AsyncOperationContext.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / NetFx40 / System.Activities / System / Activities / AsyncOperationContext.cs / 1305376 / AsyncOperationContext.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//-----------------------------------------------------------------------------

namespace System.Activities 
{
    using System; 
    using System.Activities.Runtime; 
    using System.Runtime;
    using System.Activities.Hosting; 

    class AsyncOperationContext
    {
        static AsyncCallback onResumeAsyncCodeActivityBookmark; 

        ActivityExecutor executor; 
        ActivityInstance owningActivityInstance; 
        bool hasCanceled;
        bool hasCompleted; 

        internal AsyncOperationContext(ActivityExecutor executor, ActivityInstance owningActivityInstance)
        {
            this.executor = executor; 
            this.owningActivityInstance = owningActivityInstance;
        } 
 
        internal bool IsStillActive
        { 
            get
            {
                return !this.hasCanceled && !this.hasCompleted;
            } 
        }
 
        public object UserState 
        {
            get; 
            set;
        }

        public bool HasCalledAsyncCodeActivityCancel 
        {
            get; 
            set; 
        }
 
        public bool IsAborting
        {
            get;
            set; 
        }
 
        bool ShouldCancel() 
        {
            return this.IsStillActive; 
        }

        bool ShouldComplete()
        { 
            if (this.hasCanceled)
            { 
                return false; 
            }
 
            if (this.hasCompleted)
            {
                throw FxTrace.Exception.AsError(new InvalidOperationException(SR.OperationAlreadyCompleted));
            } 

            return true; 
        } 

        internal void CancelOperation() 
        {
            if (ShouldCancel())
            {
                this.executor.CompleteOperation(this.owningActivityInstance); 
            }
 
            this.hasCanceled = true; 
        }
 
        public void CompleteOperation()
        {
            if (ShouldComplete())
            { 
                this.executor.CompleteOperation(this.owningActivityInstance);
 
                this.hasCompleted = true; 
            }
        } 

        // used by AsyncCodeActivity to efficiently complete a "true" async operation
        internal void CompleteAsyncCodeActivity(CompleteData completeData)
        { 
            Fx.Assert(completeData != null, "caller must validate this is not null");
 
            if (!this.ShouldComplete()) 
            {
                // nothing to do here 
                return;
            }

            if (onResumeAsyncCodeActivityBookmark == null) 
            {
                onResumeAsyncCodeActivityBookmark = Fx.ThunkCallback(new AsyncCallback(OnResumeAsyncCodeActivityBookmark)); 
            } 

            try 
            {
                IAsyncResult result = this.executor.BeginResumeBookmark(Bookmark.AsyncOperationCompletionBookmark,
                    completeData, TimeSpan.MaxValue, onResumeAsyncCodeActivityBookmark, this.executor);
                if (result.CompletedSynchronously) 
                {
                    this.executor.EndResumeBookmark(result); 
                } 
            }
            catch (Exception e) 
            {
                if (Fx.IsFatal(e))
                {
                    throw; 
                }
 
                this.executor.AbortWorkflowInstance(e); 
            }
        } 

        static void OnResumeAsyncCodeActivityBookmark(IAsyncResult result)
        {
            if (result.CompletedSynchronously) 
            {
                return; 
            } 

            ActivityExecutor executor = (ActivityExecutor)result.AsyncState; 

            try
            {
                executor.EndResumeBookmark(result); 
            }
            catch (Exception e) 
            { 
                if (Fx.IsFatal(e))
                { 
                    throw;
                }

                executor.AbortWorkflowInstance(e); 
            }
        } 
 
        internal abstract class CompleteData
        { 
            AsyncOperationContext context;
            bool isCancel;

            protected CompleteData(AsyncOperationContext context, bool isCancel) 
            {
                Fx.Assert(context != null, "Cannot have a null context."); 
                this.context = context; 
                this.isCancel = isCancel;
            } 

            protected ActivityExecutor Executor
            {
                get 
                {
                    return this.context.executor; 
                } 
            }
 
            public ActivityInstance Instance
            {
                get
                { 
                    return this.context.owningActivityInstance;
                } 
            } 

            protected AsyncOperationContext AsyncContext 
            {
                get
                {
                    return this.context; 
                }
            } 
 
            // This method will throw if the complete/cancel is now invalid, it will return
            // true if the complete/cancel should proceed, and return false if the complete/cancel 
            // should be ignored.
            bool ShouldCallExecutor()
            {
                if (this.isCancel) 
                {
                    return this.context.ShouldCancel(); 
                } 
                else
                { 
                    return this.context.ShouldComplete();
                }
            }
 
            // This must be called from a workflow thread
            public void CompleteOperation() 
            { 
                if (ShouldCallExecutor())
                { 
                    OnCallExecutor();

                    // We only update hasCompleted if we just did the completion work.
                    // Calling Cancel followed by Complete does not mean you've completed. 
                    if (!this.isCancel)
                    { 
                        this.context.hasCompleted = true; 
                    }
                } 

                // We update hasCanceled even if we skipped the actual work.
                // Calling Complete followed by Cancel does imply that you have canceled.
                if (this.isCancel) 
                {
                    this.context.hasCanceled = true; 
                } 
            }
 
            protected abstract void OnCallExecutor();
        }
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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AsyncOperationContext.cs source code in C# .NET

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