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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// This program uses code hyperlinks available as part of the HyperAddin Visual Studio plug-in.
// It is available from http://www.codeplex.com/hyperAddin
/* DESIGN NOTES DESIGN NOTES DESIGN NOTES DESIGN NOTES */
// DESIGN NOTES
// Over the years EventSource has become more complex and so it is important to understand
// the basic structure of the code to insure that it does not grow more complex.
//
// Basic Model
//
// PRINCIPLE: EventSource - ETW decoupling
//
// Conceptually an EventSource is something that takes event logging data from the source methods
// to the EventListener that can subscribe to them. Note that CONCEPTUALLY EVENTSOURCES DON'T
// KNOW ABOUT ETW!. The MODEL of the system is that there is a special EventListener which
// we will call the EtwEventListener, that forwards commands from ETW to EventSources and
// listens to EventSources and forwards on those events to ETW. Thus the model should
// be that you DON'T NEED ETW.
//
// Now in actual practice, EventSource have rather intimate knowledge of ETW and send events
// to it directly, but this can be VIEWED AS AN OPTIMIZATION.
//
// Basic Event Data Flow:
//
// There are two ways for event Data to enter the system
// 1) WriteEvent* and friends. This is called the 'contract' based approach because
// you write a method per event which forms a contract that is know at compile time.
// In this scheme each event is given an EVENTID (small integer), which is its identity
// 2) Write<T> methods. This is called the 'dynamic' approach because new events
// can be created on the fly. Event identity is determined by the event NAME, and these
// are not quite as efficient at runtime since you have at least a hash table lookup
// on every event write.
//
// EventSource-EventListener transfer fully supports both ways of writing events (either contract
// based (WriteEvent*) or dynamic (Write<T>)). Both ways fully support the same set of data
// types. It is recommended, however, that you use the contract based approach when the event scheme
// is known at compile time (that is whenever possible). It is more efficient, but more importantly
// it makes the contract very explicit, and centralizes all policy about logging. These are good
// things. The Write<T> API is really meant for more ad-hoc cases.
//
// Allowed Data:
//
// Note that EventSource-EventListeners have a conceptual serialization-deserialization that happens
// during the transfer. In particular object identity is not preserved, some objects are morphed,
// and not all data types are supported. In particular you can pass
//
// A Valid type to log to an EventSource include
// * Primitive data types
// * IEnumerable<T> of valid types T (this include arrays) (* New for V4.6)
// * Explicitly Opted in class or struct with public property Getters over Valid types. (* New for V4.6)
//
// This set of types is roughly a generalization of JSON support (basically primitives, bags, and arrays).
//
// Explicitly allowed structs include (* New for V4.6)
// * Marked with the EventData attribute
// * implicitly defined (e.g the C# new {x = 3, y = 5} syntax)
// * KeyValuePair<K,V> (thus dictionaries can be passed since they are an IEnumerable of KeyValuePair)
//
// When classes are returned in an EventListener, what is returned is something that implements
// IDictionary<string, T>. Thus when objects are passed to an EventSource they are transformed
// into a key-value bag (the IDictionary<string, T>) for consumption in the listener. These
// are obviously NOT the original objects.
//
// ETW serialization formats:
//
// As mentioned, conceptually EventSources send data to EventListeners and there is a conceptual
// copy/morph of that data as described above. In addition the .NET framework supports a conceptual
// ETWListener that will send the data to the ETW stream. If you use this feature, the data needs
// to be serialized in a way that ETW supports. ETW supports the following serialization formats
//
// 1) Manifest Based serialization.
// 2) SelfDescribing serialization (TraceLogging style in the TraceLogging directory)
//
// A key factor is that the Write<T> method, which supports on the fly definition of events, can't
// support the manifest based serialization because the manifest needs the schema of all events
// to be known before any events are emitted. This implies the following:
//
// If you use Write<T> and the output goes to ETW it will use the SelfDescribing format.
// If you use the EventSource(string) constructor for an eventSource (in which you don't
// create a subclass), the default is also to use Self-Describing serialization. In addition
// you can use the EventSoruce(EventSourceSettings) constructor to also explicitly specify
// Self-Describing serialization format. These affect the WriteEvent* APIs going to ETW.
//
// Note that none of this ETW serialization logic affects EventListeners. Only the ETW listener.
//
// *************************************************************************************
// *** INTERNALS: Event Propagation
//
// Data enters the system either though
//
// 1) A user defined method in the user defined subclass of EventSource which calls
// A) A typesafe type specific overload of WriteEvent(ID, ...) e.g. WriteEvent(ID, string, string)
// * which calls into the unsafe WriteEventCore(ID COUNT EventData*) WriteEventWithRelatedActivityIdCore()
// B) The typesafe overload WriteEvent(ID, object[]) which calls the private helper WriteEventVarargs(ID, Guid* object[])
// C) Directly into the unsafe WriteEventCore(ID, COUNT EventData*) or WriteEventWithRelatedActivityIdCore()
//
// All event data eventually flows to one of
// * WriteEventWithRelatedActivityIdCore(ID, Guid*, COUNT, EventData*)
// * WriteEventVarargs(ID, Guid*, object[])
//
// 2) A call to one of the overloads of Write<T>. All these overloads end up in
// * WriteImpl<T>(EventName, Options, Data, Guid*, Guid*)
//
// On output there are the following routines
// Writing to all listeners that are NOT ETW, we have the following routines
// * WriteToAllListeners(ID, Guid*, Guid*, COUNT, EventData*)
// * WriteToAllListeners(ID, Guid*, Guid*, object[])
// * WriteToAllListeners(NAME, Guid*, Guid*, EventPayload)
//
// EventPayload is the internal type that implements the IDictionary<string, object> interface
// The EventListeners will pass back for serialized classes for nested object, but
// WriteToAllListeners(NAME, Guid*, Guid*, EventPayload) unpacks this and uses the fields as if they
// were parameters to a method.
//
// The first two are used for the WriteEvent* case, and the later is used for the Write<T> case.
//
// Writing to ETW, Manifest Based
// EventProvider.WriteEvent(EventDescriptor, Guid*, COUNT, EventData*)
// EventProvider.WriteEvent(EventDescriptor, Guid*, object[])
// Writing to ETW, Self-Describing format
// WriteMultiMerge(NAME, Options, Types, EventData*)
// WriteMultiMerge(NAME, Options, Types, object[])
// WriteImpl<T> has logic that knows how to serialize (like WriteMultiMerge) but also knows
// where it will write it to
//
// All ETW writes eventually call
// EventWriteTransfer
// EventProvider.WriteEventRaw - sets last error
// EventSource.WriteEventRaw - Does EventSource exception handling logic
// WriteMultiMerge
// WriteImpl<T>
// EventProvider.WriteEvent(EventDescriptor, Guid*, COUNT, EventData*)
// EventProvider.WriteEvent(EventDescriptor, Guid*, object[])
//
// Serialization: We have a bit of a hodge-podge of serializers right now. Only the one for ETW knows
// how to deal with nested classes or arrays. I will call this serializer the 'TypeInfo' serializer
// since it is the TraceLoggingTypeInfo structure that knows how to do this. Effectively for a type you
// can call one of these
// WriteMetadata - transforms the type T into serialization meta data blob for that type
// WriteObjectData - transforms an object of T into serialization data blob for that instance
// GetData - transforms an object of T into its deserialized form suitable for passing to EventListener.
// The first two are used to serialize something for ETW. The second one is used to transform the object
// for use by the EventListener. We also have a 'DecodeObject' method that will take a EventData* and
// deserialize to pass to an EventListener, but it only works on primitive types (types supported in version V4.5).
//
// It is an important observation that while EventSource does support users directly calling with EventData*
// blobs, we ONLY support that for the primitive types (V4.5 level support). Thus while there is a EventData*
// path through the system it is only for some types. The object[] path is the more general (but less efficient) path.
//
// TODO There is cleanup needed There should be no divergence until WriteEventRaw.
//
// TODO: We should have a single choke point (right now we always have this parallel EventData* and object[] path. This
// was historical (at one point we tried to pass object directly from EventSoruce to EventListener. That was always
// fragile and a compatibility headache, but we have finally been forced into the idea that there is always a transformation.
// This allows us to use the EventData* form to be the canonical data format in the low level APIs. This also gives us the
// opportunity to expose this format to EventListeners in the future.
//
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.IO;
using System.Numerics;
using System.Reflection;
using System.Resources;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
namespace System.Diagnostics.Tracing
{
[Conditional("NEEDED_FOR_SOURCE_GENERATOR_ONLY")]
[AttributeUsage(AttributeTargets.Class)]
internal sealed class EventSourceAutoGenerateAttribute : Attribute
{
}
/// <summary>
/// This class is meant to be inherited by a user-defined event source in order to define a managed
/// ETW provider. Please See DESIGN NOTES above for the internal architecture.
/// The minimal definition of an EventSource simply specifies a number of ETW event methods that
/// call one of the EventSource.WriteEvent overloads, <see cref="WriteEventCore"/>,
/// or <see cref="WriteEventWithRelatedActivityIdCore"/> to log them. This functionality
/// is sufficient for many users.
/// <para>
/// To achieve more control over the ETW provider manifest exposed by the event source type, the
/// [<see cref="EventAttribute"/>] attributes can be specified for the ETW event methods.
/// </para><para>
/// For very advanced EventSources, it is possible to intercept the commands being given to the
/// eventSource and change what filtering is done (see EventListener.EnableEvents and
/// <see cref="EventListener.DisableEvents"/>) or cause actions to be performed by the eventSource,
/// e.g. dumping a data structure (see EventSource.SendCommand and
/// <see cref="OnEventCommand"/>).
/// </para><para>
/// The eventSources can be turned on with Windows ETW controllers (e.g. logman), immediately.
/// It is also possible to control and intercept the data dispatcher programmatically. See
/// <see cref="EventListener"/> for more.
/// </para>
/// </summary>
/// <remarks>
/// This is a minimal definition for a custom event source:
/// <code>
/// [EventSource(Name="Samples.Demos.Minimal")]
/// sealed class MinimalEventSource : EventSource
/// {
/// public static readonly MinimalEventSource Log = new MinimalEventSource();
/// public void Load(long ImageBase, string Name) { WriteEvent(1, ImageBase, Name); }
/// public void Unload(long ImageBase) { WriteEvent(2, ImageBase); }
/// private MinimalEventSource() {}
/// }
/// </code>
/// </remarks>
// The EnsureDescriptorsInitialized() method might need to access EventSource and its derived type
// members and the trimmer ensures that these members are preserved.
[DynamicallyAccessedMembers(ManifestMemberTypes)]
public partial class EventSource : IDisposable
{
internal static bool IsSupported { get; } = InitializeIsSupported();
private static bool InitializeIsSupported() =>
AppContext.TryGetSwitch("System.Diagnostics.Tracing.EventSource.IsSupported", out bool isSupported) ? isSupported : true;
#if FEATURE_EVENTSOURCE_XPLAT
#pragma warning disable CA1823 // field is used to keep listener alive
private static readonly EventListener? persistent_Xplat_Listener = IsSupported ? XplatEventLogger.InitializePersistentListener() : null;
#pragma warning restore CA1823
#endif //FEATURE_EVENTSOURCE_XPLAT
/// <summary>
/// The human-friendly name of the eventSource. It defaults to the simple name of the class
/// </summary>
public string Name => m_name;
/// <summary>
/// Every eventSource is assigned a GUID to uniquely identify it to the system.
/// </summary>
public Guid Guid => m_guid;
/// <summary>
/// Returns true if the eventSource has been enabled at all. This is the preferred test
/// to be performed before a relatively expensive EventSource operation.
/// </summary>
public bool IsEnabled()
{
return m_eventSourceEnabled;
}
/// <summary>
/// Returns true if events with greater than or equal 'level' and have one of 'keywords' set are enabled.
///
/// Note that the result of this function is only an approximation on whether a particular
/// event is active or not. It is only meant to be used as way of avoiding expensive
/// computation for logging when logging is not on, therefore it sometimes returns false
/// positives (but is always accurate when returning false). EventSources are free to
/// have additional filtering.
/// </summary>
public bool IsEnabled(EventLevel level, EventKeywords keywords)
{
return IsEnabled(level, keywords, EventChannel.None);
}
/// <summary>
/// Returns true if events with greater than or equal 'level' and have one of 'keywords' set are enabled, or
/// if 'keywords' specifies a channel bit for a channel that is enabled.
///
/// Note that the result of this function only an approximation on whether a particular
/// event is active or not. It is only meant to be used as way of avoiding expensive
/// computation for logging when logging is not on, therefore it sometimes returns false
/// positives (but is always accurate when returning false). EventSources are free to
/// have additional filtering.
/// </summary>
public bool IsEnabled(EventLevel level, EventKeywords keywords, EventChannel channel)
{
if (!IsEnabled())
return false;
if (!IsEnabledCommon(m_eventSourceEnabled, m_level, m_matchAnyKeyword, level, keywords, channel))
return false;
return true;
}
/// <summary>
/// Returns the settings for the event source instance
/// </summary>
public EventSourceSettings Settings => m_config;
// Manifest support
/// <summary>
/// Returns the GUID that uniquely identifies the eventSource defined by 'eventSourceType'.
/// This API allows you to compute this without actually creating an instance of the EventSource.
/// It only needs to reflect over the type.
/// </summary>
public static Guid GetGuid(Type eventSourceType)
{
ArgumentNullException.ThrowIfNull(eventSourceType);
EventSourceAttribute? attrib = (EventSourceAttribute?)GetCustomAttributeHelper(eventSourceType, typeof(EventSourceAttribute));
string name = eventSourceType.Name;
if (attrib != null)
{
if (attrib.Guid != null)
{
if (Guid.TryParse(attrib.Guid, out Guid g))
return g;
}
if (attrib.Name != null)
name = attrib.Name;
}
if (name == null)
{
throw new ArgumentException(SR.Argument_InvalidTypeName, nameof(eventSourceType));
}
return GenerateGuidFromName(name.ToUpperInvariant()); // Make it case insensitive.
}
/// <summary>
/// Returns the official ETW Provider name for the eventSource defined by 'eventSourceType'.
/// This API allows you to compute this without actually creating an instance of the EventSource.
/// It only needs to reflect over the type.
/// </summary>
public static string GetName(Type eventSourceType)
{
return GetName(eventSourceType, EventManifestOptions.None);
}
private const DynamicallyAccessedMemberTypes ManifestMemberTypes = DynamicallyAccessedMemberTypes.All;
/// <summary>
/// Returns a string of the XML manifest associated with the eventSourceType. The scheme for this XML is
/// documented at in EventManifest Schema https://docs.microsoft.com/en-us/windows/desktop/WES/eventmanifestschema-schema.
/// This is the preferred way of generating a manifest to be embedded in the ETW stream as it is fast and
/// the fact that it only includes localized entries for the current UI culture is an acceptable tradeoff.
/// </summary>
/// <param name="eventSourceType">The type of the event source class for which the manifest is generated</param>
/// <param name="assemblyPathToIncludeInManifest">The manifest XML fragment contains the string name of the DLL name in
/// which it is embedded. This parameter specifies what name will be used</param>
/// <returns>The XML data string</returns>
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2114:ReflectionToDynamicallyAccessedMembers",
Justification = "EnsureDescriptorsInitialized's use of GetType preserves this method which " +
"has dynamically accessed members requirements, but EnsureDescriptorsInitialized does not " +
"access this member and is safe to call.")]
public static string? GenerateManifest(
[DynamicallyAccessedMembers(ManifestMemberTypes)]
Type eventSourceType,
string? assemblyPathToIncludeInManifest)
{
return GenerateManifest(eventSourceType, assemblyPathToIncludeInManifest, EventManifestOptions.None);
}
/// <summary>
/// Returns a string of the XML manifest associated with the eventSourceType. The scheme for this XML is
/// documented at in EventManifest Schema https://docs.microsoft.com/en-us/windows/desktop/WES/eventmanifestschema-schema.
/// Pass EventManifestOptions.AllCultures when generating a manifest to be registered on the machine. This
/// ensures that the entries in the event log will be "optimally" localized.
/// </summary>
/// <param name="eventSourceType">The type of the event source class for which the manifest is generated</param>
/// <param name="assemblyPathToIncludeInManifest">The manifest XML fragment contains the string name of the DLL name in
/// which it is embedded. This parameter specifies what name will be used</param>
/// <param name="flags">The flags to customize manifest generation. If flags has bit OnlyIfNeededForRegistration specified
/// this returns null when the eventSourceType does not require explicit registration</param>
/// <returns>The XML data string or null</returns>
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2114:ReflectionToDynamicallyAccessedMembers",
Justification = "EnsureDescriptorsInitialized's use of GetType preserves this method which " +
"has dynamically accessed members requirements, but EnsureDescriptorsInitialized does not " +
"access this member and is safe to call.")]
public static string? GenerateManifest(
[DynamicallyAccessedMembers(ManifestMemberTypes)]
Type eventSourceType,
string? assemblyPathToIncludeInManifest,
EventManifestOptions flags)
{
if (!IsSupported)
{
return null;
}
ArgumentNullException.ThrowIfNull(eventSourceType);
byte[]? manifestBytes = CreateManifestAndDescriptors(eventSourceType, assemblyPathToIncludeInManifest, null, flags);
return (manifestBytes == null) ? null : Encoding.UTF8.GetString(manifestBytes, 0, manifestBytes.Length);
}
// EventListener support
/// <summary>
/// returns a list (IEnumerable) of all sources in the appdomain). EventListeners typically need this.
/// </summary>
/// <returns></returns>
public static IEnumerable<EventSource> GetSources()
{
if (!IsSupported)
{
return Array.Empty<EventSource>();
}
var ret = new List<EventSource>();
lock (EventListener.EventListenersLock)
{
Debug.Assert(EventListener.s_EventSources != null);
foreach (WeakReference<EventSource> eventSourceRef in EventListener.s_EventSources)
{
if (eventSourceRef.TryGetTarget(out EventSource? eventSource) && !eventSource.IsDisposed)
ret.Add(eventSource);
}
}
return ret;
}
/// <summary>
/// Send a command to a particular EventSource identified by 'eventSource'.
/// Calling this routine simply forwards the command to the EventSource.OnEventCommand
/// callback. What the EventSource does with the command and its arguments are from
/// that point EventSource-specific.
/// </summary>
/// <param name="eventSource">The instance of EventSource to send the command to</param>
/// <param name="command">A positive user-defined EventCommand, or EventCommand.SendManifest</param>
/// <param name="commandArguments">A set of (name-argument, value-argument) pairs associated with the command</param>
public static void SendCommand(EventSource eventSource, EventCommand command, IDictionary<string, string?>? commandArguments)
{
if (!IsSupported)
{
return;
}
ArgumentNullException.ThrowIfNull(eventSource);
// User-defined EventCommands should not conflict with the reserved commands.
if ((int)command <= (int)EventCommand.Update && (int)command != (int)EventCommand.SendManifest)
{
throw new ArgumentException(SR.EventSource_InvalidCommand, nameof(command));
}
eventSource.SendCommand(null, EventProviderType.ETW, 0, command, true, EventLevel.LogAlways, EventKeywords.None, commandArguments);
}
// Error APIs. (We don't throw by default, but you can probe for status)
/// <summary>
/// Because
///
/// 1) Logging is often optional and thus should not generate fatal errors (exceptions)
/// 2) EventSources are often initialized in class constructors (which propagate exceptions poorly)
///
/// The event source constructor does not throw exceptions. Instead we remember any exception that
/// was generated (it is also logged to Trace.WriteLine).
/// </summary>
public Exception? ConstructionException => m_constructionException;
/// <summary>
/// EventSources can have arbitrary string key-value pairs associated with them called Traits.
/// These traits are not interpreted by the EventSource but may be interpreted by EventListeners
/// (e.g. like the built in ETW listener). These traits are specified at EventSource
/// construction time and can be retrieved by using this GetTrait API.
/// </summary>
/// <param name="key">The key to look up in the set of key-value pairs passed to the EventSource constructor</param>
/// <returns>The value string associated with key. Will return null if there is no such key.</returns>
public string? GetTrait(string key)
{
if (m_traits != null)
{
for (int i = 0; i < m_traits.Length - 1; i += 2)
{
if (m_traits[i] == key)
return m_traits[i + 1];
}
}
return null;
}
/// <summary>
/// Displays the name and GUID for the eventSource for debugging purposes.
/// </summary>
public override string ToString()
{
if (!IsSupported)
return base.ToString()!;
return SR.Format(SR.EventSource_ToString, Name, Guid);
}
/// <summary>
/// Fires when a Command (e.g. Enable) comes from a an EventListener.
/// </summary>
public event EventHandler<EventCommandEventArgs>? EventCommandExecuted
{
add
{
if (value == null)
return;
m_eventCommandExecuted += value;
// If we have an EventHandler<EventCommandEventArgs> attached to the EventSource before the first command arrives
// It should get a chance to handle the deferred commands.
EventCommandEventArgs? deferredCommands = m_deferredCommands;
while (deferredCommands != null)
{
value(this, deferredCommands);
deferredCommands = deferredCommands.nextCommand;
}
}
remove
{
m_eventCommandExecuted -= value;
}
}
#region ActivityID
/// <summary>
/// When a thread starts work that is on behalf of 'something else' (typically another
/// thread or network request) it should mark the thread as working on that other work.
/// This API marks the current thread as working on activity 'activityID'. This API
/// should be used when the caller knows the thread's current activity (the one being
/// overwritten) has completed. Otherwise, callers should prefer the overload that
/// return the oldActivityThatWillContinue (below).
///
/// All events created with the EventSource on this thread are also tagged with the
/// activity ID of the thread.
///
/// It is common, and good practice after setting the thread to an activity to log an event
/// with a 'start' opcode to indicate that precise time/thread where the new activity
/// started.
/// </summary>
/// <param name="activityId">A Guid that represents the new activity with which to mark
/// the current thread</param>
public static void SetCurrentThreadActivityId(Guid activityId)
{
if (!IsSupported)
{
return;
}
TplEventSource.Log?.SetActivityId(activityId);
// We ignore errors to keep with the convention that EventSources do not throw errors.
// Note we can't access m_throwOnWrites because this is a static method.
#if FEATURE_PERFTRACING
// Set the activity id via EventPipe.
EventPipeEventProvider.EventActivityIdControl(
Interop.Advapi32.ActivityControl.EVENT_ACTIVITY_CTRL_SET_ID,
ref activityId);
#endif // FEATURE_PERFTRACING
#if TARGET_WINDOWS
// Set the activity id via ETW.
Interop.Advapi32.EventActivityIdControl(
Interop.Advapi32.ActivityControl.EVENT_ACTIVITY_CTRL_SET_ID,
ref activityId);
#endif // TARGET_WINDOWS
}
/// <summary>
/// Retrieves the ETW activity ID associated with the current thread.
/// </summary>
public static Guid CurrentThreadActivityId
{
get
{
if (!IsSupported)
{
return default;
}
// We ignore errors to keep with the convention that EventSources do not throw
// errors. Note we can't access m_throwOnWrites because this is a static method.
Guid retVal = default;
#if TARGET_WINDOWS
Interop.Advapi32.EventActivityIdControl(
Interop.Advapi32.ActivityControl.EVENT_ACTIVITY_CTRL_GET_ID,
ref retVal);
#elif FEATURE_PERFTRACING
EventPipeEventProvider.EventActivityIdControl(
Interop.Advapi32.ActivityControl.EVENT_ACTIVITY_CTRL_GET_ID,
ref retVal);
#endif // TARGET_WINDOWS
return retVal;
}
}
/// <summary>
/// When a thread starts work that is on behalf of 'something else' (typically another
/// thread or network request) it should mark the thread as working on that other work.
/// This API marks the current thread as working on activity 'activityID'. It returns
/// whatever activity the thread was previously marked with. There is a convention that
/// callers can assume that callees restore this activity mark before the callee returns.
/// To encourage this, this API returns the old activity, so that it can be restored later.
///
/// All events created with the EventSource on this thread are also tagged with the
/// activity ID of the thread.
