Ram Gandikota / Mbed OS IOTMetronome

FRDM K64F Metronome

mbed-client/source/include/smartpointer.h@0:dbad57390bd1, 2017-05-14 (annotated)

Committer:
ram54288
Date:
Sun May 14 18:37:05 2017 +0000
Revision:
0:dbad57390bd1
Initial commit

Who changed what in which revision?

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ram54288 0:dbad57390bd1 1 /*
ram54288 0:dbad57390bd1 2 * Copyright (c) 2015 ARM Limited. All rights reserved.
ram54288 0:dbad57390bd1 3 * SPDX-License-Identifier: Apache-2.0
ram54288 0:dbad57390bd1 4 * Licensed under the Apache License, Version 2.0 (the License); you may
ram54288 0:dbad57390bd1 5 * not use this file except in compliance with the License.
ram54288 0:dbad57390bd1 6 * You may obtain a copy of the License at
ram54288 0:dbad57390bd1 7 *
ram54288 0:dbad57390bd1 8 * http://www.apache.org/licenses/LICENSE-2.0
ram54288 0:dbad57390bd1 9 *
ram54288 0:dbad57390bd1 10 * Unless required by applicable law or agreed to in writing, software
ram54288 0:dbad57390bd1 11 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
ram54288 0:dbad57390bd1 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
ram54288 0:dbad57390bd1 13 * See the License for the specific language governing permissions and
ram54288 0:dbad57390bd1 14 * limitations under the License.
ram54288 0:dbad57390bd1 15 */
ram54288 0:dbad57390bd1 16 #ifndef SMART_POINTER_H
ram54288 0:dbad57390bd1 17 #define SMART_POINTER_H
ram54288 0:dbad57390bd1 18
ram54288 0:dbad57390bd1 19 class ReferenceCount
ram54288 0:dbad57390bd1 20 {
ram54288 0:dbad57390bd1 21 private:
ram54288 0:dbad57390bd1 22
ram54288 0:dbad57390bd1 23 int _count; // Reference count
ram54288 0:dbad57390bd1 24
ram54288 0:dbad57390bd1 25 public:
ram54288 0:dbad57390bd1 26
ram54288 0:dbad57390bd1 27 void add_ref()
ram54288 0:dbad57390bd1 28 {
ram54288 0:dbad57390bd1 29 // Increment the reference count
ram54288 0:dbad57390bd1 30 _count++;
ram54288 0:dbad57390bd1 31 }
ram54288 0:dbad57390bd1 32
ram54288 0:dbad57390bd1 33 int release()
ram54288 0:dbad57390bd1 34 {
ram54288 0:dbad57390bd1 35 // Decrement the reference count and
ram54288 0:dbad57390bd1 36 // return the reference count.
ram54288 0:dbad57390bd1 37 return --_count;
ram54288 0:dbad57390bd1 38 }
ram54288 0:dbad57390bd1 39 };
ram54288 0:dbad57390bd1 40
ram54288 0:dbad57390bd1 41 template < typename T > class SmartPointer
ram54288 0:dbad57390bd1 42 {
ram54288 0:dbad57390bd1 43 private:
ram54288 0:dbad57390bd1 44
ram54288 0:dbad57390bd1 45 T *_data; // Generic pointer to be stored
ram54288 0:dbad57390bd1 46 ReferenceCount *_reference; // Reference count
ram54288 0:dbad57390bd1 47
ram54288 0:dbad57390bd1 48
ram54288 0:dbad57390bd1 49 public:
ram54288 0:dbad57390bd1 50
ram54288 0:dbad57390bd1 51 SmartPointer()
ram54288 0:dbad57390bd1 52 : _data(0), _reference(0)
ram54288 0:dbad57390bd1 53 {
ram54288 0:dbad57390bd1 54 // Create a new reference
