C / C++ / MFC

Re: How to "link" two C++ applications ?

29-Apr-21 2:18

See @Victor-Nijegorodov's message below.

Message Closed

28-Apr-21 4:41

Member 14968771

28-Apr-21 4:41

Message Closed

modified 15-May-23 19:07pm.

Richard MacCutchan28-Apr-21 5:41

Re: How to "link" two C++ applications ?

28-Apr-21 5:41

Member 14968771 wrote:
I still cannot use my "old - few years " account.

Then post a question at Bugs and Suggestions[^] and the administrators will help you.

Sean Ewington28-Apr-21 5:45

Sean Ewington

28-Apr-21 5:45

Send me an email (sean@codeproject.com) and I will help get you access to your old account.

Thanks,
Sean Ewington
CodeProject

WSARecv question

ForNow25-Apr-21 17:17

CAyncSocket::Detach Fails _AFX_SOCK_THREAD_STATE* pState-> m_hSocketWindow == NULL

25-Apr-21 17:17

The WSARecv winsock api has the ability to do overlapped i/o the second parameter is the number of WSABUFs

The sixth parameter is a overlapped structure, the 5th parameter of the overlapped is one or MORE WSAevents I would be doing a

C++

WSAWaitForMultipleEvents

with each event corresponding to a buffer when WSAevent ...n is signaled WSABUF ... n would have data I would then have to put the buffer back together think I got it right

thanks

Forgot one more thing I am doing WSAAsyncSelect to have a receive notification sent to the window when that message is sent I am assuming i/o is Imminent should I create a thread to do the

C++

WSAWaitForMultipleEvents

or since I got a notification the receive is about to happen doing it in the window under the main thread is ok

thanks

modified 25-Apr-21 23:30pm.

ForNow25-Apr-21 3:57

Re: CAyncSocket::Detach Fails _AFX_SOCK_THREAD_STATE* pState-> m_hSocketWindow == NULL

25-Apr-21 3:57

hI
I create four CAsynSocket Classes in four CwinThread classes When I first create them Socket (with notification events) bind ioctl, setsockopt. I follow the CASynSocket::Socket call to sockcore.cpp and

C++

pState-> m_hSocketWindow

has a valid Hwnd Value. The context of the creation of sockets in the CwinApp after my main CFrameWnd has been created.

I then start a conversation with the server (connect send and then receive). It is at a point that I would like to give the work over to a modeless dialog. this is where things go wrong. After getting a message
from the server I try to do a detach which goes to

C++

CAsyncSocket::AsyncSelect(long lEvent)

however at this point

C++

_AFX_SOCK_THREAD_STATE* pState-> m_hSocketWindow == NULL

is NULL

Since I was debugging this in release mode I never got the subsequent assert on this.

First off in the documentation for CAsynSocket there is no mention that i need a Hwnd to process the class when I first did the CAsynSocket::Socket call with the event notification that I wanted to be informed on
I did notice that

C++

pState-> m_hSocketWindow

had a valid window

When I first started using CAsyncSocket I know very little about TCPI/IP or OO

at this point looking at Winscok API it has much more flexability so much so it seem I dont necessary need a valid Hwnd but a kernel object such as that from CreateEvent will do
more so It seems if I want to pass notification to a different windows I just do another call to

WSAAsyncSelect

with a new HWND

Still I am wondering why

C++

pState-> m_hSocketWindow

went to NULL

Mircea Neacsu25-Apr-21 5:38

Re: CAyncSocket::Detach Fails _AFX_SOCK_THREAD_STATE* pState-> m_hSocketWindow == NULL

25-Apr-21 5:38

It's probably not fair to send you down a different path, but many years ago I had similar problems and, having some spare time, I decided to make my own set of wrappers for Windows Sockets API. Over time it has grown into a quite capable set of objects that allow you to work with sockets just like you work with C++ streams.

