C / C++ / MFC

Socket Send-Receive Synchronization

17-Oct-07 2:08

cydd wrote:
You are wonderful
That was of great help.

thank you.

cydd wrote:
I ll defenitely get back to you if I need any further assistance...
Hope you ll help me

sure. with pleasure.
but what about the suggestion i have made.
please make it a habbit.

Suggestion to the members:
prefix your main thread subject with [SOLVED] if it is solved.
chandu.

Syamlal S Nair16-Oct-07 23:58

Syamlal S Nair

16-Oct-07 23:58

hi,

I have a server and client application, which are running on different machines and communicating each other thru sockets. Its using TCP sockets, for which i am using Win32 APIs(WSAStartup, socket, bind, send etc.). I am sending text data from client to server periodically, at a rate of 50 ms. When i run both client and server in one machine, the sending and receival are proper. But when i run them on different machines, sending and receival are not synchronized. When i display the buffer after a receival operation at the server end, it shows same data appended to itself several times. I guess this problem is bcoz the rate of sending and receival are not the same, or the network delay.

All ur suggestions are most welcome..

Thanks in advance,

SYAMLAL

Cedric Moonen17-Oct-07 0:07

Cedric Moonen

17-Oct-07 0:07

How are you reading the incoming data exactly ? You need to supply the number of bytes you want to read when you call the recv function. So, in order to read only one message, read only the size of the message. If it is variable, then the best way to do it would be to send the size of the message before the message. You read the size (1, 2 or 4 bytes, depending of the maximum size of your packet) and then you read exactly that number of bytes to get your packet.

Cédric Moonen
Software developer

Charting control [v1.2]

ThatsAlok17-Oct-07 1:40

ThatsAlok

17-Oct-07 1:40

Is Single Thread is dealing with every thing or there are multiple client thread!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
Never mind - my own stupidity is the source of every "problem" - Mixture

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
Support CRY- Child Relief and You

David Crow17-Oct-07 3:43

David Crow

17-Oct-07 3:43

Are you using a synchronous or an asynchronous socket?

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

led mike17-Oct-07 4:26

led mike

17-Oct-07 4:26

SyamlalS wrote:
sending and receival are not synchronized.

If you need them synchronized then you have to develop a protocol and processor for the protocol, you don't get that for free with TCP. All TCP does is guarantee the packet order. If your statement accurately describes your problem you could use a finite state machine.

Print Preview

AnayKulkarni16-Oct-07 23:53

AnayKulkarni

16-Oct-07 23:53

hello to all,
right now i am doing a project in which i have created two new view classes, other than regular view class which gets created at the time of creating ur application.Lets say those two view classes are "CA1View" and "CB1View" and after that i followed a general method for print previewing which we normally follows i.e created a view class "CReportPreview" which has a base class as "CPreviewView" and wrote methods in it which contains the code of previewing, when i access A1View then i destroy B1View and viceversa, now to get an idea where i am getting error plz refer following code,

In "CA1View" class,

CPrintPreviewState::CPrintPreviewState()
{
// set defaults
nIDMainPane = AFX_IDW_PANE_FIRST;
//nIDMainPane = 1 ;
dwStates = AFX_CONTROLBAR_MASK(AFX_IDW_STATUS_BAR);
// status bar visible if available

hMenu = NULL;
pViewActiveOld = NULL;
//hAccelTable = NULL;
}

void CA1View::OnPrintPreview()
{
CPrintPreviewState* pState = new CPrintPreviewState;

// get default print info

if(!DoPrintPreview(AFX_IDD_PREVIEW_TOOLBAR, this,
RUNTIME_CLASS(CReportPreview), pState))
{
// In derived classes, reverse special window handling here for
// Preview failure case.
TRACE0("Error: DoPrintPreview failed.\n");
AfxMessageBox(AFX_IDP_COMMAND_FAILURE);
delete pState; // Preview failed to initialize, delete State
}

// CView::OnFilePrintPreview();

}

--------------------------------------------------------------------------
In "CB1View" class,

CPrintPreviewState::CPrintPreviewState()
{
// set defaults
nIDMainPane = AFX_IDW_PANE_FIRST;
//nIDMainPane = 1 ;
dwStates = AFX_CONTROLBAR_MASK(AFX_IDW_STATUS_BAR);
// status bar visible if available

hMenu = NULL;
pViewActiveOld = NULL;
//hAccelTable = NULL;
}

void CB1View::OnPrintPreview()
{
CPrintPreviewState* pState = new CPrintPreviewState;

// get default print info

if(!DoPrintPreview(AFX_IDD_PREVIEW_TOOLBAR, this,
RUNTIME_CLASS(CReportPreview), pState))
{
// In derived classes, reverse special window handling here for
// Preview failure case.
TRACE0("Error: DoPrintPreview failed.\n");
AfxMessageBox(AFX_IDP_COMMAND_FAILURE);
delete pState; // Preview failed to initialize, delete State
}

// CView::OnFilePrintPreview();

}

but when i rebuild the code i get following linker errors,

1)
B1View.obj : error LNK2005: "public: __thiscall CPrintPreviewState::CPrintPreviewState(void)" (??0CPrintPreviewState@@QAE@XZ) already defined in A1View.obj

2)
B1View.obj : error LNK2005: "public: int __thiscall CView::DoPrintPreview(unsigned int,class CView *,struct CRuntimeClass *,struct CPrintPreviewState *)" (?DoPrintPreview@CView@@QAEHIPAV1@PAUCRuntimeClass@@PAUCPrintPreviewState@@@Z
) already defined in A1View.obj

3)
Debug/Program.exe : fatal error LNK1169: one or more multiply defined symbols found
Error executing link.exe.

what to do? can any body help me plz its urgent plz

Thanks and Regards,

Anay

Nelek17-Oct-07 0:13

Nelek

17-Oct-07 0:13

Mmm, you are giving the same name to functions in different classes, because of that comes the linker error.

