Re: Do I always need a function that's executed by only one thread to initialize synchronization objetcs? - C / C++ / MFC Discussion Boards

Re: problems with WinINet.h with visual studio 2003

prasad_som12-Oct-05 21:24

prasad_som

12-Oct-05 21:24

go to properties-->Linker-->Input-->Additional dependencies add wininet.lib there

Problems Bringing Active X Control (.ocx) Into An Application

johndavis12-Oct-05 6:06

johndavis

12-Oct-05 6:06

Hello,

I'm currently working on a project to "do away" with a given .ocx and bring that functionality into the application that used to use the ocx. I'm trying to alter the main part of the ocx from a Control to a View. That's where I'm having problems.

I've tried to use CCtrlView to take the Control and give it View properties, but I'm having trouble registering the Control class in order to use CCtrlView properly.

Any help with this would be much appreciated. Thanks.

Do I always need a function that's executed by only one thread to initialize synchronization objetcs?

Federico Milano12-Oct-05 5:55

Federico Milano

12-Oct-05 5:55

Hi,

I was wondering if its possible to create, for example, a Critical Section in a multithreaded environment. In other words, I know that you may not call InitializeCriticalSection more than once with the same pointer before you call DeleteCriticalSection. Anyway I want to know if there's a way to serialize calls to InitializeCriticalSection without using another critical section/mutex/semaphore (using it would be delaying the problem) or if you always need a method that's executed by one and only one thread to initialize all the syncronization objects in a process. This would not be a problem if initialization could be done statically.

I would really appreciate your answer,

Federico

Re: Do I always need a function that's executed by only one thread to initialize synchronization objetcs?

Rage12-Oct-05 7:05

Rage

12-Oct-05 7:05

Federico Milano wrote:
I was wondering if its possible to create, for example, a Critical Section in a multithreaded environment.

This is confusing. Why would you want to do this, meaning what do you want to achieve ultimately ? It seems like you have a problem, thought of a solution which brought you to this question. Forget the solution you have in mind, and post your problem, maybe we can solve your problem with a different approach ...

~RaGE();

Re: Do I always need a function that's executed by only one thread to initialize synchronization objetcs?

Federico Milano12-Oct-05 7:38

Federico Milano

12-Oct-05 7:38

Actually, it's almost a purely theoretical point. I'm studing pthreads synchronization objects and I realized that using posix threads you can initialize a critical section statically assigning a value to a variable (the critical section is initialized in the data segment, by compiler generated code). In posix you also have a dynamic method to initialize a critical section, just like the win32 initializeCriticalSection. So, my question is: is there a way to initizalize a critical section statically in win32? And if it's not, what are the consecuences?: do I always need a procedure/function/method/piece of code in my process that it's executed by only one thread (for example, DllMain) to initialize a critical section by a call to InitializeCriticalSection? or there's another API function that initializes the critical section the first time a thread executes it and that in the subsequent executions for the same critical section doesn't do anything?

I know that it's hard to read my english because I'm not a native speaker. I really appreciate your effort and I would be really pleased of getting anwers, suggestions, comments...

Thanks,

Federico

Re: Do I always need a function that's executed by only one thread to initialize synchronization objetcs?

Blake V. Miller13-Oct-05 18:16

Blake V. Miller

13-Oct-05 18:16

No, the only way to initialize is with the function call.

There are only two instances where the critical section needs to be iniialized, and it would be safe anyways:

1. In your main application's startup code before any other threads are started.

2. In the DLL_PROCESS_ATTACH of a DLL, in which case no other threads are executing code in the DLL anyway, so it is safe to initialize the critical sections there.

So, in essence, it is NOT ever a problem that you can't 'statically initialize' a critical section in Windows applications, because there are two safe well-known locations to do the initialization.

Re: Do I always need a function that's executed by only one thread to initialize synchronization objetcs?

Federico Milano14-Oct-05 2:20

Federico Milano

14-Oct-05 2:20

Thanks Blake!

I'm programming a library and I need to link it statically to other applications. So I don't have a DllMain with DLL_PROCESS_ATTACH, and I don't have a method that I know it will be called by just one thread, at least I require the library's user to call an initialization method only once and before any other call to the library. Is this the only way it would work for statically linked libraries?, because I would like to avoid that burden for my library's users.

Thanks,

Federico

Re: Do I always need a function that's executed by only one thread to initialize synchronization objetcs?

Blake V. Miller24-Nov-05 9:09

Blake V. Miller

24-Nov-05 9:09

If your library is written in C++, you could declare a global instance of a singleton class. The constructor of that class could initialize the critical section and the destructor would delete it. I am pretty sure the constructor of this class would be called before your progrma is 'running' or at least before most of your other code had a chane to get into trouble.

Execute and retrieve data from console

schemp9812-Oct-05 5:11

schemp98

12-Oct-05 5:11

Hello all,

I am a C++ newbie, and have what I feel is a fairly simple question....

