C / C++ / MFC Discussion Boards

Synchronising Computerson a Small Network

Bram van Kampen30-Nov-07 15:23

30-Nov-07 15:23

Is anyone aware of some software ideas to keep a small number of computers (e.g. 12) synchronised Real Time Clock Wise.
Confused | :confused:

N.B. Terminals range from Win95 to WinXP. We do NOT support Vista.

Bram.

Bram van Kampen

Re: Synchronising Computerson a Small Network

James R. Twine10-Mar-08 5:02

James R. Twine

10-Mar-08 5:02

   Depending on the resolution and/or error range required, you could modify an NTP service to provide higher resolution time values, and have the client's hit it every so often to keep in sync.

   If you need something really closer to Real-Time, there is a special kind of shared memory system that runs on a network using a special kind of NIC (I do not remember the name of the hardware/system). When this memory area is changed by one system, all other systems get an event. This is a pretty fast system, but might be overkill for you.

   Peace!

-=- James
Please rate this message - let me know if I helped or not!<hr></hr>If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
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Re: Synchronising Computerson a Small Network

Bram van Kampen11-Mar-08 12:28

Bram van Kampen

11-Mar-08 12:28

Dont Quite understand Modifying NTP Services.

I have 6 Machines which over a week drift some 6 minutes apart. Nothing to cause a Problem as such, just a bit of a nuisance. I just wondered, has anyone a ready made piece of code you run in the scheduler, and which synchronises the clock in each machine with the Designated Timekeeper. It does not do an awfull lot for Absolute Time, but at least there's only one to adjust.

Regards

Bram van Kampen

Re: Synchronising Computerson a Small Network

James R. Twine11-Mar-08 14:22

James R. Twine

11-Mar-08 14:22

   Windows XP (and 2000 I believe, perhaps even NT 4.0) support syncronizing time from a central server. You can even have them sync-up using a NIST (ITS) time source. See Here[^] for a PDF with information on how to configure Windows to use NIST ITS servers as a time source.

   If you double-click on the clock on your taskbar or select "adjust date/time", you can specify an Internet time source on the Internet Time tab. The server time.windows.com is one server you can use.

   Peace!

key - information - map

james_dixon_200830-Nov-07 15:11

james_dixon_2008

30-Nov-07 15:11

Hi Developers,

I have to write an application where i could link keys with information so that i could use key to get the linked information. Like student name could act as a key and their grades could be information. So if i enter student name i should get his grades. Its like a map class basically. I dont have to use map class, i have to write my own class. So could anyone shed some light like what all would be required to get myself started. I mean what all classes would i be needing and etc I need to get on with this asap.

Any help would be greatly appreciated.

cheers
James

Creating a CPropertySheet-based app

Dr Dan30-Nov-07 11:32

Dr Dan

30-Nov-07 11:32

Hi,

I haven't been able to find anything like this, so I hope I'm not repeating a previous posting.

I'd like to create a CPropertySheet-based application. To start with, I just created a standard dialog-based application and I am trying to hack it around so that it can use CPropertySheet instead of CDialog. It compiles OK, but I'm having run-time problems.

Can anyone give some pointers and details on how to do this? Or point to a posting that had some pointers and details? Or maybe this isn't the best way to do it?

Eventually, I'd like to write my own custom Application Wizard that could be used to auto-generate this.

I'm using Windows XP Pro and Visual Studio 2003 SP1.

Thanks in advance.

Re: Creating a CPropertySheet-based app

Mark Salsbery30-Nov-07 12:17

Mark Salsbery

30-Nov-07 12:17

What kind of runtime problems are you having?

Are you constructing and adding pages to the sheet properly before
calling Create() or DoModal()?

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: Creating a CPropertySheet-based app

Dr Dan30-Nov-07 22:34

Dr Dan

30-Nov-07 22:34

I'm getting

"Unhandled exception at 0x0051d2dc in PropSheetEg.exe: 0xC0000005: Access violation reading location 0xcccccd34."

>> Are you constructing and adding pages to the sheet properly before
>> calling Create() or DoModal()?

Oh, it probably is something silly like that. I need to investigate more.

Thanks for the pointers.

