takashi kadono / Mbed OS Nucleo446_SSD1331

Color Oled(SSD1331) connect to STMicroelectronics Nucleo-F466

Dependencies:   ssd1331

mbed-os/platform/SharedPtr.h@3:f3764f852aa8, 2018-10-11 (annotated)

Committer:
kadonotakashi
Date:
Thu Oct 11 02:27:46 2018 +0000
Revision:
3:f3764f852aa8
Parent:
0:8fdf9a60065b 
Nucreo 446 + SSD1331 test version;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kadonotakashi 0:8fdf9a60065b 1 /* mbed Microcontroller Library
kadonotakashi 0:8fdf9a60065b 2 * Copyright (c) 2006-2018 ARM Limited
kadonotakashi 0:8fdf9a60065b 3 *
kadonotakashi 0:8fdf9a60065b 4 * Licensed under the Apache License, Version 2.0 (the "License");
kadonotakashi 0:8fdf9a60065b 5 * you may not use this file except in compliance with the License.
kadonotakashi 0:8fdf9a60065b 6 * You may obtain a copy of the License at
kadonotakashi 0:8fdf9a60065b 7 *
kadonotakashi 0:8fdf9a60065b 8 * http://www.apache.org/licenses/LICENSE-2.0
kadonotakashi 0:8fdf9a60065b 9 *
kadonotakashi 0:8fdf9a60065b 10 * Unless required by applicable law or agreed to in writing, software
kadonotakashi 0:8fdf9a60065b 11 * distributed under the License is distributed on an "AS IS" BASIS,
kadonotakashi 0:8fdf9a60065b 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
kadonotakashi 0:8fdf9a60065b 13 * See the License for the specific language governing permissions and
kadonotakashi 0:8fdf9a60065b 14 * limitations under the License.
kadonotakashi 0:8fdf9a60065b 15 */
kadonotakashi 0:8fdf9a60065b 16
kadonotakashi 0:8fdf9a60065b 17 #ifndef __SHAREDPTR_H__
kadonotakashi 0:8fdf9a60065b 18 #define __SHAREDPTR_H__
kadonotakashi 0:8fdf9a60065b 19
kadonotakashi 0:8fdf9a60065b 20 #include <stdlib.h>
kadonotakashi 0:8fdf9a60065b 21
kadonotakashi 0:8fdf9a60065b 22 #include <stdint.h>
kadonotakashi 0:8fdf9a60065b 23 #include <stddef.h>
kadonotakashi 0:8fdf9a60065b 24
kadonotakashi 0:8fdf9a60065b 25 #include "platform/mbed_critical.h"
kadonotakashi 0:8fdf9a60065b 26
kadonotakashi 0:8fdf9a60065b 27 /** Shared pointer class.
kadonotakashi 0:8fdf9a60065b 28 *
kadonotakashi 0:8fdf9a60065b 29 * A shared pointer is a "smart" pointer that retains ownership of an object using
kadonotakashi 0:8fdf9a60065b 30 * reference counting accross all smart pointers referencing that object.
kadonotakashi 0:8fdf9a60065b 31 *
kadonotakashi 0:8fdf9a60065b 32 * @code
kadonotakashi 0:8fdf9a60065b 33 * #include "platform/SharedPtr.h"
kadonotakashi 0:8fdf9a60065b 34 *
kadonotakashi 0:8fdf9a60065b 35 * void test() {
kadonotakashi 0:8fdf9a60065b 36 * struct MyStruct { int a; };
kadonotakashi 0:8fdf9a60065b 37 *
kadonotakashi 0:8fdf9a60065b 38 * // Create shared pointer
kadonotakashi 0:8fdf9a60065b 39 * SharedPtr<MyStruct> ptr( new MyStruct );
kadonotakashi 0:8fdf9a60065b 40 *
kadonotakashi 0:8fdf9a60065b 41 * // Increase reference count
kadonotakashi 0:8fdf9a60065b 42 * SharedPtr<MyStruct> ptr2( ptr );
kadonotakashi 0:8fdf9a60065b 43 *
kadonotakashi 0:8fdf9a60065b 44 * ptr = NULL; // Reference to the struct instance is still held by ptr2
kadonotakashi 0:8fdf9a60065b 45 *
kadonotakashi 0:8fdf9a60065b 46 * ptr2 = NULL; // The raw pointer is freed
kadonotakashi 0:8fdf9a60065b 47 * }
kadonotakashi 0:8fdf9a60065b 48 * @endcode
kadonotakashi 0:8fdf9a60065b 49 *
kadonotakashi 0:8fdf9a60065b 50 *
kadonotakashi 0:8fdf9a60065b 51 * It is similar to the std::shared_ptr class introduced in C++11;
kadonotakashi 0:8fdf9a60065b 52 * however, this is not a compatible implementation (no weak pointer, no make_shared, no custom deleters and so on.)
