1 files changed, 144 insertions, 0 deletions
diff --git a/tests/src/GC/Performance/Tests/List_CrdMrk.cs b/tests/src/GC/Performance/Tests/List_CrdMrk.cs
new file mode 100644
index 0000000000..2d61bc30fc
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+++ b/tests/src/GC/Performance/Tests/List_CrdMrk.cs
@@ -0,0 +1,144 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+
+//Try to allocate in such a way that card marking path is hit often
+//That happens when Gen2 objects reference objects in Gen0 or Gen1
+//This test exercises gc_heap::mark_through_cards_for_segments 
+namespace List_CrdMrk
+{
+    class Node
+    {
+        public Node next = null;
+        public Object oRef = null;
+
+    }
+
+    class List_CrdMrk
+    {
+        public static int LISTSIZE = 30000000;
+        public static int ITERATIONS = 20;
+        public static int STEP = 10;
+        public static int SEED = 1234;
+        public static Node root=null;
+        static void Main(string[] args)
+        {
+            ParseArgs(args);
+
+            //create a linked list
+            root = new Node();
+
+            Node current = root;
+            //create LISTSIZE nodes
+            for (int i = 0; i < LISTSIZE-1; i++)
+            {
+                current.next = new Node();
+                current = current.next;
+            }
+            Console.WriteLine("Done creating the list");
+            //Make sure nodes get in gen2
+            GC.Collect();
+            GC.Collect();
+            
+            Random Rand = new Random(SEED);
+            //Allocate oRef for some of the nodes
+            current = root;
+        
+            for (int i = 0; i < LISTSIZE/STEP; i++)
+            {
+                int pos = Rand.Next(0, STEP);
+                AdvanceCurrent(ref current, pos);
+                byte[] bArr = new byte[3];
+                bArr[1] = 5;
+                current.oRef = bArr;
+                AdvanceCurrent(ref current, STEP - pos);
+            }
+         
+            Console.WriteLine("Done initial allocation");
+            
+            //iterate deleting the old refs and allocating new ones
+            Node current2;
+            for (int k = 0; k < ITERATIONS; k++)
+            {
+                current = root;             
+                for (int i = 0; i < LISTSIZE / STEP; i++)
+                {
+                    //delete the old ref for this section
+                    current2 = current;
+                    for (int j = 0; j < STEP; j++)
+                    {
+                        if (current2.oRef != null)
+                        {
+                            current2.oRef = null;
+                        }
+                        current2 = current.next;
+                    }
+
+                    //create a new object
+                    int pos = Rand.Next(0, STEP);
+                    AdvanceCurrent(ref current, pos);
+                    byte[] bArr = new byte[3];
+                    bArr[1] = 5;
+                    current.oRef = bArr;
+                    AdvanceCurrent(ref current, STEP - pos);
+                }
+             
+                Console.WriteLine("Done iter " + k);
+            }
+            GC.KeepAlive(root);
+        }
+
+        //advance the current pointer
+        static void AdvanceCurrent(ref Node cur, int count)
+        {
+           // Console.WriteLine("advancing" + count);
+            for (int i = 0; i < count; i++)
+            {
+                cur = cur.next;
+            }
+        }
+        static void ParseArgs(string[] args)
+        {
+            if (args.Length > 0)
+            {
+                if (args[0].CompareTo("/?") == 0)
+                {
+                    Console.WriteLine("Usage: [ArraySize(default {0})] [Iterations(default {1})] [Step(default {2})] [RandomSeed]", LISTSIZE, ITERATIONS, STEP);
+                    System.Environment.Exit(0);
+                }
+                else
+                {
+                    LISTSIZE = Int32.Parse(args[0]);
+                }
+            }
+            if (args.Length > 1)
+            {
+                ITERATIONS = Int32.Parse(args[1]);
+            }
+            if (args.Length > 2)
+            {
+                STEP = Int32.Parse(args[2]);
+            }
+            if (args.Length > 3)
+            {
+                SEED = Int32.Parse(args[3]);
+            }
+        }
+
+        //static void Print()
+        //{
+        //    Node cur = root;
+        //    while (cur != null)
+        //    {
+        //        if (cur.oRef == null)
+        //            Console.WriteLine("0");
+        //        else
+        //            Console.WriteLine("1");
+        //        cur = cur.next;
+        //    }
+        //}
+    }
+}