C++实现多线程安全的单例模式 自己 测试

根据自己另外那篇文章: 弄的:http://blog.chinaunix.net/uid-25958655-id-4297540.html
WINDOWS VC++2010下测试通过

MultiThreadSingleton.h:

#ifndef MULTI_THREAD_SINGLETON_H_
#define MULTI_THREAD_SINGLETON_H_

#ifdef WIN32
#include<iostream>
#include<windows.h>

#endif //WIN32



#ifdef WIN32
class locker
{
public:
    inline locker() { m_hMutex=CreateMutex(NULL,FALSE,NULL); std::cout<<"Locker::Locker() " ;}
    inline ~locker() { CloseHandle(m_hMutex); }
    inline void lock() { WaitForSingleObject(m_hMutex, INFINITE); }
    inline void unlock() { ReleaseMutex(m_hMutex); }
private:
    HANDLE m_hMutex;
};
#endif


/*
 * this class is responsible for the running log of tinyJSE
 * there should only exist one instance of tinyLog,
 * so we use singleton to implement tinyLog
 */
class tinyLog
{
public:
    static tinyLog *GetInstance();
    static void WriteLog(const char *FORMAT,...);
    int iTestThread;
private:
    tinyLog();
    ~tinyLog();
private:
        static tinyLog *log; //设置为static
    static locker llock;

};

#endif

MultiThreadSingleton.cpp:

#ifdef WIN32
#include<iostream>
#include<windows.h>

#endif //WIN32


#include "MultiThreadSingleton.h"



tinyLog * tinyLog::log = NULL;
locker tinyLog::llock;

tinyLog::tinyLog()
{
    printf("called tinyLog::tinyLog()\n");
}

tinyLog::~tinyLog()
{
}

/*
 * get the pointer to the only instance of tinyLog
 * use double check to assure only one instance is created
 */
tinyLog * tinyLog::GetInstance()
{
    if(NULL == log)
    {//double check
        llock.lock();
        if(NULL == log)
        {
            log = new tinyLog(); //这里最好换成{ tinyLog * tmpLog=new tinyLog(); log=tmpLog; } 原因请看我另外一篇"C++中多线程Singleton的实现"

        }
        llock.unlock();
    }
    return log;
}

/*
 * Unified handling of the log of tinyJSE
 */
void tinyLog::WriteLog(const char *FORMAT,...)
{
    va_list args;

    va_start(args, FORMAT);

    llock.lock();

    vfprintf(stdout,FORMAT,args);

    llock.unlock();

    va_end(args);

}

main.cpp:

#ifdef WIN32
#include<iostream>
#include<windows.h>

#endif



#include "MultiThreadSingleton.h"

DWORD WINAPI Fun1Proc(
    LPVOID lpParameter
    )
{
    std::cout<<"thread "<< (int)lpParameter<< ": " ;
    tinyLog *pty1=tinyLog::GetInstance();
    pty1->iTestThread ++;
    std::cout<< "in Fun1Proc thread pty="<< pty1 << "  "<< std::endl ;
    Sleep(20000);
    return 0;
}



int main()
{
    HANDLE hThread[10];


    int i;
    for(i=0; i<10; i++)
        hThread[i] = CreateThread(NULL, 0, Fun1Proc, (LPVOID)i, 0, NULL);
    std::cin>>i;


    return 0;
}

以下是运行结果: 虽然结果看起来杂乱无章: 但是我们看到tinyLog()构造函数中只被调用的了一次, 且他们的地址都相同:

Locker::Locker() thread thread 0thread thread thread thread thread 2thread threa
d thread : 37481: 569called tinyLog::tinyLog()
: : : : : : : : in Fun1Proc thread pty=in Fun1Proc thread pty=in Fun1Proc thread
 pty=in Fun1Proc thread pty=in Fun1Proc thread pty=in Fun1Proc thread pty=in Fun
1Proc thread pty=in Fun1Proc thread pty=in Fun1Proc thread pty=in Fun1Proc threa
d pty=00397250003972500039725000397250003972500039725000397250003972500039725000
397250