用户模式下线程同步之关键段

用户模式下线程同步之关键段
//注意其中的: InitializeCriticalSection是必须的,否则会报访问异常

// mycrical_section.cpp : Defines the entry point for the application.

//



#include "stdafx.h"





const int count=10;



int g_nSum =0;

CRITICAL_SECTION g_cs;



DWORD WINAPI FirstThread(PVOID pvParam)

{

EnterCriticalSection(&g_cs);

g_nSum =0;

for(int n=1;n<=count;n++)

{

g_nSum +=n;

}

LeaveCriticalSection(&g_cs);



return g_nSum;

}



DWORD WINAPI SecondThread(PVOID pvParam)

{

EnterCriticalSection(&g_cs);

g_nSum =0;

for(int n=1;n<=count;n++)

{

g_nSum +=n;

}

LeaveCriticalSection(&g_cs);



return g_nSum;

}



int APIENTRY WinMain(HINSTANCE hInstance,

HINSTANCE hPrevInstance,

LPSTR lpCmdLine,

int nCmdShow)

{

// TODO: Place code here.





DWORD dwThreadId1=0;

DWORD dwThreadId2=0;

InitializeCriticalSection(&g_cs);
//初始化，不加会报访问异常



CreateThread(NULL,0UL,FirstThread,NULL,0,&dwThreadId1);

CreateThread(NULL,0UL,SecondThread,NULL,0,&dwThreadId2);

Sleep(50);

DeleteCriticalSection(&g_cs); //清理工作

return 0;

}