mono/tests/sgen-bridge-major-fragmentation.cs

   1 using System;
   2 using System.Threading;
   3
   4 //64 / 128 size
   5 public class NonBridge {
   6         public object a,b,c,d,e,f,g,h,i,j,k,l,m,n;
   7 }
   8
   9 public class Bridge {
  10         public object a,b,c,d,e,f,g,h,i,j,k,l,m,n;
  11
  12         ~Bridge () {}
  13 }
  14
  15 class Driver {
  16         static void LogLine (string message) {
  17                 Console.WriteLine ("[" + DateTime.Now + "] " + message);
  18         }
  19         //we fill 16Mb worth of stuff, eg, 256k objects
  20         const int major_fill = 1024 * 256;
  21
  22         //4mb nursery with 64 bytes objects -> alloc half
  23         const int nursery_obj_count = 16 * 1024;
  24
  25         static void CrashMainLoop () {
  26                 var arr = new object [major_fill];
  27                 for (int i = 0; i < major_fill; ++i)
  28                         arr [i] = new NonBridge ();
  29                 GC.Collect (1);
  30                 LogLine ("major fill done");
  31
  32                 //induce massive fragmentation
  33                 for (int i = 0; i < major_fill; i += 4) {
  34                         arr [i + 1] = null;
  35                         arr [i + 2] = null;
  36                         arr [i + 3] = null;
  37                 }
  38                 GC.Collect (1);
  39                 LogLine ("fragmentation done");
  40
  41                 //since 50% is garbage, do 2 fill passes
  42                 for (int j = 0; j < 2; ++j) {
  43                         for (int i = 0; i < major_fill; ++i) {
  44                                 if ((i % 1000) == 0)
  45                                         new Bridge ();
  46                                 else
  47                                         arr [i] = new Bridge ();
  48                         }
  49                 }
  50                 LogLine ("done spewing bridges");
  51
  52                 for (int i = 0; i < major_fill; ++i)
  53                         arr [i] = null;
  54                 GC.Collect ();
  55         }
  56
  57
  58         static void Main () {
  59                 const int loops = 4;
  60                 for (int i = 0; i < loops; ++i) {
  61                         LogLine ("CrashLoop " + (i + 1) + "/" + loops);
  62                         CrashMainLoop ();
  63                 }
  64                 LogLine ("done");
  65                 GC.Collect ();
  66                 GC.WaitForPendingFinalizers ();
  67                 GC.Collect ();
  68                 GC.WaitForPendingFinalizers ();
  69         }
  70 }