///
/// It is common, and good practice after setting the thread to an activity to log an event
/// with a 'start' opcode to indicate that precise time/thread where the new activity
/// started.
/// </summary>
/// <param name="activityId">A Guid that represents the new activity with which to mark
/// the current thread</param>
/// <param name="oldActivityThatWillContinue">The Guid that represents the current activity
/// which will continue at some point in the future, on the current thread</param>
public static void SetCurrentThreadActivityId(Guid activityId, out Guid oldActivityThatWillContinue)
{
if (!IsSupported)
{
oldActivityThatWillContinue = default;
return;
}
oldActivityThatWillContinue = activityId;
// We ignore errors to keep with the convention that EventSources do not throw errors.
// Note we can't access m_throwOnWrites because this is a static method.
#if FEATURE_PERFTRACING && TARGET_WINDOWS
EventPipeEventProvider.EventActivityIdControl(
Interop.Advapi32.ActivityControl.EVENT_ACTIVITY_CTRL_SET_ID,
ref oldActivityThatWillContinue);
#elif FEATURE_PERFTRACING
EventPipeEventProvider.EventActivityIdControl(
Interop.Advapi32.ActivityControl.EVENT_ACTIVITY_CTRL_GET_SET_ID,
ref oldActivityThatWillContinue);
#endif // FEATURE_PERFTRACING && TARGET_WINDOWS
#if TARGET_WINDOWS
Interop.Advapi32.EventActivityIdControl(
Interop.Advapi32.ActivityControl.EVENT_ACTIVITY_CTRL_GET_SET_ID,
ref oldActivityThatWillContinue);
#endif // TARGET_WINDOWS
// We don't call the activityDying callback here because the caller has declared that
// it is not dying.
TplEventSource.Log?.SetActivityId(activityId);
}
#endregion
#region protected
/// <summary>
/// This is the constructor that most users will use to create their eventSource. It takes
/// no parameters. The ETW provider name and GUID of the EventSource are determined by the EventSource
/// custom attribute (so you can determine these things declaratively). If the GUID for the eventSource
/// is not specified in the EventSourceAttribute (recommended), it is Generated by hashing the name.
/// If the ETW provider name of the EventSource is not given, the name of the EventSource class is used as
/// the ETW provider name.
/// </summary>
protected EventSource()
: this(EventSourceSettings.EtwManifestEventFormat)
{
}
/// <summary>
/// By default calling the 'WriteEvent' methods do NOT throw on errors (they silently discard the event).
/// This is because in most cases users assume logging is not 'precious' and do NOT wish to have logging failures
/// crash the program. However for those applications where logging is 'precious' and if it fails the caller
/// wishes to react, setting 'throwOnEventWriteErrors' will cause an exception to be thrown if WriteEvent
/// fails. Note the fact that EventWrite succeeds does not necessarily mean that the event reached its destination
/// only that operation of writing it did not fail. These EventSources will not generate self-describing ETW events.
///
/// For compatibility only use the EventSourceSettings.ThrowOnEventWriteErrors flag instead.
/// </summary>
// [Obsolete("Use the EventSource(EventSourceSettings) overload")]
protected EventSource(bool throwOnEventWriteErrors)
: this(EventSourceSettings.EtwManifestEventFormat | (throwOnEventWriteErrors ? EventSourceSettings.ThrowOnEventWriteErrors : 0))
{ }
/// <summary>
/// Construct an EventSource with additional non-default settings (see EventSourceSettings for more)
/// </summary>
protected EventSource(EventSourceSettings settings) : this(settings, null) { }
/// <summary>
/// Construct an EventSource with additional non-default settings.
///
/// Also specify a list of key-value pairs called traits (you must pass an even number of strings).
/// The first string is the key and the second is the value. These are not interpreted by EventSource
/// itself but may be interpreted the listeners. Can be fetched with GetTrait(string).
/// </summary>
/// <param name="settings">See EventSourceSettings for more.</param>
/// <param name="traits">A collection of key-value strings (must be an even number).</param>
protected EventSource(EventSourceSettings settings, params string[]? traits)
{
if (IsSupported)
{
#if FEATURE_PERFTRACING
m_eventHandleTable = new TraceLoggingEventHandleTable();
#endif
m_config = ValidateSettings(settings);
Type myType = this.GetType();
Guid eventSourceGuid = GetGuid(myType);
string eventSourceName = GetName(myType);
Initialize(eventSourceGuid, eventSourceName, traits);
}
}
#if FEATURE_PERFTRACING
// Generate the serialized blobs that describe events for all strongly typed events (that is events that define strongly
// typed event methods. Dynamically defined events (that use Write) hare defined on the fly and are handled elsewhere.
private unsafe void DefineEventPipeEvents()
{
// If the EventSource is set to emit all events as TraceLogging events, skip this initialization.
// Events will be defined when they are emitted for the first time.
if (SelfDescribingEvents)
{
return;
}
Debug.Assert(m_eventData != null);
Debug.Assert(m_eventPipeProvider != null);
int cnt = m_eventData.Length;
for (int i = 0; i < cnt; i++)
{
uint eventID = (uint)m_eventData[i].Descriptor.EventId;
if (eventID == 0)
continue;
byte[]? metadata = EventPipeMetadataGenerator.Instance.GenerateEventMetadata(m_eventData[i]);
uint metadataLength = (metadata != null) ? (uint)metadata.Length : 0;
string eventName = m_eventData[i].Name;
long keywords = m_eventData[i].Descriptor.Keywords;
uint eventVersion = m_eventData[i].Descriptor.Version;
uint level = m_eventData[i].Descriptor.Level;
fixed (byte *pMetadata = metadata)
{
IntPtr eventHandle = m_eventPipeProvider._eventProvider.DefineEventHandle(
eventID,
eventName,
keywords,
eventVersion,
level,
pMetadata,
metadataLength);
Debug.Assert(eventHandle != IntPtr.Zero);
m_eventData[i].EventHandle = eventHandle;
}
}
}
#endif
/// <summary>
/// This method is called when the eventSource is updated by the controller.
/// </summary>
protected virtual void OnEventCommand(EventCommandEventArgs command) { }
#pragma warning disable 1591
// optimized for common signatures (no args)
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId)
{
WriteEventCore(eventId, 0, null);
}
// optimized for common signatures (ints)
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, int arg1)
{
if (IsEnabled())
{
EventData* descrs = stackalloc EventData[1];
descrs[0].DataPointer = (IntPtr)(&arg1);
descrs[0].Size = 4;
descrs[0].Reserved = 0;
WriteEventCore(eventId, 1, descrs);
}
}
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, int arg1, int arg2)
{
if (IsEnabled())
{
EventData* descrs = stackalloc EventData[2];
descrs[0].DataPointer = (IntPtr)(&arg1);
descrs[0].Size = 4;
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)(&arg2);
descrs[1].Size = 4;
descrs[1].Reserved = 0;
WriteEventCore(eventId, 2, descrs);
}
}
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, int arg1, int arg2, int arg3)
{
if (IsEnabled())
{
EventData* descrs = stackalloc EventData[3];
descrs[0].DataPointer = (IntPtr)(&arg1);
descrs[0].Size = 4;
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)(&arg2);
descrs[1].Size = 4;
descrs[1].Reserved = 0;
descrs[2].DataPointer = (IntPtr)(&arg3);
descrs[2].Size = 4;
descrs[2].Reserved = 0;
WriteEventCore(eventId, 3, descrs);
}
}
// optimized for common signatures (longs)
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, long arg1)
{
if (IsEnabled())
{
EventData* descrs = stackalloc EventData[1];
descrs[0].DataPointer = (IntPtr)(&arg1);
descrs[0].Size = 8;
descrs[0].Reserved = 0;
WriteEventCore(eventId, 1, descrs);
}
}
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, long arg1, long arg2)
{
if (IsEnabled())
{
EventData* descrs = stackalloc EventData[2];
descrs[0].DataPointer = (IntPtr)(&arg1);
descrs[0].Size = 8;
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)(&arg2);
descrs[1].Size = 8;
descrs[1].Reserved = 0;
WriteEventCore(eventId, 2, descrs);
}
}
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, long arg1, long arg2, long arg3)
{
if (IsEnabled())
{
EventData* descrs = stackalloc EventData[3];
descrs[0].DataPointer = (IntPtr)(&arg1);
descrs[0].Size = 8;
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)(&arg2);
descrs[1].Size = 8;
descrs[1].Reserved = 0;
descrs[2].DataPointer = (IntPtr)(&arg3);
descrs[2].Size = 8;
descrs[2].Reserved = 0;
WriteEventCore(eventId, 3, descrs);
}
}
// optimized for common signatures (strings)
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, string? arg1)
{
if (IsEnabled())
{
arg1 ??= "";
fixed (char* string1Bytes = arg1)
{
EventData* descrs = stackalloc EventData[1];
descrs[0].DataPointer = (IntPtr)string1Bytes;
descrs[0].Size = ((arg1.Length + 1) * 2);
descrs[0].Reserved = 0;
WriteEventCore(eventId, 1, descrs);
}
}
}
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, string? arg1, string? arg2)
{
if (IsEnabled())
{
arg1 ??= "";
arg2 ??= "";
fixed (char* string1Bytes = arg1)
fixed (char* string2Bytes = arg2)
{
EventData* descrs = stackalloc EventData[2];
descrs[0].DataPointer = (IntPtr)string1Bytes;
descrs[0].Size = ((arg1.Length + 1) * 2);
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)string2Bytes;
descrs[1].Size = ((arg2.Length + 1) * 2);
descrs[1].Reserved = 0;
WriteEventCore(eventId, 2, descrs);
}
}
}
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, string? arg1, string? arg2, string? arg3)
{
if (IsEnabled())
{
arg1 ??= "";
arg2 ??= "";
arg3 ??= "";
fixed (char* string1Bytes = arg1)
fixed (char* string2Bytes = arg2)
fixed (char* string3Bytes = arg3)
{
EventData* descrs = stackalloc EventData[3];
descrs[0].DataPointer = (IntPtr)string1Bytes;
descrs[0].Size = ((arg1.Length + 1) * 2);
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)string2Bytes;
descrs[1].Size = ((arg2.Length + 1) * 2);
descrs[1].Reserved = 0;
descrs[2].DataPointer = (IntPtr)string3Bytes;
descrs[2].Size = ((arg3.Length + 1) * 2);
descrs[2].Reserved = 0;
WriteEventCore(eventId, 3, descrs);
}
}
}
// optimized for common signatures (string and ints)
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, string? arg1, int arg2)
{
if (IsEnabled())
{
arg1 ??= "";
fixed (char* string1Bytes = arg1)
{
EventData* descrs = stackalloc EventData[2];
descrs[0].DataPointer = (IntPtr)string1Bytes;
descrs[0].Size = ((arg1.Length + 1) * 2);
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)(&arg2);
descrs[1].Size = 4;
descrs[1].Reserved = 0;
WriteEventCore(eventId, 2, descrs);
}
}
}
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, string? arg1, int arg2, int arg3)
{
if (IsEnabled())
{
arg1 ??= "";
fixed (char* string1Bytes = arg1)
{
EventData* descrs = stackalloc EventData[3];
descrs[0].DataPointer = (IntPtr)string1Bytes;
descrs[0].Size = ((arg1.Length + 1) * 2);
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)(&arg2);
descrs[1].Size = 4;
descrs[1].Reserved = 0;
descrs[2].DataPointer = (IntPtr)(&arg3);
descrs[2].Size = 4;
descrs[2].Reserved = 0;
WriteEventCore(eventId, 3, descrs);
}
}
}
// optimized for common signatures (string and longs)
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, string? arg1, long arg2)
{
if (IsEnabled())
{
arg1 ??= "";
fixed (char* string1Bytes = arg1)
{
EventData* descrs = stackalloc EventData[2];
descrs[0].DataPointer = (IntPtr)string1Bytes;
descrs[0].Size = ((arg1.Length + 1) * 2);
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)(&arg2);
descrs[1].Size = 8;
descrs[1].Reserved = 0;
WriteEventCore(eventId, 2, descrs);
}
}
}
// optimized for common signatures (long and string)
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, long arg1, string? arg2)
{
if (IsEnabled())
{
arg2 ??= "";
fixed (char* string2Bytes = arg2)
{
EventData* descrs = stackalloc EventData[2];
descrs[0].DataPointer = (IntPtr)(&arg1);
descrs[0].Size = 8;
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)string2Bytes;
descrs[1].Size = ((arg2.Length + 1) * 2);
descrs[1].Reserved = 0;
WriteEventCore(eventId, 2, descrs);
}
}
}
// optimized for common signatures (int and string)
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, int arg1, string? arg2)
{
if (IsEnabled())
{
arg2 ??= "";
fixed (char* string2Bytes = arg2)
{
EventData* descrs = stackalloc EventData[2];
descrs[0].DataPointer = (IntPtr)(&arg1);
descrs[0].Size = 4;
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)string2Bytes;
descrs[1].Size = ((arg2.Length + 1) * 2);
descrs[1].Reserved = 0;
WriteEventCore(eventId, 2, descrs);
}
}
}
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, byte[]? arg1)
{
if (IsEnabled())
{
EventData* descrs = stackalloc EventData[2];
if (arg1 == null || arg1.Length == 0)
{
int blobSize = 0;
descrs[0].DataPointer = (IntPtr)(&blobSize);
descrs[0].Size = 4;
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)(&blobSize); // valid address instead of empty content
descrs[1].Size = 0;
descrs[1].Reserved = 0;
WriteEventCore(eventId, 2, descrs);
}
else
{
int blobSize = arg1.Length;
fixed (byte* blob = &arg1[0])
{
descrs[0].DataPointer = (IntPtr)(&blobSize);
descrs[0].Size = 4;
descrs[0].Reserved = 0;
descrs[1].DataPointer = (IntPtr)blob;
descrs[1].Size = blobSize;
descrs[1].Reserved = 0;
WriteEventCore(eventId, 2, descrs);
}
}
}
}
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected unsafe void WriteEvent(int eventId, long arg1, byte[]? arg2)
{
if (IsEnabled())
{
EventData* descrs = stackalloc EventData[3];
descrs[0].DataPointer = (IntPtr)(&arg1);
descrs[0].Size = 8;
descrs[0].Reserved = 0;
if (arg2 == null || arg2.Length == 0)
{
int blobSize = 0;
descrs[1].DataPointer = (IntPtr)(&blobSize);
descrs[1].Size = 4;
descrs[1].Reserved = 0;
descrs[2].DataPointer = (IntPtr)(&blobSize); // valid address instead of empty contents
descrs[2].Size = 0;
descrs[2].Reserved = 0;
WriteEventCore(eventId, 3, descrs);
}
else
{
int blobSize = arg2.Length;
fixed (byte* blob = &arg2[0])
{
descrs[1].DataPointer = (IntPtr)(&blobSize);
descrs[1].Size = 4;
descrs[1].Reserved = 0;
descrs[2].DataPointer = (IntPtr)blob;
descrs[2].Size = blobSize;
descrs[2].Reserved = 0;
WriteEventCore(eventId, 3, descrs);
}
}
}
}
// Returns the object as a IntPtr - safe when only used for logging
internal static unsafe nint ObjectIDForEvents(object? o)
{
#pragma warning disable CS8500 // takes address of managed type
return *(nint*)&o;
#pragma warning restore CS8500
}
#pragma warning restore 1591
/// <summary>
/// A wrapper type for separating primitive types (int, long, string, etc) from other types
/// in the EventSource API. This type shouldn't be used directly, but just as implicit conversions
/// when using the WriteEvent API.
/// </summary>
public readonly struct EventSourcePrimitive
{
internal readonly object? Value;
private EventSourcePrimitive(object? value)
{
Value = value;
}
public static implicit operator EventSourcePrimitive(bool value) => new(value);
public static implicit operator EventSourcePrimitive(byte value) => new(value);
public static implicit operator EventSourcePrimitive(short value) => new(value);
public static implicit operator EventSourcePrimitive(int value) => new(value);
public static implicit operator EventSourcePrimitive(long value) => new(value);
[CLSCompliant(false)]
public static implicit operator EventSourcePrimitive(sbyte value) => new(value);
[CLSCompliant(false)]
public static implicit operator EventSourcePrimitive(ushort value) => new(value);
[CLSCompliant(false)]
public static implicit operator EventSourcePrimitive(uint value) => new(value);
[CLSCompliant(false)]
public static implicit operator EventSourcePrimitive(ulong value) => new(value);
[CLSCompliant(false)]
// Added to prevent going through the nuint -> ulong conversion
public static implicit operator EventSourcePrimitive(nuint value) => new(value);
public static implicit operator EventSourcePrimitive(float value) => new(value);
public static implicit operator EventSourcePrimitive(double value) => new(value);
public static implicit operator EventSourcePrimitive(decimal value) => new(value);
public static implicit operator EventSourcePrimitive(string? value) => new(value);
public static implicit operator EventSourcePrimitive(byte[]? value) => new(value);
public static implicit operator EventSourcePrimitive(Guid value) => new(value);
public static implicit operator EventSourcePrimitive(DateTime value) => new(value);
public static implicit operator EventSourcePrimitive(nint value) => new(value);
public static implicit operator EventSourcePrimitive(char value) => new(value);
public static implicit operator EventSourcePrimitive(Enum value) => new(value);
}
/// <summary>
/// Used to construct the data structure to be passed to the native ETW APIs - EventWrite and EventWriteTransfer.
/// </summary>
protected internal struct EventData
{
/// <summary>
/// Address where the one argument lives (if this points to managed memory you must ensure the
/// managed object is pinned.
/// </summary>
public unsafe IntPtr DataPointer
{
get => (IntPtr)(void*)m_Ptr;
set => m_Ptr = unchecked((ulong)(void*)value);
}
/// <summary>
/// Size of the argument referenced by DataPointer
/// </summary>
public int Size
{
get => m_Size;
set => m_Size = value;
}
/// <summary>
/// Reserved by ETW. This property is present to ensure that we can zero it
/// since System.Private.CoreLib uses are not zero'd.
/// </summary>
internal int Reserved
{
get => m_Reserved;
set => m_Reserved = value;
}
#region private
/// <summary>
/// Initializes the members of this EventData object to point at a previously-pinned
/// tracelogging-compatible metadata blob.
/// </summary>
/// <param name="pointer">Pinned tracelogging-compatible metadata blob.</param>
/// <param name="size">The size of the metadata blob.</param>
/// <param name="reserved">Value for reserved: 2 for per-provider metadata, 1 for per-event metadata</param>
internal unsafe void SetMetadata(byte* pointer, int size, int reserved)
{
this.m_Ptr = (ulong)pointer;
this.m_Size = size;
this.m_Reserved = reserved; // Mark this descriptor as containing tracelogging-compatible metadata.
}
// Important, we pass this structure directly to the Win32 EventWrite API, so this structure must
// be laid out exactly the way EventWrite wants it.
internal ulong m_Ptr;
internal int m_Size;
#pragma warning disable 0649
internal int m_Reserved; // Used to pad the size to match the Win32 API
#pragma warning restore 0649
#endregion
}
/// <summary>
/// This routine allows you to create efficient WriteEvent helpers, however the code that you use to
/// do this, while straightforward, is unsafe.
/// </summary>
/// <remarks>
/// <code>
/// protected unsafe void WriteEvent(int eventId, string arg1, long arg2)
/// {
/// if (IsEnabled())
/// {
/// arg2 ??= "";
/// fixed (char* string2Bytes = arg2)
/// {
/// EventSource.EventData* descrs = stackalloc EventSource.EventData[2];
/// descrs[0].DataPointer = (IntPtr)(&arg1);
/// descrs[0].Size = 8;
/// descrs[0].Reserved = 0;
/// descrs[1].DataPointer = (IntPtr)string2Bytes;
/// descrs[1].Size = ((arg2.Length + 1) * 2);
/// descrs[1].Reserved = 0;
/// WriteEventCore(eventId, 2, descrs);
/// }
/// }
/// }
/// </code>
/// </remarks>
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2112:ReflectionToRequiresUnreferencedCode",
Justification = "EnsureDescriptorsInitialized's use of GetType preserves this method which " +
"requires unreferenced code, but EnsureDescriptorsInitialized does not access this member and is safe to call.")]
[RequiresUnreferencedCode(EventSourceRequiresUnreferenceMessage)]
[CLSCompliant(false)]
protected unsafe void WriteEventCore(int eventId, int eventDataCount, EventData* data)
{
WriteEventWithRelatedActivityIdCore(eventId, null, eventDataCount, data);
}
/// <summary>
/// This routine allows you to create efficient WriteEventWithRelatedActivityId helpers, however the code
/// that you use to do this, while straightforward, is unsafe. The only difference from
/// <see cref="WriteEventCore"/> is that you pass the relatedActivityId from caller through to this API
/// </summary>
/// <remarks>
/// <code>
/// protected unsafe void WriteEventWithRelatedActivityId(int eventId, Guid relatedActivityId, string arg1, long arg2)
/// {
/// if (IsEnabled())
/// {
/// arg2 ??= "";
/// fixed (char* string2Bytes = arg2)
/// {
/// EventSource.EventData* descrs = stackalloc EventSource.EventData[2];
/// descrs[0].DataPointer = (IntPtr)(&arg1);
/// descrs[0].Size = 8;
/// descrs[1].DataPointer = (IntPtr)string2Bytes;
/// descrs[1].Size = ((arg2.Length + 1) * 2);
/// WriteEventWithRelatedActivityIdCore(eventId, relatedActivityId, 2, descrs);
/// }
/// }
/// }
/// </code>
/// </remarks>
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2112:ReflectionToRequiresUnreferencedCode",
Justification = "EnsureDescriptorsInitialized's use of GetType preserves this method which " +
"requires unreferenced code, but EnsureDescriptorsInitialized does not access this member and is safe to call.")]
[RequiresUnreferencedCode(EventSourceRequiresUnreferenceMessage)]
[CLSCompliant(false)]
protected unsafe void WriteEventWithRelatedActivityIdCore(int eventId, Guid* relatedActivityId, int eventDataCount, EventData* data)
{
if (IsEnabled())
{
Debug.Assert(m_eventData != null); // You must have initialized this if you enabled the source.
try
{
ref EventMetadata metadata = ref m_eventData[eventId];
EventOpcode opcode = (EventOpcode)metadata.Descriptor.Opcode;
Guid* pActivityId = null;
Guid activityId = Guid.Empty;
Guid relActivityId = Guid.Empty;
if (opcode != EventOpcode.Info && relatedActivityId == null &&
((metadata.ActivityOptions & EventActivityOptions.Disable) == 0))
{
if (opcode == EventOpcode.Start)
{
m_activityTracker.OnStart(m_name, metadata.Name, metadata.Descriptor.Task, ref activityId, ref relActivityId, metadata.ActivityOptions);
}
else if (opcode == EventOpcode.Stop)
{
m_activityTracker.OnStop(m_name, metadata.Name, metadata.Descriptor.Task, ref activityId);
}
if (activityId != Guid.Empty)
pActivityId = &activityId;
if (relActivityId != Guid.Empty)
relatedActivityId = &relActivityId;
}
if (!SelfDescribingEvents)
{
if (metadata.EnabledForETW && !m_etwProvider.WriteEvent(ref metadata.Descriptor, metadata.EventHandle, pActivityId, relatedActivityId, eventDataCount, (IntPtr)data))
ThrowEventSourceException(metadata.Name);
#if FEATURE_PERFTRACING
if (metadata.EnabledForEventPipe && !m_eventPipeProvider.WriteEvent(ref metadata.Descriptor, metadata.EventHandle, pActivityId, relatedActivityId, eventDataCount, (IntPtr)data))
ThrowEventSourceException(metadata.Name);
#endif // FEATURE_PERFTRACING
}
else if (metadata.EnabledForETW
#if FEATURE_PERFTRACING
|| metadata.EnabledForEventPipe
#endif // FEATURE_PERFTRACING
)
{
EventSourceOptions opt = new EventSourceOptions
{
Keywords = (EventKeywords)metadata.Descriptor.Keywords,
Level = (EventLevel)metadata.Descriptor.Level,
Opcode = (EventOpcode)metadata.Descriptor.Opcode
};
WriteMultiMerge(metadata.Name, ref opt, metadata.TraceLoggingEventTypes, pActivityId, relatedActivityId, data);
}
if (m_Dispatchers != null && metadata.EnabledForAnyListener)
{
#if MONO && !TARGET_BROWSER && !TARGET_WASI
// On Mono, managed events from NativeRuntimeEventSource are written using WriteEventCore which can be
// written doubly because EventPipe tries to pump it back up to EventListener via NativeRuntimeEventSource.ProcessEvents.
