多线程3 互锁函数

#include "stdafx.h"
#include "windows.h"
#include "iostream"
#include "process.h"

long number = 0;

unsigned int _stdcall ThreadFunc(void* param)
{
 InterlockedExchangeAdd(&number, 1);
 //number ++;
    return 0;

}

unsigned int _stdcall ThreadFunc2(void *param)
{
 InterlockedExchangeAdd(&number,3);
    //number ++;
 return 0;
}

int _tmain(int argc, _TCHAR* argv[])
{
 HANDLE hThread1 = (HANDLE)_beginthreadex(NULL,0,ThreadFunc,0,0,0);
 HANDLE hThread2 = (HANDLE)_beginthreadex(NULL,0,ThreadFunc2,0,0,0);
 WaitForSingleObject(hThread1, INFINITE);
    WaitForSingleObject(hThread2, INFINITE);
 printf("%d",number);

 return 0;
}

 

注：如果直接++的话，因为在++和移入寄存器的中间，有可能被令一个线程中断，从而导致变量的结果不争确。利用互锁函数，可以避免这种情况的发生。