Unsafe codes in a webservice

Question

Hello I try to create a webservice with VS2010 and .Net 4. This service has to execute unsafe code from an external Delphi-Dll. I have also created a console application which uses the same code and it works well. But when I execute the webservice I get error messages caused by executing code in the protected memory. Is there a configuration setting to use unsafe code in a webservice? Regards sweisse

Steffen Weisse · Answer

... yes I use the same arguments. But in the meantime I found the reason I think. Indeed it is an unhandled exception in my Delphi-Dll. There was a necessary file in the web service execution directory (..\Microsoft Shared\DevServer\...) missing. This case does never happen when I execute the console application because all the file are present in my normal application directory. The Dll uses the function ExtractFilePath(Application.Exename) and this is different in case of running as webservice. Thank you for your help.

Vulpes · Answer

Yeah the English translation of that is: An attempt was made to read or write protected memory. This is often an indication that other memory is corrupt. which IIRC is the error message you get when an AccessViolation exception is thrown. However the function's signature certainly seems innocuous enough. When you called it from the console application did you use exactly the same signature and pass it the same argument?

Steffen Weisse · Answer

...yes I use DllImport: static extern Int32 StartWaage( Int32 wgID); [ DllImport ( oasepcDLL.dll  CharSet = CharSet .Ansi CallingConvention = CallingConvention .StdCall)] the german error message is Es wurde versucht im geschützten Speicher zu lesen oder zu schreiben. Dies ist häufig ein Hinweis darauf dass anderer Speicher beschädigt ist.

Vulpes · Answer

What sort of error messages are you getting - Access Violations and that sort of stuff? Also are you using P/Invoke or COM interop to call functions in the Delphi dll?

Steffen Weisse · Answer

Thank you for your answer. The compiler switch was set for the buid options but not in the web.config. I have adjusted this but I still get the same result.

Vulpes · Answer

It sounds like the /unsafe compiler switch is not being used when the web service is being built. I'd check your web.config file for the tag which should look like the example in this link: http://msdn.microsoft.com/en-us/library/k6bttwes.aspx If it's not been done already I'd then change: compilerOptions= to: compilerOptions=/unsafe