kadonotakashi 0:8fdf9a60065b 53 *
kadonotakashi 0:8fdf9a60065b 54 * Usage: SharedPtr<Class> ptr(new Class())
kadonotakashi 0:8fdf9a60065b 55 *
kadonotakashi 0:8fdf9a60065b 56 * When ptr is passed around by value, the copy constructor and
kadonotakashi 0:8fdf9a60065b 57 * destructor manages the reference count of the raw pointer.
kadonotakashi 0:8fdf9a60065b 58 * If the counter reaches zero, delete is called on the raw pointer.
kadonotakashi 0:8fdf9a60065b 59 *
kadonotakashi 0:8fdf9a60065b 60 * To avoid loops, use "weak" references by calling the original
kadonotakashi 0:8fdf9a60065b 61 * pointer directly through ptr.get().
kadonotakashi 0:8fdf9a60065b 62 */
kadonotakashi 0:8fdf9a60065b 63
kadonotakashi 0:8fdf9a60065b 64 template <class T>
kadonotakashi 0:8fdf9a60065b 65 class SharedPtr {
kadonotakashi 0:8fdf9a60065b 66 public:
kadonotakashi 0:8fdf9a60065b 67 /**
kadonotakashi 0:8fdf9a60065b 68 * @brief Create empty SharedPtr not pointing to anything.
kadonotakashi 0:8fdf9a60065b 69 * @details Used for variable declaration.
kadonotakashi 0:8fdf9a60065b 70 */
kadonotakashi 0:8fdf9a60065b 71 SharedPtr(): _ptr(NULL), _counter(NULL)
kadonotakashi 0:8fdf9a60065b 72 {
kadonotakashi 0:8fdf9a60065b 73 }
kadonotakashi 0:8fdf9a60065b 74
kadonotakashi 0:8fdf9a60065b 75 /**
kadonotakashi 0:8fdf9a60065b 76 * @brief Create new SharedPtr
kadonotakashi 0:8fdf9a60065b 77 * @param ptr Pointer to take control over
kadonotakashi 0:8fdf9a60065b 78 */
kadonotakashi 0:8fdf9a60065b 79 SharedPtr(T *ptr): _ptr(ptr), _counter(NULL)
kadonotakashi 0:8fdf9a60065b 80 {
kadonotakashi 0:8fdf9a60065b 81 // Allocate counter on the heap, so it can be shared
kadonotakashi 0:8fdf9a60065b 82 if (_ptr != NULL) {
kadonotakashi 0:8fdf9a60065b 83 _counter = new uint32_t;
kadonotakashi 0:8fdf9a60065b 84 *_counter = 1;
kadonotakashi 0:8fdf9a60065b 85 }
kadonotakashi 0:8fdf9a60065b 86 }
kadonotakashi 0:8fdf9a60065b 87
kadonotakashi 0:8fdf9a60065b 88 /**
kadonotakashi 0:8fdf9a60065b 89 * @brief Destructor.
kadonotakashi 0:8fdf9a60065b 90 * @details Decrement reference counter, and delete object if no longer pointed to.
kadonotakashi 0:8fdf9a60065b 91 */
kadonotakashi 0:8fdf9a60065b 92 ~SharedPtr()
kadonotakashi 0:8fdf9a60065b 93 {
kadonotakashi 0:8fdf9a60065b 94 decrement_counter();
kadonotakashi 0:8fdf9a60065b 95 }
kadonotakashi 0:8fdf9a60065b 96
kadonotakashi 0:8fdf9a60065b 97 /**
kadonotakashi 0:8fdf9a60065b 98 * @brief Copy constructor.
kadonotakashi 0:8fdf9a60065b 99 * @details Create new SharedPtr from other SharedPtr by
kadonotakashi 0:8fdf9a60065b 100 * copying pointer to original object and pointer to counter.
kadonotakashi 0:8fdf9a60065b 101 * @param source Object being copied from.
