Criteo-dotnet-blog

public sealed class ContentionTraceData : TraceEvent
{
    public ContentionFlags ContentionFlags { get; }

Criteo-dotnet-blog

private void OnGCFinalizeObject(FinalizeObjectTraceData data)
{
    if (data.ProcessID != _processId)
        return;

    // the type id should have been associated to a name via a previous TypeBulkType event
    NotifyFinalize(data.TimeStamp, data.ProcessID, data.TypeID, _types[data.TypeID]);
}

Criteo-dotnet-blog

private void OnTypeBulkType(GCBulkTypeTraceData data)
{
    if (data.ProcessID != _processId)
        return;

    // keep track of the id/name type associations
    for (int currentType = 0; currentType < data.Count; currentType++)
    {
        GCBulkTypeValues value = data.Values(currentType);
        _types[value.TypeID] = value.TypeName;

Criteo-dotnet-blog

public override IEnumerable<(ulong objAddress, ClrType clrType, ulong size)> EnumerateObjectDetails()
{
    ClrHeap heap = _segments[0].Heap;
    Dictionary<ulong, ClrType> typeCache = new Dictionary<ulong, ClrType>(32768);
 
    for (int iSegment = 0; iSegment < _segments.Length; ++iSegment)
    {
        ClrSegment segment = _segments[iSegment];
 
        // unlike the default implementation, we are trying to avoid 

Criteo-dotnet-blog

private static IEnumerable<(ulong ObjAddress, ClrType clrType, ulong size)> EnumerateTypeInstances(ClrHeap heap)
{
    foreach (ulong objAddress in heap.EnumerateObjectAddresses())
    {
        ClrType type = heap.GetObjectType(objAddress);
        ulong size = type.GetSize(objAddress);
        
        yield return (objAddress, type, size);
    }
}

Criteo-dotnet-blog

private static void OnExceptionStart(ExceptionTraceData data)
{
    Console.WriteLine($"{data.EventName} --> {data.ExceptionType} : {data.ExceptionMessage}");
}

Criteo-dotnet-blog

// listen to all CLR events
userSession.Source.Clr.All += delegate (TraceEvent data)
{
    // skip verbose and unneeded events
    if (SkipEvent(data))
        return;

    // raw dump of the events
    Console.WriteLine($"{data.ProcessID,7} <{data.ProviderName}:{data.ID}>__[{data.OpcodeName}] {data.EventName} <| {data.GetType().Name}");
};

Criteo-dotnet-blog

// register handlers for events on the session source
// more on this later...

// decide which provider to listen to with filters if needed
userSession.EnableProvider(
    ClrTraceEventParser.ProviderGuid,
    TraceEventLevel.Verbose,
    (ulong)(
    ClrTraceEventParser.Keywords.Contention |  // thread contention timing
    ClrTraceEventParser.Keywords.Threading |   // threadpool events

Criteo-dotnet-blog

string sessionName = "EtwSessionForCLR_" + Guid.NewGuid().ToString();
Console.WriteLine($"Starting {sessionName}...\r\n");
using (TraceEventSession userSession = new TraceEventSession(sessionName, TraceEventSessionOptions.Create))
{
    Task.Run(() =>
    {
        // register handlers for events on the session source
        // more on this later...

        // decide which provider to listen to with filters if needed

Criteo-dotnet-blog

Console.WriteLine("Current ETW sessions:");
foreach(var session in TraceEventSession.GetActiveSessionNames())
{
  Console.WriteLine(session);
}
Console.WriteLine("--------------------------------------------");