程序代码：

#include <iostream>
#include <process.h>
#include <stdlib.h>
#include <stdio.h>
#include <windows.h>
using namespace std;


volatile long g_nLoginCount;
unsigned int _stdcall Fun(void *pPM);
const int THREAD_NUM=50;
unsigned int _stdcall Fun(void *pPM)
{
    Sleep(1000);
    //g_nLoginCount++;
    InterLockedIncrement((LPLONG)&g_nLoginCount);
    Sleep(50);
    return 0;
}
int main()
{
    int num=20;
    while(num--)
    {
        g_nLoginCount=0;
    HANDLE handle[THREAD_NUM];
    for(int i=0;i<THREAD_NUM;i++)
    {
        handle[i]=(HANDLE)_beginthreadex(NULL,0,Fun,NULL,0,NULL);
    }
        WaitForMultipleObjects(THREAD_NUM,handle,TRUE,INFINITE);
        //printf("有%d个用户登录后记录结果是%dn",THREAD_NUM,g_nLoginCount);
        cout<<"有"<<THREAD_NUM<<"个用户登录后记录结果是"<<g_nLoginCount<<endl;
    }
        return 0;
   
}