public void TestEmptyArrayDeque()
{
var deque = new ArrayDeque <int>();
Assert.That(deque.Count, Is.EqualTo(0));
Assert.That(deque.Count(), Is.EqualTo(0));
Assert.That(() => deque.First(), Throws.InvalidOperationException.With.Message.EqualTo("Sequence contains no elements"));
}
private void ProcessDispatches(
ArrayDeque <NamedWindowConsumerLatch> dispatches,
ArrayDeque <NamedWindowConsumerLatch> work,
IDictionary <EPStatementAgentInstanceHandle, Object> dispatchesPerStmt)
{
if (dispatches.Count == 1)
{
var latch = dispatches.First();
try
{
latch.Await();
var newData = latch.DeltaData.NewData;
var oldData = latch.DeltaData.OldData;
foreach (var entry in latch.DispatchTo)
{
var handle = entry.Key;
handle.StatementHandle.MetricsHandle.Call(
_metricReportingService.PerformanceCollector,
() => { ProcessHandle(handle, entry.Value, newData, oldData); });
if ((_isPrioritized) && (handle.IsPreemptive))
{
break;
}
}
}
finally
{
latch.Done();
}
return;
}
// Multiple different-result dispatches to same or different statements are needed in two situations:
// a) an event comes in, triggers two insert-into statements inserting into the same named window and the window produces 2 results
// b) a time batch is grouped in the named window, and a timer fires for both groups at the same time producing more then one result
// c) two on-merge/update/delete statements fire for the same arriving event each updating the named window
// Most likely all dispatches go to different statements since most statements are not joins of
// named windows that produce results at the same time. Therefore sort by statement handle.
// We need to process in N-element chains to preserve dispatches that are next to each other for the same thread.
while (!dispatches.IsEmpty())
{
// the first latch always gets awaited
var first = dispatches.RemoveFirst();
first.Await();
work.Add(first);
// determine which further latches are in this chain and
// add these, skipping await for any latches in the chain
dispatches.RemoveWhere(
(next, continuation) =>
{
NamedWindowConsumerLatch earlier = next.Earlier;
if (earlier == null || work.Contains(earlier))
{
work.Add(next);
return(true);
}
else
{
continuation.Value = false;
return(false);
}
});
ProcessDispatches(work, dispatchesPerStmt);
}
}