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My Dll communicates with external customised hardware and gets the data and the processed result is sent back to the client application.In the mean time if another application calls the same exported function of the dll, i will not be able send the accurate results(the hardware will not respond untill prevoius commands are serviced) to any of the client application.
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You can use some info shared among DLL instances to prevent multiple processes to access the DLL functions at the same time. A quite similar problem was neatly addressed in this article [^] (see Code Details section).
Hope that helps.
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.
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If it's an explicit load then wrap LoadLibrary with a named mutex.
If it's an implicit load then wrap all access points with one or more named muticies.
...cmk
Save the whales - collect the whole set
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i understand the logic.
Can you please send me some sample snippets if you have any? I have not worked on mutex yet and feeling difficult to understand from articles and MSDN.
My applications will be explicitly loading the Dll's.
So i understand i need to wrap the LoadLibraray() fnction in my Client application by mutex. But how will the other application know about this?
Mutex should be defined where?
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Read: http://msdn2.microsoft.com/en-us/library/ms682411.aspx[^]
In your other reply you say it is one function you need to protect.
Something like this should work (you should add appropriate error checking):
void YOUR_EXPORT_API YourFunc ( void )
{
HANDLE mtx = CreateMutex(NULL, FALSE, "YourUniqueMutexName");
WaitForSingleObject(mtx, INFINITE);
ReleaseMutex(mtx);
CloseHandle(mtx);
}
If you can you may want to move the CreateMutex/CloseHandle code to the app init/term functions.
What happens in the above code is that the first app to call YourFunc creates a new mutex. Any other apps (or threads in the creating app) that call YourFunc will get a handle to the existing mutex when they call CreateMutex. After that the Wait function allows only one thread (across all apps) to execute the protected code at a time.
...cmk
Save the whales - collect the whole set
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Thanks much for your help and Code!!
My problem is solved.
I read MSDN and learnt a new concept of using Mutex!!
Thanks again!!
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Hello,
how to to get information about how many disk is available,
and about all partitions if there more then one!?
What functions to use for that?
regards
termal
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termal wrote: What functions to use for that?
How about GetDiskFreeSpace() ?
"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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Hello,
thank you for your info, that is what i mean!
regards
termal
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termal wrote: GetDiskFreeSpace
better use GetDiskFreeSpaceEx
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You
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Hi,
thanks for info!
termal
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Hi
I am using a Tab control in my project but when I change the color of dialog box a gray tab control seemed vary bad.How can I change the color of tab control?I couldn't find this subject in my book and also my knowledge is not enough to understand the articles about owner-drawn tab controls in this site.I do not want any gray area in my dialog box.How can I do that?And if you know where can I find a source about that subject in internet,please tell it to me.
Thanks
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try to create your own class derived from CTabCtrl
then overload WM_ERASEBACKGROUND message
and in this message you can set the default background color of your control
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How do you fill a ellipse on a CDC without Floodfill?
thanks
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Select a different-colored brush into the DC before drawing. There's also FillRect() .
"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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Can you use FillRect() for an Ellipse or was that a morning glitch? I'm having those myself this morning.
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bob16972 wrote: Can you use FillRect() for an Ellipse...
I guess not. I was just assuming you'd give it a starting point somewhere within the shape and it would fill until it reached the edges. I guess that's what FloodFill() is for!
"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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thanks
yes it's very easy to fill a ellipse with current selected brush.
in fact my problem it's to do a pie chart. I draw a pie chart with 3 parts. How i can fill with colore each parts??
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jerome_data wrote: I draw a pie chart with 3 parts. How i can fill with colore each parts??
Can you call Pie() three times, using a different brush each time?
[edit]
I just tried this and it worked fine.
[/edit]
"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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yes it's work very fine thanksssss
i need to do now a code to calculate coordinate point from a percent value.
thanks
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jerome_data wrote: i need to do now a code to calculate coordinate point from a percent value.
See this article[^]
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bob16972 wrote: Can you use FillRect() for an Ellipse
Sure you can! It has the side-effect of squaring off the ellipse's corners though
"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder
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In my project, there are some kinds of data needed to be export to excel,html and word documents, and I want to produce these files without installing excel or word program.Does anyone know suitable active controls that can do this job effectively?
Developing environment:Visual C++ 6 with MFC.
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throne888 wrote: ...I want to produce these files without installing excel or word program.
Which will require you to know the format of those files. There may indeed be a solution, but I don't know of any other way except through Office Automation.
"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
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Hi ,
I am trying to build a win32 application with a GUI like photoshop's , where there are those tool windows , which are always active ( highlighted ) .
Should i be using MDI ?
Also , where can i find resources to help me build a more PRO GUI for my applications ?
Thanks in advance
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