public static void Test()
{
// Poll performance counter 4 times a second
TimeSpan pollingInterval = TimeSpan.FromSeconds(0.25);
// Take the total processor utilization performance counter
string categoryName = "Processor";
string counterName = "% Processor Time";
string instanceName = "_Total";
// Create an observable that feeds the performance counter periodically
IObservable <PerformanceCounterSample> source = new PerformanceCounterObservable(categoryName, counterName, instanceName, pollingInterval);
// Load the observable as a stream in Trill
var inputStream =
source.Select(e => StreamEvent.CreateStart(e.StartTime.Ticks, e)) // Create an IObservable of StreamEvent<>
.ToStreamable(/*OnCompletedPolicy.Flush(), PeriodicPunctuationPolicy.Count(4)*/); // Create a streamable with a punctuation every 4 events
// The query
long windowSize = TimeSpan.FromSeconds(2).Ticks;
var query = inputStream.AlterEventDuration(windowSize).Average(e => e.Value);
// Egress results and write to console
query.ToStreamEventObservable().ForEachAsync(e => WriteEvent(e)).Wait();
}
public Subscription(PerformanceCounterObservable observable, IObserver <PerformanceCounterSample> observer)
{
// create a new counter for this subscription
_counter = observable._createCounter();
_pollingInterval = observable._pollingInterval;
_observer = observer;
// seed previous sample to support computation
_previousSample = _counter.NextSample();
// create a timer to support polling counter at an interval
_timer = new Timer(Sample);
_timer.Change(_pollingInterval.Milliseconds, -1);
}
