1 files changed, 48 insertions, 0 deletions
diff --git a/src/mscorlib/src/System/Diagnostics/Eventing/TraceLogging/SimpleEventTypes.cs b/src/mscorlib/src/System/Diagnostics/Eventing/TraceLogging/SimpleEventTypes.cs
new file mode 100644
index 0000000000..9685885879
--- /dev/null
+++ b/src/mscorlib/src/System/Diagnostics/Eventing/TraceLogging/SimpleEventTypes.cs
@@ -0,0 +1,48 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+using System;
+using Interlocked = System.Threading.Interlocked;
+
+#if ES_BUILD_STANDALONE
+namespace Microsoft.Diagnostics.Tracing
+#else
+namespace System.Diagnostics.Tracing
+#endif
+{
+    /// <summary>
+    /// TraceLogging: Contains the metadata needed to emit an event, optimized
+    /// for events with one top-level compile-time-typed payload object.
+    /// </summary>
+    /// <typeparam name="T">
+    /// Type of the top-level payload object. Should be EmptyStruct if the
+    /// event has no payload.
+    /// </typeparam>
+    internal class SimpleEventTypes<T>
+        : TraceLoggingEventTypes
+    {
+        private static SimpleEventTypes<T> instance;
+
+        internal readonly TraceLoggingTypeInfo<T> typeInfo;
+
+        private SimpleEventTypes(TraceLoggingTypeInfo<T> typeInfo)
+            : base(
+                typeInfo.Name,
+                typeInfo.Tags,
+                new TraceLoggingTypeInfo[] { typeInfo })
+        {
+            this.typeInfo = typeInfo;
+        }
+
+        public static SimpleEventTypes<T> Instance
+        {
+            get { return instance ?? InitInstance(); }
+        }
+
+        private static SimpleEventTypes<T> InitInstance()
+        {
+            var newInstance = new SimpleEventTypes<T>(TraceLoggingTypeInfo<T>.Instance);
+            Interlocked.CompareExchange(ref instance, newInstance, null);
+            return instance;
+        }
+    }
+}