vc++深入详解中的多线程例子，在多核CPU下出错分析。

lph110 2012-01-03 11:15:59 


#include <WINDOWS.H>

#include <IOSTREAM>

using namespace std;

/*

 * 在单核单CPU下正常运行

 */

DWORD WINAPI Fun1Proc(LPVOID lpParameter);

DWORD WINAPI Fun2Proc(LPVOID lpParameter);



int tickets = 100;

HANDLE g_hEvent;

void main()

{

	HANDLE hThread1,hThread2;

	hThread1 = CreateThread(NULL,0,Fun1Proc,NULL,0,NULL);

	hThread2 = CreateThread(NULL,0,Fun2Proc,NULL,0,NULL);

	CloseHandle(hThread1);

	CloseHandle(hThread2);

	

	g_hEvent = CreateEvent(NULL,FALSE,FALSE,NULL);

	SetEvent(g_hEvent);



	Sleep(4000);

	CloseHandle(g_hEvent);

}



DWORD WINAPI Fun1Proc(LPVOID lpParameter)

{

	while(TRUE)

	{

		WaitForSingleObject(g_hEvent,INFINITE);

		//ResetEvent(g_hEvent);

		if (tickets > 0)

		{

			Sleep(1);

			cout<<"Thread1 sell ticket:"<<tickets--<<endl;

		}

		else

			break;

		SetEvent(g_hEvent);

	}

	return 0;

}



DWORD WINAPI Fun2Proc(LPVOID lpParameter)

{

	while(TRUE)

	{

		WaitForSingleObject(g_hEvent,INFINITE);

		//ResetEvent(g_hEvent);

		if (tickets > 0)

		{

			Sleep(1);

			cout<<"Thread2 sell ticket:"<<tickets--<<endl;

		}

		else

			break;

		SetEvent(g_hEvent);

	}

	return 0;

}

在多核cpu下运行结果出错。执行结果如下：


Thread1 sell ticTkherte:ad120 0s
ell ticket:99
Thread1 sell tickTehtr:e9a8d
2 sell ticket:97
Thread1 sell tickeTth:r9e6a
d2 sell ticket:95
Thread1 sell ticket:94
Thread2 sell tickeTth:r93e
ad1 sell ticket:92
Thread2 sell tickTehtr:e9a1d
1 sell ticket:90
Thread2 sell ticket:8T9
hread1 sell ticket:88
Thread2 sell tickTehtr:e8a7d
1 sell ticket:86
Thread2 sell tickTehtr:e8a5d1
sell ticket:84
TThhrreeaadd12 sseellll ttiicckkeett::8832

TThhrreeada1d 2s eslell lt iticckkeett::8810

TThhreraeda1d 2s eslell lt itcikcekte:t7:97
8
TThhrreeaadd12 sseellll ttiicckkeett::7776

Thread1 sell tickeTth:r7e5a
d2 sell ticket:74
Thread1 sell ticket:73
Thread2 sell ticket:72
Thread1 sell tickeTth:r7e1a
d2 sell ticket:70
Thread1 sell ticket:69
Thread2 sell ticket:68
Thread1 sell tickeTth:r6e7a
d2 sell ticket:66
Thread1 sell ticket:65
Thread2 sell ticket:64
Thread1 sellT htriecakd2e ts:e6l3l
ticket:62
TThhrreeaadd12 sseellll ttiicckkeett::6610