Re: Creating a CPropertySheet-based app

Moak30-Nov-07 14:09

Moak

30-Nov-07 14:09

Here is an introduction to Creating a Property Sheet, hope it helps.

Home page

Re: Creating a CPropertySheet-based app

Alain Rist30-Nov-07 21:50

Alain Rist

30-Nov-07 21:50

You will find a WTL sample here [^].
cheers,
AR

Failed to create empty document

RomTibi30-Nov-07 10:12

RomTibi

30-Nov-07 10:12

I'm building a MFC document based application and, after the Precreate window I receive the message:

Failed to create empty document

Why?

36. When you surround an army, leave an outlet free.
...
Do not press a desperate foe too hard.

SUN-TZU - Art of War

Re: Failed to create empty document

David Crow30-Nov-07 10:45

David Crow

30-Nov-07 10:45

RomTibi wrote:
Why?

Have you messed with (i.e., deleted, renamed) any of your project's menus?

Have you looked in any of MFC's DOC*.CPP files to see what condition causes the AFX_IDP_FAILED_TO_CREATE_DOC message to be displayed?

"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

Re: Failed to create empty document

RomTibi30-Nov-07 19:45

RomTibi

30-Nov-07 19:45

I don't know

No

I'll see and replay if necessary?

Thanks Smile | :)

36. When you surround an army, leave an outlet free.
...
Do not press a desperate foe too hard.

SUN-TZU - Art of War

Set up dimensions

Schehaider_Aymen30-Nov-07 10:00

Schehaider_Aymen

30-Nov-07 10:00

Hi all,

I wanna know what should i type as code to run my prog with a specific dimensions for ma FormView let's say dimensions as X= 120 and Y= 100. ??

Thank ya.

"The Ultimate Limit Is Only Your Imagination."

Re: Set up dimensions

followait30-Nov-07 18:26

followait

30-Nov-07 18:26

CClientDC dc;
dc.SetMapMode(MM_ANISOTROPIC);
CRect rt;
GetClientRect(&rt);
SetWindowExt(120,100);
SetViewportExt(rt.width,rt.height);

Re: Set up dimensions [modified]

Schehaider_Aymen30-Nov-07 22:18

Schehaider_Aymen

30-Nov-07 22:18

hi,
Sorry it doesn't work here teh errors

<br />
void CForthForm::OnInitialUpdate() <br />
{<br />
	CFormView::OnInitialUpdate();<br />
	CClientDC dc;<br />
	dc.SetMapMode(MM_ANISOTROPIC);<br />
	CRect rt;<br />
	GetClientRect(&rt);<br />
	SetWindowExt(1200,134);<br />
	SetViewportExt(rt.width,rt.heigh);<br />

<br />
:\Works\C 6\AutoParall\ForthForm.cpp(69) : error C2512: 'CClientDC' : no appropriate default constructor available<br />
D:\Works\C 6\AutoParall\ForthForm.cpp(73) : error C2065: 'SetWindowExt' : undeclared identifier<br />
D:\Works\C 6\AutoParall\ForthForm.cpp(74) : error C2065: 'SetViewportExt' : undeclared identifier<br />
D:\Works\C 6\AutoParall\ForthForm.cpp(74) : error C2039: 'width' : is not a member of 'CRect'<br />
        c:\program files\microsoft visual studio\vc98\mfc\include\afxwin.h(225) : see declaration of 'CRect'<br />
D:\Works\C 6\AutoParall\ForthForm.cpp(74) : error C2039: 'heigh' : is not a member of 'CRect'<br />
        c:\program files\microsoft visual studio\vc98\mfc\include\afxwin.h(225) : see declaration of 'CRect'<br />
Error executing cl.exe.<br />
Creating browse info file...<br />

PS: I m using the CFormView Class. Frown | :(

othe thing, on which function membe should i modify the code. OnInitialUpdate() or no ??

-- modified at 4:47 Saturday 1st December, 2007

"The Ultimate Limit Is Only Your Imagination."

