protected virtual void Reschedule()
{
if (IsDisposed)
{
return;
}
if (SchedulingItems.Count == 0)
{
NextExecution = null;
Timer.Change(Timeout.Infinite, Timeout.Infinite);
LastTimerInterval = Timeout.Infinite;
}
else
{
var executionTime = SchedulingItems[0].NextExecution;
DateTimeOffset now = SchedulingTimeHelpers.Now();
TimeSpan delay = executionTime.Value.Subtract(now);
long dueTime = System.Math.Max(MinJobInterval, (long)delay.TotalMilliseconds);
dueTime = System.Math.Min(dueTime, SelfTestInterval);
NextExecution = SchedulingTimeHelpers.Now().AddMilliseconds(dueTime);
Timer.Change(dueTime, Timeout.Infinite);
LastTimerInterval = dueTime;
}
LastTimerRun = SchedulingTimeHelpers.Now();
}
/// <summary>
/// Updates the internal state after an execution, and updates the
/// <see cref="LastJobEvaluation"/> and <see cref="NextExecution"/>
/// values. If the job is not supposed to run anymore, the
/// <see cref="NextExecution"/> property is set to null.
/// </summary>
protected virtual void UpdateState()
{
LastJobEvaluation = SchedulingTimeHelpers.Now();
lock (ManagedJob.SynchronizationToken)
{
if (ManagedJob.SchedulingState == SchedulingItemStateType.Aborted)
{
NextExecution = null;
return;
}
if (RemainingExecutions.HasValue)
{
//only decrease the loop counter if the job is not paused
if (ManagedJob.SchedulingState == SchedulingItemStateType.Running)
{
RemainingExecutions--;
}
//we're done if we peformend the last loop
if (RemainingExecutions == 0)
{
//we have a loop, and completed it
ManagedJob.SchedulingState = SchedulingItemStateType.Done;
NextExecution = null;
return;
}
}
//if there is no reoccurrence interval, we cannot calculate a new run
//-> cancel
if (!ManagedJob.Interval.HasValue)
{
ManagedJob.SchedulingState = SchedulingItemStateType.Aborted;
NextExecution = null;
return;
}
//schedule next execution - even if this is beyond expiration
//(we don't cancel as long as expiration happened)
NextExecution = (NextExecution.Value).Add(ManagedJob.Interval.Value);
//if the next job is beyond expiration, reset again
if (ManagedJob.ExpirationTime.HasValue && LastJobEvaluation.Value > ManagedJob.ExpirationTime)
{
ManagedJob.SchedulingState = SchedulingItemStateType.Done;
NextExecution = null;
}
}
}
protected virtual void RunPendingJobs()
{
var now = SchedulingTimeHelpers.Now();
var dueJobs = new List <SchedulingItemContext>();
SchedulingItemContext currentJob = null;
for (int i = 0; i < SchedulingItems.Count; i++)
{
var job = SchedulingItems[i];
if (job.NextExecution.Value > now)
{
break;
}
dueJobs.Add(job);
}
try
{
for (var i = dueJobs.Count - 1; i >= 0; i--)
{
currentJob = dueJobs[i];
currentJob.ExecuteAsync(this);
if (currentJob.NextExecution.HasValue)
{
IsSorted = false;
}
else
{
SchedulingItems.RemoveAt(i);
}
}
}
catch (Exception e)
{
if (!SubmitJobException(currentJob.ManagedJob, e))
{
throw;
}
}
}
/// <summary>
/// Initializes a new instance of the <see cref="T:System.Object"/> class.
/// </summary>
/// <exception cref="ArgumentNullException">If one of the parameters is
/// is a null reference.</exception>
/// <exception cref="InvalidOperationException">If the configuration does not allow
/// proper scheduling, e.g. because several loops were specified, but the inverval is
/// missing.</exception>
public SchedulingItemContext(SchedulingItem managedJob, Action <SchedulingItem> callbackAction)
{
if (managedJob == null)
{
throw new ArgumentNullException("managedJob");
}
if (callbackAction == null)
{
throw new ArgumentNullException("callbackAction");
}
//make sure we have an interval if we have more than one loop
TimeSpan?interval = managedJob.Interval;
if (interval == null)
{
if (managedJob.Loops == null || managedJob.Loops.Value > 1)
{
string msg = "Job [{0}] is invalid: Specifiy either a single run, or a loop interval.";
msg = String.Format(msg, managedJob.Id);
throw new InvalidOperationException(msg);
}
}
ManagedJob = managedJob;
CallbackAction = callbackAction;
NextExecution = managedJob.StartTime;
//adjust starting time if the initial time was in the past,
//but rather start immediately
var now = SchedulingTimeHelpers.Now();
if (NextExecution.Value < now)
{
NextExecution = now;
}
RemainingExecutions = managedJob.Loops;
}
public virtual void Submit(SchedulingItem schedulingItem, Action <SchedulingItem> callback)
{
if (schedulingItem == null)
{
throw new ArgumentNullException("schedulingItem");
}
if (callback == null)
{
throw new ArgumentNullException("callback");
}
var interval = schedulingItem.Interval;
if (interval.HasValue && interval.Value.TotalMilliseconds < MinJobInterval)
{
string msg = "Interval of {0} ms is too small - a minimum interval of {1} ms is accepted.";
msg = String.Format(msg, interval.Value.TotalMilliseconds, MinJobInterval);
throw new InvalidOperationException(msg);
}
var context = new SchedulingItemContext(schedulingItem, callback);
lock (SyncRoot)
{
if (NextExecution == null || context.NextExecution <= NextExecution.Value)
{
SchedulingItems.Insert(0, context);
if (NextExecution == null || NextExecution.Value.Subtract(SchedulingTimeHelpers.Now()).TotalMilliseconds > MinJobInterval)
{
Reschedule();
}
}
else
{
SchedulingItems.Add(context);
IsSorted = false;
}
}
}
protected virtual void VerifySystemTime()
{
if (LastTimerInterval == Timeout.Infinite)
{
return;
}
var now = SchedulingTimeHelpers.Now();
var pauseDuration = now.Subtract(LastTimerRun);
var timeDivergence = pauseDuration.TotalMilliseconds - LastTimerInterval;
if (timeDivergence > 1000 || timeDivergence < 1000)
{
bool changeExpirationTime = ReschedulingType ==
ReschedulingType.RescheduleNextExecutionAndExpirationTime;
SchedulingItems.ForEach(jc =>
{
jc.NextExecution = jc.NextExecution.Value.AddMilliseconds(timeDivergence);
if (changeExpirationTime && jc.ManagedJob.ExpirationTime.HasValue)
{
jc.ManagedJob.ExpirationTime = jc.ManagedJob.ExpirationTime.Value.AddMilliseconds(timeDivergence);
}
});
}
}
/// <summary>
/// Invokes the managed job's <see cref="CallbackAction"/> through
/// the thread pool, and updates the job's internal state.
/// </summary>
public virtual void ExecuteAsync(SchedulingService scheduler)
{
//only execute if the job is neither aborted, expired, or paused
if (ManagedJob.SchedulingState == SchedulingItemStateType.Running && (ManagedJob.ExpirationTime == null || ManagedJob.ExpirationTime >= SchedulingTimeHelpers.Now()))
{
ThreadPool.QueueUserWorkItem(s =>
{
try
{
CallbackAction(ManagedJob);
}
catch (Exception e)
{
//do not reference the scheduler instance to avoid closure
SchedulingService sch = (SchedulingService)s;
if (!sch.SubmitJobException(ManagedJob, e))
{
throw;
}
}
}, scheduler);
}
UpdateState();
}