If you need to know which class is calling the preview... why don't you code the functions in just one place and pass a parameter to specify who is calling the function? With this, the error you are having should not come anymore.

By the way... Are you in Win32 - MFC?? Because you already have printing support by default there.

Greetings.

--------
M.D.V.

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?

Help me to understand what I'm saying, and I'll explain it better to you

Wink | ;)

David Crow17-Oct-07 3:40

David Crow

17-Oct-07 3:40

Nelek wrote:
By the way... Are you in Win32 - MFC??

Did you miss the use of TRACE0, AfxMessageBox, CView, and RUNTIME_CLASS? Roll eyes | :rolleyes:

Nelek17-Oct-07 5:30

Nelek

17-Oct-07 5:30

mmmm,

maybe yes... Dead | X|

ThatsAlok17-Oct-07 20:29

ThatsAlok

17-Oct-07 20:29

Nelek wrote:
mmmm, maybe yes...

he he he what about OutputDebugString Smile | :)

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
Support CRY- Child Relief and You

Make Main Thread sleep [modified]

David Crow17-Oct-07 3:42

David Crow

17-Oct-07 3:42

You have a default constructor for CPrintPreviewState in two .cpp files. Why?

GauranG Shah16-Oct-07 23:47

16-Oct-07 23:47

Hello Friends,

Is there any way we can make the main thread sleep from within the another user created theread.

I am using the code like below

void fun(void)
{
 ...
 ...
   
   if(Some Condition)
     {
        CreateThread(0, 0, ( LPTHREAD_START_ROUTINE ) ThreadProc, 0, 0, 0 );
        //I want to show some dialog continuously and also the same function (fun) to be running. 
//And So I am using the Thread to call the Function (<code>fun()</code> )       
        DialogBox(...); //
    }
    if (Some Other condition)
        {
           //Here I want the main thread to sleep for some time
         }  

}

void ThreadProc(void)
{

    fun();

}

-- modified at 6:01 Wednesday 17th October, 2007

toxcct16-Oct-07 23:52

toxcct

16-Oct-07 23:52

GauranG33 wrote:
from within the another user created theread

WTF are you trying to say here ?! OMG | :OMG:

[VisualCalc][Binary Guide][CommDialogs] | [Forums Guidelines]

GauranG Shah17-Oct-07 0:11

17-Oct-07 0:11

Now I hav modified the Question. and Put some Example code.

ThatsAlok17-Oct-07 1:24

ThatsAlok

17-Oct-07 1:24

toxcct wrote:
WTF are you trying to say here ?!

Don't Know [ Smile | :)

]

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
Support CRY- Child Relief and You

chandu00416-Oct-07 23:56

16-Oct-07 23:56

that depends on the design and implementation of both of your threads.
and also, the context, where the sleep is required matters.
can you share them with us?

----------------------------------------------------------

Suggestion to the members:
prefix your main thread subject with [SOLVED] if it is solved.
chandu.

chandu00417-Oct-07 0:46

17-Oct-07 0:46

it seems that, you are landing in some sort of recursion here.

BTW,
i understood that, you want to do some application, which keeps a dialog displayed until you stop it.
am i right?
if so, then i can guide you better.

GauranG Shah17-Oct-07 1:40

17-Oct-07 1:40

actully I want to display the Dialog Box Continously untill some events happen and also want that my application run in the background and so i am using the thread.

chandu00417-Oct-07 1:51

17-Oct-07 1:51

thats what i meant.
i have one active X control made by me to achieve your task.
if you want, i can share it with u.
you have to use it as follows.
your main thread
{
control.start();
//your code which u call as ur background code here
........
........
//control.stop();
}
here, from ur start to stop function, the dialog will be displayed.

JudyL_MD17-Oct-07 1:51

JudyL_MD

17-Oct-07 1:51

Have the main thread create and display a modeless dialog box. This way the box is displayed but the main thread can keep working.

Judy

ThatsAlok17-Oct-07 2:01

ThatsAlok

17-Oct-07 2:01

GauranG33 wrote:
actully I want to display the Dialog Box Continously untill some events happen and also want that my application run in the background and so i am using the thread.

call a model dialog box.. it block the main thread, and you thread will continue to run in background

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
Support CRY- Child Relief and You

GauranG Shah17-Oct-07 2:28

17-Oct-07 2:28

yes it displays the modeless dialog

JudyL_MD17-Oct-07 2:42

JudyL_MD

17-Oct-07 2:42

That wasn't what I meant. I was addressing your statement from the initial post:

CreateThread(0, 0, ( LPTHREAD_START_ROUTINE ) ThreadProc, 0, 0, 0 );
//I want to show some dialog continuously and also the same function (fun) to be running.
//And So I am using the Thread to call the Function (fun() )
DialogBox(...); //

To accomplish this, consider displaying a modeless dialog box and just directly calling the function. This may not be appropriate for your program - it depends on what the function actually does, but you didn't provide enough information.

Judy

chandu00417-Oct-07 3:01