ram54288 0:dbad57390bd1 55 _reference = new ReferenceCount();
ram54288 0:dbad57390bd1 56 // Increment the reference count
ram54288 0:dbad57390bd1 57 _reference->add_ref();
ram54288 0:dbad57390bd1 58 }
ram54288 0:dbad57390bd1 59
ram54288 0:dbad57390bd1 60 SmartPointer(T* value)
ram54288 0:dbad57390bd1 61 : _data(value), _reference(0)
ram54288 0:dbad57390bd1 62 {
ram54288 0:dbad57390bd1 63 // Create a new reference
ram54288 0:dbad57390bd1 64 _reference = new ReferenceCount();
ram54288 0:dbad57390bd1 65 // Increment the reference count
ram54288 0:dbad57390bd1 66 _reference->add_ref();
ram54288 0:dbad57390bd1 67 }
ram54288 0:dbad57390bd1 68
ram54288 0:dbad57390bd1 69 SmartPointer(const SmartPointer<T>& smart_pointer)
ram54288 0:dbad57390bd1 70 : _data(smart_pointer._data), reference(smart_pointer._reference)
ram54288 0:dbad57390bd1 71 {
ram54288 0:dbad57390bd1 72 // Copy constructor
ram54288 0:dbad57390bd1 73 // Copy the data and reference pointer
ram54288 0:dbad57390bd1 74 // and increment the reference count
ram54288 0:dbad57390bd1 75 _reference->add_ref();
ram54288 0:dbad57390bd1 76 }
ram54288 0:dbad57390bd1 77
ram54288 0:dbad57390bd1 78 ~SmartPointer()
ram54288 0:dbad57390bd1 79 {
ram54288 0:dbad57390bd1 80 if(_reference->release() == 0) {
ram54288 0:dbad57390bd1 81 delete _data;
ram54288 0:dbad57390bd1 82 delete _reference;
ram54288 0:dbad57390bd1 83 }
ram54288 0:dbad57390bd1 84 }
ram54288 0:dbad57390bd1 85
ram54288 0:dbad57390bd1 86 T& operator* ()
ram54288 0:dbad57390bd1 87 {
ram54288 0:dbad57390bd1 88 return *_data;
ram54288 0:dbad57390bd1 89 }
ram54288 0:dbad57390bd1 90
ram54288 0:dbad57390bd1 91 T* operator-> ()
ram54288 0:dbad57390bd1 92 {
ram54288 0:dbad57390bd1 93 return _data;
ram54288 0:dbad57390bd1 94 }
ram54288 0:dbad57390bd1 95
ram54288 0:dbad57390bd1 96 SmartPointer<T>& operator = (const SmartPointer<T>& smart_pointer)
ram54288 0:dbad57390bd1 97 {
ram54288 0:dbad57390bd1 98 // Assignment operator
ram54288 0:dbad57390bd1 99 if (this != &SmartPointer) { // Avoid self assignment
ram54288 0:dbad57390bd1 100 // Decrement the old reference count
ram54288 0:dbad57390bd1 101 // if reference become zero delete the old data
ram54288 0:dbad57390bd1 102 if(_reference->release() == 0) {
ram54288 0:dbad57390bd1 103 delete _data;
ram54288 0:dbad57390bd1 104 delete _reference;
ram54288 0:dbad57390bd1 105 }
ram54288 0:dbad57390bd1 106
ram54288 0:dbad57390bd1 107 // Copy the data and reference pointer
ram54288 0:dbad57390bd1 108 // and increment the reference count
ram54288 0:dbad57390bd1 109 _data = SmartPointer._data;
ram54288 0:dbad57390bd1 110 _reference = SmartPointer._reference;
ram54288 0:dbad57390bd1 111 _reference->add_ref();
ram54288 0:dbad57390bd1 112 }
ram54288 0:dbad57390bd1 113 return *this;
ram54288 0:dbad57390bd1 114 }
ram54288 0:dbad57390bd1 115
ram54288 0:dbad57390bd1 116 };
ram54288 0:dbad57390bd1 117
ram54288 0:dbad57390bd1 118 #endif // SMART_POINTER_H