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feat: std::shared_ptr std::unique_ptr

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XMuli 2022-12-19 01:53:50 +08:00
parent 9894f88b7e
commit 492370ae45
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10 changed files with 98 additions and 77 deletions
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4
Studio/Studio/MemoryAlignment.h
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@ -1,7 +1,7 @@
/******************************************************************* /*******************************************************************
* Copyright (c) 2022~2023 XMuli All rights reserved. * Copyright (c) 2022~2023 XMuli All rights reserved.
* GitHub: https://github.com/XMuli * GitHub: https://github.com/XMuli
* Description: 类中字节对齐判断 * Description: 类中字节对齐判断
******************************************************************/ ******************************************************************/
// NOTE: // NOTE:

2
Studio/Studio/SharedPtr.cpp
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@ -1 +1 @@
#include "SharedPtr.h" #include "SharedPtr.h"

79
Studio/Studio/SharedPtr.h
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@ -1,8 +1,8 @@
/******************************************************************* /*******************************************************************
* Copyright (c) 2022~2023 XMuli All rights reserved. * Copyright (c) 2022~2023 XMuli All rights reserved.
* GitHub: https://github.com/XMuli * GitHub: https://github.com/XMuli
* Description: C++ 实现一个核心的 shared_ptr 智能指针模板类；实现了引用计数是线程安全的，但访问管理的资源不是线程安全的。 * Description: C++ 实现一个核心的 shared_ptr 智能指针模板类；实现了引用计数是线程安全的，但访问管理的资源不是线程安全的。
* Note: 书写测试时，若使用默认构造函数, 成员变量 _ptr、_refCount、_pMutex 在 release() 中容易崩溃；推荐带参的构造函数，无错 * Note: 书写测试时，若使用默认构造函数, 成员变量 _ptr、_refCount、_pMutex 在 release() 中容易崩溃；推荐带参的构造函数，无错
* Ref: https://juejin.cn/post/7111726931301072910#heading-8 * Ref: https://juejin.cn/post/7111726931301072910#heading-8
* https://cloud.tencent.com/developer/article/1688444 * https://cloud.tencent.com/developer/article/1688444
* https://blog.csdn.net/Z_Stand/article/details/98512756 * https://blog.csdn.net/Z_Stand/article/details/98512756
@ -20,7 +20,7 @@ public:
SharedPtr() : _ptr(nullptr), _refCount(nullptr), _pMutex(nullptr) { cout << "default constructor" << endl; }; SharedPtr() : _ptr(nullptr), _refCount(nullptr), _pMutex(nullptr) { cout << "default constructor" << endl; };
SharedPtr(T* obj) : _ptr(obj), _refCount(new int(1)), _pMutex(new mutex) { cout << "no default constructor" << endl; }; SharedPtr(T* obj) : _ptr(obj), _refCount(new int(1)), _pMutex(new mutex) { cout << "no default constructor" << endl; };
SharedPtr(const SharedPtr<T>& obj) // 其 _refCount 可以通过另外一个指针来修改，指向的是同一个地址 SharedPtr(const SharedPtr<T>& obj) // 其 _refCount 可以通过另外一个指针来修改，指向的是同一个地址
: _ptr(obj._ptr) : _ptr(obj._ptr)
, _refCount(obj._refCount) , _refCount(obj._refCount)
, _pMutex(obj._pMutex) , _pMutex(obj._pMutex)
@ -34,13 +34,13 @@ public:
cout << "copy assignment constructor" << endl; cout << "copy assignment constructor" << endl;
if (&obj != this) { if (&obj != this) {
