Programming Forums > Application Development > C++

Ooble · Nov 19th, 2004, 5:34 PM

Of course not - take your time. I'm not paying you - I realise you're giving up your own free time to take a look.

Eggbert · Nov 19th, 2004, 7:00 PM

Let's do this a bit differently, because your code has problems that keep me from getting the same error. Send me your project files so that I can get an exact duplicate of what you're seeing. That's much easier than me trying to wade my way through problematic code given as individual files but meant to be used as a whole.

Ooble · Nov 20th, 2004, 8:36 AM

Gotcha. Sorry for all the trouble this is taking. I'm using Visual C++ .NET - the project's at http://80.1.252.217/Sockets2.zip. If you replace the calls to server() or client() with the CreateThread function, it fails to build.

Thanks for the help.

Eggbert · Nov 20th, 2004, 9:18 AM

Ah, so much easier. The problem is a declaration mismatch. LPTHREAD_START_ROUTINE is defined with the following tag:

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typedef DWORD (WINAPI *PTHREAD_START_ROUTINE)(LPVOID lpThreadParameter);

Which, when we take out all of the fluff, becomes this:

(Toggle Plain Text)

typedef unsigned long (*PTHREAD_START_ROUTINE)(void *arg);

Take out the typedef and pointer to function, then change PTHREAD_START_ROUTINE to server and this is the result:

(Toggle Plain Text)

unsigned long server(void *arg);

Your actual server function is declared as

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int server(void);

So the declarations don't match up. You could use a cast and hope for the best:

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hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)server, &dwThrdParam, 0, &dwThreadID);

Or you could do some research as to why LPTHREAD_START_ROUTINE uses that declaration then decide to either use a cast (if it's safe), or change client and server to do what they're supposed to. I won't make a recommendation because it's beneficial for you if you go through the research steps.

By the way, your program has bugs. Most notable is this one:

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int Socket::error(const char *msg) {
 int errNo = (long)WSAGetLastError();
 std::cout << "Error #" << errNo << ": " << msg << std::endl;
 //
 // Comparing pointers, not strings. This wasn't intended.
 //
 if (msg != "WSAStartup")
  WSACleanup();
	
 return errNo;
}

So you'll want to put on your evil debugger hat and throw any trust in the code away until you've rooted all of the nasties out. Preferrably before you start adding threading code to the application.

Ooble · Nov 20th, 2004, 10:13 AM

Alright - thanks very much for the help. Hopefully it'll be done by tomorrow.

Nov 19th, 2004, 5:34 PM	#11
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	Of course not - take your time. I'm not paying you - I realise you're giving up your own free time to take a look. __________________ Me :: You :: Them

Nov 20th, 2004, 8:36 AM	#13
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	Gotcha. Sorry for all the trouble this is taking. I'm using Visual C++ .NET - the project's at http://80.1.252.217/Sockets2.zip. If you replace the calls to server() or client() with the CreateThread function, it fails to build. Thanks for the help. __________________ Me :: You :: Them

Nov 20th, 2004, 9:18 AM	#14
Eggbert Professional Programmer Join Date: Nov 2004 Posts: 250 Rep Power: 5	Ah, so much easier. The problem is a declaration mismatch. LPTHREAD_START_ROUTINE is defined with the following tag: (Toggle Plain Text) typedef DWORD (WINAPI PTHREAD_START_ROUTINE)(LPVOID lpThreadParameter); typedef DWORD (WINAPI PTHREAD_START_ROUTINE)(LPVOID lpThreadParameter); Which, when we take out all of the fluff, becomes this: (Toggle Plain Text) typedef unsigned long (PTHREAD_START_ROUTINE)(void arg); typedef unsigned long (PTHREAD_START_ROUTINE)(void arg); Take out the typedef and pointer to function, then change PTHREAD_START_ROUTINE to server and this is the result: (Toggle Plain Text) unsigned long server(void arg); unsigned long server(void arg); Your actual server function is declared as (Toggle Plain Text) int server(void); int server(void); So the declarations don't match up. You could use a cast and hope for the best: (Toggle Plain Text) hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)server, &dwThrdParam, 0, &dwThreadID); hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)server, &dwThrdParam, 0, &dwThreadID); Or you could do some research as to why LPTHREAD_START_ROUTINE uses that declaration then decide to either use a cast (if it's safe), or change client and server to do what they're supposed to. I won't make a recommendation because it's beneficial for you if you go through the research steps. By the way, your program has bugs. Most notable is this one: (Toggle Plain Text) int Socket::error(const char msg) { int errNo = (long)WSAGetLastError(); std::cout << "Error #" << errNo << ": " << msg << std::endl; // // Comparing pointers, not strings. This wasn't intended. // if (msg != "WSAStartup") WSACleanup(); return errNo; } int Socket::error(const char msg) { int errNo = (long)WSAGetLastError(); std::cout << "Error #" << errNo << ": " << msg << std::endl; // // Comparing pointers, not strings. This wasn't intended. // if (msg != "WSAStartup") WSACleanup(); return errNo; } So you'll want to put on your evil debugger hat and throw any trust in the code away until you've rooted all of the nasties out. Preferrably before you start adding threading code to the application.

Nov 20th, 2004, 10:13 AM	#15
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	Alright - thanks very much for the help. Hopefully it'll be done by tomorrow. __________________ Me :: You :: Them

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Nov 19th, 2004, 7:00 PM	#12
Eggbert Professional Programmer Join Date: Nov 2004 Posts: 250 Rep Power: 5	Let's do this a bit differently, because your code has problems that keep me from getting the same error. Send me your project files so that I can get an exact duplicate of what you're seeing. That's much easier than me trying to wade my way through problematic code given as individual files but meant to be used as a whole.

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Programming Forums > Application Development > C++

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