kadonotakashi 0:8fdf9a60065b 102 */
kadonotakashi 0:8fdf9a60065b 103 SharedPtr(const SharedPtr &source): _ptr(source._ptr), _counter(source._counter)
kadonotakashi 0:8fdf9a60065b 104 {
kadonotakashi 0:8fdf9a60065b 105 // Increment reference counter
kadonotakashi 0:8fdf9a60065b 106 if (_ptr != NULL) {
kadonotakashi 0:8fdf9a60065b 107 core_util_atomic_incr_u32(_counter, 1);
kadonotakashi 0:8fdf9a60065b 108 }
kadonotakashi 0:8fdf9a60065b 109 }
kadonotakashi 0:8fdf9a60065b 110
kadonotakashi 0:8fdf9a60065b 111 /**
kadonotakashi 0:8fdf9a60065b 112 * @brief Assignment operator.
kadonotakashi 0:8fdf9a60065b 113 * @details Cleanup previous reference and assign new pointer and counter.
kadonotakashi 0:8fdf9a60065b 114 * @param source Object being assigned from.
kadonotakashi 0:8fdf9a60065b 115 * @return Object being assigned.
kadonotakashi 0:8fdf9a60065b 116 */
kadonotakashi 0:8fdf9a60065b 117 SharedPtr operator=(const SharedPtr &source)
kadonotakashi 0:8fdf9a60065b 118 {
kadonotakashi 0:8fdf9a60065b 119 if (this != &source) {
kadonotakashi 0:8fdf9a60065b 120 // Clean up by decrementing counter
kadonotakashi 0:8fdf9a60065b 121 decrement_counter();
kadonotakashi 0:8fdf9a60065b 122
kadonotakashi 0:8fdf9a60065b 123 // Assign new values
kadonotakashi 0:8fdf9a60065b 124 _ptr = source.get();
kadonotakashi 0:8fdf9a60065b 125 _counter = source.get_counter();
kadonotakashi 0:8fdf9a60065b 126
kadonotakashi 0:8fdf9a60065b 127 // Increment new counter
kadonotakashi 0:8fdf9a60065b 128 if (_ptr != NULL) {
kadonotakashi 0:8fdf9a60065b 129 core_util_atomic_incr_u32(_counter, 1);
kadonotakashi 0:8fdf9a60065b 130 }
kadonotakashi 0:8fdf9a60065b 131 }
kadonotakashi 0:8fdf9a60065b 132
kadonotakashi 0:8fdf9a60065b 133 return *this;
kadonotakashi 0:8fdf9a60065b 134 }
kadonotakashi 0:8fdf9a60065b 135
kadonotakashi 0:8fdf9a60065b 136 /**
kadonotakashi 0:8fdf9a60065b 137 * @brief Replaces the managed pointer with a new unmanaged pointer.
kadonotakashi 0:8fdf9a60065b 138 * @param[in] ptr the new raw pointer to manage.
kadonotakashi 0:8fdf9a60065b 139 */
kadonotakashi 0:8fdf9a60065b 140 void reset(T *ptr)
kadonotakashi 0:8fdf9a60065b 141 {
kadonotakashi 0:8fdf9a60065b 142 // Clean up by decrementing counter
kadonotakashi 0:8fdf9a60065b 143 decrement_counter();
kadonotakashi 0:8fdf9a60065b 144
kadonotakashi 0:8fdf9a60065b 145 if (ptr != NULL) {
kadonotakashi 0:8fdf9a60065b 146 // Allocate counter on the heap, so it can be shared
kadonotakashi 0:8fdf9a60065b 147 _counter = new uint32_t;
kadonotakashi 0:8fdf9a60065b 148 *_counter = 1;
kadonotakashi 0:8fdf9a60065b 149 }
kadonotakashi 0:8fdf9a60065b 150 }
kadonotakashi 0:8fdf9a60065b 151
kadonotakashi 0:8fdf9a60065b 152 /**
kadonotakashi 0:8fdf9a60065b 153 * @brief Replace the managed pointer with a NULL pointer.
kadonotakashi 0:8fdf9a60065b 154 */
kadonotakashi 0:8fdf9a60065b 155 void reset()
kadonotakashi 0:8fdf9a60065b 156 {
kadonotakashi 0:8fdf9a60065b 157 reset(NULL);
kadonotakashi 0:8fdf9a60065b 158 }
kadonotakashi 0:8fdf9a60065b 159
kadonotakashi 0:8fdf9a60065b 160 /**
kadonotakashi 0:8fdf9a60065b 161 * @brief Raw pointer accessor.
kadonotakashi 0:8fdf9a60065b 162 * @details Get raw pointer to object pointed to.
kadonotakashi 0:8fdf9a60065b 163 * @return Pointer.
