Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Activities/System/Activities/Statements/DefaultCompensation.cs

@@ -0,0 +1,94 @@
+//----------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//----------------------------------------------------------------
+namespace System.Activities.Statements
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Runtime;
+    using System.Collections.ObjectModel;
+    using SA = System.Activities;
+
+    sealed class DefaultCompensation : NativeActivity
+    {
+        Activity body;
+
+        Variable<CompensationToken> toCompensateToken;
+
+        CompletionCallback onChildCompensated;
+
+        public DefaultCompensation()
+            : base()
+        {
+            this.toCompensateToken = new Variable<CompensationToken>();
+
+            this.body = new InternalCompensate()
+                {
+                    Target = new InArgument<CompensationToken>(toCompensateToken),
+                };
+        }
+
+        public InArgument<CompensationToken> Target
+        {
+            get;
+            set;
+        }
+
+        Activity Body
+        {
+            get { return this.body; }
+        }
+
+        protected override void CacheMetadata(NativeActivityMetadata metadata)
+        {
+            RuntimeArgument targetArgument = new RuntimeArgument("Target", typeof(CompensationToken), ArgumentDirection.In);
+            metadata.Bind(this.Target, targetArgument);
+
+            metadata.SetArgumentsCollection(new Collection<RuntimeArgument> { targetArgument });
+
+            metadata.SetImplementationVariablesCollection(new Collection<Variable> { this.toCompensateToken });
+
+            Fx.Assert(this.Body != null, "Body must be valid");
+            metadata.SetImplementationChildrenCollection(new Collection<Activity> { this.Body });
+        }
+
+        protected override void Execute(NativeActivityContext context)
+        {
+            InternalExecute(context, null);
+        }
+
+        void InternalExecute(NativeActivityContext context, ActivityInstance completedInstance)
+        {
+            CompensationExtension compensationExtension = context.GetExtension<CompensationExtension>();
+            if (compensationExtension == null)
+            {
+                throw SA.FxTrace.Exception.AsError(new InvalidOperationException(SA.SR.CompensateWithoutCompensableActivity(this.DisplayName)));
+            }
+
+            CompensationToken token = Target.Get(context);
+            CompensationTokenData tokenData = token == null ? null : compensationExtension.Get(token.CompensationId);
+
+            Fx.Assert(tokenData != null, "CompensationTokenData must be valid");
+
+            if (tokenData.ExecutionTracker.Count > 0)
+            {
+                if (this.onChildCompensated == null)
+                {
+                    this.onChildCompensated = new CompletionCallback(InternalExecute);
+                }
+
+                this.toCompensateToken.Set(context, new CompensationToken(tokenData.ExecutionTracker.Get()));
+
+                Fx.Assert(Body != null, "Body must be valid");
+                context.ScheduleActivity(Body, this.onChildCompensated);
+            }     
+        }
+
+        protected override void Cancel(NativeActivityContext context)
+        {
+            // Suppress Cancel   
+        }
+
+    }
+
+}