I've wrote a series of articles here and you can take a look see if they are of any help to you:
- Windows Sockets Streams[^]
- Windows Sockets Streams Part II - Multi-Threaded TCP Servers[^]
- Windows Sockets Streams Part III - HTTP Server[^]

Latest version of code can be downloaded from GitHub[^].

Mircea

ForNow25-Apr-21 5:52

Re: CAyncSocket::Detach Fails _AFX_SOCK_THREAD_STATE* pState-> m_hSocketWindow == NULL

25-Apr-21 5:52

Thanks talk about fair I don’t think it’s fair for Microsoft to Have us use CAsyncSocket

Just my opinion

Victor Nijegorodov25-Apr-21 5:49

Victor Nijegorodov

25-Apr-21 5:49

I'd recommend you to check out this great Joe Newcomer's essay: A Rewrite of KB192570: An MFC Asynchronous Socket Example Done Right

Re: CAyncSocket::Detach Fails _AFX_SOCK_THREAD_STATE* pState-> m_hSocketWindow == NULL

ForNow25-Apr-21 6:01

25-Apr-21 6:01

He has a detach on the server side more so before any conversation gets going
My scenario involves the main windows looks if anyone wants to start a conversation with the server if I see it happens a conversation with the server is initiated I want to pass off that socket to a mode less dialog
Thanks

Plz solve it

SARKER MD KAWSER ALOM24-Apr-21 13:11

SARKER MD KAWSER ALOM

24-Apr-21 13:11

Count the digits of a given number c programming

k505424-Apr-21 13:26

k5054

24-Apr-21 13:26

Ok. Did that. Did you?

Keep Calm and Carry On

Dave Kreskowiak24-Apr-21 15:13

Dave Kreskowiak

24-Apr-21 15:13

That's not how it works around here. We're not here to do your work for you.

We'll help you with your code if you got specific questions or problems, but that's it.

Asking questions is a skill
CodeProject Forum Guidelines
Google: C# How to debug code
Seriously, go read these articles.

Dave Kreskowiak

Aghast (nj)24-Apr-21 21:15

Aghast (nj)

24-Apr-21 21:15

Quote:
Count the digits of a given number c programming

You don't specify what kind of number it is (floating point, integer), nor how it is provided.

Is the number coming in as a string, for example from argv passed to main? Is the number passed in to a function as a parameter? Does the function need a particular name? Is the number allowed to be negative? Is there a maximum value for the number? Will there be decimal points? Is the number base 10, or base 2, or base 16, or is there a prefix at the front that specifies the radix?

What should the result be if no number is given, or an invalid number is given?

Are there any unit test cases that would provide a good example of how this is supposed to work?

Victor Nijegorodov24-Apr-21 22:08

Victor Nijegorodov

24-Apr-21 22:08

SARKER MD KAWSER ALOM wrote:
Count the digits of a given number c programming

First try to count the digits of a given number without c programming. Only with a peace of paper and a pencil!

DLL he11 - multiple versions of Visual Studio - professional guidance needed - management of SDKs.

Jerry Jeremiah4-May-21 19:41

Jerry Jeremiah

4-May-21 19:41

#include <stdio.h>
#include <math.h>
int main() {
    int number = 1234567;
    int digits = log10(number)+1;
    printf("%d has %d digits\n",number,digits);
}

Try it here[^]

charlieg20-Apr-21 12:17

charlieg

20-Apr-21 12:17

I have an ancient DLL that began life with VC++ 6. It also uses Zlib for compression, again VC++ 6.
Fast forward a boat load of years and I now have a test app in VS2019. Can't load the DLL. Cannot find old debug libraries, etc.

Given that you have a DLL, you don't necessarily have the ability to recompile it. Let's say we cannot for the moment. Am I left installing ancient SDKs so that those DLLs are available for my custom dll? Don't think how to fix this, I'm trying to understand how to manage MS's myriad versions of SDKS all over my laptop. What do you do to limit the insanity?

