Cai Song

#include "stdafx.h"
#include <stdio.h>
__declspec(thread) int g_nData = 0; //这就是两个线程都要访问的变量

DWORD WINAPI ThreadProc(LPVOID lpParameter)
{
   g_nData = 5;
   //辅线程睡眠100ms, 保证主线程的g_nData = 10; 语句执行成功
   Sleep(100);
   char szMsg[40] = {0};
   sprintf(szMsg, "Auxi thread, g_nData: %d", g_nData);
   MessageBox(NULL, szMsg, "AuxiThread", MB_ICONINFORMATION);
   return 0;
}

int APIENTRY WinMain(HINSTANCE hInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR     lpCmdLine,
                    int       nCmdShow)
{
   // TODO: Place code here.
   DWORD dwId;
   //创建线程, 并立即启动它
   HANDLE hThread = CreateThread(NULL, 1024, ThreadProc, NULL, 0, &dwId);
   assert(hThread);
   //主线程睡50ms, 保证辅线程的g_nData = 5; 语句执行成功
   Sleep(50);
   g_nData = 10;
   char szMsg[40] = {0};
   sprintf(szMsg, "Result: %d", g_nData);
   MessageBox(NULL, szMsg, "MainThread", MB_ICONINFORMATION);
   return 0;
}