if (_ptr != obj._ptr) { if (_ptr != obj._ptr) {
release(); // 先释放旧的资源 release(); // 先释放旧的资源
_ptr = obj._ptr; _ptr = obj._ptr;
_refCount = obj._refCount; _refCount = obj._refCount;
_pMutex = obj._pMutex; _pMutex = obj._pMutex;
addRefCount(); // 再技计数 +1 addRefCount(); // 再技计数 +1
} }
} }
@ -72,7 +72,7 @@ private:
bool bDelMutex = false; bool bDelMutex = false;
_pMutex->lock(); _pMutex->lock();
if (_ptr && --*_refCount == 0) { // 先校验是否存在，及计数为 0 才释放 if (_ptr && --*_refCount == 0) { // 先校验是否存在，及计数为 0 才释放
delete _ptr; delete _ptr;
delete _refCount; delete _refCount;
_ptr = nullptr; _ptr = nullptr;
@ -86,10 +86,10 @@ private:
delete _pMutex; delete _pMutex;
} }
private: // 需在构造函数中初始化 private: // 需在构造函数中初始化
T* _ptr; T* _ptr; // 指向管理资源的指针
int* _refCount; int* _refCount; // 引用计数
mutex* _pMutex; // 计数自增非原子操作，加锁解决多线程 mutex* _pMutex; // 计数自增非原子操作，加锁解决多线程
}; };
//int main() //int main()
@ -97,12 +97,12 @@ private: //
// SharedPtr<int> sp1(new int(10)); // SharedPtr<int> sp1(new int(10));
// SharedPtr<int> sp2(sp1); // SharedPtr<int> sp2(sp1);
// *sp2 = 20; // *sp2 = 20;
// //sp1 与 sp2 在管理这部分资源，引用计数为 2 // //sp1 与 sp2 在管理这部分资源，引用计数为 2
// cout << sp1.useCount() << " *ptr:" << *sp1 << endl; //2 20 // cout << sp1.useCount() << " *ptr:" << *sp1 << endl; //2 20
// cout << sp2.useCount() << " *ptr:" << *sp2 << endl; //2 20 // cout << sp2.useCount() << " *ptr:" << *sp2 << endl; //2 20
// //
// SharedPtr<int> sp3(new int(30)); // SharedPtr<int> sp3(new int(30));
// sp2 = sp3; //sp3 赋值给它，释放管理的旧资源，引用计数-1， // sp2 = sp3; //sp3 赋值给它，释放管理的旧资源，引用计数-1，
// cout << sp1.useCount() << " *ptr:" << *sp1 << endl; //1 20 // cout << sp1.useCount() << " *ptr:" << *sp1 << endl; //1 20
// cout << sp2.useCount() << " *ptr:" << *sp2 << endl; //2 30 // cout << sp2.useCount() << " *ptr:" << *sp2 << endl; //2 30
// cout << sp3.useCount() << " *ptr:" << *sp3 << endl; //2 30 // cout << sp3.useCount() << " *ptr:" << *sp3 << endl; //2 30
@ -116,31 +116,30 @@ private: //
// return 0; // return 0;
//} //}
/******************************************************************* /*****************************打印结果*******************************
* 打印结果: no default constructor
* no default constructor copy constructor
* copy constructor addRefCount
* addRefCount 2 *ptr:20
* 2 *ptr:20 2 *ptr:20
* 2 *ptr:20 no default constructor
* no default constructor copy assignment constructor
* copy assignment constructor release
* release addRefCount
* addRefCount 1 *ptr:20
* 1 *ptr:20 2 *ptr:30
* 2 *ptr:30 2 *ptr:30
* 2 *ptr:30 copy assignment constructor
* copy assignment constructor release
* release addRefCount
* addRefCount 3 *ptr:30
* 3 *ptr:30 3 *ptr:30
* 3 *ptr:30 3 *ptr:30
* 3 *ptr:30 Hello World!
* Hello World! destructor
* destructor release
* release destructor
* destructor release
* release destructor
* destructor release
* release
******************************************************************/ ******************************************************************/

1
Studio/Studio/SpecialMembers.cpp Normal file
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@ -0,0 +1 @@
#include "SpecialMembers.h"