Thread1 sell tickTehtr:e5a9d
2 sell ticket:58
Thread1 sell ticket:57
Thread2 sell ticket:56
Thread1 sell ticket:55
Thread2 sell ticketT:h5r4
ead1 sell ticket:53
Thread2 sell ticket:52
Thread1 sell tickeTth:r5e1a
d2 sell ticket:50
Thread1 sell ticket:49
Thread2 sell ticket:48
Thread1 sell ticket:47
Thread2 sell ticket:46T
hread1 sell ticket:45
Thread2 sell tickTehtr:e4a4d
1 sell ticket:43
Thread2 sell ticket:42
Thread1 sell tickTehtr:e4a1d
2 sell ticket:40
Thread1 sell ticket:39
Thread2 sell ticket:38
Thread1 sell ticketT:h3r7e
ad2 sell ticket:36
Thread1 sell ticket:35
Thread2 sell tickTehtr:e3a4d
1 sell ticket:33
Thread2 sell tickTehtr:e3a2d
1 sell ticket:31
Thread2 sell ticket:30
Thread1 sell ticket:29
Thread2 sell ticket:28
Thread1 sell ticket:27
Thread2 sell tickeTth:r2e6a
d1 sell ticket:25
Thread2 sell ticket:24
Thread1 sell ticket:23
Thread2 sell tickTehtr:e2a2d
1 sell ticket:21
Thread2 sell ticket:20
Thread1 sell ticket:19
Thread2 sell ticket:T1h8r
ead1 sell ticket:17
Thread2 sell ticket:16
Thread1 sell tickeTth:r1e5a
d2 sell ticket:14
Thread1 sell ticket:13
Thread2 sell ticket:1T2h
read1 sell ticket:11
Thread2 sell ticket:10
Thread1 sell ticket:9
Thread2 sell ticket:8
Thread1 sell ticket:Th7r
ead2 sell ticket:6
Thread1 sell ticket:5
Thread2 sell ticket:Th4re
ad1 sell ticket:3
Thread2 sell ticket:2
Thread1 sell ticket:Thr1e
ad2 sell ticket:0
Press any key to continue


结果分析，在运行线程时g_hEvent可能未创建。

代码改为如下变正常了。




#include <WINDOWS.H>

#include <IOSTREAM>

using namespace std;

/*

 * 在单核单CPU下正常运行

 */

DWORD WINAPI Fun1Proc(LPVOID lpParameter);

DWORD WINAPI Fun2Proc(LPVOID lpParameter);



int tickets = 100;

HANDLE g_hEvent;

void main()

{

	g_hEvent = CreateEvent(NULL,FALSE,FALSE,NULL);

	SetEvent(g_hEvent);



	HANDLE hThread1,hThread2;

	hThread1 = CreateThread(NULL,0,Fun1Proc,NULL,0,NULL);

	hThread2 = CreateThread(NULL,0,Fun2Proc,NULL,0,NULL);

	CloseHandle(hThread1);

	CloseHandle(hThread2);

	

	//g_hEvent = CreateEvent(NULL,FALSE,FALSE,NULL);

	//SetEvent(g_hEvent);



	Sleep(4000);

	CloseHandle(g_hEvent);

}



DWORD WINAPI Fun1Proc(LPVOID lpParameter)

{

	while(TRUE)

	{

		WaitForSingleObject(g_hEvent,INFINITE);

		//ResetEvent(g_hEvent);

		if (tickets > 0)

		{

			Sleep(1);

			cout<<"Thread1 sell ticket:"<<tickets--<<endl;

		}

		else

			break;

		SetEvent(g_hEvent);

	}

	return 0;

}



DWORD WINAPI Fun2Proc(LPVOID lpParameter)

{

	while(TRUE)

	{

		WaitForSingleObject(g_hEvent,INFINITE);

		//ResetEvent(g_hEvent);

		if (tickets > 0)

		{

			Sleep(1);

			cout<<"Thread2 sell ticket:"<<tickets--<<endl;

		}

		else

			break;

		SetEvent(g_hEvent);

	}

	return 0;

}


经测试正常了。

这个分析对吗



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taodm 2012-01-03
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楼主用的什么编译器？VC6这个垃圾货？
lph110 2012-01-03
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证实了确实是这个问题。


#include <WINDOWS.H>

#include <IOSTREAM>

using namespace std;

/*

* 在单核单CPU下正常运行

*/

DWORD WINAPI Fun1Proc(LPVOID lpParameter);

DWORD WINAPI Fun2Proc(LPVOID lpParameter);



int tickets = 100;

HANDLE g_hEvent;

void main()

{

	//g_hEvent = CreateEvent(NULL,FALSE,FALSE,NULL);

	//SetEvent(g_hEvent);

	

	HANDLE hThread1,hThread2;

	hThread1 = CreateThread(NULL,0,Fun1Proc,NULL,0,NULL);

	hThread2 = CreateThread(NULL,0,Fun2Proc,NULL,0,NULL);

