线程同步有关问题

#include<stdio.h>#include <Windows.h>long g_x=0;DWORD WINAPI ThreadProc(PVOID pvParam){         InterlockedExchangeAdd(&g_x,1);    return 0;}DWORD WINAPI ThreadProc2(PVOID pvParam){    InterlockedExchangeAdd(&g_x,1);    return 0;}int main(){            HANDLE hTherad[2];            hTherad[0]=CreateThread(NULL,0,ThreadProc,0,0,0);            hTherad[1]=CreateThread(NULL,0,ThreadProc2,0,0,0);            printf("%ld\n",g_x);            CloseHandle(hTherad[0]);            CloseHandle(hTherad[1]);            return 0;}