Basically I have a string of code that when executed in the console gives a list of user id numbers. What I want to do is make a an executable file that will give me a list of the actual user names (found in a lookup table) instead of the user id numbers.

If anyone can give me some advice or point me in the right direction, I would appreciate it. I have tried looking at some articles on this site (Execute a Console Application From VC++) but don't really understand it. Thanks in advance!

Shaun

Re: Execute and retrieve data from console

David Crow12-Oct-05 6:22

David Crow

12-Oct-05 6:22

What exactly is it that you are wanting to do: 1) execute a console application from VC++ and capture its output, or 2) create an application that will return a name given an id? These are two different things.

"One must learn from the bite of the fire to leave it alone." - Native American Proverb

Re: Execute and retrieve data from console

schemp9812-Oct-05 7:09

schemp98

12-Oct-05 7:09

Okay, basically I'm sharing a floating license for matlab, and want to get a readout of the current user names.

Currently if I open the command prompt and type in a string 'lmutil ... blah blah', it returns a list of user id numbers that are currently using matlab....

What I want to do, is change it to return user names instead of the id numbers. So I thought I could just capture the information from the matlab license checking program (which runs at the command prompt) to retrieve the id number, and then output the cooresponding user names instead.

I wanted to just click on an executable (or batch) file and have it spit out the desired output.

I hope this cleared any confusion, thanks again!

Re: Execute and retrieve data from console

Rage12-Oct-05 7:26

Rage

12-Oct-05 7:26

Two ways to do that:

1.Launch a process that calls your "lmutil ... blah blah" command and that saves the output to a text (Check ShellExecute or CreateProcess in the MSDN or here on CodeProject).
Read the text, and do the substitution.

OR

2.Launch a process that calls your "lmutil ... blah blah" command and that captures the output into a String. [This part is not easy].
Do the substitution in the String.
Have a look at this article[^] to get a start with capturing the output of a process.

Hope this helps

~RaGE();

Re: Execute and retrieve data from console

David Crow12-Oct-05 7:33

David Crow

12-Oct-05 7:33

See these two links:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/creating_a_child_process_with_redirected_input_and_output.asp[^]

http://support.microsoft.com/default.aspx?scid=kb;en-us;190351[^]

"One must learn from the bite of the fire to leave it alone." - Native American Proverb

Getting IP Address through WMI

qrverona12-Oct-05 4:23

qrverona

12-Oct-05 4:23

Dear all,
I'm writing a C++ (.NET 2003 with MFC) application that needs to query several data through WMI. I have a problem while accessing to the "IPAddress" data managed by the Win32_NetworkAdapterConfiguration WMI class.

It is stored as a string array, the first Get returns me this information, but I did not found any issue on how to get the array.

bool CMyDoc::GetWMIItemValue( IWbemClassObject *pInstance,
LPCWSTR pItemName,
CStringArray& strArray)
{
VARIANT val;
LONG lFlavour;
HRESULT hGet;
CIMTYPE cimType;

VariantInit(&val);
strArray.RemoveAll();

hGet = pInstance->Get( pItemName,
0,
&val, // val cannot hold the result
&cimType, // returns 2008 = string array
&lFlavour); // returns 0

if (hGet == WBEM_S_NO_ERROR)
{
if (cimType == (CIM_STRING | CIM_FLAG_ARRAY))
{
// val holds 0x2008 too, unusable
// how can I access the array?
}
}

Thank you for you help...

PS: Using C# is a piece of cake, but my application has been developed in C++ and I cannot convert it.

Daniele

Re: Getting IP Address through WMI

David Crow12-Oct-05 6:31

David Crow

12-Oct-05 6:31

qrverona wrote:
I have a problem while accessing to the "IPAddress" data managed by the Win32_NetworkAdapterConfiguration WMI class.

I would employ something like:

HRESULT                 hr;
_variant_t              v;
ULONG                   ulReturned;
DWORD                   dwAuthLevel;
IWbemLocator            *pLocator;
IWbemServices           *pService = NULL;
IEnumWbemClassObject    *pEnum = NULL;
IWbemClassObject        *pClass;        
        
hr = CoCreateInstance(CLSID_WbemLocator, 0, CLSCTX_INPROC_SERVER, IID_IWbemLocator, (LPVOID *) &pLocator);
if (S_OK == hr)
{
    hr = pLocator->ConnectServer(_bstr_t(L"root\\cimv2"), NULL, NULL, NULL, NULL, 0, NULL, &pService);
    if (WBEM_S_NO_ERROR == hr)
    {
        hr = CoQueryProxyBlanket(pService, NULL, NULL, NULL, &dwAuthLevel, NULL, NULL, NULL);
        hr = CoSetProxyBlanket(pService, 
                               RPC_C_AUTHN_DEFAULT, 
                               RPC_C_AUTHZ_NONE, 
                               NULL, 
                               dwAuthLevel, 
                               RPC_C_IMP_LEVEL_IMPERSONATE, 
                               NULL, 
                               EOAC_NONE);
 