// So we need to prevent this from getting written directly to the Listeners.
if (this.GetType() != typeof(NativeRuntimeEventSource))
#endif // MONO && !TARGET_BROWSER && !TARGET_WASI
{
var eventCallbackArgs = new EventWrittenEventArgs(this, eventId, pActivityId, relatedActivityId);
WriteToAllListeners(eventCallbackArgs, eventDataCount, data);
}
}
}
catch (Exception ex)
{
if (ex is EventSourceException)
throw;
else
ThrowEventSourceException(m_eventData[eventId].Name, ex);
}
}
}
/// <summary>
/// This is a varargs helper for writing an event. It does create an array and box all the arguments so it is
/// relatively inefficient and should only be used for relatively rare events (e.g. less than 100 / sec). If your
/// rates are faster than that you should use <see cref="WriteEventCore"/> to create fast helpers for your particular
/// method signature. Even if you use this for rare events, this call should be guarded by an <see cref="IsEnabled()"/>
/// check so that the varargs call is not made when the EventSource is not active.
/// </summary>
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:UnrecognizedReflectionPattern",
Justification = EventSourceSuppressMessage)]
protected void WriteEvent(int eventId, params EventSourcePrimitive[] args)
{
var argValues = new object?[args.Length];
for (int i = 0; i < args.Length; i++)
{
argValues[i] = args[i].Value;
}
unsafe
{
WriteEventVarargs(eventId, null, argValues);
}
}
// fallback varags helpers.
/// <summary>
/// This is the varargs helper for writing an event. It does create an array and box all the arguments so it is
/// relatively inefficient and should only be used for relatively rare events (e.g. less than 100 / sec). If your
/// rates are faster than that you should use <see cref="WriteEventCore"/> to create fast helpers for your particular
/// method signature. Even if you use this for rare events, this call should be guarded by an <see cref="IsEnabled()"/>
/// check so that the varargs call is not made when the EventSource is not active.
/// </summary>
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2112:ReflectionToRequiresUnreferencedCode",
Justification = "EnsureDescriptorsInitialized's use of GetType preserves this method which " +
"requires unreferenced code, but EnsureDescriptorsInitialized does not access this member and is safe to call.")]
[RequiresUnreferencedCode(EventSourceRequiresUnreferenceMessage)]
protected unsafe void WriteEvent(int eventId, params object?[] args)
{
WriteEventVarargs(eventId, null, args);
}
/// <summary>
/// This is the varargs helper for writing an event which also specifies a related activity. It is completely analogous
/// to corresponding WriteEvent (they share implementation). It does create an array and box all the arguments so it is
/// relatively inefficient and should only be used for relatively rare events (e.g. less than 100 / sec). If your
/// rates are faster than that you should use <see cref="WriteEventWithRelatedActivityIdCore"/> to create fast helpers for your
/// particular method signature. Even if you use this for rare events, this call should be guarded by an <see cref="IsEnabled()"/>
/// check so that the varargs call is not made when the EventSource is not active.
/// </summary>
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2112:ReflectionToRequiresUnreferencedCode",
Justification = "EnsureDescriptorsInitialized's use of GetType preserves this method which " +
"requires unreferenced code, but EnsureDescriptorsInitialized does not access this member and is safe to call.")]
[RequiresUnreferencedCode(EventSourceRequiresUnreferenceMessage)]
protected unsafe void WriteEventWithRelatedActivityId(int eventId, Guid relatedActivityId, params object?[] args)
{
WriteEventVarargs(eventId, &relatedActivityId, args);
}
#endregion
#region IDisposable Members
/// <summary>
/// Disposes of an EventSource.
/// </summary>
public void Dispose()
{
this.Dispose(true);
GC.SuppressFinalize(this);
}
/// <summary>
/// Disposes of an EventSource.
/// </summary>
/// <remarks>
/// Called from Dispose() with disposing=true, and from the finalizer (~EventSource) with disposing=false.
/// Guidelines:
/// 1. We may be called more than once: do nothing after the first call.
/// 2. Avoid throwing exceptions if disposing is false, i.e. if we're being finalized.
/// </remarks>
/// <param name="disposing">True if called from Dispose(), false if called from the finalizer.</param>
protected virtual void Dispose(bool disposing)
{
// NOTE: If !IsSupported, we use ILLink.Substitutions to nop out the finalizer.
// Do not add any code before this line (or you'd need to delete the substitution).
if (!IsSupported)
{
return;
}
// Do not invoke Dispose under the lock as this can lead to a deadlock.
// See https://github.com/dotnet/runtime/issues/48342 for details.
Debug.Assert(!Monitor.IsEntered(EventListener.EventListenersLock));
if (disposing)
{
// Send the manifest one more time to ensure circular buffers have a chance to get to this information
// even in scenarios with a high volume of ETW events.
if (m_eventSourceEnabled)
{
try
{
SendManifest(m_rawManifest);
}
catch { } // If it fails, simply give up.
m_eventSourceEnabled = false;
}
if (m_etwProvider != null)
{
m_etwProvider.Dispose();
m_etwProvider = null!;
}
#if FEATURE_PERFTRACING
if (m_eventPipeProvider != null)
{
m_eventPipeProvider.Dispose();
m_eventPipeProvider = null!;
}
#endif
}
m_eventSourceEnabled = false;
m_eventSourceDisposed = true;
}
/// <summary>
/// Finalizer for EventSource
/// </summary>
~EventSource()
{
// NOTE: we nop out this method body if !IsSupported using ILLink.Substitutions.
this.Dispose(false);
}
#endregion
#region private
private unsafe void WriteEventRaw(
string? eventName,
ref EventDescriptor eventDescriptor,
IntPtr eventHandle,
Guid* activityID,
Guid* relatedActivityID,
int dataCount,
IntPtr data)
{
bool allAreNull = m_etwProvider == null;
if (m_etwProvider != null
&& !m_etwProvider.WriteEventRaw(ref eventDescriptor, eventHandle, activityID, relatedActivityID, dataCount, data))
{
ThrowEventSourceException(eventName);
}
#if FEATURE_PERFTRACING
allAreNull &= (m_eventPipeProvider == null);
if (m_eventPipeProvider != null
&& !m_eventPipeProvider.WriteEventRaw(ref eventDescriptor, eventHandle, activityID, relatedActivityID, dataCount, data))
{
ThrowEventSourceException(eventName);
}
#endif // FEATURE_PERFTRACING
if (allAreNull)
{
ThrowEventSourceException(eventName);
}
}
// FrameworkEventSource is on the startup path for the framework, so we have this internal overload that it can use
// to prevent the working set hit from looking at the custom attributes on the type to get the Guid.
internal EventSource(Guid eventSourceGuid, string eventSourceName)
: this(eventSourceGuid, eventSourceName, EventSourceSettings.EtwManifestEventFormat)
{ }
// Used by the internal FrameworkEventSource constructor and the TraceLogging-style event source constructor
internal EventSource(Guid eventSourceGuid, string eventSourceName, EventSourceSettings settings, string[]? traits = null)
{
if (IsSupported)
{
#if FEATURE_PERFTRACING
m_eventHandleTable = new TraceLoggingEventHandleTable();
#endif
m_config = ValidateSettings(settings);
Initialize(eventSourceGuid, eventSourceName, traits);
}
}
/// <summary>
/// This method is responsible for the common initialization path from our constructors. It must
/// not leak any exceptions (otherwise, since most EventSource classes define a static member,
/// "Log", such an exception would become a cached exception for the initialization of the static
/// member, and any future access to the "Log" would throw the cached exception).
/// </summary>
private unsafe void Initialize(Guid eventSourceGuid, string eventSourceName, string[]? traits)
{
try
{
m_traits = traits;
if (m_traits != null && m_traits.Length % 2 != 0)
{
throw new ArgumentException(SR.EventSource_TraitEven, nameof(traits));
}
if (eventSourceGuid == Guid.Empty)
{
throw new ArgumentException(SR.EventSource_NeedGuid);
}
if (eventSourceName == null)
{
throw new ArgumentException(SR.EventSource_NeedName);
}
m_name = eventSourceName;
m_guid = eventSourceGuid;
// Enable Implicit Activity tracker
m_activityTracker = ActivityTracker.Instance;
#if !DEBUG
if (ProviderMetadata.Length == 0)
#endif
{
// Create and register our provider traits. We do this early because it is needed to log errors
// In the self-describing event case.
InitializeProviderMetadata();
}
// Register the provider with ETW
var etwProvider = new OverrideEventProvider(this, EventProviderType.ETW);
etwProvider.Register(this);
#if FEATURE_PERFTRACING
// Register the provider with EventPipe
var eventPipeProvider = new OverrideEventProvider(this, EventProviderType.EventPipe);
lock (EventListener.EventListenersLock)
{
eventPipeProvider.Register(this);
}
#endif
// Add the eventSource to the global (weak) list.
// This also sets m_id, which is the index in the list.
EventListener.AddEventSource(this);
// OK if we get this far without an exception, then we can at least write out error messages.
// Set m_provider, which allows this.
m_etwProvider = etwProvider;
#if TARGET_WINDOWS
// API available on OS >= Win 8 and patched Win 7.
// Disable only for FrameworkEventSource to avoid recursion inside exception handling.
if (this.Name != "System.Diagnostics.Eventing.FrameworkEventSource" || Environment.IsWindows8OrAbove)
{
var providerMetadata = ProviderMetadata;
fixed (byte* pMetadata = providerMetadata)
{
m_etwProvider.SetInformation(
Interop.Advapi32.EVENT_INFO_CLASS.SetTraits,
pMetadata,
(uint)providerMetadata.Length);
}
}
#endif // TARGET_WINDOWS
#if FEATURE_PERFTRACING
m_eventPipeProvider = eventPipeProvider;
#endif
Debug.Assert(!m_eventSourceEnabled); // We can't be enabled until we are completely initted.
// We are logically completely initialized at this point.
m_completelyInited = true;
}
catch (Exception e)
{
m_constructionException ??= e;
ReportOutOfBandMessage("ERROR: Exception during construction of EventSource " + Name + ": " + e.Message);
}
// Once m_completelyInited is set, you can have concurrency, so all work is under the lock.
lock (EventListener.EventListenersLock)
{
// If there are any deferred commands, we can do them now.
// This is the most likely place for exceptions to happen.
// Note that we are NOT resetting m_deferredCommands to NULL here,
// We are giving for EventHandler<EventCommandEventArgs> that will be attached later
EventCommandEventArgs? deferredCommands = m_deferredCommands;
while (deferredCommands != null)
{
DoCommand(deferredCommands); // This can never throw, it catches them and reports the errors.
deferredCommands = deferredCommands.nextCommand;
}
}
}
private static string GetName(Type eventSourceType, EventManifestOptions flags)
{
ArgumentNullException.ThrowIfNull(eventSourceType);
EventSourceAttribute? attrib = (EventSourceAttribute?)GetCustomAttributeHelper(eventSourceType, typeof(EventSourceAttribute), flags);
if (attrib != null && attrib.Name != null)
return attrib.Name;
return eventSourceType.Name;
}
private static Guid GenerateGuidFromName(string name)
{
ReadOnlySpan<byte> namespaceBytes =
[
0x48, 0x2C, 0x2D, 0xB2, 0xC3, 0x90, 0x47, 0xC8,
0x87, 0xF8, 0x1A, 0x15, 0xBF, 0xC1, 0x30, 0xFB,
];
byte[] bytes = Encoding.BigEndianUnicode.GetBytes(name);
Sha1ForNonSecretPurposes hash = default;
hash.Start();
hash.Append(namespaceBytes);
hash.Append(bytes);
Array.Resize(ref bytes, 16);
hash.Finish(bytes);
bytes[7] = unchecked((byte)((bytes[7] & 0x0F) | 0x50)); // Set high 4 bits of octet 7 to 5, as per RFC 4122
return new Guid(bytes);
}
private static unsafe void DecodeObjects(object?[] decodedObjects, Type[] parameterTypes, EventData* data)
{
for (int i = 0; i < decodedObjects.Length; i++, data++)
{
IntPtr dataPointer = data->DataPointer;
Type dataType = parameterTypes[i];
object? decoded;
if (dataType == typeof(string))
{
goto String;
}
else if (dataType == typeof(int))
{
Debug.Assert(data->Size == 4);
decoded = *(int*)dataPointer;
}
else
{
TypeCode typeCode = Type.GetTypeCode(dataType);
int size = data->Size;
if (size == 4)
{
if ((uint)(typeCode - TypeCode.SByte) <= TypeCode.Int32 - TypeCode.SByte)
{
Debug.Assert(dataType.IsEnum);
// Enums less than 4 bytes in size should be treated as int.
decoded = *(int*)dataPointer;
}
else if (typeCode == TypeCode.UInt32)
{
decoded = *(uint*)dataPointer;
}
else if (typeCode == TypeCode.Single)
{
decoded = *(float*)dataPointer;
}
else if (typeCode == TypeCode.Boolean)
{
// The manifest defines a bool as a 32bit type (WIN32 BOOL), not 1 bit as CLR Does.
decoded = *(int*)dataPointer == 1;
}
else if (dataType == typeof(byte[]))
{
// byte[] are written to EventData* as an int followed by a blob
Debug.Assert(*(int*)dataPointer == (data + 1)->Size);
data++;
goto BytePtr;
}
else if (IntPtr.Size == 4 && dataType == typeof(IntPtr))
{
decoded = *(IntPtr*)dataPointer;
}
else
{
goto Unknown;
}
}
else if (size <= 2)
{
Debug.Assert(!dataType.IsEnum);
if (typeCode == TypeCode.Byte)
{
Debug.Assert(size == 1);
decoded = *(byte*)dataPointer;
}
else if (typeCode == TypeCode.SByte)
{
Debug.Assert(size == 1);
decoded = *(sbyte*)dataPointer;
}
else if (typeCode == TypeCode.Int16)
{
Debug.Assert(size == 2);
decoded = *(short*)dataPointer;
}
else if (typeCode == TypeCode.UInt16)
{
Debug.Assert(size == 2);
decoded = *(ushort*)dataPointer;
}
else if (typeCode == TypeCode.Char)
{
Debug.Assert(size == 2);
decoded = *(char*)dataPointer;
}
else
{
goto Unknown;
}
}
else if (size == 8)
{
if (typeCode == TypeCode.Int64)
{
decoded = *(long*)dataPointer;
}
else if (typeCode == TypeCode.UInt64)
{
decoded = *(ulong*)dataPointer;
}
else if (typeCode == TypeCode.Double)
{
decoded = *(double*)dataPointer;
}
else if (typeCode == TypeCode.DateTime)
{
decoded = DateTime.FromFileTimeUtc(*(long*)dataPointer);
}
else if (IntPtr.Size == 8 && dataType == typeof(IntPtr))
{
decoded = *(IntPtr*)dataPointer;
}
else
{
goto Unknown;
}
}
else if (typeCode == TypeCode.Decimal)
{
Debug.Assert(size == 16);
decoded = *(decimal*)dataPointer;
}
else if (dataType == typeof(Guid))
{
Debug.Assert(size == 16);
decoded = *(Guid*)dataPointer;
}
else
{
goto Unknown;
}
}
goto Store;
Unknown:
if (dataType != typeof(byte*))
{
// Everything else is marshaled as a string.
goto String;
}
BytePtr:
if (data->Size == 0)
{
decoded = Array.Empty<byte>();
}
else
{
var blob = new byte[data->Size];
Marshal.Copy(data->DataPointer, blob, 0, blob.Length);
decoded = blob;
}
goto Store;
String:
// ETW strings are NULL-terminated, so marshal everything up to the first null in the string.
AssertValidString(data);
decoded = dataPointer == IntPtr.Zero ? null : new string((char*)dataPointer, 0, (data->Size >> 1) - 1);
Store:
decodedObjects[i] = decoded;
}
}
[Conditional("DEBUG")]
private static unsafe void AssertValidString(EventData* data)
{
Debug.Assert(data->Size >= 0 && data->Size % 2 == 0, "String size should be even");
char* charPointer = (char*)data->DataPointer;
int charLength = data->Size / 2 - 1;
for (int i = 0; i < charLength; i++)
{
Debug.Assert(*(charPointer + i) != 0, "String may not contain null chars");
}
Debug.Assert(*(charPointer + charLength) == 0, "String must be null terminated");
}
// Finds the Dispatcher (which holds the filtering state), for a given dispatcher for the current
// eventSource).
private EventDispatcher? GetDispatcher(EventListener? listener)
{
EventDispatcher? dispatcher = m_Dispatchers;
while (dispatcher != null)
{
if (dispatcher.m_Listener == listener)
return dispatcher;
dispatcher = dispatcher.m_Next;
}
return dispatcher;
}
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2112:ReflectionToRequiresUnreferencedCode",
Justification = "EnsureDescriptorsInitialized's use of GetType preserves this method which " +
"requires unreferenced code, but EnsureDescriptorsInitialized does not access this member and is safe to call.")]
[RequiresUnreferencedCode(EventSourceRequiresUnreferenceMessage)]
private unsafe void WriteEventVarargs(int eventId, Guid* childActivityID, object?[] args)
{
if (IsEnabled())
{
Debug.Assert(m_eventData != null); // You must have initialized this if you enabled the source.
try
{
ref EventMetadata metadata = ref m_eventData[eventId];
if (childActivityID != null)
{
// If you use WriteEventWithRelatedActivityID you MUST declare the first argument to be a GUID
// with the name 'relatedActivityID, and NOT pass this argument to the WriteEvent method.
// During manifest creation we modify the ParameterInfo[] that we store to strip out any
// first parameter that is of type Guid and named "relatedActivityId." Thus, if you call
// WriteEventWithRelatedActivityID from a method that doesn't name its first parameter correctly
// we can end up in a state where the ParameterInfo[] doesn't have its first parameter stripped,
// and this leads to a mismatch between the number of arguments and the number of ParameterInfos,
// which would cause a cryptic IndexOutOfRangeException later if we don't catch it here.
if (!metadata.HasRelatedActivityID)
{
throw new ArgumentException(SR.EventSource_NoRelatedActivityId);
}
}
LogEventArgsMismatches(eventId, args);
Guid* pActivityId = null;
Guid activityId = Guid.Empty;
Guid relatedActivityId = Guid.Empty;
EventOpcode opcode = (EventOpcode)metadata.Descriptor.Opcode;
EventActivityOptions activityOptions = metadata.ActivityOptions;
if (childActivityID == null &&
((activityOptions & EventActivityOptions.Disable) == 0))
{
if (opcode == EventOpcode.Start)
{
m_activityTracker.OnStart(m_name, metadata.Name, metadata.Descriptor.Task, ref activityId, ref relatedActivityId, metadata.ActivityOptions);
}
else if (opcode == EventOpcode.Stop)
{
m_activityTracker.OnStop(m_name, metadata.Name, metadata.Descriptor.Task, ref activityId);
}
if (activityId != Guid.Empty)
pActivityId = &activityId;
if (relatedActivityId != Guid.Empty)
childActivityID = &relatedActivityId;
}
if (metadata.EnabledForETW
#if FEATURE_PERFTRACING
|| metadata.EnabledForEventPipe
#endif // FEATURE_PERFTRACING
)
{
if (!SelfDescribingEvents)
{
if (!m_etwProvider.WriteEvent(ref metadata.Descriptor, metadata.EventHandle, pActivityId, childActivityID, args))
ThrowEventSourceException(metadata.Name);
#if FEATURE_PERFTRACING
if (!m_eventPipeProvider.WriteEvent(ref metadata.Descriptor, metadata.EventHandle, pActivityId, childActivityID, args))
ThrowEventSourceException(metadata.Name);
#endif // FEATURE_PERFTRACING
}
else
{
// TODO: activity ID support
EventSourceOptions opt = new EventSourceOptions
{
Keywords = (EventKeywords)metadata.Descriptor.Keywords,
Level = (EventLevel)metadata.Descriptor.Level,
Opcode = (EventOpcode)metadata.Descriptor.Opcode
};
WriteMultiMerge(metadata.Name, ref opt, metadata.TraceLoggingEventTypes, pActivityId, childActivityID, args);
}
}
if (m_Dispatchers != null && metadata.EnabledForAnyListener)
{
// Maintain old behavior - object identity is preserved
if (!LocalAppContextSwitches.PreserveEventListenerObjectIdentity)
{
args = SerializeEventArgs(eventId, args);
}
var eventCallbackArgs = new EventWrittenEventArgs(this, eventId, pActivityId, childActivityID)
{
Payload = new ReadOnlyCollection<object?>(args)
};
DispatchToAllListeners(eventCallbackArgs);
}
}
catch (Exception ex)
{
if (ex is EventSourceException)
throw;
else
ThrowEventSourceException(m_eventData[eventId].Name, ex);
}
}
}
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2112:ReflectionToRequiresUnreferencedCode",
Justification = "EnsureDescriptorsInitialized's use of GetType preserves this method which " +
"requires unreferenced code, but EnsureDescriptorsInitialized does not access this member and is safe to call.")]
[RequiresUnreferencedCode(EventSourceRequiresUnreferenceMessage)]
private unsafe object?[] SerializeEventArgs(int eventId, object?[] args)
{
Debug.Assert(m_eventData != null);
TraceLoggingEventTypes eventTypes = m_eventData[eventId].TraceLoggingEventTypes;
int paramCount = Math.Min(eventTypes.typeInfos.Length, args.Length); // parameter count mismatch get logged in LogEventArgsMismatches
var eventData = new object?[eventTypes.typeInfos.Length];
for (int i = 0; i < paramCount; i++)
{
eventData[i] = eventTypes.typeInfos[i].GetData(args[i]);
}
return eventData;
}
/// <summary>
/// We expect that the arguments to the Event method and the arguments to WriteEvent match. This function
/// checks that they in fact match and logs a warning to the debugger if they don't.
/// </summary>
/// <param name="eventId"></param>
/// <param name="args"></param>
private void LogEventArgsMismatches(int eventId, object?[] args)
{
Debug.Assert(m_eventData != null);
ParameterInfo[] infos = m_eventData[eventId].Parameters;
if (args.Length != infos.Length)
{
ReportOutOfBandMessage(SR.Format(SR.EventSource_EventParametersMismatch, eventId, args.Length, infos.Length));
return;
}
for (int i = 0; i < args.Length; i++)
{
Type pType = infos[i].ParameterType;
object? arg = args[i];
// Checking to see if the Parameter types (from the Event method) match the supplied argument types.
