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Hi everyone,
I have a UDP client running.
I wanted to know if I can use the flag MSG_PEEK when doing a Receive. I keep getting an error (WSAEMSGSIZE (10040)) which says the message is too long.
What is currently in the buffer is a 12 bytes message. I want to just peek at the first 4 bytes so that I know how to process it. I have a temp buffer declared as 4 bytes to store and determine what kind of message it is, but it keeps reading all 12 bytes, trancating, and returning an error. What I want it to do is peek at the buffer and then process each type of message. In the process method of each type, that is where I would like to take the info out the buffer.
I do this same method for TCP client and it works fine.
What should I be doing to have this perform like I want and how I have it in my TCP client app?
Thanks in advance.
Jimmy
Just cause I am 15, doesn't mean I'm dumb! (I'll really be 4 on Feb. 29...the year 2004)
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With UDP sockets you have to call ReceiveFrom instead of Receive. Thats why it works with TCP.
Bunburry
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Developing, building, and testing. How do it the best? Learning from the world leader - Microsoft
I'm very interested in how the developing/build/testing workflow @ Microsoft looks like. I think Microsoft as world leader in software developing business must have a very good workflow. Does anyone know how the development flow @ Microsoft looks like?
I'm also interested in the workflow in your company perhaps the workflow in your company better then @ Microsoft? What do you think about test driven development?
Regards,
Gicio
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Back when the company I was working for was embarking on a big BizTalk Server project, we had two Microsoft consultants come in for a week and brief us on what we needed in order to mature to the next level. I don't remember everything that was discussed but one thing that stuck with me was out of all the ideas/suggestions that are submitted (for new products or enhancements to existing products), only 10% of them are approved, which is why most of their products do very well. They can quickly determine if the work can be justified. If it can't, they don't bother with it. In most other companies, work is work, and it all gets done whether it has an ROI or not. It was quickly brought to their attention that Microsoft is the only company that could afford to be proactive, and that the other companies had no choice but to be reactive. They acknowledge that.
Shortly thereafter, myself and a few others took a trip to Redmond for some more training on getting the BizTalk Server project to its next phase. The net result was that BizTalk Server, as good as it was, was not yet ready for the task at hand. The other group that we were working with, Washington Publishing, was the copyright holder for an EDI document that was being fed into BizTalk Server. The output was supposed to be something generic that could be imported into SQL Server. Anyway, enough of that.
Microsoft definitely has some processes in place. For a price, they are happy to teach them to you. Surprisingly, most of what was taught to us was nothing new. It was mostly a matter of just doing it.
Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?
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Hi.
My previous question was whether I need the platform SDk for WInsock. I want to use WSA.., connect, etc type of calls instead of MFC ones. I assume the answer is still the same and I do not need the platform SDK.
The next question I got is this. EACH port can only connect to ONE server. Is this correct?
I want to write a client class that will connect to a server. It will then spawn a thread to handle the reading of the data as it comes so as to get the data as soon as possible. If only ONE connection is possible, then I can just use the event method to signal that data has come in. Is this the best way? THis way I know when things come in and when a write is finished if I need it. I don't think I will have too many clients on the computer so that creating a thread for each socket port is probably OK. I just want to make sure my thinking is along the right lines.
THanks!!!
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Each port can simultaneously connect to a single server, so that is correct.
However, you can start a seperate thread which monitors ALL the open ports. Afterall, checking a port isn't a long process, so this shouldn't cause any timing issues.
Now, instead of opening dozens of ports, I suggest that you formulate the data sent by the server, if that is possible. Place a identification number in front of each data packet to tell your program from which 'virtual port' this packet is coming from. This way you can open 'multiple' connections to a single server using only single physical port.
The event driven method is appropriate, considering that you created a seperate thread to handle the port. Now, when a port event occurs, the handler thread is notified. At this point, save the data to a temporary variable, free the port and notify your application that new data is available. This way the port is freed quickly, but the transfer of data from the port to the application isn't in a terrible hurry. This is called data buffering.
-Antti Keskinen
----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.
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Sorry, 'bout that, now I understand what you are asking.
No you don't need SDK.
Theoretically, constructing WsaData explicitly requires SockAddr_in struct but I had an instructor once who said that dynamic sockets are possible but never showed me how.
Also, I've never tried to use a "Send" socket and a "Receive" socket (I assume this is what you are trying). I'll have to think more about this one using winsock2.
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Stan the man wrote:
EACH port can only connect to ONE server. Is this correct?