61
Studio/Studio/SpecialMembers.h
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@ -1,8 +1,8 @@
/******************************************************************* /*******************************************************************
* Copyright (c) 2022~2023 XMuli All rights reserved. * Copyright (c) 2022~2023 XMuli All rights reserved.
* GitHub: https://github.com/XMuli * GitHub: https://github.com/XMuli
* Description: C++ 类的特殊五个函数 * Description: C++ 类的特殊五个函数
* Ref：https://en.cppreference.com/w/cpp/language/rule_of_three https://en.wikipedia.org/wiki/Special_member_functions * Ref：https://en.cppreference.com/w/cpp/language/rule_of_three https://en.wikipedia.org/wiki/Special_member_functions
******************************************************************/ ******************************************************************/
#pragma once #pragma once
@ -51,7 +51,7 @@ public:
return *this; return *this;
} }
A(A&& other) noexcept // 行参无 const A(A&& other) noexcept // 行参无 const
: m_ptr(nullptr) { : m_ptr(nullptr) {
std::cout << "move constructor" << endl; std::cout << "move constructor" << endl;
if (other.m_ptr) if (other.m_ptr)
@ -60,7 +60,7 @@ public:
other.m_ptr = nullptr; other.m_ptr = nullptr;
} }
A& operator=(A&& other) noexcept { // 行参无 const A& operator=(A&& other) noexcept { // 行参无 const
std::cout << "move assignment constructor" << endl; std::cout << "move assignment constructor" << endl;
if (this != &other) { if (this != &other) {
delete[] m_ptr; // Free the existing resource. delete[] m_ptr; // Free the existing resource.
@ -89,20 +89,37 @@ A fn() {
return t; return t;
} }
//int main() int main()
//{ {
// A a1("a1"); // default constructor A a1("a1"); // default constructor
// A a2(a1); // copy constructor A a2(a1); // copy constructor
// A a3 = a1; // copy constructor A a3 = a1; // copy constructor
// a1 = a3; // copy assignment constructor a1 = a3; // copy assignment constructor
// std::cout << "----------------------------\n\n";
// std::cout << "----------------------------\n\n";
// //fn(); // function returning a A object
// //fn(); // function returning a A object A a5 = std::move(a1); // move constructor
// A a5 = std::move(a1); // move constructor A a6; // default constructor
// A a6; // default constructor a6 = std::move(a1); // move assignment constructor
// a6 = std::move(a1); // move assignment constructor std::cout << "Hello World!\n";
// std::cout << "Hello World!\n";
// return 0;
// return 0; }
//}
/*************************** 运行结果 *******************************
* no-default-val constructor
copy constructor
copy constructor
copy assignment constructor
----------------------------
move constructor
default constructor
move assignment constructor
Hello World!
destructor
destructor
destructor
destructor
destructor
******************************************************************/

2
Studio/Studio/Studio.cpp
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@ -1,4 +1,4 @@
// Studio.cpp : This file contains the 'main' function. Program execution begins and ends there. // Studio.cpp : This file contains the 'main' function. Program execution begins and ends there.
// //
#include <iostream> #include <iostream>

1
Studio/Studio/Studio.vcxproj
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@ -140,6 +140,7 @@
</ItemDefinitionGroup> </ItemDefinitionGroup>
<ItemGroup> <ItemGroup>
<ClCompile Include="SharedPtr.cpp" /> <ClCompile Include="SharedPtr.cpp" />
<ClCompile Include="SpecialMembers.cpp" />
<ClCompile Include="Studio.cpp" /> <ClCompile Include="Studio.cpp" />
<ClCompile Include="UniquePtr.cpp" /> <ClCompile Include="UniquePtr.cpp" />
</ItemGroup> </ItemGroup>

9
Studio/Studio/Studio.vcxproj.filters
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@ -24,19 +24,22 @@
<ClCompile Include="UniquePtr.cpp"> <ClCompile Include="UniquePtr.cpp">
<Filter>Source Files</Filter> <Filter>Source Files</Filter>
</ClCompile> </ClCompile>
<ClCompile Include="SpecialMembers.cpp">
<Filter>Source Files</Filter>
</ClCompile>
</ItemGroup> </ItemGroup>
<ItemGroup> <ItemGroup>
<ClInclude Include="MemoryAlignment.h"> <ClInclude Include="MemoryAlignment.h">
<Filter>Header Files</Filter> <Filter>Header Files</Filter>
</ClInclude> </ClInclude>
<ClInclude Include="SpecialMembers.h">
<Filter>Header Files</Filter>
</ClInclude>
<ClInclude Include="SharedPtr.h"> <ClInclude Include="SharedPtr.h">
<Filter>Header Files</Filter> <Filter>Header Files</Filter>
</ClInclude> </ClInclude>
<ClInclude Include="UniquePtr.h"> <ClInclude Include="UniquePtr.h">
<Filter>Header Files</Filter> <Filter>Header Files</Filter>
</ClInclude> </ClInclude>
<ClInclude Include="SpecialMembers.h">
<Filter>Header Files</Filter>
</ClInclude>
</ItemGroup> </ItemGroup>
</Project> </Project>

