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G1ANT - disposing of unmanaged code in C# macros

I am enjoying using G1ANT's "macros" capability to call unmanaged code, but the unmanaged objects are of course not being automatically garbage collected absent code to do it.
My request is specifically for best practices in disposing of unmanaged code in these G1ANT C# macros, not for disposing of the same in C# generally, and it is not a request to fix the code below, which runs as is just fine.
If I were coding in C# using Visual Studio, I would likely use a System.Runtime.InteropServices.SafeHandle class, override the Finalize method, or use one of the other approaches in common use (see also this post on disposing of unmanaged objects in C#).
But none of these approaches appear to be a good fit for G1ANT macros per se, at least with my novice experience of them.
For illustration purposes I'm referring to this G1ANT code, but WITHOUT the last line in the macro (ahk.Reset()), because it runs fine with that line, more than once. (I'm painfully aware that there must be a much better example, but as I'm new to G1ANT, this is the only thing I have so far.) What I'm after is C# code that works in G1ANT when there is no explicit disposal of the unmanaged object:
addon core version 4.100.19170.929
addon language version 4.100.19170.929
-dialog ♥macrodlls
♥macrodlls = System.dll,System.Drawing.dll,System.Windows.Forms.dll,AutoHotkey.Interop.dll,System.Runtime.InteropServices.dll
-dialog ♥macrodlls
♥macronamespaces = System,AutoHotkey.Interop,System.Windows.Forms
⊂
var ahk = AutoHotkeyEngine.Instance;
//Load a library or exec scripts in a file
ahk.LoadFile("functions.ahk");
//execute a specific function (found in functions.ahk), with 2 parameters
ahk.ExecFunction("MyFunction", "Hello", "World");
string sayHelloFunction = "SayHello(name) \r\n { \r\n MsgBox, Hello %name% \r\n return \r\n }";
ahk.ExecRaw(sayHelloFunction);
//execute's newly made function\
ahk.ExecRaw(#"SayHello(""Mario"") ");
var add5Results = ahk.ExecFunction("Add5", "5");
MessageBox.Show("ExecFunction: Result of 5 with Add5 func is" + add5Results);
addon core version 4.100.19170.929
addon language version 4.100.19170.929
-dialog ♥macrodlls
♥macrodlls = System.dll,System.Drawing.dll,System.Windows.Forms.dll,AutoHotkey.Interop.dll,System.Runtime.InteropServices.dll,System.Reflection.dll,Microsoft.CSharp.dll
-dialog ♥macrodlls
♥macronamespaces = System,AutoHotkey.Interop,System.Windows.Forms,System.Reflection
⊂
var ahk = AutoHotkeyEngine.Instance;
//Load a library or exec scripts in a file
ahk.LoadFile("functions.ahk");
//execute a specific function (found in functions.ahk), with 2 parameters
ahk.ExecFunction("MyFunction", "Hello", "World");
string sayHelloFunction = "SayHello(name) \r\n { \r\n MsgBox, Hello %name% \r\n return \r\n }";
ahk.ExecRaw(sayHelloFunction);
//executes new function
ahk.ExecRaw(#"SayHello(""Mario"") ");
var add5Results = ahk.ExecFunction("Add5", "5");
MessageBox.Show("ExecFunction: Result of 5 with Add5 func is" + add5Results);
ahk.Reset();
⊃
⊃
It's taken nearly verbatim from the AutoHotkey.Interop github page.
Without the last line in the macro ('ahk.Reset()), the code runs perfectly the first time through, but on the second run G1ANT still sees the included AutoHotkey file, and warns of duplicate function definitions, but continues and still functions properly. The as-far-as-I-can-tell-undocumented AutoHotkey.Interop command Reset() takes care of the garbage collection problem by calling
public void Terminate()
{
AutoHotkeyDll.ahkTerminate(1000);
}
public void Reset() {
Terminate();
AutoHotkeyDll.ahkReload();
AutoHotkeyDll.ahktextdll("", "", "");
}
Thus, the AutoHotkeyEngine instance itself appears to be garbage collected, even without the ahk.Reset();, but the AutoHotkey script it loads into an object is not.
Stopping the G1ANT.Robot application and restarting, then reloading the script above (as mentioned, without the line ahk.Reset();), works just fine, but once again only for a single run.
Edit: The given answer's advice on treatment of singletons is what I will use henceforth when loading of AutoHotkey function scripts and the DLL itself. It seems prudent and good practice to check to see if the DLL or function file have been loaded, whether problems exist or not. "An ounce of prevention", etc. In addition, I have forked the AutoHotkey.Interop repo here, adding a boolean check to see if the AutoHotkeyEngine instance is ready.
Best regards,
burque505

