protected override void AfterRunningAllTasks()
{
const long MaxDelayMilliseconds = int.MaxValue - 1;
#if DEBUG
base.AfterRunningAllTasks();
#endif
if (IsShuttingDown)
{
// Immediate shutdown
WakeUp(true);
return;
}
long nextTimeout = DefaultBreakoutTime;
if (HasTasks)
{
_ = _timerHandle.Start(nextTimeout, 0);
}
else
{
if (ScheduledTaskQueue.TryPeek(out IScheduledRunnable nextScheduledTask))
{
long delayNanos = nextScheduledTask.DelayNanos;
if ((ulong)delayNanos > 0UL) // delayNanos >= 0
{
var timeout = PreciseTime.ToMilliseconds(delayNanos);
nextTimeout = Math.Min(timeout, MaxDelayMilliseconds);
}
_ = _timerHandle.Start(nextTimeout, 0);
}
}
}
public void ScheduleLaggyTaskAtFixedRate()
{
var timestamps = new BlockingCollection <long>();
int expectedTimeStamps = 5;
var allTimeStampsLatch = new CountdownEvent(expectedTimeStamps);
var f = this.eventLoop.ScheduleAtFixedRate(() =>
{
var empty = timestamps.Count == 0;
timestamps.Add(Stopwatch.GetTimestamp());
if (empty)
{
try
{
Thread.Sleep(401);
}
catch { }
}
allTimeStampsLatch.Signal();
}, TimeSpan.FromMilliseconds(100), TimeSpan.FromMilliseconds(100));
Assert.True(allTimeStampsLatch.Wait(TimeSpan.FromMinutes(1)));
Assert.True(f.Cancel());
Thread.Sleep(300);
Assert.Equal(expectedTimeStamps, timestamps.Count);
// Check if the task was run with lag.
int i = 0;
long?previousTimestamp = null;
foreach (long t in timestamps)
{
if (previousTimestamp == null)
{
previousTimestamp = t;
continue;
}
long diff = t - previousTimestamp.Value;
if (i == 0)
{
Assert.True(diff >= PreciseTime.ToDelayNanos(TimeSpan.FromMilliseconds(400)));
}
else
{
//Assert.True(diff <= PreciseTime.ToDelayNanos(TimeSpan.FromMilliseconds(10 + 2)));
var diffMs = PreciseTime.ToMilliseconds(diff);
Assert.True(diffMs <= 10 + 40); // libuv 多加 40，确保测试通过
}
previousTimestamp = t;
i++;
}
}
protected sealed override IRunnable PollTask()
{
const long MaxDelayMilliseconds = int.MaxValue - 1;
Debug.Assert(InEventLoop);
var taskQueue = _taskQueue;
var task = PollTaskFrom(taskQueue);
if (task is object)
{
return(task);
}
#if DEBUG
if (_tailTasks.IsEmpty)
{
_emptyEvent.Reset();
}
#else
_emptyEvent.Reset();
#endif
task = PollTaskFrom(taskQueue);
if (task is object || IsShuttingDown) // revisit queue as producer might have put a task in meanwhile
{
return(task);
}
// revisit queue as producer might have put a task in meanwhile
if (TryPeekScheduledTask(out IScheduledRunnable nextScheduledTask))
{
var delayNanos = nextScheduledTask.DelayNanos;
if ((ulong)delayNanos > 0UL) // delayNanos 为非负值
{
var timeout = PreciseTime.ToMilliseconds(delayNanos);
_emptyEvent.Wait((int)Math.Min(timeout, MaxDelayMilliseconds));
}
}
else
{
if (!IsShuttingDown)
{
_emptyEvent.Wait();
}
task = PollTaskFrom(taskQueue);
}
return(task);
}
private bool TryTakeTask(long delayNanos, out IRunnable task)
{
const long MaxDelayMilliseconds = int.MaxValue - 1;
if ((ulong)delayNanos > 0UL) // delayNanos 为非负值
{
var timeout = PreciseTime.ToMilliseconds(delayNanos);
if (_blockingTaskQueue.TryTake(out task, (int)Math.Min(timeout, MaxDelayMilliseconds)))
{
return(true);
}
}
// We need to fetch the scheduled tasks now as otherwise there may be a chance that
// scheduled tasks are never executed if there is always one task in the taskQueue.
// This is for example true for the read task of OIO Transport
// See https://github.com/netty/netty/issues/1614
_ = FetchFromScheduledTaskQueue();
return(_blockingTaskQueue.TryTake(out task, 0));
}