Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Memory cannot be referenced error

Posted on 2001-08-15
8
Medium Priority
?
1,155 Views
Last Modified: 2012-08-14
Hi,

I have this C++ codes that I cut and paste from a working program, but to my dismay gives me the following run time error:

The instruction at "0x0012f9de" referenced memory at "0x0000000000". The memory could not be "read".

Click on OK to terminate program
Click on Cancel to debug

Pls help.

-------------------

// Source code is as follows:

typedef WORD (*OPEN)(WORD, BYTE*, WORD*)
....

OPEN my_open
BYTE msg[256];
WORD rlen;
WORD rcode;

hDLL = LoadLibrary(_T("myopen.dll"));
if (hDLL!=NULL)
{
   my_open = (OPEN)GetProcAddress(hDLL, "_my_open@12");
   if (my_open!=NULL)
   {
     // Run time error traced to below call
     rcode = (my_open)(0, msg, &rlen);
   }
}

----------





0
Comment
Question by:oohchild
8 Comments
 
LVL 14

Expert Comment

by:AlexVirochovsky
ID: 6391355
May be problem in name of function from dll. For know exectly all name of functions I use TDump utility of Borland.  
0
 
LVL 5

Expert Comment

by:ekc
ID: 6394781
> May be problem in name of function from dll. For know exectly all name of functions I use TDump utility
of Borland.  

I don't think this is the problem, because the GetProcAddress() would return NULL in this case...
I suspect the problem coud be in the variable msg. You are reserving 256 bytes of the memory for it. Are you sure that your DLL function is accessing only that range of memory?
Do you have access to the myopen.dll code?
0
 
LVL 14

Expert Comment

by:AlexVirochovsky
ID: 6395805
O may be number/type of parameters wrong. Really need see code/description of "_my_open@12"
0
Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Author Comment

by:oohchild
ID: 6427350
Nothing wrong with the parameters, strange thing is it can work in debug version but crashes in release version, any idea?
0
 
LVL 14

Expert Comment

by:AlexVirochovsky
ID: 6427636
O, it is difference between Debug and Release version in VC. There are many Q in EE about this issue, but I work in BC and can't help you. Sorry.
0
 
LVL 2

Expert Comment

by:udil
ID: 6445066
The problem could be in the implementation of the function
in the DLL. One of the differences between Realese and
Debug, is that Debug version gives you some protection, such as "preparing" the stack with padding characters.
It could be that the function you call, is has a fault
which causes it not to run properly in a Release version.
0
 
LVL 2

Expert Comment

by:udil
ID: 6447502
I've just read the Etiquette page, and I wanted to
apologize on sending an Answer, instead of a Comment.

Udil
0
 
LVL 49

Accepted Solution

by:
DanRollins earned 800 total points
ID: 6515108
oohchild,
Do you still need help with this?

The answer is almost certainly that you have reversed the correct order of parameters.  

Perhaps there is an old version of myopen.dll that used different parameter type or sequence.   If that copy of myopen.dll is in the Release directory, it would be called.  While the good one (in your Debug directory) would be working fine for debug builds.

-- Dan
0

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Errors will happen. It is a fact of life for the programmer. How and when errors are detected have a great impact on quality and cost of a product. It is better to detect errors at compile time, when possible and practical. Errors that make their wa…
  Included as part of the C++ Standard Template Library (STL) is a collection of generic containers. Each of these containers serves a different purpose and has different pros and cons. It is often difficult to decide which container to use and …
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.
The viewer will learn how to use the return statement in functions in C++. The video will also teach the user how to pass data to a function and have the function return data back for further processing.
Suggested Courses

916 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question