多线程：InterlockedIncrement

#include <stdio.h>  
#include <windows.h>  
volatile long g_nLoginCount; //登录次数  
unsigned int __stdcall Fun(void *pPM); //线程函数  
const DWORD THREAD_NUM = 50;//启动线程数 

DWORD WINAPI ThreadFun(void *pPM)  
{  
    Sleep(100);//some work should to do  
    //g_nLoginCount++;  
    InterlockedIncrement((LPLONG)&g_nLoginCount);  
    Sleep(50);  
    return 0;  
}  

int main()  
{  
    printf("     原子操作 Interlocked系列函数的使用\n");  
    printf(" -- by MoreWindows( http://blog.csdn.net/MoreWindows ) --\n\n");  
      
    //重复20次以便观察多线程访问同一资源时导致的冲突  
    int num= 20;  
    while (num--)  
    {     
        g_nLoginCount = 0;  
        int i;  
        HANDLE  handle[THREAD_NUM];  
        for (i = 0; i < THREAD_NUM; i++)  
            handle[i] = CreateThread(NULL, 0, ThreadFun, NULL, 0, NULL);  
        WaitForMultipleObjects(THREAD_NUM, handle, TRUE, INFINITE);  
        printf("有%d个用户登录后记录结果是%d\n", THREAD_NUM, g_nLoginCount);  
    }  
    return 0;  
}