180 elements = BufferSize; 00181 } 00182 core_util_critical_section_exit(); 00183 return elements; 00184 } 00185 00186 /** Peek into circular buffer without popping 00187 * 00188 * @param data Data to be peeked from the buffer 00189 * @return True if the buffer is not empty and data contains a transaction, false otherwise 00190 */ 00191 bool peek(T &data) const 00192 { 00193 bool data_updated = false; 00194 core_util_critical_section_enter(); 00195 if (!empty()) { 00196 data = _pool[_tail]; 00197 data_updated = true; 00198 } 00199 core_util_critical_section_exit(); 00200 return data_updated; 00201 } 00202 00203 private: 00204 T _pool[BufferSize]; 00205 CounterType _head; 00206 CounterType _tail; 00207 bool _full; 00208 }; 00209 00210 /**@}*/ 00211 00212 /**@}*/ 00213 00214 } 00215 00216 #endif
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