学步园

问题：

编写一个程序，开启3个线程，这3个线程的ID分别为A、B、C，每个线程将自己的ID在屏幕上打印10遍，要求输出结果必须按ABC的顺序显示；如：ABCABC….依次递推。

解答：

在这里我们将题简化为循环打印5遍

HANDLE g_eventA;
HANDLE g_eventB;
HANDLE g_eventC;
unsigned int __stdcall threadFuncA(LPVOID param)
{
 int id = GetCurrentThreadId();
	for (int i = 0; i<5; ++i)
	{
		WaitForSingleObject(g_eventA,INFINITE);
		cout <<"线程ID="<<id<<endl;
		SetEvent(g_eventB);
		Sleep(200);
	}
	return 0;
}
unsigned int __stdcall threadFuncB(LPVOID param)
{
	 int id = GetCurrentThreadId();
	for (int i = 0; i<5; ++i)
	{
		WaitForSingleObject(g_eventB,INFINITE);
		cout <<"线程ID="<<id<<endl;
		SetEvent(g_eventC);
				Sleep(200);
	}
	return 0;
}
unsigned int __stdcall threadFuncC(LPVOID param)
{
	 int id = GetCurrentThreadId();
	for (int i = 0; i<5; ++i)
	{
		WaitForSingleObject(g_eventC,INFINITE);
		cout <<"线程ID="<<id<<endl;
		SetEvent(g_eventA);
				Sleep(200);
	}
	return 0;
}
int main(int argc, char **argv)
{
	g_eventA = CreateEvent(NULL,false,true,NULL);
	g_eventB = CreateEvent(NULL,false,false,NULL);
	g_eventC = CreateEvent(NULL,false,false,NULL);

	HANDLE hdl[3];
	hdl[0] =(HANDLE)_beginthreadex(NULL,0,threadFuncA,NULL,0,NULL);
	hdl[1] =(HANDLE)_beginthreadex(NULL,0,threadFuncB,NULL,0,NULL);
	hdl[2] =(HANDLE)_beginthreadex(NULL,0,threadFuncC,NULL,0,NULL);

	WaitForMultipleObjects(3,hdl,true,INFINITE);
	for (int i =0; i<3; ++i)
	{
		CloseHandle(hdl[i]);
	}
	CloseHandle(g_eventA);
	CloseHandle(g_eventB);
	CloseHandle(g_eventC);
	return 0;
}