// Fail if one of two things hold : either the argument type is not equal or assignable to the parameter type, or the
// argument is null and the parameter type is a non-Nullable<T> value type.
if ((arg != null && !pType.IsAssignableFrom(arg.GetType()))
|| (arg == null && (pType.IsValueType && !(pType.IsGenericType && pType.GetGenericTypeDefinition() == typeof(Nullable<>))))
)
{
ReportOutOfBandMessage(SR.Format(SR.EventSource_VarArgsParameterMismatch, eventId, infos[i].Name));
return;
}
}
}
private unsafe void WriteToAllListeners(EventWrittenEventArgs eventCallbackArgs, int eventDataCount, EventData* data)
{
Debug.Assert(m_eventData != null);
ref EventMetadata metadata = ref m_eventData[eventCallbackArgs.EventId];
if (eventDataCount != metadata.EventListenerParameterCount)
{
ReportOutOfBandMessage(SR.Format(SR.EventSource_EventParametersMismatch, eventCallbackArgs.EventId, eventDataCount, metadata.Parameters.Length));
}
object?[] args;
if (eventDataCount == 0)
{
eventCallbackArgs.Payload = ReadOnlyCollection<object?>.Empty;
}
else
{
args = new object?[Math.Min(eventDataCount, metadata.Parameters.Length)];
if (metadata.AllParametersAreString)
{
for (int i = 0; i < args.Length; i++, data++)
{
AssertValidString(data);
IntPtr dataPointer = data->DataPointer;
args[i] = dataPointer == IntPtr.Zero ? null : new string((char*)dataPointer, 0, (data->Size >> 1) - 1);
}
}
else if (metadata.AllParametersAreInt32)
{
for (int i = 0; i < args.Length; i++, data++)
{
Debug.Assert(data->Size == 4);
args[i] = *(int*)data->DataPointer;
}
}
else
{
DecodeObjects(args, metadata.ParameterTypes, data);
}
eventCallbackArgs.Payload = new ReadOnlyCollection<object?>(args);
}
DispatchToAllListeners(eventCallbackArgs);
}
internal unsafe void DispatchToAllListeners(EventWrittenEventArgs eventCallbackArgs)
{
int eventId = eventCallbackArgs.EventId;
Exception? lastThrownException = null;
for (EventDispatcher? dispatcher = m_Dispatchers; dispatcher != null; dispatcher = dispatcher.m_Next)
{
Debug.Assert(dispatcher.m_EventEnabled != null);
if (eventId == -1 || dispatcher.m_EventEnabled[eventId])
{
{
try
{
dispatcher.m_Listener.OnEventWritten(eventCallbackArgs);
}
catch (Exception e)
{
ReportOutOfBandMessage("ERROR: Exception during EventSource.OnEventWritten: "
+ e.Message);
lastThrownException = e;
}
}
}
}
if (lastThrownException != null && ThrowOnEventWriteErrors)
{
throw new EventSourceException(lastThrownException);
}
}
// WriteEventString is used for logging an error message (or similar) to
// ETW and EventPipe providers. It is not a general purpose API, it will
// log the message with Level=LogAlways and Keywords=All to make sure whoever
// is listening gets the message.
private unsafe void WriteEventString(string msgString)
{
bool allAreNull = m_etwProvider == null;
#if FEATURE_PERFTRACING
allAreNull &= (m_eventPipeProvider == null);
#endif // FEATURE_PERFTRACING
if (allAreNull)
{
return;
}
EventLevel level = EventLevel.LogAlways;
long keywords = -1;
const string EventName = "EventSourceMessage";
if (SelfDescribingEvents)
{
EventSourceOptions opt = new EventSourceOptions
{
Keywords = (EventKeywords)unchecked(keywords),
Level = level
};
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:RequiresUnreferencedCode",
Justification = "The call to TraceLoggingEventTypes with the below parameter values are trim safe")]
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2119",
Justification = "DAM on EventSource references this compiler-generated local function which calls a " +
"constructor that requires unreferenced code. EventSource will not access this local function.")]
static TraceLoggingEventTypes GetTrimSafeTraceLoggingEventTypes() =>
new TraceLoggingEventTypes(EventName, EventTags.None, new Type[] { typeof(string) });
var tlet = GetTrimSafeTraceLoggingEventTypes();
WriteMultiMergeInner(EventName, ref opt, tlet, null, null, msgString);
}
else
{
// We want the name of the provider to show up so if we don't have a manifest we create
// on that at least has the provider name (I don't define any events).
if (m_rawManifest == null && m_outOfBandMessageCount == 1)
{
ManifestBuilder manifestBuilder = new ManifestBuilder(Name, Guid, Name, null, EventManifestOptions.None);
manifestBuilder.StartEvent(EventName, new EventAttribute(0) { Level = level, Task = (EventTask)0xFFFE });
manifestBuilder.AddEventParameter(typeof(string), "message");
manifestBuilder.EndEvent();
SendManifest(manifestBuilder.CreateManifest());
}
// We use this low level routine to bypass the enabled checking, since the eventSource itself is only partially inited.
fixed (char* msgStringPtr = msgString)
{
EventDescriptor descr = new EventDescriptor(0, 0, 0, (byte)level, 0, 0, keywords);
EventProvider.EventData data = default;
data.Ptr = (ulong)msgStringPtr;
data.Size = (uint)(2 * (msgString.Length + 1));
data.Reserved = 0;
m_etwProvider?.WriteEvent(ref descr, IntPtr.Zero, null, null, 1, (IntPtr)((void*)&data));
#if FEATURE_PERFTRACING
if (m_eventPipeProvider != null)
{
if (m_writeEventStringEventHandle == IntPtr.Zero)
{
if (m_createEventLock is null)
{
Interlocked.CompareExchange(ref m_createEventLock, new object(), null);
}
lock (m_createEventLock)
{
if (m_writeEventStringEventHandle == IntPtr.Zero)
{
string eventName = "EventSourceMessage";
EventParameterInfo paramInfo = default(EventParameterInfo);
paramInfo.SetInfo("message", typeof(string));
byte[]? metadata = EventPipeMetadataGenerator.Instance.GenerateMetadata(0, eventName, keywords, (uint)level, 0, EventOpcode.Info, new EventParameterInfo[] { paramInfo });
uint metadataLength = (metadata != null) ? (uint)metadata.Length : 0;
fixed (byte* pMetadata = metadata)
{
m_writeEventStringEventHandle = m_eventPipeProvider._eventProvider.DefineEventHandle(0, eventName, keywords, 0, (uint)level,
pMetadata, metadataLength);
}
}
}
}
m_eventPipeProvider.WriteEvent(ref descr, m_writeEventStringEventHandle, null, null, 1, (IntPtr)((void*)&data));
}
#endif // FEATURE_PERFTRACING
}
}
}
private static ReadOnlyCollection<string>? s_errorPayloadNames;
/// <summary>
/// Since this is a means of reporting errors (see ReportoutOfBandMessage) any failure encountered
/// while writing the message to any one of the listeners will be silently ignored.
/// </summary>
private void WriteStringToAllListeners(string eventName, string msg)
{
var eventCallbackArgs = new EventWrittenEventArgs(this, 0)
{
EventName = eventName,
Message = msg,
Payload = new ReadOnlyCollection<object?>(new object[] { msg }),
PayloadNames = s_errorPayloadNames ??= new ReadOnlyCollection<string>(new string[] { "message" })
};
for (EventDispatcher? dispatcher = m_Dispatchers; dispatcher != null; dispatcher = dispatcher.m_Next)
{
bool dispatcherEnabled = false;
if (dispatcher.m_EventEnabled == null)
{
// if the listeners that weren't correctly initialized, we will send to it
// since this is an error message and we want to see it go out.
dispatcherEnabled = true;
}
else
{
// if there's *any* enabled event on the dispatcher we'll write out the string
// otherwise we'll treat the listener as disabled and skip it
for (int evtId = 0; evtId < dispatcher.m_EventEnabled.Length; ++evtId)
{
if (dispatcher.m_EventEnabled[evtId])
{
dispatcherEnabled = true;
break;
}
}
}
try
{
if (dispatcherEnabled)
dispatcher.m_Listener.OnEventWritten(eventCallbackArgs);
}
catch
{
// ignore any exceptions thrown by listeners' OnEventWritten
}
}
}
/// <summary>
/// Returns true if 'eventNum' is enabled if you only consider the level and matchAnyKeyword filters.
/// It is possible that eventSources turn off the event based on additional filtering criteria.
/// </summary>
private bool IsEnabledByDefault(int eventNum, bool enable, EventLevel currentLevel, EventKeywords currentMatchAnyKeyword)
{
if (!enable)
return false;
Debug.Assert(m_eventData != null);
EventLevel eventLevel = (EventLevel)m_eventData[eventNum].Descriptor.Level;
EventKeywords eventKeywords = unchecked((EventKeywords)((ulong)m_eventData[eventNum].Descriptor.Keywords & (~(SessionMask.All.ToEventKeywords()))));
EventChannel channel = unchecked((EventChannel)m_eventData[eventNum].Descriptor.Channel);
return IsEnabledCommon(enable, currentLevel, currentMatchAnyKeyword, eventLevel, eventKeywords, channel);
}
private bool IsEnabledCommon(bool enabled, EventLevel currentLevel, EventKeywords currentMatchAnyKeyword,
EventLevel eventLevel, EventKeywords eventKeywords, EventChannel eventChannel)
{
if (!enabled)
return false;
// does is pass the level test?
if ((currentLevel != 0) && (currentLevel < eventLevel))
return false;
// if yes, does it pass the keywords test?
if (currentMatchAnyKeyword != 0 && eventKeywords != 0)
{
// is there a channel with keywords that match currentMatchAnyKeyword?
if (eventChannel != EventChannel.None && this.m_channelData != null && this.m_channelData.Length > (int)eventChannel)
{
EventKeywords channel_keywords = unchecked((EventKeywords)(m_channelData[(int)eventChannel] | (ulong)eventKeywords));
if (channel_keywords != 0 && (channel_keywords & currentMatchAnyKeyword) == 0)
return false;
}
else
{
if ((unchecked((ulong)eventKeywords & (ulong)currentMatchAnyKeyword)) == 0)
return false;
}
}
return true;
}
[MethodImpl(MethodImplOptions.NoInlining)]
private void ThrowEventSourceException(string? eventName, Exception? innerEx = null)
{
// If we fail during out of band logging we may end up trying
// to throw another EventSourceException, thus hitting a StackOverflowException.
// Avoid StackOverflow by making sure we do not recursively call this method.
if (m_EventSourceExceptionRecurenceCount > 0)
return;
try
{
m_EventSourceExceptionRecurenceCount++;
string errorPrefix = "EventSourceException";
if (eventName != null)
{
errorPrefix += " while processing event \"" + eventName + "\"";
}
// TODO Create variations of EventSourceException that indicate more information using the error code.
switch (EventProvider.GetLastWriteEventError())
{
case EventProvider.WriteEventErrorCode.EventTooBig:
ReportOutOfBandMessage(errorPrefix + ": " + SR.EventSource_EventTooBig);
if (ThrowOnEventWriteErrors) throw new EventSourceException(SR.EventSource_EventTooBig, innerEx);
break;
case EventProvider.WriteEventErrorCode.NoFreeBuffers:
ReportOutOfBandMessage(errorPrefix + ": " + SR.EventSource_NoFreeBuffers);
if (ThrowOnEventWriteErrors) throw new EventSourceException(SR.EventSource_NoFreeBuffers, innerEx);
break;
case EventProvider.WriteEventErrorCode.NullInput:
ReportOutOfBandMessage(errorPrefix + ": " + SR.EventSource_NullInput);
if (ThrowOnEventWriteErrors) throw new EventSourceException(SR.EventSource_NullInput, innerEx);
break;
case EventProvider.WriteEventErrorCode.TooManyArgs:
ReportOutOfBandMessage(errorPrefix + ": " + SR.EventSource_TooManyArgs);
if (ThrowOnEventWriteErrors) throw new EventSourceException(SR.EventSource_TooManyArgs, innerEx);
break;
default:
if (innerEx != null)
{
innerEx = innerEx.GetBaseException();
ReportOutOfBandMessage(errorPrefix + ": " + innerEx.GetType() + ":" + innerEx.Message);
}
else
ReportOutOfBandMessage(errorPrefix);
if (ThrowOnEventWriteErrors) throw new EventSourceException(innerEx);
break;
}
}
finally
{
m_EventSourceExceptionRecurenceCount--;
}
}
internal static EventOpcode GetOpcodeWithDefault(EventOpcode opcode, string? eventName)
{
if (opcode == EventOpcode.Info && eventName != null)
{
if (eventName.EndsWith(ActivityStartSuffix, StringComparison.Ordinal))
{
return EventOpcode.Start;
}
else if (eventName.EndsWith(ActivityStopSuffix, StringComparison.Ordinal))
{
return EventOpcode.Stop;
}
}
return opcode;
}
/// <summary>
/// This class lets us hook the 'OnEventCommand' from the eventSource.
/// </summary>
private sealed class OverrideEventProvider : EventProvider
{
public OverrideEventProvider(EventSource eventSource, EventProviderType providerType)
: base(providerType)
{
this.m_eventSource = eventSource;
this.m_eventProviderType = providerType;
}
internal override void OnControllerCommand(ControllerCommand command, IDictionary<string, string?>? arguments,
int perEventSourceSessionId)
{
// We use null to represent the ETW EventListener.
EventListener? listener = null;
m_eventSource.SendCommand(listener, m_eventProviderType, perEventSourceSessionId,
(EventCommand)command, IsEnabled(), Level, MatchAnyKeyword, arguments);
}
private readonly EventSource m_eventSource;
private readonly EventProviderType m_eventProviderType;
}
/// <summary>
/// Used to hold all the static information about an event. This includes everything in the event
/// descriptor as well as some stuff we added specifically for EventSource. see the
/// code:m_eventData for where we use this.
/// </summary>
internal partial struct EventMetadata
{
public EventDescriptor Descriptor;
public IntPtr EventHandle; // EventPipeEvent handle.
public EventTags Tags;
public bool EnabledForAnyListener; // true if any dispatcher has this event turned on
public bool EnabledForETW; // is this event on for ETW?
#if FEATURE_PERFTRACING
public bool EnabledForEventPipe; // is this event on for EventPipe?
#endif
public bool HasRelatedActivityID; // Set if the event method's first parameter is a Guid named 'relatedActivityId'
public string Name; // the name of the event
public string? Message; // If the event has a message associated with it, this is it.
public ParameterInfo[] Parameters; // TODO can we remove?
public int EventListenerParameterCount;
public bool AllParametersAreString;
public bool AllParametersAreInt32;
public EventActivityOptions ActivityOptions;
private TraceLoggingEventTypes _traceLoggingEventTypes;
public TraceLoggingEventTypes TraceLoggingEventTypes
{
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2112:ReflectionToRequiresUnreferencedCode",
Justification = "EnsureDescriptorsInitialized's use of GetType preserves this method which " +
"requires unreferenced code, but EnsureDescriptorsInitialized does not access this member and is safe to call.")]
[RequiresUnreferencedCode(EventSourceRequiresUnreferenceMessage)]
get
{
if (_traceLoggingEventTypes is null)
{
var tlet = new TraceLoggingEventTypes(Name, Tags, Parameters);
Interlocked.CompareExchange(ref _traceLoggingEventTypes, tlet, null);
}
return _traceLoggingEventTypes;
}
}
private ReadOnlyCollection<string>? _parameterNames;
public ReadOnlyCollection<string> ParameterNames
{
get
{
if (_parameterNames is null)
{
ParameterInfo[] parameters = Parameters;
var names = new string[parameters.Length];
for (int i = 0; i < names.Length; i++)
{
names[i] = parameters[i].Name!;
}
_parameterNames = new ReadOnlyCollection<string>(names);
}
return _parameterNames;
}
}
private Type[]? _parameterTypes;
public Type[] ParameterTypes
{
get
{
return _parameterTypes ??= GetParameterTypes(Parameters);
static Type[] GetParameterTypes(ParameterInfo[] parameters)
{
var types = new Type[parameters.Length];
for (int i = 0; i < types.Length; i++)
{
types[i] = parameters[i].ParameterType;
}
return types;
}
}
}
}
// This is the internal entry point that code:EventListeners call when wanting to send a command to a
// eventSource. The logic is as follows
//
// * if Command == Update
// * perEventSourceSessionId specifies the per-provider ETW session ID that the command applies
// to (if listener != null)
// perEventSourceSessionId = 0 - reserved for EventListeners
// perEventSourceSessionId = 1..SessionMask.MAX - reserved for activity tracing aware ETW sessions
// perEventSourceSessionId-1 represents the bit in the reserved field (bits 44..47) in
// Keywords that identifies the session
// perEventSourceSessionId = SessionMask.MAX+1 - reserved for legacy ETW sessions; these are
// discriminated by etwSessionId
// * etwSessionId specifies a machine-wide ETW session ID; this allows correlation of
// activity tracing across different providers (which might have different sessionIds
// for the same ETW session)
// * enable, level, matchAnyKeywords are used to set a default for all events for the
// eventSource. In particular, if 'enabled' is false, 'level' and
// 'matchAnyKeywords' are not used.
// * OnEventCommand is invoked, which may cause calls to
// code:EventSource.EnableEventForDispatcher which may cause changes in the filtering
// depending on the logic in that routine.
// * else (command != Update)
// * Simply call OnEventCommand. The expectation is that filtering is NOT changed.
// * The 'enabled' 'level', matchAnyKeyword' arguments are ignored (must be true, 0, 0).
//
// dispatcher == null has special meaning. It is the 'ETW' dispatcher.
internal void SendCommand(EventListener? listener, EventProviderType eventProviderType, int perEventSourceSessionId,
EventCommand command, bool enable,
EventLevel level, EventKeywords matchAnyKeyword,
IDictionary<string, string?>? commandArguments)
{
if (!IsSupported)
{
return;
}
var commandArgs = new EventCommandEventArgs(command, commandArguments, this, listener, eventProviderType, perEventSourceSessionId, enable, level, matchAnyKeyword);
lock (EventListener.EventListenersLock)
{
if (m_completelyInited)
{
// After the first command arrive after construction, we are ready to get rid of the deferred commands
this.m_deferredCommands = null;
// We are fully initialized, do the command
DoCommand(commandArgs);
}
else
{
// We can't do the command, simply remember it and we do it when we are fully constructed.
if (m_deferredCommands == null)
{
m_deferredCommands = commandArgs; // create the first entry
}
else
{
// We have one or more entries, find the last one and add it to that.
EventCommandEventArgs lastCommand = m_deferredCommands;
while (lastCommand.nextCommand != null)
lastCommand = lastCommand.nextCommand;
lastCommand.nextCommand = commandArgs;
}
}
}
}
/// <summary>
/// We want the eventSource to be fully initialized when we do commands because that way we can send
/// error messages and other logging directly to the event stream. Unfortunately we can get callbacks
/// when we are not fully initialized. In that case we store them in 'commandArgs' and do them later.
/// This helper actually does all actual command logic.
/// </summary>
internal void DoCommand(EventCommandEventArgs commandArgs)
{
if (!IsSupported)
{
return;
}
// PRECONDITION: We should be holding the EventListener.EventListenersLock
// We defer commands until we are completely inited. This allows error messages to be sent.
Debug.Assert(m_completelyInited);
if (m_etwProvider == null) // If we failed to construct
return;
#if FEATURE_PERFTRACING
if (m_eventPipeProvider == null)
return;
#endif
m_outOfBandMessageCount = 0;
try
{
EnsureDescriptorsInitialized();
Debug.Assert(m_eventData != null);
// Find the per-EventSource dispatcher corresponding to registered dispatcher
commandArgs.dispatcher = GetDispatcher(commandArgs.listener);
if (commandArgs.dispatcher == null && commandArgs.listener != null) // dispatcher == null means ETW dispatcher
{
throw new ArgumentException(SR.EventSource_ListenerNotFound);
}
commandArgs.Arguments ??= new Dictionary<string, string?>();
if (commandArgs.Command == EventCommand.Update)
{
// Set it up using the 'standard' filtering bitfields (use the "global" enable, not session specific one)
for (int i = 0; i < m_eventData.Length; i++)
EnableEventForDispatcher(commandArgs.dispatcher, commandArgs.eventProviderType, i, IsEnabledByDefault(i, commandArgs.enable, commandArgs.level, commandArgs.matchAnyKeyword));
if (commandArgs.enable)
{
if (!m_eventSourceEnabled)
{
// EventSource turned on for the first time, simply copy the bits.
m_level = commandArgs.level;
m_matchAnyKeyword = commandArgs.matchAnyKeyword;
}
else
{
// Already enabled, make it the most verbose of the existing and new filter
if (commandArgs.level > m_level)
m_level = commandArgs.level;
if (commandArgs.matchAnyKeyword == 0)
m_matchAnyKeyword = 0;
else if (m_matchAnyKeyword != 0)
m_matchAnyKeyword = unchecked(m_matchAnyKeyword | commandArgs.matchAnyKeyword);
}
}
// interpret perEventSourceSessionId's sign, and adjust perEventSourceSessionId to
// represent 0-based positive values
bool bSessionEnable = (commandArgs.perEventSourceSessionId >= 0);
if (commandArgs.perEventSourceSessionId == 0 && !commandArgs.enable)
bSessionEnable = false;
if (commandArgs.listener == null)
{
if (!bSessionEnable)
commandArgs.perEventSourceSessionId = -commandArgs.perEventSourceSessionId;
// for "global" enable/disable (passed in with listener == null and
// perEventSourceSessionId == 0) perEventSourceSessionId becomes -1
--commandArgs.perEventSourceSessionId;
}
commandArgs.Command = bSessionEnable ? EventCommand.Enable : EventCommand.Disable;
// perEventSourceSessionId = -1 when ETW sent a notification, but the set of active sessions
// hasn't changed.
// sesisonId = SessionMask.MAX when one of the legacy ETW sessions changed
// 0 <= perEventSourceSessionId < SessionMask.MAX for activity-tracing aware sessions
Debug.Assert(commandArgs.perEventSourceSessionId >= -1 && commandArgs.perEventSourceSessionId <= SessionMask.MAX);
// Send the manifest if we are enabling an ETW session
if (bSessionEnable && commandArgs.dispatcher == null)
{
// eventSourceDispatcher == null means this is the ETW manifest
// Note that we unconditionally send the manifest whenever we are enabled, even if
// we were already enabled. This is because there may be multiple sessions active
// and we can't know that all the sessions have seen the manifest.
if (!SelfDescribingEvents)
SendManifest(m_rawManifest);
}
// Turn on the enable bit before making the OnEventCommand callback This allows you to do useful
// things like log messages, or test if keywords are enabled in the callback.
if (commandArgs.enable)
{
Debug.Assert(m_eventData != null);
m_eventSourceEnabled = true;
}
if (!commandArgs.enable)
{
// If we are disabling, maybe we can turn on 'quick checks' to filter
// quickly. These are all just optimizations (since later checks will still filter)
// There is a good chance EnabledForAnyListener are not as accurate as
// they could be, go ahead and get a better estimate.
for (int i = 0; i < m_eventData.Length; i++)
{
bool isEnabledForAnyListener = false;
for (EventDispatcher? dispatcher = m_Dispatchers; dispatcher != null; dispatcher = dispatcher.m_Next)
{
Debug.Assert(dispatcher.m_EventEnabled != null);
if (dispatcher.m_EventEnabled[i])
{
isEnabledForAnyListener = true;
break;
}
}
m_eventData[i].EnabledForAnyListener = isEnabledForAnyListener;
}
// If no events are enabled, disable the global enabled bit.
if (!AnyEventEnabled())
{
m_level = 0;
m_matchAnyKeyword = 0;
m_eventSourceEnabled = false;
}
}
this.OnEventCommand(commandArgs);
this.m_eventCommandExecuted?.Invoke(this, commandArgs);
}
else
{
if (commandArgs.Command == EventCommand.SendManifest)
{
// TODO: should we generate the manifest here if we hadn't already?
if (m_rawManifest != null)
SendManifest(m_rawManifest);
}
// These are not used for non-update commands and thus should always be 'default' values
// Debug.Assert(enable == true);
// Debug.Assert(level == EventLevel.LogAlways);
// Debug.Assert(matchAnyKeyword == EventKeywords.None);
this.OnEventCommand(commandArgs);
m_eventCommandExecuted?.Invoke(this, commandArgs);
}
}
catch (Exception e)
{
// When the ETW session is created after the EventSource has registered with the ETW system
// we can send any error messages here.
ReportOutOfBandMessage("ERROR: Exception in Command Processing for EventSource " + Name + ": " + e.Message);
// We never throw when doing a command.
}
}
/// <summary>
/// If 'value is 'true' then set the eventSource so that 'dispatcher' will receive event with the eventId
/// of 'eventId. If value is 'false' disable the event for that dispatcher. If 'eventId' is out of
/// range return false, otherwise true.