You use AutoHotkeyEngine.Instance, so I guess it's a singleton. It will stay loaded in memory as long as the corresponding dll is kept there, and the latter is loaded and lives as long as the its domain lives. The macro app domain (the place where script stuff is placed) currently lives as long as Robot's app domain, so in fact your singleton instance lives as long as Robot.
Either:
don't use singleton,
or reset it right after obtaining the instance (kinda what you already did),
or treat it as a singleton that has life span longer than your app. In this case after obtaining singleton instance do a check if your functions file has been already loaded and only load it if it wasn't done already.

Unknown exception at declaration and initalisation of a Class

The main Problem is completely different, please skip to the Edit
I have an exception of an unknown type which doesn't even get thrown properly. Following Code provides the Context:
MMDataAccess.InitDemoDB();
MMDataAccess.InitInternalDB();
MMDataAccess.InitMaintDB();
try
{
SQLiteToDBLib sqltdbl = new SQLiteToDBLib();
sqltdbl.WriteToSQLite();
}
catch(Exception ex)
{
string message = ex.Message;
}
These are the very first lines of my first Activity in my app. The first 3 lines belong to my very own implementation of an in-memory database and are behaving nicely. The problem rises with the next two lines inside the try-block. The declaration and initalistation of the sqltdbl variable never happens. The constructor of SQLiteToDBLib looks like this:
public SQLiteToDBLib()
{
msc = new MSConnection();
}
The MSConnection class doesn't even have a constructor (except for the default one of course).
As you can see i've tried to catch any exceptions, but without success. everything i can figure out is, that a exception is thrown because of the debugger going into the catch section while ignoring everything that has to do with "ex". Without breakpoints everything seems fine. Just without the call to WriteToSQLite which should create a .sqlite file on the external Memory.
What can I do to resolve this error? Is there anything i can catch except the default Exception?
Edit:
After some testing with commented code something interresting happened. I could step into commented code. Well not exactly the commented code, but the code that was there before my changes. Visual Studio somehow shows me the things, that are changed in the file, but is compiling the old code. Up to now i tried to rebuild, clean and build the project in various combinations, unload and reload the project, Restart Visual Studio and restart Windows. Nothing has changed so far. I Will now proceed to create a new .cs File With the exact same Code. I'm working with VS 2013 Community

add static constructor to your SQLiteToDBLib class and perform all static objects initialization in it:
static SQLiteToDBLib()
{
// initialize static members here
}
If this doesn't give you a clue, try enabling CLRE exceptions-break in visual-studio:
DEBUG
Exceptions
Check the 'Common Language Runtime Exceptions' option (under the 'Thrown' column)
Press OK
Restart your app and try again

