public ActivitySource(string name, string?version = "")
{
if (name == null)
{
throw new ArgumentNullException(nameof(name));
}
Name = name;
Version = version;
s_activeSources.Add(this);
if (s_allListeners.Count > 0)
{
s_allListeners.EnumWithAction((listener, source) =>
{
Func <ActivitySource, bool>?shouldListenTo = listener.ShouldListenTo;
if (shouldListenTo != null)
{
var activitySource = (ActivitySource)source;
if (shouldListenTo(activitySource))
{
activitySource.AddListener(listener);
}
}
}, this);
}
GC.KeepAlive(DiagnosticSourceEventSource.Logger);
}
public static void AddActivityListener(ActivityListener listener)
{
if (listener == null)
{
throw new ArgumentNullException(nameof(listener));
}
if (s_allListeners.AddIfNotExist(listener))
{
s_activeSources.EnumWithAction((source, obj) => {
var shouldListenTo = ((ActivityListener)obj).ShouldListenTo;
if (shouldListenTo != null && shouldListenTo(source))
{
source.AddListener((ActivityListener)obj);
}
}, listener);
}
}
internal void NotifyActivityStop(Activity activity)
{
Debug.Assert(activity != null);
// _listeners can get assigned to null in Dispose.
SynchronizedList <ActivityListener>?listeners = _listeners;
if (listeners != null && listeners.Count > 0)
{
listeners.EnumWithAction((listener, obj) => listener.ActivityStopped?.Invoke((Activity)obj), activity);
}
}
private Activity?StartActivity(string name, ActivityKind kind, ActivityContext context, string?parentId, IEnumerable <KeyValuePair <string, object?> >?tags, IEnumerable <ActivityLink>?links, DateTimeOffset startTime)
{
// _listeners can get assigned to null in Dispose.
SynchronizedList <ActivityListener>?listeners = _listeners;
if (listeners == null || listeners.Count == 0)
{
return(null);
}
Activity?activity = null;
ActivityTagsCollection?samplerTags;
ActivitySamplingResult samplingResult = ActivitySamplingResult.None;
if (parentId != null)
{
var aco = new ActivityCreationOptions <string>(this, name, parentId, kind, tags, links);
var acoContext = new ActivityCreationOptions <ActivityContext>(this, name, aco.GetContext(), kind, tags, links);
listeners.EnumWithFunc((ActivityListener listener, ref ActivityCreationOptions <string> data, ref ActivitySamplingResult result, ref ActivityCreationOptions <ActivityContext> dataWithContext) => {
SampleActivity <string>?sampleUsingParentId = listener.SampleUsingParentId;
if (sampleUsingParentId != null)
{
ActivitySamplingResult sr = sampleUsingParentId(ref data);
if (sr > result)
{
result = sr;
}
}
else
{
// In case we have a parent Id and the listener not providing the SampleUsingParentId, we'll try to find out if the following conditions are true:
// - The listener is providing the Sample callback
// - Can convert the parent Id to a Context. ActivityCreationOptions.TraceId != default means parent id converted to a valid context.
// Then we can call the listener Sample callback with the constructed context.
SampleActivity <ActivityContext>?sample = listener.Sample;
if (sample != null && data.GetContext() != default) // data.GetContext() != default means parent Id parsed correctly to a context
{
ActivitySamplingResult sr = sample(ref dataWithContext);
if (sr > result)
{
result = sr;
}
}
}
}, ref aco, ref samplingResult, ref acoContext);
if (context == default && aco.GetContext() != default)
{
context = aco.GetContext();
parentId = null;
}
samplerTags = aco.GetSamplingTags();
ActivityTagsCollection?atc = acoContext.GetSamplingTags();
if (atc != null)
{
if (samplerTags == null)
{
samplerTags = atc;
}
else
{
foreach (KeyValuePair <string, object?> tag in atc)
{
samplerTags.Add(tag);
}
}
}
}
else
{
bool useCurrentActivityContext = context == default && Activity.Current != null;
var aco = new ActivityCreationOptions <ActivityContext>(this, name, useCurrentActivityContext ? Activity.Current !.Context : context, kind, tags, links);
listeners.EnumWithFunc((ActivityListener listener, ref ActivityCreationOptions <ActivityContext> data, ref ActivitySamplingResult result, ref ActivityCreationOptions <ActivityContext> unused) => {
SampleActivity <ActivityContext>?sample = listener.Sample;
if (sample != null)
{
ActivitySamplingResult dr = sample(ref data);
if (dr > result)
{
result = dr;
}
}
}, ref aco, ref samplingResult, ref aco);
if (!useCurrentActivityContext)
{
// We use the context stored inside ActivityCreationOptions as it is possible the trace id get automatically generated during the sampling.
// We don't use the context stored inside ActivityCreationOptions only in case if we used Activity.Current context, the reason is we need to
// create the new child activity with Parent set to Activity.Current.
context = aco.GetContext();
}
samplerTags = aco.GetSamplingTags();
}
if (samplingResult != ActivitySamplingResult.None)
{
activity = Activity.CreateAndStart(this, name, kind, parentId, context, tags, links, startTime, samplerTags, samplingResult);
listeners.EnumWithAction((listener, obj) => listener.ActivityStarted?.Invoke((Activity)obj), activity);
}
return(activity);
}