/// </summary>
internal bool EnableEventForDispatcher(EventDispatcher? dispatcher, EventProviderType eventProviderType, int eventId, bool value)
{
if (!IsSupported)
return false;
Debug.Assert(m_eventData != null);
if (dispatcher == null)
{
if (eventId >= m_eventData.Length)
return false;
if (m_etwProvider != null && eventProviderType == EventProviderType.ETW)
m_eventData[eventId].EnabledForETW = value;
#if FEATURE_PERFTRACING
if (m_eventPipeProvider != null && eventProviderType == EventProviderType.EventPipe)
m_eventData[eventId].EnabledForEventPipe = value;
#endif
}
else
{
Debug.Assert(dispatcher.m_EventEnabled != null);
if (eventId >= dispatcher.m_EventEnabled.Length)
return false;
dispatcher.m_EventEnabled[eventId] = value;
if (value)
m_eventData[eventId].EnabledForAnyListener = true;
}
return true;
}
/// <summary>
/// Returns true if any event at all is on.
/// </summary>
private bool AnyEventEnabled()
{
Debug.Assert(m_eventData != null);
for (int i = 0; i < m_eventData.Length; i++)
if (m_eventData[i].EnabledForETW || m_eventData[i].EnabledForAnyListener
#if FEATURE_PERFTRACING
|| m_eventData[i].EnabledForEventPipe
#endif // FEATURE_PERFTRACING
)
return true;
return false;
}
private bool IsDisposed => m_eventSourceDisposed;
private void EnsureDescriptorsInitialized()
{
Debug.Assert(Monitor.IsEntered(EventListener.EventListenersLock));
if (m_eventData == null)
{
// get the metadata via reflection.
Debug.Assert(m_rawManifest == null);
m_rawManifest = CreateManifestAndDescriptors(this.GetType(), Name, this);
Debug.Assert(m_eventData != null);
// TODO Enforce singleton pattern
if (!AllowDuplicateSourceNames)
{
Debug.Assert(EventListener.s_EventSources != null, "should be called within lock on EventListener.EventListenersLock which ensures s_EventSources to be initialized");
foreach (WeakReference<EventSource> eventSourceRef in EventListener.s_EventSources)
{
if (eventSourceRef.TryGetTarget(out EventSource? eventSource) && eventSource.Guid == m_guid && !eventSource.IsDisposed)
{
if (eventSource != this)
{
throw new ArgumentException(SR.Format(SR.EventSource_EventSourceGuidInUse, m_guid));
}
}
}
}
// Make certain all dispatchers also have their arrays initialized
EventDispatcher? dispatcher = m_Dispatchers;
while (dispatcher != null)
{
dispatcher.m_EventEnabled ??= new bool[m_eventData.Length];
dispatcher = dispatcher.m_Next;
}
#if FEATURE_PERFTRACING
// Initialize the EventPipe event handles.
DefineEventPipeEvents();
#endif
}
}
// Send out the ETW manifest XML out to ETW
// Today, we only send the manifest to ETW, custom listeners don't get it.
private unsafe void SendManifest(byte[]? rawManifest)
{
if (rawManifest == null)
{
return;
}
Debug.Assert(!SelfDescribingEvents);
fixed (byte* dataPtr = rawManifest)
{
// we don't want the manifest to show up in the event log channels so we specify as keywords
// everything but the first 8 bits (reserved for the 8 channels)
var manifestDescr = new EventDescriptor(0xFFFE, 1, 0, 0, 0xFE, 0xFFFE, 0x00ffFFFFffffFFFF);
ManifestEnvelope envelope = default;
envelope.Format = ManifestEnvelope.ManifestFormats.SimpleXmlFormat;
envelope.MajorVersion = 1;
envelope.MinorVersion = 0;
envelope.Magic = 0x5B; // An unusual number that can be checked for consistency.
int dataLeft = rawManifest.Length;
envelope.ChunkNumber = 0;
EventProvider.EventData* dataDescrs = stackalloc EventProvider.EventData[2];
dataDescrs[0].Ptr = (ulong)&envelope;
dataDescrs[0].Size = (uint)sizeof(ManifestEnvelope);
dataDescrs[0].Reserved = 0;
dataDescrs[1].Ptr = (ulong)dataPtr;
dataDescrs[1].Reserved = 0;
int chunkSize = ManifestEnvelope.MaxChunkSize;
TRY_AGAIN_WITH_SMALLER_CHUNK_SIZE:
envelope.TotalChunks = (ushort)((dataLeft + (chunkSize - 1)) / chunkSize);
while (dataLeft > 0)
{
dataDescrs[1].Size = (uint)Math.Min(dataLeft, chunkSize);
if (m_etwProvider != null)
{
if (!m_etwProvider.WriteEvent(ref manifestDescr, IntPtr.Zero, null, null, 2, (IntPtr)dataDescrs))
{
// Turns out that if users set the BufferSize to something less than 64K then WriteEvent
// can fail. If we get this failure on the first chunk try again with something smaller
// The smallest BufferSize is 1K so if we get to 256 (to account for envelope overhead), we can give up making it smaller.
if (EventProvider.GetLastWriteEventError() == EventProvider.WriteEventErrorCode.EventTooBig)
{
if (envelope.ChunkNumber == 0 && chunkSize > 256)
{
chunkSize /= 2;
goto TRY_AGAIN_WITH_SMALLER_CHUNK_SIZE;
}
}
if (ThrowOnEventWriteErrors)
ThrowEventSourceException("SendManifest");
break;
}
}
dataLeft -= chunkSize;
dataDescrs[1].Ptr += (uint)chunkSize;
envelope.ChunkNumber++;
// For large manifests we want to not overflow any receiver's buffer. Most manifests will fit within
// 5 chunks, so only the largest manifests will hit the pause.
if ((envelope.ChunkNumber % 5) == 0)
{
Thread.Sleep(15);
}
}
}
}
// Helper to deal with the fact that the type we are reflecting over might be loaded in the ReflectionOnly context.
// When that is the case, we have to build the custom assemblies on a member by hand.
internal static bool IsCustomAttributeDefinedHelper(
MemberInfo member,
Type attributeType,
EventManifestOptions flags = EventManifestOptions.None)
{
// AllowEventSourceOverride is an option that allows either Microsoft.Diagnostics.Tracing or
// System.Diagnostics.Tracing EventSource to be considered valid. This should not mattter anywhere but in Microsoft.Diagnostics.Tracing (nuget package).
if (!member.Module.Assembly.ReflectionOnly && (flags & EventManifestOptions.AllowEventSourceOverride) == 0)
{
// Let the runtime do the work for us, since we can execute code in this context.
return member.IsDefined(attributeType, inherit: false);
}
foreach (CustomAttributeData data in CustomAttributeData.GetCustomAttributes(member))
{
if (AttributeTypeNamesMatch(attributeType, data.Constructor.ReflectedType!))
{
return true;
}
}
return false;
}
// Helper to deal with the fact that the type we are reflecting over might be loaded in the ReflectionOnly context.
// When that is the case, we have the build the custom assemblies on a member by hand.
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2114:ReflectionToDynamicallyAccessedMembers",
Justification = "EnsureDescriptorsInitialized's use of GetType preserves this method which " +
"has dynamically accessed members requirements, but EnsureDescriptorsInitialized does not "+
"access this member and is safe to call.")]
internal static Attribute? GetCustomAttributeHelper(
MemberInfo member,
[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.PublicProperties)]
Type attributeType,
EventManifestOptions flags = EventManifestOptions.None)
{
Debug.Assert(attributeType == typeof(EventAttribute) || attributeType == typeof(EventSourceAttribute));
// AllowEventSourceOverride is an option that allows either Microsoft.Diagnostics.Tracing or
// System.Diagnostics.Tracing EventSource to be considered valid. This should not mattter anywhere but in Microsoft.Diagnostics.Tracing (nuget package).
if (!member.Module.Assembly.ReflectionOnly && (flags & EventManifestOptions.AllowEventSourceOverride) == 0)
{
// Let the runtime do the work for us, since we can execute code in this context.
return member.GetCustomAttribute(attributeType, inherit: false);
}
foreach (CustomAttributeData data in CustomAttributeData.GetCustomAttributes(member))
{
if (AttributeTypeNamesMatch(attributeType, data.Constructor.ReflectedType!))
{
Attribute? attr = null;
Debug.Assert(data.ConstructorArguments.Count <= 1);
if (data.ConstructorArguments.Count == 1)
{
attr = (Attribute?)Activator.CreateInstance(attributeType, new object?[] { data.ConstructorArguments[0].Value });
}
else if (data.ConstructorArguments.Count == 0)
{
attr = (Attribute?)Activator.CreateInstance(attributeType);
}
if (attr != null)
{
foreach (CustomAttributeNamedArgument namedArgument in data.NamedArguments)
{
PropertyInfo p = attributeType.GetProperty(namedArgument.MemberInfo.Name, BindingFlags.Public | BindingFlags.Instance)!;
object value = namedArgument.TypedValue.Value!;
if (p.PropertyType.IsEnum)
{
string val = value.ToString()!;
value = Enum.Parse(p.PropertyType, val);
}
p.SetValue(attr, value, null);
}
return attr;
}
}
}
return null;
}
/// <summary>
/// Evaluates if two related "EventSource"-domain types should be considered the same
/// </summary>
/// <param name="attributeType">The attribute type in the load context - it's associated with the running
/// EventSource type. This type may be different fromt he base type of the user-defined EventSource.</param>
/// <param name="reflectedAttributeType">The attribute type in the reflection context - it's associated with
/// the user-defined EventSource, and is in the same assembly as the eventSourceType passed to
/// </param>
/// <returns>True - if the types should be considered equivalent, False - otherwise</returns>
private static bool AttributeTypeNamesMatch(Type attributeType, Type reflectedAttributeType)
{
return
// are these the same type?
attributeType == reflectedAttributeType ||
// are the full typenames equal?
string.Equals(attributeType.FullName, reflectedAttributeType.FullName, StringComparison.Ordinal) ||
// are the typenames equal and the namespaces under "Diagnostics.Tracing" (typically
// either Microsoft.Diagnostics.Tracing or System.Diagnostics.Tracing)?
string.Equals(attributeType.Name, reflectedAttributeType.Name, StringComparison.Ordinal) &&
attributeType.Namespace!.EndsWith("Diagnostics.Tracing", StringComparison.Ordinal) &&
reflectedAttributeType.Namespace!.EndsWith("Diagnostics.Tracing", StringComparison.Ordinal);
}
private static Type? GetEventSourceBaseType(Type eventSourceType, bool allowEventSourceOverride, bool reflectionOnly)
{
Type? ret = eventSourceType;
// return false for "object" and interfaces
if (ret.BaseType == null)
return null;
// now go up the inheritance chain until hitting a concrete type ("object" at worse)
do
{
ret = ret.BaseType;
}
while (ret != null && ret.IsAbstract);
if (ret != null)
{
if (!allowEventSourceOverride)
{
if (reflectionOnly && ret.FullName != typeof(EventSource).FullName ||
!reflectionOnly && ret != typeof(EventSource))
return null;
}
else
{
if (ret.Name != "EventSource")
return null;
}
}
return ret;
}
// Use reflection to look at the attributes of a class, and generate a manifest for it (as UTF8) and
// return the UTF8 bytes. It also sets up the code:EventData structures needed to dispatch events
// at run time. 'source' is the event source to place the descriptors. If it is null,
// then the descriptors are not created, and just the manifest is generated.
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2114:ReflectionToDynamicallyAccessedMembers",
Justification = "EnsureDescriptorsInitialized's use of GetType preserves this method which " +
"has dynamically accessed members requirements, but its use of this method satisfies " +
"these requirements because it passes in the result of GetType with the same annotations.")]
private static byte[]? CreateManifestAndDescriptors(
[DynamicallyAccessedMembers(ManifestMemberTypes)]
Type eventSourceType,
string? eventSourceDllName,
EventSource? source,
EventManifestOptions flags = EventManifestOptions.None)
{
ManifestBuilder? manifest = null;
bool bNeedsManifest = source != null ? !source.SelfDescribingEvents : true;
Exception? exception = null; // exception that might get raised during validation b/c we couldn't/didn't recover from a previous error
byte[]? res = null;
if (eventSourceType.IsAbstract && (flags & EventManifestOptions.Strict) == 0)
return null;
try
{
MethodInfo[] methods = eventSourceType.GetMethods(BindingFlags.DeclaredOnly | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
EventAttribute defaultEventAttribute;
int eventId = 1; // The number given to an event that does not have a explicitly given ID.
EventMetadata[]? eventData = null;
Dictionary<string, string>? eventsByName = null;
if (source != null || (flags & EventManifestOptions.Strict) != 0)
{
eventData = new EventMetadata[methods.Length + 1];
eventData[0].Name = ""; // Event 0 is the 'write messages string' event, and has an empty name.
}
// See if we have localization information.
ResourceManager? resources = null;
EventSourceAttribute? eventSourceAttrib = (EventSourceAttribute?)GetCustomAttributeHelper(eventSourceType, typeof(EventSourceAttribute), flags);
if (eventSourceAttrib != null && eventSourceAttrib.LocalizationResources != null)
resources = new ResourceManager(eventSourceAttrib.LocalizationResources, eventSourceType.Assembly);
if (source?.GetType() == typeof(NativeRuntimeEventSource))
{
// Don't emit nor generate the manifest for NativeRuntimeEventSource i.e., Microsoft-Windows-DotNETRuntime.
manifest = new ManifestBuilder(resources, flags);
bNeedsManifest = false;
}
else
{
// Try to get name and GUID directly from the source. Otherwise get it from the Type's attribute.
string providerName = source?.Name ?? GetName(eventSourceType, flags);
Guid providerGuid = source?.Guid ?? GetGuid(eventSourceType);
manifest = new ManifestBuilder(providerName, providerGuid, eventSourceDllName, resources, flags);
}
// Add an entry unconditionally for event ID 0 which will be for a string message.
manifest.StartEvent("EventSourceMessage", new EventAttribute(0) { Level = EventLevel.LogAlways, Task = (EventTask)0xFFFE });
manifest.AddEventParameter(typeof(string), "message");
manifest.EndEvent();
// eventSourceType must be sealed and must derive from this EventSource
if ((flags & EventManifestOptions.Strict) != 0)
{
bool typeMatch = GetEventSourceBaseType(eventSourceType, (flags & EventManifestOptions.AllowEventSourceOverride) != 0, eventSourceType.Assembly.ReflectionOnly) != null;
if (!typeMatch)
{
manifest.ManifestError(SR.EventSource_TypeMustDeriveFromEventSource);
}
if (!eventSourceType.IsAbstract && !eventSourceType.IsSealed)
{
manifest.ManifestError(SR.EventSource_TypeMustBeSealedOrAbstract);
}
}
// Collect task, opcode, keyword and channel information
foreach (string providerEnumKind in (ReadOnlySpan<string>)["Keywords", "Tasks", "Opcodes"])
{
Type? nestedType = eventSourceType.GetNestedType(providerEnumKind);
if (nestedType != null)
{
if (eventSourceType.IsAbstract)
{
manifest.ManifestError(SR.Format(SR.EventSource_AbstractMustNotDeclareKTOC, nestedType.Name));
}
else
{
foreach (FieldInfo staticField in nestedType.GetFields(BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static))
{
AddProviderEnumKind(manifest, staticField, providerEnumKind);
}
}
}
}
// ensure we have keywords for the session-filtering reserved bits
{
manifest.AddKeyword("Session3", (long)0x1000 << 32);
manifest.AddKeyword("Session2", (long)0x2000 << 32);
manifest.AddKeyword("Session1", (long)0x4000 << 32);
manifest.AddKeyword("Session0", (long)0x8000 << 32);
}
if (eventSourceType != typeof(EventSource))
{
for (int i = 0; i < methods.Length; i++)
{
MethodInfo method = methods[i];
// Compat: until v4.5.1 we ignored any non-void returning methods as well as virtual methods for
// the only reason of limiting the number of methods considered to be events. This broke a common
// design of having event sources implement specific interfaces. To fix this in a compatible way
// we will now allow both non-void returning and virtual methods to be Event methods, as long
// as they are marked with the [Event] attribute
if (/* method.IsVirtual || */ method.IsStatic)
{
continue;
}
// Get the EventDescriptor (from the Custom attributes)
EventAttribute? eventAttribute = (EventAttribute?)GetCustomAttributeHelper(method, typeof(EventAttribute), flags);
if (eventSourceType.IsAbstract)
{
if (eventAttribute != null)
{
manifest.ManifestError(SR.Format(SR.EventSource_AbstractMustNotDeclareEventMethods, method.Name, eventAttribute.EventId));
}
continue;
}
else if (eventAttribute == null)
{
// Methods that don't return void can't be events, if they're NOT marked with [Event].
// (see Compat comment above)
if (method.ReturnType != typeof(void))
{
continue;
}
// Continue to ignore virtual methods if they do NOT have the [Event] attribute
// (see Compat comment above)
if (method.IsVirtual)
{
continue;
}
// If we explicitly mark the method as not being an event, then honor that.
if (IsCustomAttributeDefinedHelper(method, typeof(NonEventAttribute), flags))
continue;
defaultEventAttribute = new EventAttribute(eventId);
eventAttribute = defaultEventAttribute;
}
else if (eventAttribute.EventId <= 0)
{
manifest.ManifestError(SR.EventSource_NeedPositiveId, true);
continue; // don't validate anything else for this event
}
if (method.Name.LastIndexOf('.') >= 0)
{
manifest.ManifestError(SR.Format(SR.EventSource_EventMustNotBeExplicitImplementation, method.Name, eventAttribute.EventId));
}
eventId++;
string eventName = method.Name;
if (eventAttribute.Opcode == EventOpcode.Info) // We are still using the default opcode.
{
// By default pick a task ID derived from the EventID, starting with the highest task number and working back
bool noTask = (eventAttribute.Task == EventTask.None);
if (noTask)
eventAttribute.Task = (EventTask)(0xFFFE - eventAttribute.EventId);
// Unless we explicitly set the opcode to Info (to override the auto-generate of Start or Stop opcodes,
// pick a default opcode based on the event name (either Info or start or stop if the name ends with that suffix).
if (!eventAttribute.IsOpcodeSet)
eventAttribute.Opcode = GetOpcodeWithDefault(EventOpcode.Info, eventName);
// Make the stop opcode have the same task as the start opcode.
if (noTask)
{
if (eventAttribute.Opcode == EventOpcode.Start)
{
if (eventName.EndsWith(ActivityStartSuffix, StringComparison.Ordinal))
{
string taskName = eventName[..^ActivityStartSuffix.Length]; // Remove the Start suffix to get the task name
// Add a task that is just the task name for the start event. This suppress the auto-task generation
// That would otherwise happen (and create 'TaskName'Start as task name rather than just 'TaskName'
manifest.AddTask(taskName, (int)eventAttribute.Task);
}
}
else if (eventAttribute.Opcode == EventOpcode.Stop)
{
// Find the start associated with this stop event. We require start to be immediately before the stop
int startEventId = eventAttribute.EventId - 1;
if (eventData != null && startEventId < eventData.Length)
{
Debug.Assert(0 <= startEventId); // Since we reserve id 0, we know that id-1 is <= 0
EventMetadata startEventMetadata = eventData[startEventId];
// If you remove the Stop and add a Start does that name match the Start Event's Name?
// Ideally we would throw an error
if (startEventMetadata.Descriptor.Opcode == (byte)EventOpcode.Start &&
startEventMetadata.Name.EndsWith(ActivityStartSuffix, StringComparison.Ordinal) &&
eventName.EndsWith(ActivityStopSuffix, StringComparison.Ordinal) &&
startEventMetadata.Name.AsSpan()[..^ActivityStartSuffix.Length].SequenceEqual(
eventName.AsSpan()[..^ActivityStopSuffix.Length]))
{
// Make the stop event match the start event
eventAttribute.Task = (EventTask)startEventMetadata.Descriptor.Task;
noTask = false;
}
}
if (noTask && (flags & EventManifestOptions.Strict) != 0) // Throw an error if we can compatibly.
{
throw new ArgumentException(SR.EventSource_StopsFollowStarts);
}
}
}
}
ParameterInfo[] args = method.GetParameters();
bool hasRelatedActivityID = RemoveFirstArgIfRelatedActivityId(ref args);
if (!(source != null && source.SelfDescribingEvents))
{
manifest.StartEvent(eventName, eventAttribute);
for (int fieldIdx = 0; fieldIdx < args.Length; fieldIdx++)
{
manifest.AddEventParameter(args[fieldIdx].ParameterType, args[fieldIdx].Name!);
}
manifest.EndEvent();
}
if (source != null || (flags & EventManifestOptions.Strict) != 0)
{
Debug.Assert(eventData != null);
// Do checking for user errors (optional, but not a big deal so we do it).
DebugCheckEvent(ref eventsByName, eventData, method, eventAttribute, manifest, flags);
// add the channel keyword for Event Viewer channel based filters. This is added for creating the EventDescriptors only
// and is not required for the manifest
if (eventAttribute.Channel != EventChannel.None)
{
unchecked
{
eventAttribute.Keywords |= (EventKeywords)manifest.GetChannelKeyword(eventAttribute.Channel, (ulong)eventAttribute.Keywords);
}
}
if (manifest.HasResources)
{
string eventKey = "event_" + eventName;
if (manifest.GetLocalizedMessage(eventKey, CultureInfo.CurrentUICulture, etwFormat: false) is string msg)
{
// overwrite inline message with the localized message
eventAttribute.Message = msg;
}
}
AddEventDescriptor(ref eventData, eventName, eventAttribute, args, hasRelatedActivityID);
}
}
}
// Tell the TraceLogging stuff where to start allocating its own IDs.
