Only one process can be run, and processes can be run

Only one process can be run, and processes can be run

// Copyright (c) // All rights reserved.////Describe : Only can run single program.//Author   : Qing//Date     : 2014-08-14#ifndef __SINGLE_PROGRAM_H__#define __SINGLE_PROGRAM_H__#include <string>#include <Windows.h>namespace Qing{    class SingleProgram    {    public:        SingleProgram(void) : m_Mutex(NULL)        {        }        ~SingleProgram(void)        {            MandatoryDestoryInstance();        }        bool CreateSingleInstance(const std::string &ProgramName)        {            m_Mutex = ::CreateMutexA(NULL, TRUE, ProgramName.c_str());            DWORD LastError =::GetLastError();            if(m_Mutex != NULL)            {                ::ReleaseMutex(m_Mutex);            }            if(LastError == ERROR_ALREADY_EXISTS)            {                m_Mutex = NULL;                return false;            }            return true;        }        void MandatoryDestoryInstance()        {            if(m_Mutex != NULL)            {                ::CloseHandle(m_Mutex);                m_Mutex = NULL;            }        }    private:        SingleProgram(const SingleProgram&);        SingleProgram& operator=(const SingleProgram&);    private:        HANDLE m_Mutex;    };}#endif