/// <summary>Return a registered event metric instance for the provided event metric definition.</summary>
/// <remarks><para>If the provided event metric definition is an unregistered raw definition, it will be registered
/// as a completed definition (or a matching registered event metric definition will be used in place of it), but
/// an inability to successfully register the definition will result in an ArgumentException, as with calling
/// the Register() method in EventMetricDefinition. Using a properly-registered definition is preferred.</para>
/// <para>If an event metric with that instance name already exists for that registered definition, it will be
/// returned. Otherwise, one will be created from that definition and returned.</para></remarks>
/// <param name="definition">The metric definition for the desired metric instance.</param>
/// <param name="instanceName">The desired instance name (may be null for the default instance).</param>
/// <returns>The EventMetric object for the requested event metric instance.</returns>
/// <example>
/// See the <see cref="EventMetric">EventMetric Class Overview</see> for an example.
/// </example>
public static EventMetric Register(EventMetricDefinition definition, string instanceName)
{
if (definition == null)
{
// Uh-oh. They gave us a non-EventMetricDefinition?
return(null);
}
EventMetricDefinition metricDefinition;
lock (definition.Lock)
{
if (definition.IsReadOnly == false)
{
// Uh-oh. They gave us a raw event metric definition which wasn't registered.
// But they're calling Register(), so they'd expect us to complete registration for them in this call.
metricDefinition = definition.Register();
}
else
{
// Assume this is a registered definition. ToDo: Make sure they only get IsReadOnly when actually registered.
metricDefinition = definition;
}
}
EventMetric eventMetric;
EventMetricCollection metrics = metricDefinition.Metrics;
lock (metrics.Lock)
{
if (metrics.TryGetValue(instanceName, out eventMetric) == false)
{
eventMetric = metrics.Add(instanceName);
}
}
return(eventMetric);
}
public Enumerator(EventMetricCollection collection, IEnumerator <Monitor.EventMetric> enumerator)
{
m_Collection = collection;
m_Enumerator = enumerator;
}
