线程同步问题

// 04 线程同步的问题.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <windows.h>
int g_n;

DWORD WINAPI ThreadPro1(LPVOID lpThreadParameter){
    for (int i = 0; i < 100000; i++)
    {
        g_n++;
        //printf("我在线程1：%d
", g_n);
    }
        //
        //InterlockedAdd((LONG*)&g_n, 1);
    return 0;
}
DWORD WINAPI ThreadPro2(LPVOID lpThreadParameter){
    for (int i = 0; i < 100000; i++)
    {
        g_n++;
        //printf("我在线程2：%d
", g_n);
    }
        //g_n++;
        //InterlockedAdd((LONG*)&g_n, 1);
    return 0;
}
int _tmain(int argc, _TCHAR* argv[]){
    HANDLE hThread1 = 0, hThread2;
    hThread1 = CreateThread(NULL, NULL, ThreadPro1, NULL, NULL, NULL);
    hThread2 = CreateThread(NULL, NULL, ThreadPro2, NULL, NULL, NULL);
    WaitForSingleObject(hThread1, -1);
    WaitForSingleObject(hThread2, -1);
    printf("%d", g_n);
    return 0;
}