kadonotakashi 0:8fdf9a60065b 164 */
kadonotakashi 0:8fdf9a60065b 165 T *get() const
kadonotakashi 0:8fdf9a60065b 166 {
kadonotakashi 0:8fdf9a60065b 167 return _ptr;
kadonotakashi 0:8fdf9a60065b 168 }
kadonotakashi 0:8fdf9a60065b 169
kadonotakashi 0:8fdf9a60065b 170 /**
kadonotakashi 0:8fdf9a60065b 171 * @brief Reference count accessor.
kadonotakashi 0:8fdf9a60065b 172 * @return Reference count.
kadonotakashi 0:8fdf9a60065b 173 */
kadonotakashi 0:8fdf9a60065b 174 uint32_t use_count() const
kadonotakashi 0:8fdf9a60065b 175 {
kadonotakashi 0:8fdf9a60065b 176 if (_ptr != NULL) {
kadonotakashi 0:8fdf9a60065b 177 core_util_critical_section_enter();
kadonotakashi 0:8fdf9a60065b 178 uint32_t current_counter = *_counter;
kadonotakashi 0:8fdf9a60065b 179 core_util_critical_section_exit();
kadonotakashi 0:8fdf9a60065b 180 return current_counter;
kadonotakashi 0:8fdf9a60065b 181 } else {
kadonotakashi 0:8fdf9a60065b 182 return 0;
kadonotakashi 0:8fdf9a60065b 183 }
kadonotakashi 0:8fdf9a60065b 184 }
kadonotakashi 0:8fdf9a60065b 185
kadonotakashi 0:8fdf9a60065b 186 /**
kadonotakashi 0:8fdf9a60065b 187 * @brief Dereference object operator.
kadonotakashi 0:8fdf9a60065b 188 * @details Override to return the object pointed to.
kadonotakashi 0:8fdf9a60065b 189 */
kadonotakashi 0:8fdf9a60065b 190 T &operator*() const
kadonotakashi 0:8fdf9a60065b 191 {
kadonotakashi 0:8fdf9a60065b 192 return *_ptr;
kadonotakashi 0:8fdf9a60065b 193 }
kadonotakashi 0:8fdf9a60065b 194
kadonotakashi 0:8fdf9a60065b 195 /**
kadonotakashi 0:8fdf9a60065b 196 * @brief Dereference object member operator.
kadonotakashi 0:8fdf9a60065b 197 * @details Override to return return member in object pointed to.
kadonotakashi 0:8fdf9a60065b 198 */
kadonotakashi 0:8fdf9a60065b 199 T *operator->() const
kadonotakashi 0:8fdf9a60065b 200 {
kadonotakashi 0:8fdf9a60065b 201 return _ptr;
kadonotakashi 0:8fdf9a60065b 202 }
kadonotakashi 0:8fdf9a60065b 203
kadonotakashi 0:8fdf9a60065b 204 /**
kadonotakashi 0:8fdf9a60065b 205 * @brief Boolean conversion operator.
kadonotakashi 0:8fdf9a60065b 206 * @return Whether or not the pointer is NULL.
kadonotakashi 0:8fdf9a60065b 207 */
kadonotakashi 0:8fdf9a60065b 208 operator bool() const
kadonotakashi 0:8fdf9a60065b 209 {
kadonotakashi 0:8fdf9a60065b 210 return (_ptr != NULL);
kadonotakashi 0:8fdf9a60065b 211 }
kadonotakashi 0:8fdf9a60065b 212
kadonotakashi 0:8fdf9a60065b 213 private:
kadonotakashi 0:8fdf9a60065b 214 /**
kadonotakashi 0:8fdf9a60065b 215 * @brief Get pointer to reference counter.
kadonotakashi 0:8fdf9a60065b 216 * @return Pointer to reference counter.
kadonotakashi 0:8fdf9a60065b 217 */
kadonotakashi 0:8fdf9a60065b 218 uint32_t *get_counter() const
kadonotakashi 0:8fdf9a60065b 219 {
kadonotakashi 0:8fdf9a60065b 220 return _counter;
kadonotakashi 0:8fdf9a60065b 221 }
kadonotakashi 0:8fdf9a60065b 222
kadonotakashi 0:8fdf9a60065b 223 /**
kadonotakashi 0:8fdf9a60065b 224 * @brief Decrement reference counter.
kadonotakashi 0:8fdf9a60065b 225 * @details If count reaches zero, free counter and delete object pointed to.