NameInfo.ReserveEventIDsBelow(eventId);
if (source != null)
{
Debug.Assert(eventData != null);
TrimEventDescriptors(ref eventData);
source.m_eventData = eventData; // officially initialize it. We do this at most once (it is racy otherwise).
source.m_channelData = manifest.GetChannelData();
}
// if this is an abstract event source we've already performed all the validation we can
if (!eventSourceType.IsAbstract && (source == null || !source.SelfDescribingEvents))
{
bNeedsManifest = (flags & EventManifestOptions.OnlyIfNeededForRegistration) == 0 || manifest.GetChannelData().Length > 0;
// if the manifest is not needed and we're not requested to validate the event source return early
if (!bNeedsManifest && (flags & EventManifestOptions.Strict) == 0)
return null;
res = manifest.CreateManifest();
res = (res.Length > 0) ? res : null;
}
}
catch (Exception e)
{
// if this is a runtime manifest generation let the exception propagate
if ((flags & EventManifestOptions.Strict) == 0)
throw;
// else store it to include it in the Argument exception we raise below
exception = e;
}
if ((flags & EventManifestOptions.Strict) != 0 && (manifest?.Errors.Count > 0 || exception != null))
{
string msg = string.Empty;
if (manifest?.Errors.Count > 0)
{
bool firstError = true;
foreach (string error in manifest.Errors)
{
if (!firstError)
msg += Environment.NewLine;
firstError = false;
msg += error;
}
}
else
msg = "Unexpected error: " + exception!.Message;
throw new ArgumentException(msg, exception);
}
return bNeedsManifest ? res : null;
}
private static bool RemoveFirstArgIfRelatedActivityId(ref ParameterInfo[] args)
{
// If the first parameter is (case insensitive) 'relatedActivityId' then skip it.
if (args.Length > 0 && args[0].ParameterType == typeof(Guid) &&
string.Equals(args[0].Name, "relatedActivityId", StringComparison.OrdinalIgnoreCase))
{
var newargs = new ParameterInfo[args.Length - 1];
Array.Copy(args, 1, newargs, 0, args.Length - 1);
args = newargs;
return true;
}
return false;
}
// adds a enumeration (keyword, opcode, task or channel) represented by 'staticField'
// to the manifest.
private static void AddProviderEnumKind(ManifestBuilder manifest, FieldInfo staticField, string providerEnumKind)
{
bool reflectionOnly = staticField.Module.Assembly.ReflectionOnly;
Type staticFieldType = staticField.FieldType;
if (!reflectionOnly && (staticFieldType == typeof(EventOpcode)) || AttributeTypeNamesMatch(staticFieldType, typeof(EventOpcode)))
{
if (providerEnumKind != "Opcodes") goto Error;
int value = (int)staticField.GetRawConstantValue()!;
manifest.AddOpcode(staticField.Name, value);
}
else if (!reflectionOnly && (staticFieldType == typeof(EventTask)) || AttributeTypeNamesMatch(staticFieldType, typeof(EventTask)))
{
if (providerEnumKind != "Tasks") goto Error;
int value = (int)staticField.GetRawConstantValue()!;
manifest.AddTask(staticField.Name, value);
}
else if (!reflectionOnly && (staticFieldType == typeof(EventKeywords)) || AttributeTypeNamesMatch(staticFieldType, typeof(EventKeywords)))
{
if (providerEnumKind != "Keywords") goto Error;
ulong value = unchecked((ulong)(long)staticField.GetRawConstantValue()!);
manifest.AddKeyword(staticField.Name, value);
}
return;
Error:
manifest.ManifestError(SR.Format(SR.EventSource_EnumKindMismatch, staticField.FieldType.Name, providerEnumKind));
}
// Helper used by code:CreateManifestAndDescriptors to add a code:EventData descriptor for a method
// with the code:EventAttribute 'eventAttribute'. resourceManger may be null in which case we populate it
// it is populated if we need to look up message resources
private static void AddEventDescriptor(
[NotNull] ref EventMetadata[] eventData,
string eventName,
EventAttribute eventAttribute,
ParameterInfo[] eventParameters,
bool hasRelatedActivityID)
{
if (eventData.Length <= eventAttribute.EventId)
{
EventMetadata[] newValues = new EventMetadata[Math.Max(eventData.Length + 16, eventAttribute.EventId + 1)];
Array.Copy(eventData, newValues, eventData.Length);
eventData = newValues;
}
ref EventMetadata metadata = ref eventData[eventAttribute.EventId];
metadata.Descriptor = new EventDescriptor(
eventAttribute.EventId,
eventAttribute.Version,
(byte)eventAttribute.Channel,
(byte)eventAttribute.Level,
(byte)eventAttribute.Opcode,
(int)eventAttribute.Task,
unchecked((long)((ulong)eventAttribute.Keywords | SessionMask.All.ToEventKeywords())));
metadata.Tags = eventAttribute.Tags;
metadata.Name = eventName;
metadata.Parameters = eventParameters;
metadata.Message = eventAttribute.Message;
metadata.ActivityOptions = eventAttribute.ActivityOptions;
metadata.HasRelatedActivityID = hasRelatedActivityID;
metadata.EventHandle = IntPtr.Zero;
// We represent a byte[] with 2 EventData entries: an integer denoting the length and a blob of bytes in the data pointer.
// This causes a spurious warning because eventDataCount is off by one for the byte[] case.
// When writing to EventListeners, we want to check that the number of parameters is correct against the byte[] case.
int eventListenerParameterCount = eventParameters.Length;
bool allParametersAreInt32 = true;
bool allParametersAreString = true;
foreach (ParameterInfo parameter in eventParameters)
{
Type dataType = parameter.ParameterType;
if (dataType == typeof(string))
{
allParametersAreInt32 = false;
}
else if (dataType == typeof(int) ||
(dataType.IsEnum && Type.GetTypeCode(dataType.GetEnumUnderlyingType()) <= TypeCode.UInt32))
{
// Int32 or an enum with a 1/2/4 byte backing type
allParametersAreString = false;
}
else
{
if (dataType == typeof(byte[]))
{
eventListenerParameterCount++;
}
allParametersAreInt32 = false;
allParametersAreString = false;
}
}
metadata.AllParametersAreInt32 = allParametersAreInt32;
metadata.AllParametersAreString = allParametersAreString;
metadata.EventListenerParameterCount = eventListenerParameterCount;
}
// Helper used by code:CreateManifestAndDescriptors that trims the m_eventData array to the correct
// size after all event descriptors have been added.
private static void TrimEventDescriptors(ref EventMetadata[] eventData)
{
int idx = eventData.Length;
while (0 < idx)
{
--idx;
if (eventData[idx].Descriptor.EventId != 0)
break;
}
if (eventData.Length - idx > 2) // allow one wasted slot.
{
EventMetadata[] newValues = new EventMetadata[idx + 1];
Array.Copy(eventData, newValues, newValues.Length);
eventData = newValues;
}
}
// Helper used by code:EventListener.AddEventSource and code:EventListener.EventListener
// when a listener gets attached to a eventSource
internal void AddListener(EventListener listener)
{
lock (EventListener.EventListenersLock)
{
bool[]? enabledArray = null;
if (m_eventData != null)
enabledArray = new bool[m_eventData.Length];
m_Dispatchers = new EventDispatcher(m_Dispatchers, enabledArray, listener);
listener.OnEventSourceCreated(this);
}
}
// Helper used by code:CreateManifestAndDescriptors to find user mistakes like reusing an event
// index for two distinct events etc. Throws exceptions when it finds something wrong.
private static void DebugCheckEvent(ref Dictionary<string, string>? eventsByName,
EventMetadata[] eventData, MethodInfo method, EventAttribute eventAttribute,
ManifestBuilder manifest, EventManifestOptions options)
{
int evtId = eventAttribute.EventId;
string evtName = method.Name;
int eventArg = GetHelperCallFirstArg(method);
if (eventArg >= 0 && evtId != eventArg)
{
manifest.ManifestError(SR.Format(SR.EventSource_MismatchIdToWriteEvent, evtName, evtId, eventArg), true);
}
if (evtId < eventData.Length && eventData[evtId].Descriptor.EventId != 0)
{
manifest.ManifestError(SR.Format(SR.EventSource_EventIdReused, evtName, evtId), true);
}
// We give a task to things if they don't have one.
// TODO this is moderately expensive (N*N). We probably should not even bother....
Debug.Assert(eventAttribute.Task != EventTask.None || eventAttribute.Opcode != EventOpcode.Info);
for (int idx = 0; idx < eventData.Length; ++idx)
{
// skip unused Event IDs.
if (eventData[idx].Name == null)
continue;
if (eventData[idx].Descriptor.Task == (int)eventAttribute.Task && eventData[idx].Descriptor.Opcode == (int)eventAttribute.Opcode)
{
manifest.ManifestError(SR.Format(SR.EventSource_TaskOpcodePairReused,
evtName, evtId, eventData[idx].Name, idx));
// If we are not strict stop on first error. We have had problems with really large providers taking forever. because of many errors.
if ((options & EventManifestOptions.Strict) == 0)
break;
}
}
// for non-default event opcodes the user must define a task!
if (eventAttribute.Opcode != EventOpcode.Info)
{
bool failure = false;
if (eventAttribute.Task == EventTask.None)
failure = true;
else
{
// If you have the auto-assigned Task, then you did not explicitly set one.
// This is OK for Start events because we have special logic to assign the task to a prefix derived from the event name
// But all other cases we want to catch the omission.
var autoAssignedTask = (EventTask)(0xFFFE - evtId);
if (eventAttribute.Opcode != EventOpcode.Start && eventAttribute.Opcode != EventOpcode.Stop && eventAttribute.Task == autoAssignedTask)
failure = true;
}
if (failure)
{
manifest.ManifestError(SR.Format(SR.EventSource_EventMustHaveTaskIfNonDefaultOpcode, evtName, evtId));
}
}
// If we ever want to enforce the rule: MethodName = TaskName + OpcodeName here's how:
// (the reason we don't is backwards compat and the need for handling this as a non-fatal error
// by eventRegister.exe)
// taskName & opcodeName could be passed in by the caller which has opTab & taskTab handy
// if (!(((int)eventAttribute.Opcode == 0 && evtName == taskName) || (evtName == taskName+opcodeName)))
// {
// throw new WarningException(SR.EventSource_EventNameDoesNotEqualTaskPlusOpcode);
// }
eventsByName ??= new Dictionary<string, string>();
if (eventsByName.ContainsKey(evtName))
{
manifest.ManifestError(SR.Format(SR.EventSource_EventNameReused, evtName), true);
}
eventsByName[evtName] = evtName;
}
/// <summary>
/// This method looks at the IL and tries to pattern match against the standard
/// 'boilerplate' event body
/// <code>
/// { if (Enabled()) WriteEvent(#, ...) }
/// </code>
/// If the pattern matches, it returns the literal number passed as the first parameter to
/// the WriteEvent. This is used to find common user errors (mismatching this
/// number with the EventAttribute ID). It is only used for validation.
/// </summary>
/// <param name="method">The method to probe.</param>
/// <returns>The literal value or -1 if the value could not be determined. </returns>
#if !NATIVEAOT
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:RequiresUnreferencedCode",
Justification = "The method calls MethodBase.GetMethodBody. Trimming application can change IL of various methods" +
"which can lead to change of behavior. This method only uses this to validate usage of event source APIs." +
"In the worst case it will not be able to determine the value it's looking for and will not perform" +
"any validation.")]
#endif
private static int GetHelperCallFirstArg(MethodInfo method)
{
#if !NATIVEAOT
// Currently searches for the following pattern
//
// ... // CAN ONLY BE THE INSTRUCTIONS BELOW
// LDARG0
// LDC.I4 XXX
// ... // CAN ONLY BE THE INSTRUCTIONS BELOW CAN'T BE A BRANCH OR A CALL
// CALL
// NOP // 0 or more times
// RET
//
// If we find this pattern we return the XXX. Otherwise we return -1.
byte[] instrs = method.GetMethodBody()!.GetILAsByteArray()!;
int retVal = -1;
for (int idx = 0; idx < instrs.Length;)
{
switch (instrs[idx])
{
case 0: // NOP
case 1: // BREAK
case 2: // LDARG_0
case 3: // LDARG_1
case 4: // LDARG_2
case 5: // LDARG_3
case 6: // LDLOC_0
case 7: // LDLOC_1
case 8: // LDLOC_2
case 9: // LDLOC_3
case 10: // STLOC_0
case 11: // STLOC_1
case 12: // STLOC_2
case 13: // STLOC_3
break;
case 14: // LDARG_S
case 16: // STARG_S
idx++;
break;
case 20: // LDNULL
break;
case 21: // LDC_I4_M1
case 22: // LDC_I4_0
case 23: // LDC_I4_1
case 24: // LDC_I4_2
case 25: // LDC_I4_3
case 26: // LDC_I4_4
case 27: // LDC_I4_5
case 28: // LDC_I4_6
case 29: // LDC_I4_7
case 30: // LDC_I4_8
if (idx > 0 && instrs[idx - 1] == 2) // preceded by LDARG0
retVal = instrs[idx] - 22;
break;
case 31: // LDC_I4_S
if (idx > 0 && instrs[idx - 1] == 2) // preceded by LDARG0
retVal = instrs[idx + 1];
idx++;
break;
case 32: // LDC_I4
idx += 4;
break;
case 37: // DUP
break;
case 40: // CALL
idx += 4;
if (retVal >= 0)
{
// Is this call just before return?
for (int search = idx + 1; search < instrs.Length; search++)
{
if (instrs[search] == 42) // RET
return retVal;
if (instrs[search] != 0) // NOP
break;
}
}
retVal = -1;
break;
case 44: // BRFALSE_S
case 45: // BRTRUE_S
retVal = -1;
idx++;
break;
case 57: // BRFALSE
case 58: // BRTRUE
retVal = -1;
idx += 4;
break;
case 103: // CONV_I1
case 104: // CONV_I2
case 105: // CONV_I4
case 106: // CONV_I8
case 109: // CONV_U4
case 110: // CONV_U8
break;
case 140: // BOX
case 141: // NEWARR
idx += 4;
break;
case 162: // STELEM_REF
break;
case 254: // PREFIX
idx++;
// Covers the CEQ instructions used in debug code for some reason.
if (idx >= instrs.Length || instrs[idx] >= 6)
goto default;
break;
default:
/* Debug.Fail("Warning: User validation code sub-optimial: Unsupported opcode " + instrs[idx] +
" at " + idx + " in method " + method.Name); */
return -1;
}
idx++;
}
#endif
return -1;
}
/// <summary>
/// Sends an error message to the debugger (outputDebugString), as well as the EventListeners
/// It will do this even if the EventSource is not enabled.
/// </summary>
internal void ReportOutOfBandMessage(string msg)
{
try
{
if (m_outOfBandMessageCount < 16 - 1) // Note this is only if size byte
{
m_outOfBandMessageCount++;
}
else
{
if (m_outOfBandMessageCount == 16)
return;
m_outOfBandMessageCount = 16; // Mark that we hit the limit. Notify them that this is the case.
msg = "Reached message limit. End of EventSource error messages.";
}
// send message to debugger
Debugger.Log(0, null, $"EventSource Error: {msg}{Environment.NewLine}");
// Send it to all listeners.
WriteEventString(msg);
WriteStringToAllListeners("EventSourceMessage", msg);
}
catch { } // If we fail during last chance logging, well, we have to give up....
}
private static EventSourceSettings ValidateSettings(EventSourceSettings settings)
{
const EventSourceSettings evtFormatMask = EventSourceSettings.EtwManifestEventFormat |
EventSourceSettings.EtwSelfDescribingEventFormat;
if ((settings & evtFormatMask) == evtFormatMask)
{
throw new ArgumentException(SR.EventSource_InvalidEventFormat, nameof(settings));
}
// If you did not explicitly ask for manifest, you get self-describing.
if ((settings & evtFormatMask) == 0)
settings |= EventSourceSettings.EtwSelfDescribingEventFormat;
return settings;
}
private bool ThrowOnEventWriteErrors => (m_config & EventSourceSettings.ThrowOnEventWriteErrors) != 0;
private bool SelfDescribingEvents
{
get
{
Debug.Assert(((m_config & EventSourceSettings.EtwManifestEventFormat) != 0) !=
((m_config & EventSourceSettings.EtwSelfDescribingEventFormat) != 0));
return (m_config & EventSourceSettings.EtwSelfDescribingEventFormat) != 0;
}
}
// private instance state
private string m_name = null!; // My friendly name (privided in ctor)
internal int m_id; // A small integer that is unique to this instance.
private Guid m_guid; // GUID representing the ETW eventSource to the OS.
internal volatile EventMetadata[]? m_eventData; // None per-event data
private volatile byte[]? m_rawManifest; // Bytes to send out representing the event schema
private EventHandler<EventCommandEventArgs>? m_eventCommandExecuted;
private readonly EventSourceSettings m_config; // configuration information
private bool m_eventSourceDisposed; // has Dispose been called.
// Enabling bits
private bool m_eventSourceEnabled; // am I enabled (any of my events are enabled for any dispatcher)
internal EventLevel m_level; // highest level enabled by any output dispatcher
internal EventKeywords m_matchAnyKeyword; // the logical OR of all levels enabled by any output dispatcher (zero is a special case) meaning 'all keywords'
// Dispatching state
internal volatile EventDispatcher? m_Dispatchers; // Linked list of code:EventDispatchers we write the data to (we also do ETW specially)
private volatile OverrideEventProvider m_etwProvider = null!; // This hooks up ETW commands to our 'OnEventCommand' callback
#if FEATURE_PERFTRACING
private object? m_createEventLock;
private IntPtr m_writeEventStringEventHandle = IntPtr.Zero;
private volatile OverrideEventProvider m_eventPipeProvider = null!;
#endif
private bool m_completelyInited; // The EventSource constructor has returned without exception.
private Exception? m_constructionException; // If there was an exception construction, this is it
private byte m_outOfBandMessageCount; // The number of out of band messages sent (we throttle them
private EventCommandEventArgs? m_deferredCommands; // If we get commands before we are fully we store them here and run the when we are fully inited.
private string[]? m_traits; // Used to implement GetTraits
[ThreadStatic]
private static byte m_EventSourceExceptionRecurenceCount; // current recursion count inside ThrowEventSourceException
internal volatile ulong[]? m_channelData;
// We use a single instance of ActivityTracker for all EventSources instances to allow correlation between multiple event providers.
// We have m_activityTracker field simply because instance field is more efficient than static field fetch.
private ActivityTracker m_activityTracker = null!;
internal const string ActivityStartSuffix = "Start";
internal const string ActivityStopSuffix = "Stop";
// This switch controls an opt-in, off-by-default mechanism for allowing multiple EventSources to have the same
// name and by extension GUID. This is not considered a mainline scenario and is explicitly intended as a release
// valve for users that make heavy use of AssemblyLoadContext and experience exceptions from EventSource.
// This does not solve any issues that might arise from this configuration. For instance:
//
// * If multiple manifest-mode EventSources have the same name/GUID, it is ambiguous which manifest should be used by an ETW parser.
// This can result in events being incorrectly parse. The data will still be there, but EventTrace (or other libraries) won't
// know how to parse it.
// * Potential issues in parsing self-describing EventSources that use the same name/GUID, event name, and payload type from the same AssemblyLoadContext
// but have different event IDs set.
//
// Most users should not turn this on.
internal const string DuplicateSourceNamesSwitch = "System.Diagnostics.Tracing.EventSource.AllowDuplicateSourceNames";
private static readonly bool AllowDuplicateSourceNames = AppContext.TryGetSwitch(DuplicateSourceNamesSwitch, out bool isEnabled) ? isEnabled : false;
#endregion
}
/// <summary>
/// Enables specifying event source configuration options to be used in the EventSource constructor.
/// </summary>
[Flags]
public enum EventSourceSettings
{
/// <summary>
/// This specifies none of the special configuration options should be enabled.
/// </summary>
Default = 0,
/// <summary>
/// Normally an EventSource NEVER throws; setting this option will tell it to throw when it encounters errors.
/// </summary>
ThrowOnEventWriteErrors = 1,
/// <summary>
/// Setting this option is a directive to the ETW listener should use manifest-based format when
/// firing events. This is the default option when defining a type derived from EventSource
/// (using the protected EventSource constructors).
/// Only one of EtwManifestEventFormat or EtwSelfDescribingEventFormat should be specified
/// </summary>
EtwManifestEventFormat = 4,
/// <summary>
/// Setting this option is a directive to the ETW listener should use self-describing event format
/// when firing events. This is the default option when creating a new instance of the EventSource
/// type (using the public EventSource constructors).
/// Only one of EtwManifestEventFormat or EtwSelfDescribingEventFormat should be specified
/// </summary>
EtwSelfDescribingEventFormat = 8,
}
/// <summary>
/// An EventListener represents a target for the events generated by EventSources (that is subclasses
/// of <see cref="EventSource"/>), in the current appdomain. When a new EventListener is created
/// it is logically attached to all eventSources in that appdomain. When the EventListener is Disposed, then
/// it is disconnected from the event eventSources. Note that there is a internal list of STRONG references
/// to EventListeners, which means that relying on the lack of references to EventListeners to clean up
/// EventListeners will NOT work. You must call EventListener.Dispose explicitly when a dispatcher is no
/// longer needed.
/// <para>
/// Once created, EventListeners can enable or disable on a per-eventSource basis using verbosity levels
/// (<see cref="EventLevel"/>) and bitfields (<see cref="EventKeywords"/>) to further restrict the set of
/// events to be sent to the dispatcher. The dispatcher can also send arbitrary commands to a particular
/// eventSource using the 'SendCommand' method. The meaning of the commands are eventSource specific.
/// </para><para>
/// The Null Guid (that is (new Guid()) has special meaning as a wildcard for 'all current eventSources in
/// the appdomain'. Thus it is relatively easy to turn on all events in the appdomain if desired.
/// </para><para>
/// It is possible for there to be many EventListener's defined in a single appdomain. Each dispatcher is
/// logically independent of the other listeners. Thus when one dispatcher enables or disables events, it
/// affects only that dispatcher (other listeners get the events they asked for). It is possible that
/// commands sent with 'SendCommand' would do a semantic operation that would affect the other listeners
/// (like doing a GC, or flushing data ...), but this is the exception rather than the rule.
/// </para><para>
/// Thus the model is that each EventSource keeps a list of EventListeners that it is sending events
/// to. Associated with each EventSource-dispatcher pair is a set of filtering criteria that determine for
/// that eventSource what events that dispatcher will receive.
/// </para><para>
/// Listeners receive the events on their 'OnEventWritten' method. Thus subclasses of EventListener must
/// override this method to do something useful with the data.
/// </para><para>
/// In addition, when new eventSources are created, the 'OnEventSourceCreate' method is called. The
/// invariant associated with this callback is that every eventSource gets exactly one
/// 'OnEventSourceCreate' call for ever eventSource that can potentially send it log messages. In
/// particular when a EventListener is created, typically a series of OnEventSourceCreate' calls are
/// made to notify the new dispatcher of all the eventSources that existed before the EventListener was
/// created.
/// </para>
/// </summary>
public abstract class EventListener : IDisposable
{
private event EventHandler<EventSourceCreatedEventArgs>? _EventSourceCreated;
/// <summary>
/// This event is raised whenever a new eventSource is 'attached' to the dispatcher.
/// This can happen for all existing EventSources when the EventListener is created
/// as well as for any EventSources that come into existence after the EventListener
/// has been created.
///
/// These 'catch up' events are called during the construction of the EventListener.
/// Subclasses need to be prepared for that.
///
/// In a multi-threaded environment, it is possible that 'EventSourceEventWrittenCallback'
/// events for a particular eventSource to occur BEFORE the EventSourceCreatedCallback is issued.
/// </summary>
public event EventHandler<EventSourceCreatedEventArgs>? EventSourceCreated
{
add
{
CallBackForExistingEventSources(false, value);
this._EventSourceCreated = (EventHandler<EventSourceCreatedEventArgs>?)Delegate.Combine(_EventSourceCreated, value);
}
remove
{
this._EventSourceCreated = (EventHandler<EventSourceCreatedEventArgs>?)Delegate.Remove(_EventSourceCreated, value);
}
}
/// <summary>
/// This event is raised whenever an event has been written by a EventSource for which
/// the EventListener has enabled events.
/// </summary>
public event EventHandler<EventWrittenEventArgs>? EventWritten;
/// <summary>
/// Create a new EventListener in which all events start off turned off (use EnableEvents to turn
/// them on).
/// </summary>
protected EventListener()
{
// This will cause the OnEventSourceCreated callback to fire.
CallBackForExistingEventSources(true, (obj, args) =>
args.EventSource!.AddListener((EventListener)obj!));
}
/// <summary>
/// Dispose should be called when the EventListener no longer desires 'OnEvent*' callbacks. Because
/// there is an internal list of strong references to all EventListeners, calling 'Dispose' directly
/// is the only way to actually make the listen die. Thus it is important that users of EventListener
/// call Dispose when they are done with their logging.
/// </summary>
public virtual void Dispose()
{
lock (EventListenersLock)
{
if (s_Listeners != null)
{
if (this == s_Listeners)
{
EventListener cur = s_Listeners;
s_Listeners = this.m_Next;
RemoveReferencesToListenerInEventSources(cur);
}
else
{
// Find 'this' from the s_Listeners linked list.
EventListener prev = s_Listeners;
while (true)
{
EventListener? cur = prev.m_Next;
if (cur == null)
break;
if (cur == this)
{
// Found our Listener, remove references to it in the eventSources
prev.m_Next = cur.m_Next; // Remove entry.
RemoveReferencesToListenerInEventSources(cur);
break;
}
prev = cur;
}
}
}
Validate();
}
#if FEATURE_PERFTRACING
// Remove the listener from the EventPipe dispatcher. EventCommand.Update with enable==false removes it.
EventPipeEventDispatcher.Instance.SendCommand(this, EventCommand.Update, false, EventLevel.LogAlways, (EventKeywords)0);
#endif // FEATURE_PERFTRACING
}
// We don't expose a Dispose(bool), because the contract is that you don't have any non-syncronous
// 'cleanup' associated with this object
/// <summary>
/// Enable all events from the eventSource identified by 'eventSource' to the current
/// dispatcher that have a verbosity level of 'level' or lower.
///
/// This call can have the effect of REDUCING the number of events sent to the
/// dispatcher if 'level' indicates a less verbose level than was previously enabled.
///
/// This call never has an effect on other EventListeners.
