I'm using Visual Studio 2005 to write a C/C++ program.

I declare the following struct that contains an array:


I call a function that creates a struct for MetaFrag,
ParaFrag etc..(showing the MetaFrag Example):

The program compiles fine, but it only works if I call 3 or
less of the data elements.
For example, I can call createmetafile, createparafile and
create phenofile and it works fine. However, if I add the 4th call, create phenopfile, it blows up when I try to run it.  I've switched the calls around to make sure it wasn't specific to the function being called.

Does anyone see what I'm doing wrong?  Any help is greatly appreciated

Try this for starters
Does that run out of memory?  If it doesn't then check your procedures.  Check that none of your strcpy to Fragment and FragDisplay are over 44 chars.

That's all I can think of for now.

I think it's impossible to exhaust all heap memory resources with near 140 Kb request (on 32-bit C++ implementation;).
IMHO, better use more clear (and efficient) initialization code, for example:
There are some alignment gaps in your structure (for example, between Fragment and FragVal members). Are you sure it's OK?..

Thanks,

I will try your advice today and let you know what happens.

Found out a little more...

When I try and run the program using three of the four
data elements, I get the Run-Time Check Failure #2 - Stack around variable 'CF_PKA was corrupted.

I run the debugger and get the following message:
Unhandled exception at 07c911430 in jrun.exe:0xC0000005: Access violation reading location 0x2a432a47.

The error is happening in Malloc.c:

The stack shows its error at:
ntdll.dll!7c911430

Does anyone know how to go about trouble-shooting this?

Thanks

> Access violation reading location 0x2a432a47
Which, if you take those hex values, is a string "*C*G"
Do you have anything which writes this string, or it's reversed version "G*C*" ?
If you do have, then following exactly where that goes can be pretty useful.

> Stack around variable 'CF_PKA was corrupted.
Sounds like you may have passed &myPtr rather than myPtr to some other function, and that's written all over the pointer itself rather than where it was pointing.

I take it you don't have any compiler warnings.
If you're running with a .net compiler, then change the warning level to /W4.

Microsoft have made a pretty good job of cleaning up all their header files for max warning level.  VC6 was useless at W4 level due to too much crud in their own header files.

> The error is happening in Malloc.c:
The memory allocators are just very good at noticing that there is "a problem".  It rarely tells you immediately where the problem is.

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