Next question - best, most sane approach to move forward? Seems to me I need to rebuild the dll, the test app, etc so they all sync up. But I'm concerned about my customer elsewhere in the world. Do they need to install and SDK? I suspect I need to create an MSI that includes specific runtime kits.

Appreciate any guidance.

Charlie Gilley
<italic>Stuck in a dysfunctional matrix from which I must escape...

"Where liberty dwells, there is my country." B. Franklin, 1783
“They who can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.” BF, 1759

Re: DLL he11 - multiple versions of Visual Studio - professional guidance needed - management of SDKs.

Mircea Neacsu20-Apr-21 13:28

Re: DLL he11 - multiple versions of Visual Studio - professional guidance needed - management of SDKs.

20-Apr-21 13:28

Not sure if it will fit your case but here is how I got about a similar problem:
1. make a clean virtual machine (VMware, VirtualBox, whatever you want)
2. install your DLL and use DEPENDS to find what missing SDK libraries you need
3. try to run your test app and fine tune between different versions of SDK until you make it run.

The advantage of working on a VM is that you can go back to known snapshot points and not get the "it runs on my machine" situation.

Going forward, I'd say the best thing would be to rebuild your DLL with as little external dependencies as possible. Link everything, including the runtime libraries, as static libraries. That way you can distribute your DLL without worrying about needed SDKs.

Mircea

Daniel Pfeffer20-Apr-21 21:07

Daniel Pfeffer

20-Apr-21 21:07

This is good advice, with one caveat.

Linking with static libraries will solve the problem only if the only parameters passed between the caller and the DLL are simple objects (char, int, ...), pointers to simple objects, or pointers to arrays of simple objects. If you try to pass something like a FILE*, there is no guarantee that the caller and the DLL agree on the format.

Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.
-- 6079 Smith W.

Re: DLL he11 - multiple versions of Visual Studio - professional guidance needed - management of SDKs.

charlieg21-Apr-21 1:38

charlieg

21-Apr-21 1:38

Truth there. The good news is that I know who my customers are and all of the data types are simple.
Shudder, I cannot imagine passing a file pointer but I guess someone might do it Smile | :)

Re: DLL he11 - multiple versions of Visual Studio - professional guidance needed - management of SDKs.

charlieg21-Apr-21 1:36

charlieg

21-Apr-21 1:36

I admit I'm rusty here and rebuilding my knowledge base on how all of this works. I do have a clean Xp machines, excellent suggestion.

Re: DLL he11 - multiple versions of Visual Studio - professional guidance needed - management of SDKs.

Richard MacCutchan20-Apr-21 21:25

Re: DLL he11 - multiple versions of Visual Studio - professional guidance needed - management of SDKs.

20-Apr-21 21:25

You could try running the code with modern libraries, and it is possible (although less probable) that it would work. But much safer to rebuild completely, since the dependencies are often hidden deep in the libraries or OS. One thing you may like to consider is whether you really need your library as a DLL rather than static. The only advantage of using a dll is in situations where you have multiple active applications that are all calling in to it. If it is only used by a single application then a static library, or even no library, is a better choice.

Mircea Neacsu21-Apr-21 0:57

Re: DLL he11 - multiple versions of Visual Studio - professional guidance needed - management of SDKs.

21-Apr-21 0:57

Quote:
The only advantage of using a dll is in situations where you have multiple active applications that are all calling in to it.

There are some other cases. Once I had a data collection app that needed to interface with potentially hundreds of different instruments. Having a monolithic app would have been impractical.

Mircea

Richard MacCutchan21-Apr-21 0:59

Re: DLL he11 - multiple versions of Visual Studio - professional guidance needed - management of SDKs.

21-Apr-21 0:59

Well once it is in memory and the dll is loaded it will take up pretty much the same space as it would with a static library.

Mircea Neacsu21-Apr-21 1:09