        hr = pService->CreateInstanceEnum(_bstr_t("Win32_NetworkAdapterConfiguration"), 
                                          WBEM_FLAG_RETURN_IMMEDIATELY | WBEM_FLAG_FORWARD_ONLY, 
                                          NULL, 
                                          &pEnum);
        if (WBEM_S_NO_ERROR == hr)
        {
            do
            {
                hr = pEnum->Next(WBEM_INFINITE, 1, &pClass, &ulReturned);
                if (WBEM_S_NO_ERROR == hr)
                {
                    hr = pClass->Get(L"IPAddress", 0, &v, NULL, NULL);
                    if (v.vt != VT_NULL)
                        ...
 
                    pClass->Release();
                }
            } while (WBEM_S_NO_ERROR == hr);
        }
    }
}

"One must learn from the bite of the fire to leave it alone." - Native American Proverb

Application getting stuck because of load ?

Amarelia12-Oct-05 3:25

Amarelia

12-Oct-05 3:25

Hi I have a simple dialog based MFC application which I have developed using CBannerStatic project available here at "http://www.codeproject.com/staticctrl/bannerstatic2.asp#xxxx"

Here when I make my font size very big, the banner gets very slow and stucks sometime when I have more load on my CPU by some other application running

Is there a way to give some amount of CPU to only my Banner application or is there a way to assign some value through which Banner doesn't gets affected because other running application ?

Thanking you.

Amarelia Maehsh
Gujarat
India

Re: Application getting stuck because of load ?

John M. Drescher12-Oct-05 5:08

John M. Drescher

12-Oct-05 5:08

Please quit posting the same question in the wrong forum multiple times.

John

Re: Application getting stuck because of load ?

Bob Stanneveld12-Oct-05 6:01

Bob Stanneveld

12-Oct-05 6:01

Hello,

You could try the following:

::SetPriorityClass(::GetCurrentProcess(), ABOVE_NORMAL_PRIORITY_CLASS);

IMHO you should not change your process priority for reasons like this. If the user has a high CPU load, he or she is doing something important most of the time. The user would get very annoyed if your banner will consume more CPU than the users 'important' processes.

Behind every great black man...
... is the police. - Conspiracy brother

Blog[^]

Re: Application getting stuck because of load ?

Amarelia12-Oct-05 22:17

Amarelia

12-Oct-05 22:17

Hi Bob

Thankx a lot to give kind attention to my question

I tried but it gives error at compile time if i use ABOVE_NORMAL_PRIORITY_CLASS flag, Instead if i use HIGH_PRIORITY_CLASS it works but it takes all the CPU and takes too long time to execute other processes....

What seems to be the reason that it gives error for ABOVE_NORMAL_PRIORITY_CLASS ? The error is :

"error C2065: 'ABOVE_NORMAL_PRIORITY_CLASS' : undeclared identifier"

Any idea what to do ?

Thankx

Amarelia Maehsh
Gujarat
India

Re: Application getting stuck because of load ?

David Crow13-Oct-05 3:05

David Crow

13-Oct-05 3:05

Amarelia wrote:
What seems to be the reason that it gives error for ABOVE_NORMAL_PRIORITY_CLASS ? The error is :

"error C2065: 'ABOVE_NORMAL_PRIORITY_CLASS' : undeclared identifier"

Are you on a Windows 2000 or XP machine? What is the value of _WIN32_WINNT?

"One must learn from the bite of the fire to leave it alone." - Native American Proverb

Re: Application getting stuck because of load ?

Amarelia13-Oct-05 3:09

Amarelia

13-Oct-05 3:09

Hi David

I am using Windows 2000

And not getting what do you mean by ,"What is the value of _WIN#@_WINNT?"

Thankx

Amarelia Maehsh
Gujarat
India

Re: Application getting stuck because of load ?

David Crow13-Oct-05 3:38

David Crow

13-Oct-05 3:38

Amarelia wrote:
And not getting what do you mean by ,"What is the value of _WIN#@_WINNT?"

I was going to suggest that it had to be greater than or equal to a certain value, but after looking in winbase.h, I see that is not the issue. I can only suggest that you verify the spelling of ABOVE_NORMAL_PRIORITY_CLASS.

"One must learn from the bite of the fire to leave it alone." - Native American Proverb

Application getting stuck because of load ?

Amarelia12-Oct-05 3:21

Amarelia

12-Oct-05 3:21

Hi

Amarelia Maehsh
Gujarat
India

Application getting stuck because of load ?

Amarelia12-Oct-05 3:21

Amarelia

12-Oct-05 3:21

Hi

Amarelia Maehsh
Gujarat
India

CBitmapButton Transparency

NewVCbie12-Oct-05 3:18

NewVCbie

12-Oct-05 3:18

Good day,

How can I make transparency in CBitmapButton. I dont want to display image part with color RGB(255,0,255).

Thanks.

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