2
Studio/Studio/UniquePtr.cpp
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@ -1 +1 @@
#include "UniquePtr.h" #include "UniquePtr.h"

14
Studio/Studio/UniquePtr.h
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@ -1,7 +1,7 @@
/******************************************************************* /*******************************************************************
* Copyright (c) 2022~2023 XMuli All rights reserved. * Copyright (c) 2022~2023 XMuli All rights reserved.
* GitHub: https://github.com/XMuli * GitHub: https://github.com/XMuli
* Description: C++ 实现一个核心的 unique_ptr 智能指针模板类； * Description: C++ 实现一个核心的 unique_ptr 智能指针模板类；
* Ref: https://www.jianshu.com/p/77c2988be336 * Ref: https://www.jianshu.com/p/77c2988be336
* https://juejin.cn/post/7122641980315680782 * https://juejin.cn/post/7122641980315680782
* https://juejin.cn/post/7099967913594978341 * https://juejin.cn/post/7099967913594978341
@ -37,7 +37,7 @@ public:
return *this; return *this;
} }
UniquePtr(const UniquePtr<T>& obj) = delete; // C++11 delete 禁止方式，C++98 用 private 来隐藏 UniquePtr(const UniquePtr<T>& obj) = delete; // C++11 delete 禁止方式，C++98 用 private 来隐藏
UniquePtr<T>& operator=(const UniquePtr<T>& obj) = delete; UniquePtr<T>& operator=(const UniquePtr<T>& obj) = delete;
~UniquePtr() ~UniquePtr()
@ -78,15 +78,15 @@ private:
//{ //{
// UniquePtr<int> up1(new int(10)); // UniquePtr<int> up1(new int(10));
// cout << "up1:" << up1.get() << " *ptr:" << *up1 << endl; // cout << "up1:" << up1.get() << " *ptr:" << *up1 << endl;
// UniquePtr<int> up2(std::move(up1)); // 控制权变更 // UniquePtr<int> up2(std::move(up1)); // 控制权变更
// cout << "up1:" << up1.get() << endl; // nullptr, 此时 up1 已无控制权 // cout << "up1:" << up1.get() << endl; // nullptr, 此时 up1 已无控制权
// cout << "up2:" << up2.get() << " *ptr:" << *up2 << endl; // cout << "up2:" << up2.get() << " *ptr:" << *up2 << endl;
// //
// UniquePtr<int> up3(new int(30)); // UniquePtr<int> up3(new int(30));
// UniquePtr<int> up4(new int(40)); // UniquePtr<int> up4(new int(40));
// cout << "up3:" << up3.get() << " *ptr:" << *up3 << endl; // cout << "up3:" << up3.get() << " *ptr:" << *up3 << endl;
// cout << "up4:" << up4.get() << " *ptr:" << *up4 << endl; // cout << "up4:" << up4.get() << " *ptr:" << *up4 << endl;
// up3 = std::move(up2); // 控制权变更 // up3 = std::move(up2); // 控制权变更
// cout << "up3:" << up3.get() << " *ptr:" << *up3 << endl; // cout << "up3:" << up3.get() << " *ptr:" << *up3 << endl;
// cout << "up4:" << up4.get() << " *ptr:" << *up4 << endl; // cout << "up4:" << up4.get() << " *ptr:" << *up4 << endl;
// up3.swap(up4); // up3.swap(up4);
@ -101,7 +101,7 @@ private:
//} //}
/******************************************************************* /*******************************************************************
* 打印结果: * 打印结果:
* no default constructor * no default constructor
* up1:01355E78 *ptr:10 * up1:01355E78 *ptr:10
* move constructor * move constructor