下载本文示例代码
多线程的变量同步问题,一直是困扰广大VC程序员的一大难题,其主要表现是在多线程模式下,线程间共享变量的存取不再安全,程序员无法确保变量的值在存取时是否准确可信,对此,微软给出的解决方案是使用临界区对象加以保护。但是,临界区对象使用太过于繁琐,需要不断地加锁和解锁,很容易搞忘,引起新的Bug。
这里,东楼给出多线程安全的变量模板,由此模板,可派生绝大多数变量类型,实现线程间各种变量的安全互访。本模板已经重载了几乎全部运算符,大家可以很方便地使用++、――、+=、-=等操作,方便编程使用。
#ifndef _XiaoGeMVarTempleteHasBeenDefined_#define _XiaoGeMVarTempleteHasBeenDefined_#include <Afxmt.h>
template <class MVAR_TYPE>class MVAR{public: MVAR() { m_pBegin=new char[sizeof(MVAR_TYPE)]; memset(m_pBegin,0,sizeof(MVAR_TYPE)); } ~MVAR(){delete[] m_pBegin;} int GetLength(){return sizeof(MVAR_TYPE);} MVAR_TYPE Set(MVAR_TYPE& value) { m_csLockHandle.Lock(); memcpy(m_pBegin,(char*)&value,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return value; } MVAR_TYPE Get() { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); myValue=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator~() { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue=~myValue; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator (int) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue ; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator () { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue ; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator--(int) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue--; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator--() { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue--; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator (MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue =value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator-(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue-=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator*(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue*=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator/(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue/=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator&(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue&=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator|(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue|=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator^(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue^=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator =(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue =value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator-=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue-=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator*=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue*=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator/=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue/=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator&=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue&=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator|=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue|=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator^=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue^=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } BOOL operator>(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue>value); m_csLockHandle.Unlock(); return bRet; } BOOL operator<(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue<value); m_csLockHandle.Unlock(); return bRet; } BOOL operator>=(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue>=value); m_csLockHandle.Unlock(); return bRet; } BOOL operator<=(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue<=value); m_csLockHandle.Unlock(); return bRet; } BOOL operator==(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue==value); m_csLockHandle.Unlock(); return bRet; } BOOL operator!=(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue!=value); m_csLockHandle.Unlock(); return bRet; }private: char* m_pBegin; CCriticalSection m_csLockHandle;};
typedef MVAR<char> MCHAR;typedef MVAR<unsigned char> MUCHAR;typedef MVAR<short> MSHORT;typedef MVAR<unsigned short> MUSHORT;typedef MVAR<int> MINT;typedef MVAR<unsigned int> MUINT;typedef MVAR<long> MLONG;typedef MVAR<unsigned long> MULONG;typedef MVAR<float> MFLOAT;typedef MVAR<double> MDOUBLE;typedef MVAR<BOOL> MBOOL;typedef MVAR<LPVOID> MLPVOID;typedef MVAR<BYTE> MBYTE;
#endif //_XiaoGeMVarTempleteHasBeenDefined_
大家只需要把这段代码放入Mvar.h文件,在stdafx.h中include这个头文件,即可在程序中自由使用变量。以上仅仅是东楼根据自己的需要,派生的几个常用类型,大家也可以尝试派生新的类型使用。 注意,当派生的变量需要取得其中的值时,必须使用.Get()成员函数,这是唯一一点不如普通变量方便的地方。
下面给出一个控制例子,大家可以参考:
#includen “mvar.h”class CMyClass{public:CMyClass();~ CMyClass();protected: static UINT MyThread(LPVOID pParam); //线程函数 MBOOL m_bThreadContinue; //线程循环标志 MUINT m_nThreadCount; //线程计数器};
CMyClass::CMyClass(){ m_bThreadContinue=TRUE; m_nThreadCount=0; int i; //开启100个线程 for(i=0;i<100;i ) { m_nThreadCount ; //一定要在开启线程前累加线程计数器 AfxBeginThread(MyThread,this); //开启线程,以本对象指针为参数}}CMyClass::~CMyClass(){ m_bThreadContinue=FALSE; //通知线程关闭 while(m_nThreadCount!=0) {} //等待所有线程退出 //此时退出,线程已经全部安全退出!!!}UINT CMyClass::MyThread(LPVOID pParam){ CMyClass* pThis=(CMyClass*)pParam; //得到本对象指针 while(pThis->m_bThreadContinue) { //循环体 Sleep(100);}pThis->m_nThreadCount --; //线程计数器减1return 0;}
如果有问题,欢迎大家提问,如果有Bug,也请大家及时向东楼提出。
多线程的变量同步问题,一直是困扰广大VC程序员的一大难题,其主要表现是在多线程模式下,线程间共享变量的存取不再安全,程序员无法确保变量的值在存取时是否准确可信,对此,微软给出的解决方案是使用临界区对象加以保护。但是,临界区对象使用太过于繁琐,需要不断地加锁和解锁,很容易搞忘,引起新的Bug。
