c++设计模式之单例模式

  1 #pragma once
  2 #include <mutex>
  3 
  4 
  5 class singleton
  6 {
  7 public:
  8     static singleton* singleton_;
  9     static singleton* getInstance();
 10     void doSomeThing();
 11 private:
 12     static std::mutex mutex_;
 13     singleton();
 14     ~singleton();
 15 };
 16 
 17 
 18 //singleton.cpp----此为懒汉式
 19 #include "pch.h"
 20 #include <iostream>
 21 #include "singleton.h"
 22 
 23 singleton *singleton::singleton_ = NULL;
 24 std::mutex singleton::mutex_;
 25 
 26 singleton::singleton()
 27 {
 28 }
 29 
 30 
 31 singleton::~singleton()
 32 {
 33     if (singleton_) 
 34     {
 35         delete singleton_;
 36         singleton_ = NULL;
 37     }
 38 }
 39 
 40 singleton* singleton::getInstance() 
 41 {
 42     if (singleton_==NULL)
 43     {
 44         std::lock_guard<std::mutex> lock(mutex_);
 45         if (singleton_==NULL)
 46         {
 47             singleton_ = new singleton();
 48         }
 49     }
 50     return singleton_;
 51 }
 52 
 53 void singleton::doSomeThing() 
 54 {
 55     std::cout << "do some thing!";
 56 }
 57 
 58 //singleton.cpp----此为恶汉式
 59 #include "pch.h"
 60 #include <iostream>
 61 #include "singleton.h"
 62 
 63 singleton *singleton::singleton_ =  new singleton();;
 64 std::mutex singleton::mutex_;
 65 
 66 singleton::singleton()
 67 {
 68 }
 69 
 70 
 71 singleton::~singleton()
 72 {
 73     if (singleton_) 
 74     {
 75         delete singleton_;
 76         singleton_ = NULL;
 77     }
 78 }
 79 
 80 singleton* singleton::getInstance() 
 81 {
 82     return singleton_;
 83 }
 84 
 85 void singleton::doSomeThing() 
 86 {
 87     std::cout << "do some thing!";
 88 }
 89 
 90 
 91 //测试代码
 92 #include "pch.h"
 93 #include <iostream>
 94 #include "singleton.h"
 95 
 96 int main()
 97 {
 98     singleton::getInstance()->doSomeThing();
 99     getchar();
100 }