Determining interop function caller

I'm exposing a C# class to COM using these attributes:
[ComVisible(true)]
[ClassInterface(ClassInterfaceType.AutoDual)]
[GuidAttribute("2325EBEB-DB5F-4D29-B220-64845379D9C5")]
[ComSourceInterfaces(typeof(WrapperEvents))]
in this class I have a function:
public void shutdownService()
This function is meant to be called just once from a VB6 client via COM Interop. Everything works fine. But somehow, it's being called more than once. My C# codes doesn't call this function directly. So I'm guessing the problem is in VB6 code. Unfortunately, that's not what the VB6 team thinks.
Is there a way to determine the caller of this function, ie. from my C#code or the VB6 code?
Right now I'm using a simple function to get the stacktrace:
public void LogStack()
{
var trace = new System.Diagnostics.StackTrace();
foreach (var frame in trace.GetFrames())
{
var method = frame.GetMethod();
if (method.Name.Equals("LogStack")) continue;
logger.Debug(string.Format("LogStack: {0}::{1}",
method.ReflectedType != null ? method.ReflectedType.Name : string.Empty, method.Name));
}
}
Obviously, I got somthing like this on the log:
2011-12-23 08:28:40,067 1 DEBUG (null) LogStack: Service::shutdownService
Since the only line of LogStack is the COM exposed function, I assume it's being called from vb6. But that's not enough proof for the VB6 team. Any idea how to really prove where function ?

You can try several things:
set a breakpoint in your code to trigger the debugger, then look at the call stack.
You could do an application dump here from visual studio and send it to them or screenshot the stack.
ex. Debugger.Break
http://www.netsplore.com/PublicPortal/blog.aspx?EntryID=12
Dump with "Savre Dump As"
http://msdn.microsoft.com/en-us/library/d5zhxt22.aspx
Use the com tracing
from a system level see
http://support.microsoft.com/kb/926098
I also recall a tool being installed with visual studio 6 do to this as well

How do I use the Mono.CSharp interpreter in Microsoft.NET

I was under the impression Mono's compiler was usable in Microsoft.NET
edit: updated blog posting here that I originally missed that explains some of it (is consistent with Justin's answers)
I created a simple class to try to use it
[TestFixture]
class Class1
{
[Test]
public void EXPR()
{
Evaluator.Run("using System;");
int sum = (int)Evaluator.Evaluate("1+2");
}
}
And a project in Visual Studio 2010 that references C:\Program Files (x86)\Mono-2.10.1\lib\mono\4.0\Mono.CSharp.dll.
However when I try to run this task I get the following exception, thrown at the Evaluator.Run call:
System.TypeInitializationException was unhandled by user code
Message=The type initializer for 'Mono.CSharp.Evaluator' threw an exception.
Source=Mono.CSharp
TypeName=Mono.CSharp.Evaluator
StackTrace:
at Mono.CSharp.Evaluator.Run(String statement)
at Experiments.Class1.EXPR() in W:\Experiments\Class1.cs:line 16
InnerException: System.TypeLoadException
Message=Method 'Mono.CSharp.Location.ToString()' is security transparent, but is a member of a security critical type.
Source=Mono.CSharp
TypeName=Mono.CSharp.Location.ToString()
StackTrace:
at Mono.CSharp.Evaluator..cctor()
InnerException:
A google confirms one other person asking this question but no answer. I tried to start reading the microsoft article on security transparent code but got confused quite quickly. Would someone be able to suggest a quick workaround to allow me to use this? And possibly summarise the security implications, if any, to me (in the context of my situation - in the future I hope to package it with a thick client application, to be used both internally and by end-users)

It has worked under .NET since April of last year.
Small point but I notice you are missing a semi-colon in your expression for sum.
int sum = (int)Evaluator.Evaluate("1+2;");
I only have Mono 2.11 (from git) at the moment and they have changed to using a multi-instance version of the compiler instead of the static version. So, my code looks a little different:
using System;
using Mono.CSharp;
namespace REPLtest
{
class MainClass
{
public static void Main (string[] args)
{
var r = new Report (new ConsoleReportPrinter ());
var cmd = new CommandLineParser (r);
var settings = cmd.ParseArguments (args);
if (settings == null || r.Errors > 0)
Environment.Exit (1);
var evaluator = new Evaluator (settings, r);
evaluator.Run("using System;");
int sum = (int) evaluator.Evaluate("1+2;");
Console.WriteLine ("The sum of 1 + 2 is {0}", sum);
}
}
}
EDIT: I guess I should confirm that I did in fact successfully execute this on .NET 4 (using Visual C# Express 2010 on Windows XP)
EDIT AGAIN: If you have Visual Studio, you can download the latest version of Mono.CSharp and compile it yourself. There is a .sln (solution file) included with the source so you can build it on Windows without Mono. The resulting assembly would run the code above. Miguel has a post explaining the new Mono.CSharp here.
FINAL EDIT: I uploaded the compiled Mono.CSharp.dll assembly that I actually used here. Include it as a reference to compile the code above.