这里,东楼给出多线程安全的变量模板,由此模板,可派生绝大多数变量类型,实现线程间各种变量的安全互访。本模板已经重载了几乎全部运算符,大家可以很方便地使用++、――、+=、-=等操作,方便编程使用。
#ifndef _XiaoGeMVarTempleteHasBeenDefined_#define _XiaoGeMVarTempleteHasBeenDefined_#include <Afxmt.h>
template <class MVAR_TYPE>class MVAR{public: MVAR() { m_pBegin=new char[sizeof(MVAR_TYPE)]; memset(m_pBegin,0,sizeof(MVAR_TYPE)); } ~MVAR(){delete[] m_pBegin;} int GetLength(){return sizeof(MVAR_TYPE);} MVAR_TYPE Set(MVAR_TYPE& value) { m_csLockHandle.Lock(); memcpy(m_pBegin,(char*)&value,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return value; } MVAR_TYPE Get() { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); myValue=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator~() { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue=~myValue; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator (int) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue ; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator () { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue ; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator--(int) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue--; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator--() { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue--; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator (MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue =value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator-(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue-=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator*(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue*=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator/(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue/=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator&(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue&=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator|(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue|=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator^(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue^=value; m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator =(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue =value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator-=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue-=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator*=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue*=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator/=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue/=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator&=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue&=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator|=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue|=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } MVAR_TYPE operator^=(MVAR_TYPE value) { MVAR_TYPE myValue; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); myValue^=value; memcpy(m_pBegin,(char*)&myValue,sizeof(MVAR_TYPE)); m_csLockHandle.Unlock(); return myValue; } BOOL operator>(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue>value); m_csLockHandle.Unlock(); return bRet; } BOOL operator<(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue<value); m_csLockHandle.Unlock(); return bRet; } BOOL operator>=(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue>=value); m_csLockHandle.Unlock(); return bRet; } BOOL operator<=(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue<=value); m_csLockHandle.Unlock(); return bRet; } BOOL operator==(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue==value); m_csLockHandle.Unlock(); return bRet; } BOOL operator!=(MVAR_TYPE value) { MVAR_TYPE myValue; BOOL bRet; m_csLockHandle.Lock(); memcpy((char*)&myValue,m_pBegin,sizeof(MVAR_TYPE)); bRet=(myValue!=value); m_csLockHandle.Unlock(); return bRet; }private: char* m_pBegin; CCriticalSection m_csLockHandle;};
typedef MVAR<char> MCHAR;typedef MVAR<unsigned char> MUCHAR;typedef MVAR<short> MSHORT;typedef MVAR<unsigned short> MUSHORT;typedef MVAR<int> MINT;typedef MVAR<unsigned int> MUINT;typedef MVAR<long> MLONG;typedef MVAR<unsigned long> MULONG;typedef MVAR<float> MFLOAT;typedef MVAR<double> MDOUBLE;typedef MVAR<BOOL> MBOOL;typedef MVAR<LPVOID> MLPVOID;typedef MVAR<BYTE> MBYTE;
#endif //_XiaoGeMVarTempleteHasBeenDefined_
大家只需要把这段代码放入Mvar.h文件,在stdafx.h中include这个头文件,即可在程序中自由使用变量。以上仅仅是东楼根据自己的需要,派生的几个常用类型,大家也可以尝试派生新的类型使用。 注意,当派生的变量需要取得其中的值时,必须使用.Get()成员函数,这是唯一一点不如普通变量方便的地方。
下面给出一个控制例子,大家可以参考:
#includen “mvar.h”class CMyClass{public:CMyClass();~ CMyClass();protected: static UINT MyThread(LPVOID pParam); //线程函数 MBOOL m_bThreadContinue; //线程循环标志 MUINT m_nThreadCount; //线程计数器};
CMyClass::CMyClass(){ m_bThreadContinue=TRUE; m_nThreadCount=0; int i; //开启100个线程 for(i=0;i<100;i ) { m_nThreadCount ; //一定要在开启线程前累加线程计数器 AfxBeginThread(MyThread,this); //开启线程,以本对象指针为参数}}CMyClass::~CMyClass(){ m_bThreadContinue=FALSE; //通知线程关闭 while(m_nThreadCount!=0) {} //等待所有线程退出 //此时退出,线程已经全部安全退出!!!}UINT CMyClass::MyThread(LPVOID pParam){ CMyClass* pThis=(CMyClass*)pParam; //得到本对象指针 while(pThis->m_bThreadContinue) { //循环体 Sleep(100);}pThis->m_nThreadCount --; //线程计数器减1return 0;}
如果有问题,欢迎大家提问,如果有Bug,也请大家及时向东楼提出。
下载本文示例代码
多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板多线程安全的变量模板