C / C++ / MFC

13-Apr-04 10:26

I realize what's going on now, but I can't fix it. Take a look at this an it'll explain my situation.

#define VERY_LARGE_NUM 9999...

main()
{
double dummy[VERY_LARGE_NUM]

for(i...
{
//create a few threads
createThread....
}
....
}

The program bombs out when I try this because the dummy array allocates more than the 1 meg. Hence, I change the stack reserve and commit to a large value. This fixes the bombing out problem, but creates a new one. The create thread function will only create X num of threads while I want Y num of threads. I tried setting the stack param in the create thread func but it did nothing for me. What can be done. The /3GB flag is not an option because the target machine's OS does not support it.

Anonymous13-Apr-04 10:27

13-Apr-04 10:27

Other than spinning a new process. Is there a soluation.

Daniel Turini13-Apr-04 10:58

Daniel Turini

13-Apr-04 10:58

Risking asking a stupid question, have you considered allocating it on the heap (double *p = new double[BIGNUMBER]), not on the stack?
If for some strange reason you need to allocate it on the stack, the CreateThread API function allows you to specify a bigger stack size.

I see dumb people

Anonymous14-Apr-04 1:07

14-Apr-04 1:07

The example was simply to demonstrate the situation. The real app uses all these classes. The original design called for them to be globals to make communicating between all the threads that we created. Hence, we, in essensce, have a main with a ton of classes that spin up a ton of threads. Your create thread suggestion leads me to my 2nd problem. I specified a bigger stack inside my project setting (Stack reserve and Stack commit). This move fixed my stack over-flow problem when running the app. However, I can't seem to call CreateThread pass a certain number of threads. I'm aware of the stack size parameter inside the API call, but it seems not to solve the problem. Does the stack reserve/commit set the stack size for all threads and the main process?

Check the Status of a URL

Paul Ranson14-Apr-04 4:20

Paul Ranson

14-Apr-04 4:20

I don't understand why you're allocating such a large array from the stack. Why not 'new' and 'delete' or 'std::vector<double>'?
How many threads are a 'ton'?
Why so many threads? In general if your threads are ready to run then there's no point in having more than the number of CPUs your machine has. If they're not ready to run, they're waiting for input, then you still don't want more than a relatively small number (let's say less than 25) due to the overhead of thread creation, context switching and stack usage(!). In this case you should investigate a thread pool and overlapped IO.

Paul

Release Mode ATL Problem

nlecren13-Apr-04 9:58

nlecren

13-Apr-04 9:58

i have the following problem, if i declare a variable in a local function and then assign a value in a try block under release min dependency the value is corrupt or the same as it was before the try block upon entering the catch. Please what am i doing wrong?? The code is below:

STDMETHODIMP CCMI_BioWrapper::QueryTemplate(BSTR Badge,BSTR *Response)
{
AFX_MANAGE_STATE(AfxGetStaticModuleState())

int nRetCode;
CString strVal;

nRetCode = 0;

try
{
nRetCode = 99;
return S_OK;
}
catch(...)
{
// I would expect nRetCode to be 99 here
// however it is always 0, unless i do a debug build
// then it always works

strVal.Format("Q0 %d",nRetCode);
*Response = strVal.AllocSysString();

return S_OK;
}
}

Renjith Ramachandran13-Apr-04 8:20

Renjith Ramachandran

13-Apr-04 8:20

how can i check the status of a URL, like http://www.codeproject.com
is active / down , Winsock or any other ..????

I want to change Myself..Can u help me? Smile | :)

David Crow13-Apr-04 8:31

David Crow

13-Apr-04 8:31

How about InternetCheckConnection()?

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Renjith Ramachandran13-Apr-04 8:43

Renjith Ramachandran

13-Apr-04 8:43

Great..Thankyou

I want to change Myself..Can u help me? Smile | :)

basementman13-Apr-04 9:50

basementman

13-Apr-04 9:50

You can look at this example prog: [^]

onwards and upwards...

Renjith Ramachandran13-Apr-04 21:01

Renjith Ramachandran

13-Apr-04 21:01

I need the API, not the exes..
D'Oh! | :doh:

I want to change Myself..Can u help me? Smile | :)

Unmanaged pointer in a managed class? (C3160)

basementman14-Apr-04 3:56

basementman

14-Apr-04 3:56

Here is the source for the app (bear in mind that this is just a quicky example app and not necessarily coded well Unsure | :~

) [^]

onwards and upwards...

mccoyn13-Apr-04 8:19

mccoyn

13-Apr-04 8:19

I am porting an old project to be able to use .Net. There is a struct type that needs to be used by an old library written in C and a new class library written with .Net. When I try to have a pointer to this struct as a member of a managed class I get the following error:

error C3160: 'piData' : cannot declare interior __gc pointer or reference as a member of 'PatInfo'

Here is the struct definition in a header file used in both projects:

typedef struct _reportFull{
ReportHeader * header;
ReportStruct * st;
ReportAngio * angio;
ReportNonSaved * ns;
} ReportFull;

Here is part of the PatInfo class definition from another header file:

__gc class PatInfo {
public:
PatInfo();
~PatInfo();

ReportFull __nogc *piData;
ReportFull __nogc *temp_data;
ReportFull __nogc *defaults_reference;

UserControl* dlg;
};

The error occurs when I try to make a derived class from PatInfo. I suspect that it would occur any time I use PatInfo.

Anyone know of a way to use pointers to unmanaged types within a managed class?

Stack overflow problem

Anonymous13-Apr-04 8:16