It looks like this is a bug in Mono.
.NET 4 abandoned Code Access Security but kept the concept of Security Transparent Code. In a nutshell, low-level code that does stuff, like call unmanaged code, must be "security critical". Application level code is marked "transparent". "Transparent" code cannot call into "security critical" code.
It sounds like Mono.CSharp.Location.ToString() needs to be marked with the [SecuritySafeCritical] attribute if you want the Mono 2.10 code to work with .NET 4. Maybe even better would be marking all of Mono.CSharp as SecuritySafeCritical.
http://msdn.microsoft.com/en-us/library/system.security.securitycriticalattribute.aspx
PS. Sorry to have multiple answers for one question. After I realized that 2.11 would work, I became more curious about what the error with 2.10 meant. I cannot really combine this answer with the others.

I decided I should have kept the code more like the question but I did not want to overwrite my previous answer:
The code below works with version 2.11 of Mono.CSharp (available here including a solution file for building with Visual Studio/.NET). It was tested with .NET 4 on Windows XP. I do not have access to Mono 2.10 at the moment.
[TestFixture]
class Class1
{
private Evaluator evaluator;
public Class1()
{
var report = new Report(new ConsoleReportPrinter());
evaluator = new Evaluator(new CompilerSettings(), report);
}
[Test]
public void EXPR()
{
evaluator.Run("using System;");
int sum = (int)evaluator.Evaluate("1+2;");
}
}
EDIT: I uploaded the Mono.CSharp.dll assembly that I actually used here. Include it as a reference to compile the code above.

Why do 'requires' statements fail when loading (iron)ruby script via a C# program?

IronRuby and VS2010 noob question:
I'm trying to do a spike to test the feasibility of interop between a C# project and an existing RubyGem rather than re-invent that particular wheel in .net. I've downloaded and installed IronRuby and the RubyGems package, as well as the gem I'd ultimately like to use.
Running .rb files or working in the iirb Ruby console is without problems. I can load the both the RubyGems package, and the gem itself and use it, so, at least for that use case, my environment is set up correctly.
However, when I try to do the same sort of thing from within a C# (4.0) console app, it complains about the very first line:
require 'RubyGems'
With the error:
no such file to load -- rubygems
My Console app looks like this:
using System;
using IronRuby;
namespace RubyInteropSpike
{
class Program
{
static void Main(string[] args)
{
var runtime = Ruby.CreateRuntime();
var scope = runtime.ExecuteFile("test.rb");
Console.ReadKey();
}
}
}
Removing the dependencies and just doing some basic self-contained Ruby stuff works fine, but including any kind of 'requires' statement seems to cause it to fail.
I'm hoping that I just need to pass some additional information (paths, etc) to the ruby runtime when I create it, and really hoping that this isn't some kind of limitation, because that would make me sad.

Short answer: Yes, this will work how you want it to.You need to use the engine's SetSearchPaths method to do what you wish.
A more complete example
(Assumes you loaded your IronRuby to C:\IronRubyRC2 as the root install dir)
var engine = IronRuby.Ruby.CreateEngine();
engine.SetSearchPaths(new[] {
#"C:\IronRubyRC2\Lib\ironruby",
#"C:\IronRubyRC2\Lib\ruby\1.8",
#"C:\IronRubyRC2\Lib\ruby\site_ruby\1.8"
});
engine.Execute("require 'rubygems'"); // without SetSearchPaths, you get a LoadError
/*
engine.Execute("require 'restclient'"); // install through igem, then check with igem list
engine.Execute("puts RestClient.get('http://localhost/').body");
*/
Console.ReadKey();