SynchronizationFilter.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / WF / Common / AuthoringOM / Filters / SynchronizationFilter.cs / 1305376 / SynchronizationFilter.cs
                        

                        
                            // **************************************************************************** 
// Copyright (C) 2000-2001 Microsoft Corporation.  All rights reserved.
//
// CONTENTS
//     Synchronization Interceptor/Filter Executor 
//
// DESCRIPTION 
// 
// ***************************************************************************
namespace System.Workflow.ComponentModel 
{
    using System;
    using System.Diagnostics;
    using System.Collections; 
    using System.Collections.Generic;
    using System.Workflow.ComponentModel.Design; 
 
    internal sealed class SynchronizationFilter : ActivityExecutionFilter, IActivityEventListener, IActivityEventListener
    { 
        public override ActivityExecutionStatus Execute(Activity activity, ActivityExecutionContext executionContext)
        {
            if (executionContext == null)
                throw new ArgumentNullException("executionContext"); 
            if (activity == null)
                throw new ArgumentNullException("activity"); 
 
            //Make sure first thing we do is hold lock on StatusChange.
            activity.RegisterForStatusChange(Activity.LockCountOnStatusChangeChangedEvent, this); 
            activity.HoldLockOnStatusChange(this);			

            if (executionContext.AcquireLocks(this))
                return ExecuteActivityNow(executionContext); 

            return activity.ExecutionStatus; 
        } 

        private ActivityExecutionStatus ExecuteActivityNow(ActivityExecutionContext context) 
        {
            return ((ActivityExecutor)NextActivityExecutorInChain(context.Activity)).Execute(context.Activity, context);
        }
 
        #region IActivityEventListener Members
 
        public void OnEvent(object sender, ActivityExecutionStatusChangedEventArgs e) 
 		{
			ActivityExecutionContext context = sender as ActivityExecutionContext; 
			if (context.Activity.HasPrimaryClosed && context.Activity.LockCountOnStatusChange == 1)
			{
 				// release locks and status change locks
				context.ReleaseLocks(false); 
 				context.Activity.UnregisterForStatusChange(Activity.LockCountOnStatusChangeChangedEvent, this);
 				context.Activity.ReleaseLockOnStatusChange(this); 
			} 
 		}
 
        #endregion

        #region IActivityEventListener Members
 
        public void OnEvent(object sender, EventArgs e)
        { 
            ActivityExecutionContext context = (ActivityExecutionContext)sender; 

            // only if activity is still executing, then run it 
            if (context.Activity.ExecutionStatus == ActivityExecutionStatus.Executing)
            {
                ActivityExecutionStatus newStatus = ExecuteActivityNow(context);
                if (newStatus == ActivityExecutionStatus.Closed) 
                    context.CloseActivity();
            } 
        } 

        #endregion 
}
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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