kadonotakashi 0:8fdf9a60065b 226 */
kadonotakashi 0:8fdf9a60065b 227 void decrement_counter()
kadonotakashi 0:8fdf9a60065b 228 {
kadonotakashi 0:8fdf9a60065b 229 if (_ptr != NULL) {
kadonotakashi 0:8fdf9a60065b 230 uint32_t new_value = core_util_atomic_decr_u32(_counter, 1);
kadonotakashi 0:8fdf9a60065b 231 if (new_value == 0) {
kadonotakashi 0:8fdf9a60065b 232 delete _counter;
kadonotakashi 0:8fdf9a60065b 233 _counter = NULL;
kadonotakashi 0:8fdf9a60065b 234 delete _ptr;
kadonotakashi 0:8fdf9a60065b 235 _ptr = NULL;
kadonotakashi 0:8fdf9a60065b 236 }
kadonotakashi 0:8fdf9a60065b 237 }
kadonotakashi 0:8fdf9a60065b 238 }
kadonotakashi 0:8fdf9a60065b 239
kadonotakashi 0:8fdf9a60065b 240 private:
kadonotakashi 0:8fdf9a60065b 241 // Pointer to shared object
kadonotakashi 0:8fdf9a60065b 242 T *_ptr;
kadonotakashi 0:8fdf9a60065b 243
kadonotakashi 0:8fdf9a60065b 244 // Pointer to shared reference counter
kadonotakashi 0:8fdf9a60065b 245 uint32_t *_counter;
kadonotakashi 0:8fdf9a60065b 246 };
kadonotakashi 0:8fdf9a60065b 247
kadonotakashi 0:8fdf9a60065b 248 /** Non-member relational operators.
kadonotakashi 0:8fdf9a60065b 249 */
kadonotakashi 0:8fdf9a60065b 250 template <class T, class U>
kadonotakashi 0:8fdf9a60065b 251 bool operator== (const SharedPtr<T> &lhs, const SharedPtr<U> &rhs)
kadonotakashi 0:8fdf9a60065b 252 {
kadonotakashi 0:8fdf9a60065b 253 return (lhs.get() == rhs.get());
kadonotakashi 0:8fdf9a60065b 254 }
kadonotakashi 0:8fdf9a60065b 255
kadonotakashi 0:8fdf9a60065b 256 template <class T, typename U>
kadonotakashi 0:8fdf9a60065b 257 bool operator== (const SharedPtr<T> &lhs, U rhs)
kadonotakashi 0:8fdf9a60065b 258 {
kadonotakashi 0:8fdf9a60065b 259 return (lhs.get() == (T *) rhs);
kadonotakashi 0:8fdf9a60065b 260 }
kadonotakashi 0:8fdf9a60065b 261
kadonotakashi 0:8fdf9a60065b 262 template <class T, typename U>
kadonotakashi 0:8fdf9a60065b 263 bool operator== (U lhs, const SharedPtr<T> &rhs)
kadonotakashi 0:8fdf9a60065b 264 {
kadonotakashi 0:8fdf9a60065b 265 return ((T *) lhs == rhs.get());
kadonotakashi 0:8fdf9a60065b 266 }
kadonotakashi 0:8fdf9a60065b 267
kadonotakashi 0:8fdf9a60065b 268 /** Non-member relational operators.
kadonotakashi 0:8fdf9a60065b 269 */
kadonotakashi 0:8fdf9a60065b 270 template <class T, class U>
kadonotakashi 0:8fdf9a60065b 271 bool operator!= (const SharedPtr<T> &lhs, const SharedPtr<U> &rhs)
kadonotakashi 0:8fdf9a60065b 272 {
kadonotakashi 0:8fdf9a60065b 273 return (lhs.get() != rhs.get());
kadonotakashi 0:8fdf9a60065b 274 }
kadonotakashi 0:8fdf9a60065b 275
kadonotakashi 0:8fdf9a60065b 276 template <class T, typename U>
kadonotakashi 0:8fdf9a60065b 277 bool operator!= (const SharedPtr<T> &lhs, U rhs)
kadonotakashi 0:8fdf9a60065b 278 {
kadonotakashi 0:8fdf9a60065b 279 return (lhs.get() != (T *) rhs);
kadonotakashi 0:8fdf9a60065b 280 }
kadonotakashi 0:8fdf9a60065b 281
kadonotakashi 0:8fdf9a60065b 282 template <class T, typename U>
kadonotakashi 0:8fdf9a60065b 283 bool operator!= (U lhs, const SharedPtr<T> &rhs)
kadonotakashi 0:8fdf9a60065b 284 {
kadonotakashi 0:8fdf9a60065b 285 return ((T *) lhs != rhs.get());
kadonotakashi 0:8fdf9a60065b 286 }
kadonotakashi 0:8fdf9a60065b 287
kadonotakashi 0:8fdf9a60065b 288 #endif // __SHAREDPTR_H__