/// <summary>
/// Schedules an action to be executed after dueTime.
/// </summary>
/// <typeparam name="TState">The type of the state passed to the scheduled action.</typeparam>
/// <param name="state">State passed to the action to be executed.</param>
/// <param name="action">Action to be executed.</param>
/// <param name="dueTime">Relative time after which to execute the action.</param>
/// <returns>The disposable object used to cancel the scheduled action (best effort).</returns>
/// <exception cref="ArgumentNullException"><paramref name="action"/> is <c>null</c>.</exception>
/// <exception cref="ObjectDisposedException">The scheduler has been disposed and doesn't accept new work.</exception>
public override IDisposable Schedule <TState>(TState state, TimeSpan dueTime, Func <IScheduler, TState, IDisposable> action)
{
if (null == action)
{
throw new ArgumentNullException(nameof(action));
}
var due = stopwatch.Elapsed + dueTime;
var si = new ScheduledItem <TimeSpan, TState>(this, state, action, due);
lock (gate)
{
if (disposed)
{
throw new ObjectDisposedException("");
}
if (dueTime <= TimeSpan.Zero)
{
readyList.Enqueue(si);
_evt.Release();
}
else
{
queue.Enqueue(si);
_evt.Release();
}
EnsureThread();
}
return(si);
}
/// <summary>
/// Compares the work item with another work item based on absolute time values.
/// </summary>
/// <param name="other">Work item to compare the current work item to.</param>
/// <returns>Relative ordering between this and the specified work item.</returns>
/// <remarks>The inequality operators are overloaded to provide results consistent with the <see cref="IComparable"/> implementation. Equality operators implement traditional reference equality semantics.</remarks>
public int CompareTo(ScheduledItem <TAbsolute> other)
{
// MSDN: By definition, any object compares greater than null, and two null references compare equal to each other.
if (other is null)
{
return(1);
}
return(comparer.Compare(DueTime, other.DueTime));
}
private void Tick(object state)
{
lock (gate)
{
if (!disposed)
{
var item = (ScheduledItem <TimeSpan>)state;
if (item == nextItem)
{
nextItem = null;
}
if (queue.Remove(item))
{
readyList.Enqueue(item);
}
_evt.Release();
}
}
}
/// <summary> /// Removes the specified work item from the scheduler queue. /// </summary> /// <param name="scheduledItem">Work item to be removed from the scheduler queue.</param> /// <returns><c>true</c> if the item was found; <c>false</c> otherwise.</returns> public bool Remove(ScheduledItem <TAbsolute> scheduledItem) => queue.Remove(scheduledItem);
/// <summary> /// Enqueues the specified work item to be scheduled. /// </summary> /// <param name="scheduledItem">Work item to be scheduled.</param> public void Enqueue(ScheduledItem <TAbsolute> scheduledItem) => queue.Enqueue(scheduledItem);
/// <summary>
/// Event loop scheduled on the designated event loop thread. The loop is suspended/resumed using the event
/// which gets set by calls to Schedule, the next item timer, or calls to Dispose.
/// </summary>
private void Run()
{
while (true)
{
_evt.Wait();
var ready = default(ScheduledItem <TimeSpan>[]);
lock (gate)
{
//
// Bug fix that ensures the number of calls to Release never greatly exceeds the number of calls to Wait.
// See work item #37: https://rx.codeplex.com/workitem/37
//
while (_evt.CurrentCount > 0)
{
_evt.Wait();
}
//
// The event could have been set by a call to Dispose. This takes priority over anything else. We quit the
// loop immediately. Subsequent calls to Schedule won't ever create a new thread.
//
if (disposed)
{
_evt.Dispose();
return;
}
while (queue.Count > 0 && queue.Peek().DueTime <= stopwatch.Elapsed)
{
var item = queue.Dequeue();
readyList.Enqueue(item);
}
if (queue.Count > 0)
{
var next = queue.Peek();
if (next != nextItem)
{
nextItem = next;
var due = next.DueTime - stopwatch.Elapsed;
Disposable.TrySetSerial(ref nextTimer, ConcurrencyAbstraction.Current.StartTimer(Tick, next, due));
}
}
if (readyList.Count > 0)
{
ready = readyList.ToArray();
readyList.Clear();
}
}
if (null != ready)
{
foreach (var item in ready)
{
if (!item.IsCanceled)
{
item.Invoke();
}
}
}
if (ExitIfEmpty)
{
lock (gate)
{
if (readyList.Count == 0 && queue.Count == 0)
{
thread = null;
return;
}
}
}
}
}
/// <summary>
/// Schedules an action to be executed after dueTime.
/// </summary>
/// <typeparam name="TState">The type of the state passed to the scheduled action.</typeparam>
/// <param name="state">State passed to the action to be executed.</param>
/// <param name="action">Action to be executed.</param>
/// <param name="dueTime">Relative time after which to execute the action.</param>
/// <returns>The disposable object used to cancel the scheduled action (best effort).</returns>
/// <exception cref="ArgumentNullException"><paramref name="action"/> is <c>null</c>.</exception>
public override IDisposable Schedule <TState>(TState state, TimeSpan dueTime, Func <IScheduler, TState, IDisposable> action)
{
if (null == action)
{
throw new ArgumentNullException(nameof(action));
}
SchedulerQueue <TimeSpan> queue;
// There is no timed task and no task is currently running
if (false == running)
{
running = true;
if (TimeSpan.Zero < dueTime)
{
ConcurrencyAbstraction.Current.Sleep(dueTime);
}
// execute directly without queueing
IDisposable disposable;
try
{
disposable = action(this, state);
}
catch
{
SetQueue(null);
running = false;
throw;
}
// did recursive tasks arrive?
queue = GetQueue();
// yes, run those in the queue as well
if (null != queue)
{
try
{
Trampoline.Run(queue);
}
finally
{
SetQueue(null);
running = false;
}
}
else
{
running = false;
}
return(disposable);
}
queue = GetQueue();
// if there is a task running or there is a queue
if (null == queue)
{
queue = new SchedulerQueue <TimeSpan>(4);
SetQueue(queue);
}
var dt = Time + Scheduler.Normalize(dueTime);
// queue up more work
var si = new ScheduledItem <TimeSpan, TState>(this, state, action, dt);
queue.Enqueue(si);
return(si);
}