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//-----------------------------------------------------------------------------
// 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();
}
}
}
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