多线程,临界区的使用

以下程序用通知事件和临界区来同步
// Multhread.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <stdio.h>
#include <iostream>
#include <process.h>
#include <windows.h>//for HANDLE

using namespace std;

long g_nNum;
unsigned int __stdcall Fun(void* pPM);
const int THREAD_NUM = 10;
HANDLE g_hThreadEvent;
//临界区
CRITICAL_SECTION g_csThreadCode;

int main()
{
    printf("线程同步事件\n");
    g_hThreadEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
    InitializeCriticalSection(&g_csThreadCode);

    HANDLE handle[THREAD_NUM];
    g_nNum = 0;
    int i = 0;
    while (i < THREAD_NUM)
    {
        //创建NUM个线程
        handle[i] = (HANDLE)_beginthreadex(NULL, 0, Fun, &i, 0, NULL);
        WaitForSingleObject(g_hThreadEvent, INFINITE);
        ++i;
    }
    //等待所有线程运行完毕
    WaitForMultipleObjects(THREAD_NUM, handle, TRUE, INFINITE);

    //销毁事件和关键段
    CloseHandle(g_hThreadEvent);
    DeleteCriticalSection(&g_csThreadCode);
    getchar();
    return 0;
}

unsigned int __stdcall Fun(void* pPM)
{
    int nThreadNum = *(int *)pPM;
    SetEvent(g_hThreadEvent);
    Sleep(50);
    
    EnterCriticalSection(&g_csThreadCode);//进入临界区
    g_nNum++;
    //Sleep(10);
    cout << "\n线程ID = " << nThreadNum << "  全局资源值为: " << g_nNum;
    LeaveCriticalSection(&g_csThreadCode);//退出临界区
    return 0;
}