1 files changed, 29 insertions, 0 deletions
diff --git a/src/System.Private.CoreLib/shared/System/Collections/HashHelpers.SerializationInfoTable.cs b/src/System.Private.CoreLib/shared/System/Collections/HashHelpers.SerializationInfoTable.cs
new file mode 100644
index 000000000..d91dfd878
--- /dev/null
+++ b/src/System.Private.CoreLib/shared/System/Collections/HashHelpers.SerializationInfoTable.cs
@@ -0,0 +1,29 @@
+// 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.
+
+// Used by Hashtable and Dictionary's SeralizationInfo .ctor's to store the SeralizationInfo
+// object until OnDeserialization is called.
+
+using System.Threading;
+using System.Runtime.CompilerServices;
+using System.Runtime.Serialization;
+
+namespace System.Collections
+{
+    internal static partial class HashHelpers
+    {        
+        private static ConditionalWeakTable<object, SerializationInfo> s_serializationInfoTable;
+
+        public static ConditionalWeakTable<object, SerializationInfo> SerializationInfoTable
+        {
+            get
+            {
+                if (s_serializationInfoTable == null)
+                    Interlocked.CompareExchange(ref s_serializationInfoTable, new ConditionalWeakTable<object, SerializationInfo>(), null);
+
+                return s_serializationInfoTable;
+            }
+        }
+    }
+}
+\ No newline at end of file