IRunnable PollTask()
{
Contract.Assert(this.InLoop);
IRunnable task;
if (!this.taskQueue.TryDequeue(out task))
{
this.emptyEvent.Reset();
if (!this.taskQueue.TryDequeue(out task) && !this.IsShuttingDown) // revisit queue as producer might have put a task in meanwhile
{
IScheduledRunnable nextScheduledTask = this.ScheduledTaskQueue.Peek();
if (nextScheduledTask != null)
{
PreciseTimeSpan wakeupTimeout = nextScheduledTask.Deadline - PreciseTimeSpan.FromStart;
if (wakeupTimeout.Ticks > 0)
{
if (this.emptyEvent.Wait(wakeupTimeout.ToTimeSpan()))
{
// woken up before the next scheduled task was due
this.taskQueue.TryDequeue(out task);
}
}
}
else
{
this.emptyEvent.Wait();
this.taskQueue.TryDequeue(out task);
}
}
}
return(task);
}
IRunnable PollTask()
{
IRunnable task;
if (!this.taskQueue.TryDequeue(out task))
{
this.emptyEvent.Reset();
if (!this.taskQueue.TryDequeue(out task) && !this.IsShuttingDown)
{
IScheduledRunnable nextScheduledTask = this.ScheduledTaskQueue.Peek();
if (nextScheduledTask != null)
{
PreciseTimeSpan wakeupTimeout = nextScheduledTask.Deadline - PreciseTimeSpan.FromStart;
if (wakeupTimeout.Ticks > 0)
{
if (this.emptyEvent.Wait(wakeupTimeout.ToTimeSpan()))
{
this.taskQueue.TryDequeue(out task);
}
}
}
else
{
this.emptyEvent.Wait();
this.taskQueue.TryDequeue(out task);
}
}
}
return(task);
}