Click here to Skip to main content
15,304,276 members
Please Sign up or sign in to vote.
5.00/5 (1 vote)
See more:
I have C# windows application which calling C++ unmanaged dll function. this application is working fine at windows XP x86 environment. now i move this application to WIN7 64 bit environment. I complied c++ dll at x64, and build my C# application at x64 as well. when i run my application, I got error message showed "System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt." when my application calling c++ dll function.

the code in my C# as show below:

C#
[DllImport("SpotForwardSimDLL.dll")]
private static extern long CalSpotForwardSimulation(int A, int B, int C,
int vDate, int sDate, int eDate, double[] hisCurve, double[] monthVol,
double[] dailyVol, double[] forwardCurves, string[] curveNames,
double[] dailyVal, double[] monthVal,double[] corrVal)

CalSpotForwardSimulation(numFactors, numLoc, numSims,lCobDate, lStartDate, lendDate, hisCurves, monthVol, dailyVol,forwardCurves, curveNames, dailyVal, monthVal, corrVal);



the code in C++ as show below:
C++
__declspec(dllexport) long __stdcall
CalSpotForwardSimulation(int ltempOfFactors, int ltempOfLoc,
int ltempOfSims ,int vDate,int sDate,int eDate,
double * tempCurveHistorical,double * tempMonthlyVol,
double * tempDailyVol,double * tempForwardCurve,
char ** curveName,double dailyRet[],
double monthRet[],double corrRet[])


I have been working on this issue for weeks, any suggestion to solve this problem?
Posted
Updated 3-Mar-11 6:10am
v2

1 solution

Chances are, you're trying to work with some Win32 executable, like a DLL. You cannot do it, and the problem is only manifested during run-time. For example, how do you know "SpotForwardSimDLL.dll" is not 32-bit?

The components built as 64-bit and 32-bit work on a 64-bit systems in a different platforms. Your 64-bit code runs on the native platform, but a 32-bit process works on the platform called WoW64, see http://en.wikipedia.org/wiki/WOW64[^].

Moreover, there are two separate 64-bit platforms: x86-64 (http://en.wikipedia.org/wiki/X86-64[^]) and IA-64 "Itanium" (http://en.wikipedia.org/wiki/Itanium[^]). They are incompatible. You version of OS supports one of them, depending on your CPU architectures, so all 64-bit software components you obtain should match one of these two architectures, but any 32-bit component will work. If you accidentally try to mix them up, you will get run-time crash of the same kind.

The only option to use a 32-bit component in 64-bit application is running both as different processes and use any kind in inter-process communications between them.

Another simple resolution would be keeping all of your 32-bit codes; chances are, they will successfully run on top of WoW64.

—SA
   
v5
Comments
   
Thank you for accepting my Answer.
Did you solve your problem though?
--SA
IvyLi 3-Mar-11 14:38pm
   
how can i make sure that SpotForwardSimDLL.dll is build at 64-bit? my vs.net is installed at program file(x86). are you saying that even i changed my configuration to x64 the dll generated might not 64-bit?
   
No, no. You see, I don't see you project(s), so I don't know what components you're using. Of course, what you compile will be compiled to the platform you want, but how about other linked components, statically or dynamically? I only know that what worked in win32 stopped to work, and that the only reason I can see.
You know what... Get http://www.dependencywalker.com/, it will help you to study your case.
--SA
   
OP commented:

how can i make sure that SpotForwardSimDLL.dll is build at 64-bit? my vs.net is installed at program file(x86).
   
VS.NET may run as x86, it does not matter. What matters is that the platform your compilation is targeted for.
--SA
IvyLi 3-Mar-11 16:24pm
   
thank you for your information. i will keep trying.
   
You're welcome.
Thank you for accepting my Answer.
Good luck, call again.
--SA
Espen Harlinn 24-Mar-11 3:50am
   
Seems your advice was spot on, my 5 :)
   
Thank you, Espen.
--SA
phantom_ml 3-Nov-14 1:30am
   
Hi, did you solve this problem? Now I have same problem. But I can't find solution.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)



CodeProject, 20 Bay Street, 11th Floor Toronto, Ontario, Canada M5J 2N8 +1 (416) 849-8900