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LCI wrote: I have 4 threads that call a method in a .dll
If you want only intraprocess synchronisation, IMHO then go for CriticalSection, and don't bother about the Mutex questions.
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I used this same concept for writing to another file and had no issues.
Here is what i do:
HANDLE hmutex = OpenMutex(MUTEX_ALL_ACCESS. FALSE, TEXT("2354fg-45gefgg"));
if (NULL != hMUTEX)
{
WaitforSingleObject(hMutex, INFINITE);
Begin writing to file
}
ReleaseMutex(hMutex);
CloseHandle(hMutex);
Looks like the mutex returns null so i never get to write to my file.
Maybe there is something wrong with the name(third parameter)??
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OpenMutex get the mutex Handle for an existing mutex. You must have a Mutex Created with CreateMutex. what about Critical section?
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LCI wrote: 1. Do i use CreateMutex or OpenMutex
In the thread initializations, use CreateMutex(). If the mutex already exists then you'll get a
handle to it and GetLastError() returns ERROR_ALREADY_EXISTS. If it's a new mutex you'll still get
a handle to it.
As others have mentioned, you don't need a named mutex if your threads are all in the same process -
which includes your DLL.
LCI wrote: 2. If i use CreateMutex, can someone guide me on where to find the
attribute list for the 1st parameter.
Windows security is beyond the scope of this board, but there is documentation[^]
Pass NULL if in doubt.
LCI wrote: . On both Create and Open Murtex, the last parameter 'LPCSTR' is supposed
to be a name of the mutex. Can i just create any name? Should it
be a GUID?
You can use a GUID (converted to a character string). Any unique string.
But again, no need for a named mutex if you only have one process - you can use a critical section instead.
Mark
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://codeproject.freetls.fastly.net/script/Forums/Images/coffee.gif)
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Hi all,
I have a TCHAR string i want to retrieve first element of this string.
Which API i should use for getting this....
Thanks in advance
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TCHAR firstChar = yourTCharString[0];
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neha.agarwal27 wrote: i want to retrieve first element of this string.
what do you mean by element, may be the first token seperated by delimiters.
Specify exactly what you need.
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pls help me to Get the caption of active window...
::GetActiveWindow()->GetWindowText(strCap); //ERROR
error C2039: 'GetWindowTextA' : is not a member of 'HWND__'
c:\program files\microsoft visual studio\vc98\include\windef.h(195) : see declaration of 'HWND__'
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I don't know what exactly are you trying to do. But for the code you've posted I see the following:
GetActiveWindow() return a HWND handle, there are not members functions to access from it. So, after saving your handle like this:
HWND hwnd = GetActiveWindow();
Then you could call GetWindowText like this:
GetWindowText(hwnd, strCap, sizeof(strCap))
Demian.
"I have always wished that my computer would be as easy to use as my
telephone. My wish has come true. I no longer know how to use my telephone."
-Bjarne Stroustrup, computer science professor, designer of C++
programming language (1950- )
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Or he can combine them into one:
GetWindowText(GetActiveWindow(), strCap, sizeof(strcap)); That assumes that strcap is a definitive size. The last parameter may need to change if it happens to be a CString or strring or pointer to some buffer.
Good luck.
Karl - WK5M
PP-ASEL-IA (N43CS)
PGP Key: 0xDB02E193
PGP Key Fingerprint: 8F06 5A2E 2735 892B 821C 871A 0411 94EA DB02 E193
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Oh yeah, of course.
Demian.
"I have always wished that my computer would be as easy to use as my
telephone. My wish has come true. I no longer know how to use my telephone."
-Bjarne Stroustrup, computer science professor, designer of C++
programming language (1950- )
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ptr_Electron wrote: ::GetActiveWindow()->GetWindowText(strCap); //ERROR
use CWnd::GetActiveWindow()
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Rajkumar R wrote: use CWnd::GetActiveWindow()
Only if he is using MFC. 
Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.
Codeproject.com: Visual C++ MVP
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see this, ::GetActiveWindow()->GetWindowText(strCap); //ERROR
It looks like calling a member function using a class instance, possibly CWnd * (from GetActiveWindow), and :: makes the Global scope rather CWnd.
Rajesh R Subramanian wrote: Only if he is using MFC
I implicitly telling him to move to MFC.
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Rajkumar R wrote: I implicitly telling him to move to MFC.
Nobody can give you wiser advice than yourself. - Cicero
.·´¯`·->Rajesh<-·´¯`·.
Codeproject.com: Visual C++ MVP
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Rajkumar R wrote: I implicitly telling him to move to MFC.
Why this bad suggestion?
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.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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to use CWnd::GetActiveWindow()
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yeap am using MFC, thank you all Friends...
CWnd::GetActiveWindow()->GetWindowText(strCap); did the job
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Probably he is (there's namespace scope specification).
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.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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namespace scope can be used in non-MFC C++.
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It is redundant: if you don't need it, don't use it.
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.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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int CMyNonMFCFrameWorkNameSpace::GetWindowText(HWND hWnd,
LPTSTR lpString,
int nMaxCount
)
{
CMyNonMFCFrameWorkLog log("GetWindowText");
return ::GetWindowText(hWnd, lpString, nMaxCount);
}
There are useful example with other API's, though the above is not a so useful example, it is possible to have such situation that is not redundant. otherwise namespace concept is not needed. I can give example exactly that match OPs statement without MFC classes and other namespace.
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Rajkumar R wrote: the above is not a so useful example
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.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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Plz, Help!
I need to set colored text in win32 window - in code.
but it must be no only one color - it must be 3 colors to
specified texts - one text blue, one text - red one - text green
and all texts must be at ones in one window.
plz, help!
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