Question

I want to generate IL for a multithreaded application. As the first step
I wrote a simple application and inspected, generated IL using ILSpy.

public class ThreadTesting
{
    public static void Main()
    {
        Thread thread = new Thread(() => Print("Hello from t!"));
        thread.Start();
    }

    public static void Print(string message)
    {
        Console.WriteLine(message);
    }
}

.method public hidebysig static 
    void Main () cil managed 
{
    // Method begins at RVA 0x2060
    // Code size 46 (0x2e)
    .maxstack 3
    .entrypoint
    .locals init (
        [0] class [mscorlib]System.Threading.Thread
    )

    IL_0000: nop
    IL_0001: ldsfld class [mscorlib]System.Threading.ThreadStart ThreadTesting::'CS$<>9__CachedAnonymousMethodDelegate1'
    IL_0006: brtrue.s IL_001b

    IL_0008: ldnull
    IL_0009: ldftn void ThreadTesting::'<Main>b__0'()
    IL_000f: newobj instance void [mscorlib]System.Threading.ThreadStart::.ctor(object, native int)
    IL_0014: stsfld class [mscorlib]System.Threading.ThreadStart ThreadTesting::'CS$<>9__CachedAnonymousMethodDelegate1'
    IL_0019: br.s IL_001b

    IL_001b: ldsfld class [mscorlib]System.Threading.ThreadStart ThreadTesting::'CS$<>9__CachedAnonymousMethodDelegate1'
    IL_0020: newobj instance void [mscorlib]System.Threading.Thread::.ctor(class [mscorlib]System.Threading.ThreadStart)
    IL_0025: stloc.0
    IL_0026: ldloc.0
    IL_0027: callvirt instance void [mscorlib]System.Threading.Thread::Start()
    IL_002c: nop
    IL_002d: ret
} // end of method ThreadTesting::Main

I was able to generate most of the above IL codes using System.Reflection.Emit
namespace.

Unfortunate I couldn’t figure out how to generate
following IL code using System.Reflection.Emit.

IL_0001: ldsfld class [mscorlib]System.Threading.ThreadStart ThreadTesting::'CS$<>9__CachedAnonymousMethodDelegate1'

So can somebody help me to figure out
how to generate IL for Anonymous methods?

Answer 1

That IL is simply the way the compiler caches the delegate instance – it isn’t part of the method itself. If you are using DynamicMethod (which you probably should be) then just call CreateDelegate({your delegate type}), cast it to your desired delegate type (probably ThreadStart), and store the (typed) delegate instance anywhere.