///
/// </summary>
public void EnableEvents(EventSource eventSource, EventLevel level)
{
EnableEvents(eventSource, level, EventKeywords.None);
}
/// <summary>
/// Enable all events from the eventSource identified by 'eventSource' to the current
/// dispatcher that have a verbosity level of 'level' or lower and have a event keyword
/// matching any of the bits in 'matchAnyKeyword'.
///
/// This call can have the effect of REDUCING the number of events sent to the
/// dispatcher if 'level' indicates a less verbose level than was previously enabled or
/// if 'matchAnyKeyword' has fewer keywords set than where previously set.
///
/// This call never has an effect on other EventListeners.
/// </summary>
public void EnableEvents(EventSource eventSource, EventLevel level, EventKeywords matchAnyKeyword)
{
EnableEvents(eventSource, level, matchAnyKeyword, null);
}
/// <summary>
/// Enable all events from the eventSource identified by 'eventSource' to the current
/// dispatcher that have a verbosity level of 'level' or lower and have a event keyword
/// matching any of the bits in 'matchAnyKeyword' as well as any (eventSource specific)
/// effect passing additional 'key-value' arguments 'arguments' might have.
///
/// This call can have the effect of REDUCING the number of events sent to the
/// dispatcher if 'level' indicates a less verbose level than was previously enabled or
/// if 'matchAnyKeyword' has fewer keywords set than where previously set.
///
/// This call never has an effect on other EventListeners.
/// </summary>
public void EnableEvents(EventSource eventSource, EventLevel level, EventKeywords matchAnyKeyword, IDictionary<string, string?>? arguments)
{
ArgumentNullException.ThrowIfNull(eventSource);
eventSource.SendCommand(this, EventProviderType.None, 0, EventCommand.Update, true, level, matchAnyKeyword, arguments);
#if FEATURE_PERFTRACING
if (eventSource.GetType() == typeof(NativeRuntimeEventSource))
{
EventPipeEventDispatcher.Instance.SendCommand(this, EventCommand.Update, true, level, matchAnyKeyword);
}
#endif // FEATURE_PERFTRACING
}
/// <summary>
/// Disables all events coming from eventSource identified by 'eventSource'.
///
/// This call never has an effect on other EventListeners.
/// </summary>
public void DisableEvents(EventSource eventSource)
{
ArgumentNullException.ThrowIfNull(eventSource);
eventSource.SendCommand(this, EventProviderType.None, 0, EventCommand.Update, false, EventLevel.LogAlways, EventKeywords.None, null);
#if FEATURE_PERFTRACING
if (eventSource.GetType() == typeof(NativeRuntimeEventSource))
{
EventPipeEventDispatcher.Instance.SendCommand(this, EventCommand.Update, false, EventLevel.LogAlways, EventKeywords.None);
}
#endif // FEATURE_PERFTRACING
}
/// <summary>
/// EventSourceIndex is small non-negative integer (suitable for indexing in an array)
/// identifying EventSource. It is unique per-appdomain. Some EventListeners might find
/// it useful to store additional information about each eventSource connected to it,
/// and EventSourceIndex allows this extra information to be efficiently stored in a
/// (growable) array (eg List(T)).
/// </summary>
protected internal static int EventSourceIndex(EventSource eventSource) { return eventSource.m_id; }
/// <summary>
/// This method is called whenever a new eventSource is 'attached' to the dispatcher.
/// This can happen for all existing EventSources when the EventListener is created
/// as well as for any EventSources that come into existence after the EventListener
/// has been created.
///
/// These 'catch up' events are called during the construction of the EventListener.
/// Subclasses need to be prepared for that.
///
/// In a multi-threaded environment, it is possible that 'OnEventWritten' callbacks
/// for a particular eventSource to occur BEFORE the OnEventSourceCreated is issued.
/// </summary>
/// <param name="eventSource"></param>
protected internal virtual void OnEventSourceCreated(EventSource eventSource)
{
EventHandler<EventSourceCreatedEventArgs>? callBack = this._EventSourceCreated;
if (callBack != null)
{
EventSourceCreatedEventArgs args = new EventSourceCreatedEventArgs();
args.EventSource = eventSource;
callBack(this, args);
}
}
/// <summary>
/// This method is called whenever an event has been written by a EventSource for which
/// the EventListener has enabled events.
/// </summary>
/// <param name="eventData"></param>
protected internal virtual void OnEventWritten(EventWrittenEventArgs eventData)
{
this.EventWritten?.Invoke(this, eventData);
}
#region private
/// <summary>
/// This routine adds newEventSource to the global list of eventSources, it also assigns the
/// ID to the eventSource (which is simply the ordinal in the global list).
///
/// EventSources currently do not pro-actively remove themselves from this list. Instead
/// when eventSources's are GCed, the weak handle in this list naturally gets nulled, and
/// we will reuse the slot. Today this list never shrinks (but we do reuse entries
/// that are in the list). This seems OK since the expectation is that EventSources
/// tend to live for the lifetime of the appdomain anyway (they tend to be used in
/// global variables).
/// </summary>
/// <param name="newEventSource"></param>
internal static void AddEventSource(EventSource newEventSource)
{
lock (EventListenersLock)
{
Debug.Assert(s_EventSources != null);
// Periodically search the list for existing entries to reuse, this avoids
// unbounded memory use if we keep recycling eventSources (an unlikely thing).
int newIndex = -1;
if (s_EventSources.Count % 64 == 63) // on every block of 64, fill up the block before continuing
{
int i = s_EventSources.Count; // Work from the top down.
while (0 < i)
{
--i;
WeakReference<EventSource> weakRef = s_EventSources[i];
if (!weakRef.TryGetTarget(out _))
{
newIndex = i;
weakRef.SetTarget(newEventSource);
break;
}
}
}
if (newIndex < 0)
{
newIndex = s_EventSources.Count;
s_EventSources.Add(new WeakReference<EventSource>(newEventSource));
}
newEventSource.m_id = newIndex;
#if DEBUG
// Disable validation of EventSource/EventListener connections in case a call to EventSource.AddListener
// causes a recursive call into this method.
bool previousValue = s_ConnectingEventSourcesAndListener;
s_ConnectingEventSourcesAndListener = true;
try
{
#endif
// Add every existing dispatcher to the new EventSource
for (EventListener? listener = s_Listeners; listener != null; listener = listener.m_Next)
newEventSource.AddListener(listener);
#if DEBUG
}
finally
{
s_ConnectingEventSourcesAndListener = previousValue;
}
#endif
Validate();
}
}
// Whenever we have async callbacks from native code, there is an ugly issue where
// during .NET shutdown native code could be calling the callback, but the CLR
// has already prohibited callbacks to managed code in the appdomain, causing the CLR
// to throw a COMPLUS_BOOT_EXCEPTION. The guideline we give is that you must unregister
// such callbacks on process shutdown or appdomain so that unmanaged code will never
// do this. This is what this callback is for.
// See bug 724140 for more
internal static void DisposeOnShutdown()
{
Debug.Assert(EventSource.IsSupported);
List<EventSource> sourcesToDispose = new List<EventSource>();
lock (EventListenersLock)
{
Debug.Assert(s_EventSources != null);
foreach (WeakReference<EventSource> esRef in s_EventSources)
{
if (esRef.TryGetTarget(out EventSource? es))
{
sourcesToDispose.Add(es);
}
}
}
// Do not invoke Dispose under the lock as this can lead to a deadlock.
// See https://github.com/dotnet/runtime/issues/48342 for details.
Debug.Assert(!Monitor.IsEntered(EventListenersLock));
foreach (EventSource es in sourcesToDispose)
{
es.Dispose();
}
}
// If an EventListener calls Dispose without calling DisableEvents first we want to issue the Disable command now
private static void CallDisableEventsIfNecessary(EventDispatcher eventDispatcher, EventSource eventSource)
{
#if DEBUG
// Disable validation of EventSource/EventListener connections in case a call to EventSource.AddListener
// causes a recursive call into this method.
bool previousValue = s_ConnectingEventSourcesAndListener;
s_ConnectingEventSourcesAndListener = true;
try
{
#endif
if (eventDispatcher.m_EventEnabled == null)
{
return;
}
for (int i = 0; i < eventDispatcher.m_EventEnabled.Length; ++i)
{
if (eventDispatcher.m_EventEnabled[i])
{
eventDispatcher.m_Listener.DisableEvents(eventSource);
}
}
#if DEBUG
}
finally
{
s_ConnectingEventSourcesAndListener = previousValue;
}
#endif
}
/// <summary>
/// Helper used in code:Dispose that removes any references to 'listenerToRemove' in any of the
/// eventSources in the appdomain.
///
/// The EventListenersLock must be held before calling this routine.
/// </summary>
private static void RemoveReferencesToListenerInEventSources(EventListener listenerToRemove)
{
Debug.Assert(Monitor.IsEntered(EventListenersLock));
// Foreach existing EventSource in the appdomain
Debug.Assert(s_EventSources != null);
// First pass to call DisableEvents
WeakReference<EventSource>[] eventSourcesSnapshot = s_EventSources.ToArray();
foreach (WeakReference<EventSource> eventSourceRef in eventSourcesSnapshot)
{
if (eventSourceRef.TryGetTarget(out EventSource? eventSource))
{
EventDispatcher? cur = eventSource.m_Dispatchers;
while (cur != null)
{
if (cur.m_Listener == listenerToRemove)
{
CallDisableEventsIfNecessary(cur!, eventSource);
}
cur = cur.m_Next;
}
}
}
// DisableEvents can call back to user code and we have to start over since s_EventSources and
// eventSource.m_Dispatchers could have mutated
foreach (WeakReference<EventSource> eventSourceRef in s_EventSources)
{
if (eventSourceRef.TryGetTarget(out EventSource? eventSource)
&& eventSource.m_Dispatchers != null)
{
// Is the first output dispatcher the dispatcher we are removing?
if (eventSource.m_Dispatchers.m_Listener == listenerToRemove)
{
eventSource.m_Dispatchers = eventSource.m_Dispatchers.m_Next;
}
else
{
// Remove 'listenerToRemove' from the eventSource.m_Dispatchers linked list.
EventDispatcher? prev = eventSource.m_Dispatchers;
while (true)
{
EventDispatcher? cur = prev.m_Next;
if (cur == null)
{
Debug.Fail("EventSource did not have a registered EventListener!");
break;
}
if (cur.m_Listener == listenerToRemove)
{
prev.m_Next = cur.m_Next; // Remove entry.
break;
}
prev = cur;
}
}
}
}
}
/// <summary>
/// Checks internal consistency of EventSources/Listeners.
/// </summary>
[Conditional("DEBUG")]
internal static void Validate()
{
#if DEBUG
// Don't run validation code if we're in the middle of modifying the connections between EventSources and EventListeners.
if (s_ConnectingEventSourcesAndListener)
{
return;
}
#endif
lock (EventListenersLock)
{
Debug.Assert(s_EventSources != null);
// Get all listeners
Dictionary<EventListener, bool> allListeners = new Dictionary<EventListener, bool>();
EventListener? cur = s_Listeners;
while (cur != null)
{
allListeners.Add(cur, true);
cur = cur.m_Next;
}
// For all eventSources
int id = -1;
foreach (WeakReference<EventSource> eventSourceRef in s_EventSources)
{
id++;
if (!eventSourceRef.TryGetTarget(out EventSource? eventSource))
continue;
Debug.Assert(eventSource.m_id == id, "Unexpected event source ID.");
// None listeners on eventSources exist in the dispatcher list.
EventDispatcher? dispatcher = eventSource.m_Dispatchers;
while (dispatcher != null)
{
Debug.Assert(allListeners.ContainsKey(dispatcher.m_Listener), "EventSource has a listener not on the global list.");
dispatcher = dispatcher.m_Next;
}
// Every dispatcher is on Dispatcher List of every eventSource.
foreach (EventListener listener in allListeners.Keys)
{
dispatcher = eventSource.m_Dispatchers;
while (true)
{
Debug.Assert(dispatcher != null, "Listener is not on all eventSources.");
if (dispatcher.m_Listener == listener)
break;
dispatcher = dispatcher.m_Next;
}
}
}
}
}
/// <summary>
/// Gets a global lock that is intended to protect the code:s_Listeners linked list and the
/// code:s_EventSources list. (We happen to use the s_EventSources list as the lock object)
/// </summary>
internal static object EventListenersLock
{
get
{
if (s_EventSources == null)
{
Interlocked.CompareExchange(ref s_EventSources, new List<WeakReference<EventSource>>(2), null);
#if FEATURE_PERFTRACING
// It is possible that another thread could observe the s_EventSources list at this point and it
// won't have the NativeRuntimeEventSource in it. In the past we guaranteed that the NativeRuntimeEventSource
// was always visible in the list by initializing it in the EventListener static constructor, however doing it
// that way triggered deadlocks between the static constructor and an OS ETW lock. There is no known issue here
// having a small window of time where NativeRuntimeEventSource is not in the list as long
// as we still guarantee it gets initialized eventually.
GC.KeepAlive(NativeRuntimeEventSource.Log);
#endif
}
return s_EventSources;
}
}
private void CallBackForExistingEventSources(bool addToListenersList, EventHandler<EventSourceCreatedEventArgs>? callback)
{
lock (EventListenersLock)
{
Debug.Assert(s_EventSources != null);
// Disallow creating EventListener reentrancy.
if (s_CreatingListener)
{
throw new InvalidOperationException(SR.EventSource_ListenerCreatedInsideCallback);
}
try
{
s_CreatingListener = true;
if (addToListenersList)
{
// Add to list of listeners in the system, do this BEFORE firing the 'OnEventSourceCreated' so that
// Those added sources see this listener.
this.m_Next = s_Listeners;
s_Listeners = this;
}
if (callback != null)
{
// Find all existing eventSources call OnEventSourceCreated to 'catchup'
// Note that we DO have reentrancy here because 'AddListener' calls out to user code (via OnEventSourceCreated callback)
// We tolerate this by iterating over a copy of the list here. New event sources will take care of adding listeners themselves
// EventSources are not guaranteed to be added at the end of the s_EventSource list -- We re-use slots when a new source
// is created.
WeakReference<EventSource>[] eventSourcesSnapshot = s_EventSources.ToArray();
#if DEBUG
bool previousValue = s_ConnectingEventSourcesAndListener;
s_ConnectingEventSourcesAndListener = true;
try
{
#endif
for (int i = 0; i < eventSourcesSnapshot.Length; i++)
{
WeakReference<EventSource> eventSourceRef = eventSourcesSnapshot[i];
if (eventSourceRef.TryGetTarget(out EventSource? eventSource))
{
EventSourceCreatedEventArgs args = new EventSourceCreatedEventArgs();
args.EventSource = eventSource;
callback(this, args);
}
}
#if DEBUG
}
finally
{
s_ConnectingEventSourcesAndListener = previousValue;
}
#endif
}
Validate();
}
finally
{
s_CreatingListener = false;
}
}
}
// Instance fields
internal volatile EventListener? m_Next; // These form a linked list in s_Listeners
// static fields
/// <summary>
/// The list of all listeners in the appdomain. Listeners must be explicitly disposed to remove themselves
/// from this list. Note that EventSources point to their listener but NOT the reverse.
/// </summary>
internal static EventListener? s_Listeners;
/// <summary>
/// The list of all active eventSources in the appdomain. Note that eventSources do NOT
/// remove themselves from this list this is a weak list and the GC that removes them may
/// not have happened yet. Thus it can contain event sources that are dead (thus you have
/// to filter those out.
/// </summary>
internal static List<WeakReference<EventSource>>? s_EventSources;
/// <summary>
/// Used to disallow reentrancy.
/// </summary>
private static bool s_CreatingListener;
#if DEBUG
/// <summary>
/// Used to disable validation of EventSource and EventListener connectivity.
/// This is needed when an EventListener is in the middle of being published to all EventSources
/// and another EventSource is created as part of the process.
/// </summary>
[ThreadStatic]
private static bool s_ConnectingEventSourcesAndListener;
#endif
#endregion
}
/// <summary>
/// Passed to the code:EventSource.OnEventCommand callback
/// </summary>
public class EventCommandEventArgs : EventArgs
{
/// <summary>
/// Gets the command for the callback.
/// </summary>
public EventCommand Command { get; internal set; }
/// <summary>
/// Gets the arguments for the callback.
/// </summary>
public IDictionary<string, string?>? Arguments { get; internal set; }
/// <summary>
/// Enables the event that has the specified identifier.
/// </summary>
/// <param name="eventId">Event ID of event to be enabled</param>
/// <returns>true if eventId is in range</returns>
public bool EnableEvent(int eventId)
{
if (Command != EventCommand.Enable && Command != EventCommand.Disable)
throw new InvalidOperationException();
return eventSource.EnableEventForDispatcher(dispatcher, eventProviderType, eventId, true);
}
/// <summary>
/// Disables the event that have the specified identifier.
/// </summary>
/// <param name="eventId">Event ID of event to be disabled</param>
/// <returns>true if eventId is in range</returns>
public bool DisableEvent(int eventId)
{
if (Command != EventCommand.Enable && Command != EventCommand.Disable)
throw new InvalidOperationException();
return eventSource.EnableEventForDispatcher(dispatcher, eventProviderType, eventId, false);
}
#region private
internal EventCommandEventArgs(EventCommand command, IDictionary<string, string?>? arguments, EventSource eventSource,
EventListener? listener, EventProviderType eventProviderType, int perEventSourceSessionId, bool enable, EventLevel level, EventKeywords matchAnyKeyword)
{
this.Command = command;
this.Arguments = arguments;
this.eventSource = eventSource;
this.listener = listener;
this.eventProviderType = eventProviderType;
this.perEventSourceSessionId = perEventSourceSessionId;
this.enable = enable;
this.level = level;
this.matchAnyKeyword = matchAnyKeyword;
}
internal EventSource eventSource;
internal EventDispatcher? dispatcher;
internal EventProviderType eventProviderType;
// These are the arguments of sendCommand and are only used for deferring commands until after we are fully initialized.
internal EventListener? listener;
internal int perEventSourceSessionId;
internal bool enable;
internal EventLevel level;
internal EventKeywords matchAnyKeyword;
internal EventCommandEventArgs? nextCommand; // We form a linked list of these deferred commands.
#endregion
}
/// <summary>
/// EventSourceCreatedEventArgs is passed to <see cref="EventListener.EventSourceCreated"/>
/// </summary>
public class EventSourceCreatedEventArgs : EventArgs
{
/// <summary>
/// The EventSource that is attaching to the listener.
/// </summary>
public EventSource? EventSource
{
get;
internal set;
}
}
/// <summary>
/// EventWrittenEventArgs is passed to the user-provided override for
/// <see cref="EventListener.OnEventWritten"/> when an event is fired.
/// </summary>
public class EventWrittenEventArgs : EventArgs
{
private ref EventSource.EventMetadata Metadata => ref EventSource.m_eventData![EventId];
/// <summary>
/// The name of the event.
/// </summary>
public string? EventName
{
get => _moreInfo?.EventName ?? (EventId <= 0 ? null : Metadata.Name);
internal set => MoreInfo.EventName = value;
}
/// <summary>
/// Gets the event ID for the event that was written.
/// </summary>
public int EventId { get; }
private Guid _activityId;
/// <summary>
/// Gets the activity ID for the thread on which the event was written.
/// </summary>
public Guid ActivityId
{
get
{
if (_activityId == Guid.Empty)
{
_activityId = EventSource.CurrentThreadActivityId;
}
return _activityId;
}
}
/// <summary>
/// Gets the related activity ID if one was specified when the event was written.
/// </summary>
public Guid RelatedActivityId => _moreInfo?.RelatedActivityId ?? default;
/// <summary>
/// Gets the payload for the event.
/// </summary>
public ReadOnlyCollection<object?>? Payload { get; internal set; }
/// <summary>
/// Gets the payload argument names.
/// </summary>
public ReadOnlyCollection<string>? PayloadNames
{
get => _moreInfo?.PayloadNames ?? (EventId <= 0 ? null : Metadata.ParameterNames);
internal set => MoreInfo.PayloadNames = value;
}
/// <summary>
/// Gets the event source object.
/// </summary>
public EventSource EventSource { get; }
/// <summary>
/// Gets the keywords for the event.
/// </summary>
public EventKeywords Keywords
{
get => EventId <= 0 ? (_moreInfo?.Keywords ?? default) : (EventKeywords)Metadata.Descriptor.Keywords;
internal set => MoreInfo.Keywords = value;
}
/// <summary>
/// Gets the operation code for the event.
/// </summary>
public EventOpcode Opcode
{
get => EventId <= 0 ? (_moreInfo?.Opcode ?? default) : (EventOpcode)Metadata.Descriptor.Opcode;
internal set => MoreInfo.Opcode = value;
}
/// <summary>
/// Gets the task for the event.
/// </summary>
public EventTask Task => EventId <= 0 ? EventTask.None : (EventTask)Metadata.Descriptor.Task;
/// <summary>
/// Any provider/user defined options associated with the event.
/// </summary>
public EventTags Tags
{
get => EventId <= 0 ? (_moreInfo?.Tags ?? default) : Metadata.Tags;
internal set => MoreInfo.Tags = value;
}
/// <summary>
/// Gets the message for the event. If the message has {N} parameters they are NOT substituted.
/// </summary>
public string? Message
{
get => _moreInfo?.Message ?? (EventId <= 0 ? null : Metadata.Message);
internal set => MoreInfo.Message = value;
}
/// <summary>
/// Gets the channel for the event.
/// </summary>
public EventChannel Channel => EventId <= 0 ? EventChannel.None : (EventChannel)Metadata.Descriptor.Channel;
/// <summary>
/// Gets the version of the event.
/// </summary>
public byte Version => EventId <= 0 ? (byte)0 : Metadata.Descriptor.Version;
/// <summary>
/// Gets the level for the event.
/// </summary>
public EventLevel Level
{
get => EventId <= 0 ? (_moreInfo?.Level ?? default) : (EventLevel)Metadata.Descriptor.Level;
internal set => MoreInfo.Level = value;
}
/// <summary>
/// Gets the identifier for the OS thread that wrote the event.
/// </summary>
public long OSThreadId
{
get
{
ref long? osThreadId = ref MoreInfo.OsThreadId;
if (!osThreadId.HasValue)
{
osThreadId = (long)Thread.CurrentOSThreadId;
}
return osThreadId.Value;
}
internal set => MoreInfo.OsThreadId = value;
}
/// <summary>
/// Gets a UTC DateTime that specifies when the event was written.
/// </summary>
public DateTime TimeStamp { get; internal set; }
internal EventWrittenEventArgs(EventSource eventSource, int eventId)
{
EventSource = eventSource;
EventId = eventId;
TimeStamp = DateTime.UtcNow;
}
internal unsafe EventWrittenEventArgs(EventSource eventSource, int eventId, Guid* pActivityID, Guid* pChildActivityID)
: this(eventSource, eventId)
{
if (pActivityID != null)
{
_activityId = *pActivityID;
}
if (pChildActivityID != null)
{
MoreInfo.RelatedActivityId = *pChildActivityID;
}
}
private MoreEventInfo? _moreInfo;
private MoreEventInfo MoreInfo => _moreInfo ??= new MoreEventInfo();
private sealed class MoreEventInfo
{
public string? Message;
public string? EventName;
public ReadOnlyCollection<string>? PayloadNames;
public Guid RelatedActivityId;
public long? OsThreadId;
public EventTags Tags;
public EventOpcode Opcode;
public EventLevel Level;
public EventKeywords Keywords;
}
}
/// <summary>
/// Allows customizing defaults and specifying localization support for the event source class to which it is applied.
/// </summary>
[AttributeUsage(AttributeTargets.Class)]
public sealed class EventSourceAttribute : Attribute
{
/// <summary>
/// Overrides the ETW name of the event source (which defaults to the class name)
/// </summary>
public string? Name { get; set; }
/// <summary>
/// Overrides the default (calculated) Guid of an EventSource type. Explicitly defining a GUID is discouraged,
/// except when upgrading existing ETW providers to using event sources.