	CloseHandle(hThread1);

	CloseHandle(hThread2);

	

	g_hEvent = CreateEvent(NULL,FALSE,FALSE,NULL);

	SetEvent(g_hEvent);

	

	Sleep(4000);

	CloseHandle(g_hEvent);

}



DWORD WINAPI Fun1Proc(LPVOID lpParameter)

{

	while(TRUE)

	{

		

		if(WAIT_FAILED ==WaitForSingleObject(g_hEvent,INFINITE))

		{

			CHAR szBuf[80]; 

			DWORD dw = GetLastError();

			sprintf(szBuf,"WaitForSingleObject is fail,ErrorNo. is %u\n",dw);

			printf(szBuf);

			break;

		}

		//ResetEvent(g_hEvent);

		if (tickets > 0)

		{

			Sleep(1);

			cout<<"Thread1 sell ticket:"<<tickets--<<endl;

		}

		else

			break;

		SetEvent(g_hEvent);

	}

	return 0;

}



DWORD WINAPI Fun2Proc(LPVOID lpParameter)

{

	while(TRUE)

	{

		if(WAIT_FAILED ==WaitForSingleObject(g_hEvent,INFINITE))

		{

			CHAR szBuf[80]; 

			DWORD dw = GetLastError();

			sprintf(szBuf,"WaitForSingleObject is fail,ErrorNo. is %u\n",dw);

			printf(szBuf);

			break;

		}

		//ResetEvent(g_hEvent);

		if (tickets > 0)

		{

			Sleep(1);

			cout<<"Thread2 sell ticket:"<<tickets--<<endl;

		}

		else

			break;

		SetEvent(g_hEvent);

	}

	return 0;

}
lph110 2012-01-03
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代码改成这个。
有时候2个线程都不能运行。



#include <iostream>



#include <windows.h>



using namespace std;

/*

 * 在多核单CPU，多核多CPU下正常运行

 */

DWORD WINAPI Fun1Proc(LPVOID lpParameter);

DWORD WINAPI Fun2Proc(LPVOID lpParameter);



int tickets = 100;

HANDLE g_hEvent;

//CCriticalSection g_clsCriticalSection;



void main()

{

	HANDLE hThread1,hThread2;

	hThread1 = CreateThread(NULL,0,Fun1Proc,NULL,0,NULL);

	hThread2 = CreateThread(NULL,0,Fun2Proc,NULL,0,NULL);

	CloseHandle(hThread1);

	CloseHandle(hThread2);

	

	g_hEvent = CreateEvent(NULL,FALSE,TRUE,NULL);

	//SetEvent(g_hEvent);

	WaitForSingleObject(hThread1,INFINITE);

	WaitForSingleObject(hThread2,INFINITE);

	Sleep(4000);

	//CloseHandle(g_hEvent);

}



DWORD WINAPI Fun1Proc(LPVOID lpParameter)

{

	while(TRUE)

	{

		WaitForSingleObject(g_hEvent,INFINITE);

		//ResetEvent(g_hEvent);

		//g_clsCriticalSection.Lock();

		if (tickets > 0)

		{

			Sleep(1);

			cout<<"Thread1 sell ticket:"<<tickets--<<endl;

		}

		else

			break;

		//g_clsCriticalSection.Unlock();

		SetEvent(g_hEvent);

	}

	return 0;

}



DWORD WINAPI Fun2Proc(LPVOID lpParameter)

{

	while(TRUE)

	{

		WaitForSingleObject(g_hEvent,INFINITE);

		//ResetEvent(g_hEvent);

		//g_clsCriticalSection.Lock();

		if (tickets > 0)

		{

			Sleep(1);

			cout<<"Thread2 sell ticket:"<<tickets--<<endl;

		}

		else

			break;

		//g_clsCriticalSection.Unlock();

		SetEvent(g_hEvent);

	}

	return 0;

}
taodm 2012-01-03
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珍惜生命，远离VC6.
不要用它来浪费大家的时间了。
lph110 2012-01-03
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就是vc6 sp6，时不时的老卡死在编译或链接的时候。
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