TimerEventSubscriptionCollection.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / WF / RunTime / TimerEventSubscriptionCollection.cs / 1305376 / TimerEventSubscriptionCollection.cs
                        
                        
                            using System; 
using System.Collections.Generic;
using System.Text;
using System.Workflow.Runtime.Hosting;
using System.Workflow.ComponentModel; 
using System.Diagnostics;
using System.Collections; 
 
namespace System.Workflow.Runtime
{ 
    [Serializable]
    public class TimerEventSubscriptionCollection : ICollection
    {
        public readonly static DependencyProperty TimerCollectionProperty = DependencyProperty.RegisterAttached("TimerCollection", typeof(TimerEventSubscriptionCollection), typeof(TimerEventSubscriptionCollection)); 

        private object locker = new Object(); 
        private KeyedPriorityQueue queue = new KeyedPriorityQueue(); 
#pragma warning disable 0414
        private bool suspended = false; // no longer used but required for binary compatibility of serialization format 
#pragma warning restore 0414
        [NonSerialized]
        private IWorkflowCoreRuntime executor;
        private Guid instanceId; 

        internal TimerEventSubscriptionCollection(IWorkflowCoreRuntime executor, Guid instanceId) 
        { 
            this.executor = executor;
            this.instanceId = instanceId; 
            WorkflowTrace.Host.TraceEvent(TraceEventType.Information, 0, "TimerEventSubscriptionQueue: {0} Created", instanceId);
            this.queue.FirstElementChanged += OnFirstElementChanged;
        }
 
        internal void Enqueue(TimerEventSubscription timerEventSubscription)
        { 
            lock (locker) 
            {
                WorkflowTrace.Host.TraceEvent(TraceEventType.Information, 0, "TimerEventSubscriptionQueue: {0} Enqueue Timer {1} for {2} ", instanceId, timerEventSubscription.SubscriptionId, timerEventSubscription.ExpiresAt); 
                queue.Enqueue(timerEventSubscription.SubscriptionId, timerEventSubscription, timerEventSubscription.ExpiresAt);
            }
        }
 
        internal IWorkflowCoreRuntime Executor
        { 
            get { return executor; } 
            set { executor = value; }
        } 

        public TimerEventSubscription Peek()
        {
            lock (locker) 
            {
                return queue.Peek(); 
            } 
        }
 
        internal TimerEventSubscription Dequeue()
        {
            lock (locker)
            { 
                TimerEventSubscription retval = queue.Dequeue();
                if(retval != null) 
                    WorkflowTrace.Host.TraceEvent(TraceEventType.Information, 0, "TimerEventSubscriptionQueue: {0} Dequeue Timer {1} for {2} ", instanceId, retval.SubscriptionId, retval.ExpiresAt); 
                return retval;
            } 
        }

        public void Remove(Guid timerSubscriptionId)
        { 
            lock (locker)
            { 
                WorkflowTrace.Host.TraceEvent(TraceEventType.Information, 0, "TimerEventSubscriptionQueue: {0} Remove Timer {1}", instanceId, timerSubscriptionId); 
                queue.Remove(timerSubscriptionId);
            } 
        }

        private void OnFirstElementChanged(object source, KeyedPriorityQueueHeadChangedEventArgs e)
        { 
            lock (locker)
            { 
                ITimerService timerService = this.executor.GetService(typeof(ITimerService)) as ITimerService; 
                if (e.NewFirstElement != null && executor != null)
                { 
                    WorkflowTrace.Host.TraceEvent(TraceEventType.Information, 0, "TimerEventSubscriptionQueue: {0} Schedule Timer {1} for {2} ", instanceId, e.NewFirstElement.SubscriptionId, e.NewFirstElement.ExpiresAt);
                    timerService.ScheduleTimer(executor.ProcessTimersCallback, e.NewFirstElement.WorkflowInstanceId, e.NewFirstElement.ExpiresAt, e.NewFirstElement.SubscriptionId);
                }
                if (e.OldFirstElement != null) 
                {
                    WorkflowTrace.Host.TraceEvent(TraceEventType.Information, 0, "TimerEventSubscriptionQueue: {0} Unschedule Timer {1} for {2} ", instanceId, e.OldFirstElement.SubscriptionId, e.OldFirstElement.ExpiresAt); 
                    timerService.CancelTimer(e.OldFirstElement.SubscriptionId); 
                }
            } 
        }

        internal void SuspendDelivery()
        { 
            lock (locker)
            { 
                WorkflowTrace.Host.TraceEvent(TraceEventType.Information, 0, "TimerEventSubscriptionQueue: {0} Suspend", instanceId); 
                WorkflowSchedulerService schedulerService = this.executor.GetService(typeof(WorkflowSchedulerService)) as WorkflowSchedulerService;
                TimerEventSubscription sub = queue.Peek(); 
                if (sub != null)
                {
                    schedulerService.Cancel(sub.SubscriptionId);
                } 
            }
        } 
 
        internal void ResumeDelivery()
        { 
            lock (locker)
            {
                WorkflowTrace.Host.TraceEvent(TraceEventType.Information, 0, "TimerEventSubscriptionQueue: {0} Resume", instanceId);
                WorkflowSchedulerService schedulerService = this.executor.GetService(typeof(WorkflowSchedulerService)) as WorkflowSchedulerService; 
                TimerEventSubscription sub = queue.Peek();
                if (sub != null) 
                { 
                    schedulerService.Schedule(executor.ProcessTimersCallback, sub.WorkflowInstanceId, sub.ExpiresAt, sub.SubscriptionId);
                } 
            }
        }

        public void Add(TimerEventSubscription item) 
        {
            if (item == null) 
                throw new ArgumentNullException("item"); 
            this.Enqueue(item);
        } 


        public void Remove(TimerEventSubscription item)
        { 
            if (item == null)
                throw new ArgumentNullException("item"); 
            this.Remove(item.SubscriptionId); 
        }
 
        #region ICollection Members

        public void CopyTo(Array array, int index)
        { 
            TimerEventSubscription[] tes = null;
            lock (locker) 
            { 
                tes = new TimerEventSubscription[queue.Count];
                queue.Values.CopyTo(tes, 0); 
            }
            if(tes != null)
                tes.CopyTo(array, index);
        } 

        public int Count 
        { 
            get
            { 
                return queue.Count;
            }
        }
 
        public bool IsSynchronized
        { 
            get 
            {
                return true; 
            }
        }

        public object SyncRoot 
        {
            get 
            { 
                return locker;
            } 
        }

        #endregion
 
        #region IEnumerable Members
 
        public IEnumerator GetEnumerator() 
        {
            return queue.Values.GetEnumerator(); 
        }

        #endregion
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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TimerEventSubscriptionCollection.cs source code in C# .NET

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