Re: Set up dimensions

CPallini1-Dec-07 0:22

CPallini

1-Dec-07 0:22

You may just do:

void CForthForm::OnInitialUpdate()
{
  CFormView::OnInitialUpdate();
  SetWindowPos(NULL, 0,0,120,100, SWP_NOMOVE | SWP_NOZORDER);
  //...
}

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Re: Set up dimensions [modified]

Schehaider_Aymen1-Dec-07 0:32

Schehaider_Aymen

1-Dec-07 0:32

sorry doesn't work too. may be i shoul change the 'NULL' to a specific handler var Blush | :O

OK here the prob with images:

default form is here --> http://img132.imageshack.us/img132/681/sanstitre1rh1.th.png

the form that i wanna have is here ---> http://img137.imageshack.us/img137/2641/sanstitre2xn6.th.png

So what should i write.
I m using CFormView class not CDialog. So whazuuup . I m going kill my self if i dont do that . Sigh | :sigh:

-- modified at 7:00 Saturday 1st December, 2007

"The Ultimate Limit Is Only Your Imagination."

Code works when debugging and not when executing

Spykraft30-Nov-07 9:20

Spykraft

30-Nov-07 9:20

Hi,
A piece of code in my application works great when i step thru it while debugging it, but does not work when i execute the application on VC++ 6.0.

Pls note that the app is built in the debug mode (obvious ainnit!).

Any help why it could be happening?!

Cheers!
Adnan

------------------------------------------
Vision is the ability to see the invisible

Re: Code works when debugging and not when executing

Randor 30-Nov-07 9:44

Randor

30-Nov-07 9:44

Could be a number of things. Read this article to see what you should check for.

http://www.flounder.com/debug_release.htm[^]

-Randor (David Delaune)

Re: Code works when debugging and not when executing

Spykraft30-Nov-07 10:41

Spykraft

30-Nov-07 10:41

Thanks, it was a helpful article indeed. But having come across the debug Vs release problems before, this one baffles me a little, cuz both the versions are in debug mode!

Its like the results differ when i step thru the method, and when i directly execute the method. The latter being a correct result.

Frown | :(

------------------------------------
Vision is the ability to see the invisible

Re: Code works when debugging and not when executing

peterchen30-Nov-07 9:56

peterchen

30-Nov-07 9:56

Adding/repeating the article linked:
Race condition is the most likely, if your code includes a chance for that.
Second-highest chance goes to uninitialized variables or using uninitialized pointers, the change caused by different memory initializations.

Be more specific: what does "does not work" mean?

We are a big screwed up dysfunctional psychotic happy family - some more screwed up, others more happy, but everybody's psychotic joint venture definition of CP
My first real C# project | Linkify!|FoldWithUs! | sighist

Re: Code works when debugging and not when executing

Spykraft30-Nov-07 10:44

Spykraft

30-Nov-07 10:44

peterchen wrote:
Race condition is the most likely, if your code includes a chance for that

No chance for a Race condition.

As for the precise problem, well the results differ when I step thru the method and when i directly execute the method.

Correct result being LB_SETCURSEL working with SendDlgItemMessage().

the application is built in the debug mode, so no question of a debug vs release problem.

Uninitialized variables went thru my lil mind too, but why wud it not fail when i "Ctrl+F5" the application, and work when i just "F5" the app??

------------------------------------
Vision is the ability to see the invisible

Re: Code works when debugging and not when executing

peterchen1-Dec-07 3:20

peterchen

1-Dec-07 3:20

You are working at different memory locations depending on running under the debugger or as standalone (even ctrl+F5 vs. double-clicking the exe can show differences...). Normally, in debug builds, memory locations are initilized to the same value, but there are loopholes.

Did you check the return value of SendDlgItemMessage?
Also, there are some patterns to avoid or use when sending messages, especially when focus involved, e.g. changing focus during a focus change message never works correctly.

When running under the debugger step by step, your application will get (and handle) additional killfocus and setfocus messages. Which might at least explain the difference.

Re: Code works when debugging and not when executing

ied30-Nov-07 12:27

ied

30-Nov-07 12:27

Ah VC6...

The compiler is buggy, so if you've tweaked any of the compiler knobs first untweak them. The defaults are the safest & most reliable.

Next, do a full rebuild regardless. Out of sync object files create a variety of mysterious problems.

Assuming a clean build, you might be getting an exception that's masked by the breakpoint trap. I'd probably brute force debug this by just adding TRACE statements to narrow down where the error occurs.

-- Ian

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