1. Yes, but only if you use TCP, because it is connection oriented.
2. No, if use UDP datagramms. Datagramms are "broadcasted" therefore they can have several recipients.
Bunburry
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Hi,
How can I evaluate the value of checkbox called "check1" (or something like it), in my setup project, if the box is checked, I need to place a shortcut on the desktop!
Thanks!
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If this is MFC, use CButton::GetCheck(). Otherwise, send a BM_GETCHECK message to the control.
Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?
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OK, but this isn't MFC --> this is a SETUP project!
As far is I know this one has nothing to do with MFC (or am I wrong?)
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Well, since your question was posted in the VC++ forum, it was assumed to be a VC++ question or an MFC question.
Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?
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That's right,
but where do I have to place my question (I don't know!)?
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My first thought would be in a forum specializing in the language in which your setup application is written.
Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?
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Okay,
I've written my application in mfc c++, but what has that to do with my setup project? I jsut need an answer for the development projects, not for mfc!
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BoudewijnEctor wrote:
I've written my application in mfc c++...
Yet here you indicate otherwise. I initially provided you an answer for both VC++ and MFC. One of them will apply.
BoudewijnEctor wrote:
I jsut need an answer for the development projects, not for mfc!
The fact that you are writing a setup project (it could be a game, an accounting package, a printer driver, etc) is irrelevant. You wanted to know how to "evaluate the value" of a checkbox and I provided you with two options. If those answers are not right for your situation, perhaps you should rethink your initial question.
Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?
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what setup ? there are tons of them ...
Maximilien Lincourt
"Never underestimate the bandwidth of a station wagon filled with backup tapes." ("Computer Networks" by Andrew S Tannenbaum )
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My program is setting the default printer to Distiller which is then receiving the print job and writing PDF's to the specified location i.e. Distillers Port.
On some Windows 2000 PC's we are unable to set the Distiller Port, so I was wondering whether it is possible to reset the Distiller Port in code, on Windows 2000.
I am setting the Default Printer to Distiller with SetDefaultPrinter( ... ) and then issuing a Windows Broadcast message to all apps. For NT4 I am using WriteProfileString( ... ) and then issung a Broadcast message.
I would appreciate any help, or advise from anyone who has had a similar issue with Distiller and not being able to Add a PDF Port to a Windows 2000 PC.
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Hi everyone,
I wasn't sure if this is a COM issue or MFC issue, so I also posted this question in the COM message board...
I have an MFC app (with a CWinApp-derived object) that uses COM objects (Crystal Reports). The COM library is imported into my project via the #import directive. I'm using VStudio 6.0 sp5.
I've created a global object called _com_init:
struct ComInit {
ComInit() { ::CoInitialize(NULL); }
~ComInit() { ::CoUninitialize(); }
} _com_init_;
This way, I guarantee that COM will initialize before the _main() and terminate after the _main().
When my program reaches ~ComInit() and calls ::CoUninitialize(), I see the following message in my Debug Output Window:
First-chance exception in MyApp.exe (OLE32.DLL): 0xC0000005: Access Violation.
Any ideas? I've looked up other CoUninitialize threads in these forums, but couldn't figure out something that would solve my problem...
Thanks.
/=/=/=/=
Deus
/=/=/=/=
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The most important aspect of using COM with MFC is to initialize and uninitialize COM correctly.
Instead of using a global object, I suggest that you put ::CoInitialize(NULL) in the start of your CWinApp-derived application's 'InitInstance' and ::CoUninitialize() o the end of the same application's 'ExitInstance' (Before return call). This way, the initialization and uninitialization are handled smoothly.
As for the actual problem, I have just about no idea of where it lies. I suggest using the above methodology to utilize COM server.
-Antti Keskinen
----------------------------------------------
The definition of impossible is strictly dependant
on what we think is possible.
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I already tried that. It was a lot worse when I did that. The result was about a zillion "Access Violation" messages instead of just one. I think there was also a "Stack overflow" message somewhere among them...
Also, it may have been unclear earlier, but the program doesn't abort with an Access Violation MESSAGE BOX. I only see the message in the debug output window. If I try what you suggested, I also get an Access Violation message box...
/=/=/=/=
Deus
/=/=/=/=
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Have you determined that the COM server is indeed initialized?
if(::CoInitialize()!=S_OK)
MessageBox(_T("COM INIT FAILED"),NULL,MB_ICONERROR);
??
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Yes, I have. I get S_OK.
/=/=/=/=
Deus
/=/=/=/=
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HI.
I am starting out on Winsock stuff. I have been lookin gat the articles. For using any Winsock type commands, I need the Platform SDK? Is there an way without the Platform SDK? I was looking at how to down load this, do I only need the CORE SDK?
Thanks.
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For winsock stuff, you dont need anything other than what you get in VisualStudio.
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