mono/tests/dynamic-method-resurrection.cs

   1 using System;
   2 using System.Reflection;
   3 using System.Reflection.Emit;
   4 using System.Runtime.InteropServices;
   5 using System.Runtime.CompilerServices;
   6 using System.Threading;
   7
   8 delegate int Getter ();
   9
  10 class Host {
  11
  12         static int Field = 42;
  13
  14         Getter g;
  15
  16         public Host (Getter g) {
  17                 this.g = g;
  18         }
  19
  20         ~Host () {
  21                 Console.WriteLine ("got finalizated");
  22                 Program.resed = g;
  23         }
  24 }
  25
  26
  27 class Program {
  28                 internal static Getter resed;
  29                 static int result;
  30                 static void DoStuff ()
  31         {
  32                         DynamicMethod method = new DynamicMethod ("GetField",
  33                         typeof (int), new Type [0], Type.GetType ("Host"));
  34
  35                         ILGenerator il = method.GetILGenerator ();
  36                         il.Emit (OpCodes.Ldsfld, typeof (Host).GetField ("Field", BindingFlags.Static | BindingFlags.NonPublic));
  37                         il.Emit (OpCodes.Ret);
  38
  39                         var g = (Getter)method.CreateDelegate (typeof (Getter));
  40                         new Host (g);
  41         }
  42
  43                 static bool CheckStuff () {
  44                         if (resed == null)
  45                                 return false;
  46                         Program.result = resed ();
  47                         resed = null;
  48                         return true;
  49                 }
  50
  51                 public static int Main ()
  52         {
  53                         int cnt = 5;
  54                         var t = new Thread (DoStuff);
  55                         t.Start ();
  56                         t.Join ();
  57                         do {
  58                                 if (CheckStuff ())
  59                                         break;
  60                                 GC.Collect ();
  61                                 GC.WaitForPendingFinalizers ();
  62                                 Thread.Sleep (10);
  63                         } while (cnt-- > 0);
  64                         GC.Collect ();
  65                         GC.WaitForPendingFinalizers ();
  66                         Console.WriteLine ("done with finalizers");
  67                         return result == 42 ? 0 : 1;
  68                 }
  69 }