/// </summary>
public string? Guid { get; set; }
/// <summary>
/// <para>
/// EventSources support localization of events. The names used for events, opcodes, tasks, keywords and maps
/// can be localized to several languages if desired. This works by creating a ResX style string table
/// (by simply adding a 'Resource File' to your project). This resource file is given a name e.g.
/// 'DefaultNameSpace.ResourceFileName' which can be passed to the ResourceManager constructor to read the
/// resources. This name is the value of the LocalizationResources property.
/// </para><para>
/// If LocalizationResources property is non-null, then EventSource will look up the localized strings for events by
/// using the following resource naming scheme
/// </para>
/// <para>* event_EVENTNAME</para>
/// <para>* task_TASKNAME</para>
/// <para>* keyword_KEYWORDNAME</para>
/// <para>* map_MAPNAME</para>
/// <para>
/// where the capitalized name is the name of the event, task, keyword, or map value that should be localized.
/// Note that the localized string for an event corresponds to the Message string, and can have {0} values
/// which represent the payload values.
/// </para>
/// </summary>
public string? LocalizationResources { get; set; }
}
/// <summary>
/// Any instance methods in a class that subclasses <see cref="EventSource"/> and that return void are
/// assumed by default to be methods that generate an ETW event. Enough information can be deduced from the
/// name of the method and its signature to generate basic schema information for the event. The
/// <see cref="EventAttribute"/> class allows you to specify additional event schema information for an event if
/// desired.
/// </summary>
[AttributeUsage(AttributeTargets.Method)]
public sealed class EventAttribute : Attribute
{
/// <summary>Construct an EventAttribute with specified eventId</summary>
/// <param name="eventId">ID of the ETW event (an integer between 1 and 65535)</param>
public EventAttribute(int eventId)
{
EventId = eventId;
Level = EventLevel.Informational;
}
/// <summary>Event's ID</summary>
public int EventId { get; }
/// <summary>Event's severity level: indicates the severity or verbosity of the event</summary>
public EventLevel Level { get; set; }
/// <summary>Event's keywords: allows classification of events by "categories"</summary>
public EventKeywords Keywords { get; set; }
/// <summary>Event's operation code: allows defining operations, generally used with Tasks</summary>
public EventOpcode Opcode
{
get => m_opcode;
set
{
m_opcode = value;
m_opcodeSet = true;
}
}
internal bool IsOpcodeSet => m_opcodeSet;
/// <summary>Event's task: allows logical grouping of events</summary>
public EventTask Task { get; set; }
/// <summary>Event's channel: defines an event log as an additional destination for the event</summary>
public EventChannel Channel { get; set; }
/// <summary>Event's version</summary>
public byte Version { get; set; }
/// <summary>
/// This can be specified to enable formatting and localization of the event's payload. You can
/// use standard .NET substitution operators (eg {1}) in the string and they will be replaced
/// with the 'ToString()' of the corresponding part of the event payload.
/// </summary>
public string? Message { get; set; }
/// <summary>
/// User defined options associated with the event. These do not have meaning to the EventSource but
/// are passed through to listeners which given them semantics.
/// </summary>
public EventTags Tags { get; set; }
/// <summary>
/// Allows fine control over the Activity IDs generated by start and stop events
/// </summary>
public EventActivityOptions ActivityOptions { get; set; }
#region private
private EventOpcode m_opcode;
private bool m_opcodeSet;
#endregion
}
/// <summary>
/// By default all instance methods in a class that subclasses code:EventSource that and return
/// void are assumed to be methods that generate an event. This default can be overridden by specifying
/// the code:NonEventAttribute
/// </summary>
[AttributeUsage(AttributeTargets.Method)]
public sealed class NonEventAttribute : Attribute
{
/// <summary>
/// Constructs a default NonEventAttribute
/// </summary>
public NonEventAttribute() { }
}
/// <summary>
/// EventChannelAttribute allows customizing channels supported by an EventSource. This attribute must be
/// applied to an member of type EventChannel defined in a Channels class nested in the EventSource class:
/// <code>
/// public static class Channels
/// {
/// [Channel(Enabled = true, EventChannelType = EventChannelType.Admin)]
/// public const EventChannel Admin = (EventChannel)16;
///
/// [Channel(Enabled = false, EventChannelType = EventChannelType.Operational)]
/// public const EventChannel Operational = (EventChannel)17;
/// }
/// </code>
/// </summary>
[AttributeUsage(AttributeTargets.Field)]
internal sealed class EventChannelAttribute : Attribute
{
/// <summary>
/// Specified whether the channel is enabled by default
/// </summary>
public bool Enabled { get; set; }
/// <summary>
/// Legal values are in EventChannelType
/// </summary>
public EventChannelType EventChannelType { get; set; }
// TODO: there is a convention that the name is the Provider/Type Should we provide an override?
// public string Name { get; set; }
}
/// <summary>
/// Allowed channel types
/// </summary>
internal enum EventChannelType
{
/// <summary>The admin channel</summary>
Admin = 1,
/// <summary>The operational channel</summary>
Operational,
/// <summary>The Analytic channel</summary>
Analytic,
/// <summary>The debug channel</summary>
Debug,
}
/// <summary>
/// Describes the pre-defined command (EventCommandEventArgs.Command property) that is passed to the OnEventCommand callback.
/// </summary>
public enum EventCommand
{
/// <summary>
/// Update EventSource state
/// </summary>
Update = 0,
/// <summary>
/// Request EventSource to generate and send its manifest
/// </summary>
SendManifest = -1,
/// <summary>
/// Enable event
/// </summary>
Enable = -2,
/// <summary>
/// Disable event
/// </summary>
Disable = -3
}
#region private classes
// holds a bitfield representing a session mask
/// <summary>
/// A SessionMask represents a set of (at most MAX) sessions as a bit mask. The perEventSourceSessionId
/// is the index in the SessionMask of the bit that will be set. These can translate to
/// EventSource's reserved keywords bits using the provided ToEventKeywords() and
/// FromEventKeywords() methods.
/// </summary>
internal struct SessionMask
{
public SessionMask(SessionMask m)
{ m_mask = m.m_mask; }
public SessionMask(uint mask = 0)
{ m_mask = mask & MASK; }
public bool IsEqualOrSupersetOf(SessionMask m)
{
return (this.m_mask | m.m_mask) == this.m_mask;
}
public static SessionMask All => new SessionMask(MASK);
public static SessionMask FromId(int perEventSourceSessionId)
{
Debug.Assert(perEventSourceSessionId < MAX);
return new SessionMask((uint)1 << perEventSourceSessionId);
}
public ulong ToEventKeywords()
{
return (ulong)m_mask << SHIFT_SESSION_TO_KEYWORD;
}
public static SessionMask FromEventKeywords(ulong m)
{
return new SessionMask((uint)(m >> SHIFT_SESSION_TO_KEYWORD));
}
public bool this[int perEventSourceSessionId]
{
get
{
Debug.Assert(perEventSourceSessionId < MAX);
return (m_mask & (1 << perEventSourceSessionId)) != 0;
}
set
{
Debug.Assert(perEventSourceSessionId < MAX);
if (value) m_mask |= ((uint)1 << perEventSourceSessionId);
else m_mask &= ~((uint)1 << perEventSourceSessionId);
}
}
public static SessionMask operator |(SessionMask m1, SessionMask m2) =>
new SessionMask(m1.m_mask | m2.m_mask);
public static SessionMask operator &(SessionMask m1, SessionMask m2) =>
new SessionMask(m1.m_mask & m2.m_mask);
public static SessionMask operator ^(SessionMask m1, SessionMask m2) =>
new SessionMask(m1.m_mask ^ m2.m_mask);
public static SessionMask operator ~(SessionMask m) =>
new SessionMask(MASK & ~(m.m_mask));
public static explicit operator ulong(SessionMask m) => m.m_mask;
public static explicit operator uint(SessionMask m) => m.m_mask;
private uint m_mask;
internal const int SHIFT_SESSION_TO_KEYWORD = 44; // bits 44-47 inclusive are reserved
internal const uint MASK = 0x0fU; // the mask of 4 reserved bits
internal const uint MAX = 4; // maximum number of simultaneous ETW sessions supported
}
/// <summary>
/// code:EventDispatchers are a simple 'helper' structure that holds the filtering state
/// (m_EventEnabled) for a particular EventSource X EventListener tuple
///
/// Thus a single EventListener may have many EventDispatchers (one for every EventSource
/// that EventListener has activate) and a Single EventSource may also have many
/// event Dispatchers (one for every EventListener that has activated it).
///
/// Logically a particular EventDispatcher belongs to exactly one EventSource and exactly
/// one EventListener (although EventDispatcher does not 'remember' the EventSource it is
/// associated with.
/// </summary>
internal sealed class EventDispatcher
{
internal EventDispatcher(EventDispatcher? next, bool[]? eventEnabled, EventListener listener)
{
m_Next = next;
m_EventEnabled = eventEnabled;
m_Listener = listener;
}
// Instance fields
internal readonly EventListener m_Listener; // The dispatcher this entry is for
internal bool[]? m_EventEnabled; // For every event in a the eventSource, is it enabled?
// Only guaranteed to exist after a InsureInit()
internal EventDispatcher? m_Next; // These form a linked list in code:EventSource.m_Dispatchers
// Of all listeners for that eventSource.
}
/// <summary>
/// Flags that can be used with EventSource.GenerateManifest to control how the ETW manifest for the EventSource is
/// generated.
/// </summary>
[Flags]
public enum EventManifestOptions
{
/// <summary>
/// Only the resources associated with current UI culture are included in the manifest
/// </summary>
None = 0x0,
/// <summary>
/// Throw exceptions for any inconsistency encountered
/// </summary>
Strict = 0x1,
/// <summary>
/// Generate a "resources" node under "localization" for every satellite assembly provided
/// </summary>
AllCultures = 0x2,
/// <summary>
/// Generate the manifest only if the event source needs to be registered on the machine,
/// otherwise return null (but still perform validation if Strict is specified)
/// </summary>
OnlyIfNeededForRegistration = 0x4,
/// <summary>
/// When generating the manifest do *not* enforce the rule that the current EventSource class
/// must be the base class for the user-defined type passed in. This allows validation of .net
/// event sources using the new validation code
/// </summary>
AllowEventSourceOverride = 0x8,
}
/// <summary>
/// ManifestBuilder is designed to isolate the details of the message of the event from the
/// rest of EventSource. This one happens to create XML.
/// </summary>
internal sealed class ManifestBuilder
{
/// <summary>
/// Build a manifest for 'providerName' with the given GUID, which will be packaged into 'dllName'.
/// 'resources, is a resource manager. If specified all messages are localized using that manager.
/// </summary>
public ManifestBuilder(string providerName, Guid providerGuid, string? dllName, ResourceManager? resources,
EventManifestOptions flags) : this(resources, flags)
{
this.providerName = providerName;
sb = new StringBuilder();
events = new StringBuilder();
templates = new StringBuilder();
sb.AppendLine("<instrumentationManifest xmlns=\"http://schemas.microsoft.com/win/2004/08/events\">");
sb.AppendLine(" <instrumentation xmlns:xs=\"http://www.w3.org/2001/XMLSchema\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:win=\"http://manifests.microsoft.com/win/2004/08/windows/events\">");
sb.AppendLine(" <events xmlns=\"http://schemas.microsoft.com/win/2004/08/events\">");
sb.Append($"<provider name=\"{providerName}\" guid=\"{{{providerGuid}}}\"");
if (dllName != null)
sb.Append($" resourceFileName=\"{dllName}\" messageFileName=\"{dllName}\"");
string symbolsName = providerName.Replace("-", "").Replace('.', '_'); // Period and - are illegal replace them.
sb.AppendLine($" symbol=\"{symbolsName}\">");
}
/// <summary>
/// <term>Will NOT build a manifest!</term> If the intention is to build a manifest don't use this constructor.
///'resources, is a resource manager. If specified all messages are localized using that manager.
/// </summary>
internal ManifestBuilder(ResourceManager? resources, EventManifestOptions flags)
{
providerName = "";
this.flags = flags;
this.resources = resources;
sb = null;
events = null;
templates = null;
opcodeTab = new Dictionary<int, string>();
stringTab = new Dictionary<string, string>();
errors = new List<string>();
perEventByteArrayArgIndices = new Dictionary<string, List<int>>();
}
public void AddOpcode(string name, int value)
{
if ((flags & EventManifestOptions.Strict) != 0)
{
if (value <= 10 || value >= 239)
{
ManifestError(SR.Format(SR.EventSource_IllegalOpcodeValue, name, value));
}
if (opcodeTab.TryGetValue(value, out string? prevName) && !name.Equals(prevName, StringComparison.Ordinal))
{
ManifestError(SR.Format(SR.EventSource_OpcodeCollision, name, prevName, value));
}
}
opcodeTab[value] = name;
}
public void AddTask(string name, int value)
{
if ((flags & EventManifestOptions.Strict) != 0)
{
if (value <= 0 || value >= 65535)
{
ManifestError(SR.Format(SR.EventSource_IllegalTaskValue, name, value));
}
if (taskTab != null && taskTab.TryGetValue(value, out string? prevName) && !name.Equals(prevName, StringComparison.Ordinal))
{
ManifestError(SR.Format(SR.EventSource_TaskCollision, name, prevName, value));
}
}
taskTab ??= new Dictionary<int, string>();
taskTab[value] = name;
}
public void AddKeyword(string name, ulong value)
{
if ((value & (value - 1)) != 0) // Must be zero or a power of 2
{
ManifestError(SR.Format(SR.EventSource_KeywordNeedPowerOfTwo, $"0x{value:x}", name), true);
}
if ((flags & EventManifestOptions.Strict) != 0)
{
if (value >= 0x0000100000000000UL && !name.StartsWith("Session", StringComparison.Ordinal))
{
ManifestError(SR.Format(SR.EventSource_IllegalKeywordsValue, name, $"0x{value:x}"));
}
if (keywordTab != null && keywordTab.TryGetValue(value, out string? prevName) && !name.Equals(prevName, StringComparison.Ordinal))
{
ManifestError(SR.Format(SR.EventSource_KeywordCollision, name, prevName, $"0x{value:x}"));
}
}
keywordTab ??= new Dictionary<ulong, string>();
keywordTab[value] = name;
}
/// <summary>
/// Add a channel. channelAttribute can be null
/// </summary>
public void AddChannel(string? name, int value, EventChannelAttribute? channelAttribute)
{
EventChannel chValue = (EventChannel)value;
if (value < (int)EventChannel.Admin || value > 255)
ManifestError(SR.Format(SR.EventSource_EventChannelOutOfRange, name, value));
else if (chValue >= EventChannel.Admin && chValue <= EventChannel.Debug &&
channelAttribute != null && EventChannelToChannelType(chValue) != channelAttribute.EventChannelType)
{
// we want to ensure developers do not define EventChannels that conflict with the builtin ones,
// but we want to allow them to override the default ones...
ManifestError(SR.Format(SR.EventSource_ChannelTypeDoesNotMatchEventChannelValue,
name, ((EventChannel)value).ToString()));
}
// TODO: validate there are no conflicting manifest exposed names (generally following the format "provider/type")
ulong kwd = GetChannelKeyword(chValue);
channelTab ??= new Dictionary<int, ChannelInfo>(4);
channelTab[value] = new ChannelInfo { Name = name, Keywords = kwd, Attribs = channelAttribute };
}
private static EventChannelType EventChannelToChannelType(EventChannel channel)
{
Debug.Assert(channel >= EventChannel.Admin && channel <= EventChannel.Debug);
return (EventChannelType)((int)channel - (int)EventChannel.Admin + (int)EventChannelType.Admin);
}
private static EventChannelAttribute GetDefaultChannelAttribute(EventChannel channel)
{
EventChannelAttribute attrib = new EventChannelAttribute();
attrib.EventChannelType = EventChannelToChannelType(channel);
if (attrib.EventChannelType <= EventChannelType.Operational)
attrib.Enabled = true;
return attrib;
}
public ulong[] GetChannelData()
{
if (this.channelTab == null)
{
return Array.Empty<ulong>();
}
// We create an array indexed by the channel id for fast look up.
// E.g. channelMask[Admin] will give you the bit mask for Admin channel.
int maxkey = -1;
foreach (int item in this.channelTab.Keys)
{
if (item > maxkey)
{
maxkey = item;
}
}
ulong[] channelMask = new ulong[maxkey + 1];
foreach (KeyValuePair<int, ChannelInfo> item in this.channelTab)
{
channelMask[item.Key] = item.Value.Keywords;
}
return channelMask;
}
public void StartEvent(string eventName, EventAttribute eventAttribute)
{
Debug.Assert(numParams == 0);
Debug.Assert(this.eventName == null);
this.eventName = eventName;
numParams = 0;
byteArrArgIndices = null;
events?.Append(" <event value=\"").Append(eventAttribute.EventId).
Append("\" version=\"").Append(eventAttribute.Version).
Append("\" level=\"");
AppendLevelName(events, eventAttribute.Level);
events?.Append("\" symbol=\"").Append(eventName).Append('"');
// at this point we add to the manifest's stringTab a message that is as-of-yet
// "untranslated to manifest convention", b/c we don't have the number or position
// of any byte[] args (which require string format index updates)
WriteMessageAttrib(events, "event", eventName, eventAttribute.Message);
if (eventAttribute.Keywords != 0)
{
events?.Append(" keywords=\"");
AppendKeywords(events, (ulong)eventAttribute.Keywords, eventName);
events?.Append('"');
}
if (eventAttribute.Opcode != 0)
{
string? str = GetOpcodeName(eventAttribute.Opcode, eventName);
events?.Append(" opcode=\"").Append(str).Append('"');
}
if (eventAttribute.Task != 0)
{
string? str = GetTaskName(eventAttribute.Task, eventName);
events?.Append(" task=\"").Append(str).Append('"');
}
if (eventAttribute.Channel != 0)
{
string? str = GetChannelName(eventAttribute.Channel, eventName, eventAttribute.Message);
events?.Append(" channel=\"").Append(str).Append('"');
}
}
public void AddEventParameter(Type type, string name)
{
if (numParams == 0)
templates?.Append(" <template tid=\"").Append(eventName).AppendLine("Args\">");
if (type == typeof(byte[]))
{
// mark this index as "extraneous" (it has no parallel in the managed signature)
// we use these values in TranslateToManifestConvention()
byteArrArgIndices ??= new List<int>(4);
byteArrArgIndices.Add(numParams);
// add an extra field to the template representing the length of the binary blob
numParams++;
templates?.Append(" <data name=\"").Append(name).AppendLine("Size\" inType=\"win:UInt32\"/>");
}
numParams++;
templates?.Append(" <data name=\"").Append(name).Append("\" inType=\"").Append(GetTypeName(type)).Append('"');
// TODO: for 'byte*' types it assumes the user provided length is named using the same naming convention
// as for 'byte[]' args (blob_arg_name + "Size")
if ((type.IsArray || type.IsPointer) && type.GetElementType() == typeof(byte))
{
// add "length" attribute to the "blob" field in the template (referencing the field added above)
templates?.Append(" length=\"").Append(name).Append("Size\"");
}
// ETW does not support 64-bit value maps, so we don't specify these as ETW maps
if (type.IsEnum && Enum.GetUnderlyingType(type) != typeof(ulong) && Enum.GetUnderlyingType(type) != typeof(long))
{
templates?.Append(" map=\"").Append(type.Name).Append('"');
mapsTab ??= new Dictionary<string, Type>();
mapsTab.TryAdd(type.Name, type); // Remember that we need to dump the type enumeration
}
templates?.AppendLine("/>");
}
public void EndEvent()
{
Debug.Assert(eventName != null);
if (numParams > 0)
{
templates?.AppendLine(" </template>");
events?.Append(" template=\"").Append(eventName).Append("Args\"");
}
events?.AppendLine("/>");
if (byteArrArgIndices != null)
perEventByteArrayArgIndices[eventName] = byteArrArgIndices;
// at this point we have all the information we need to translate the C# Message
// to the manifest string we'll put in the stringTab
string prefixedEventName = "event_" + eventName;
if (stringTab.TryGetValue(prefixedEventName, out string? msg))
{
msg = TranslateToManifestConvention(msg, eventName);
stringTab[prefixedEventName] = msg;
}
eventName = null;
numParams = 0;
byteArrArgIndices = null;
}
// Channel keywords are generated one per channel to allow channel based filtering in event viewer. These keywords are autogenerated
// by mc.exe for compiling a manifest and are based on the order of the channels (fields) in the Channels inner class (when advanced
// channel support is enabled), or based on the order the predefined channels appear in the EventAttribute properties (for simple
// support). The manifest generated *MUST* have the channels specified in the same order (that's how our computed keywords are mapped
// to channels by the OS infrastructure).
// If channelKeyworkds is present, and has keywords bits in the ValidPredefinedChannelKeywords then it is
// assumed that the keyword for that channel should be that bit.
// otherwise we allocate a channel bit for the channel.
// explicit channel bits are only used by WCF to mimic an existing manifest,
// so we don't dont do error checking.
public ulong GetChannelKeyword(EventChannel channel, ulong channelKeyword = 0)
{
// strip off any non-channel keywords, since we are only interested in channels here.
channelKeyword &= ValidPredefinedChannelKeywords;
channelTab ??= new Dictionary<int, ChannelInfo>(4);
if (channelTab.Count == MaxCountChannels)
ManifestError(SR.EventSource_MaxChannelExceeded);
if (!channelTab.TryGetValue((int)channel, out ChannelInfo? info))
{
// If we were not given an explicit channel, allocate one.
if (channelKeyword == 0)
{
channelKeyword = nextChannelKeywordBit;
nextChannelKeywordBit >>= 1;
}
}
else
{
channelKeyword = info.Keywords;
}
return channelKeyword;
}
public byte[] CreateManifest()
{
string str = CreateManifestString();
return (str != "") ? Encoding.UTF8.GetBytes(str) : Array.Empty<byte>();
}
public IList<string> Errors => errors;
public bool HasResources => resources != null;
/// <summary>
/// When validating an event source it adds the error to the error collection.
/// When not validating it throws an exception if runtimeCritical is "true".
/// Otherwise the error is ignored.
/// </summary>
/// <param name="msg"></param>
/// <param name="runtimeCritical"></param>
public void ManifestError(string msg, bool runtimeCritical = false)
{
if ((flags & EventManifestOptions.Strict) != 0)
errors.Add(msg);
else if (runtimeCritical)
throw new ArgumentException(msg);
}
private string CreateManifestString()
{
Span<char> ulongHexScratch = stackalloc char[16]; // long enough for ulong.MaxValue formatted as hex
// Write out the channels
if (channelTab != null)
{
sb?.AppendLine(" <channels>");
var sortedChannels = new List<KeyValuePair<int, ChannelInfo>>();
foreach (KeyValuePair<int, ChannelInfo> p in channelTab) { sortedChannels.Add(p); }
sortedChannels.Sort((p1, p2) => -Comparer<ulong>.Default.Compare(p1.Value.Keywords, p2.Value.Keywords));
foreach (KeyValuePair<int, ChannelInfo> kvpair in sortedChannels)
{
int channel = kvpair.Key;
ChannelInfo channelInfo = kvpair.Value;
string? channelType = null;
bool enabled = false;
string? fullName = null;
if (channelInfo.Attribs != null)
{
EventChannelAttribute attribs = channelInfo.Attribs;
if (Enum.IsDefined(attribs.EventChannelType))
channelType = attribs.EventChannelType.ToString();
enabled = attribs.Enabled;
}
fullName ??= providerName + "/" + channelInfo.Name;
sb?.Append(" <channel chid=\"").Append(channelInfo.Name).Append("\" name=\"").Append(fullName).Append('"');
Debug.Assert(channelInfo.Name != null);
WriteMessageAttrib(sb, "channel", channelInfo.Name, null);
sb?.Append(" value=\"").Append(channel).Append('"');
if (channelType != null)
sb?.Append(" type=\"").Append(channelType).Append('"');
sb?.Append(" enabled=\"").Append(enabled ? "true" : "false").AppendLine("\"/>");
}
sb?.AppendLine(" </channels>");
}
// Write out the tasks
if (taskTab != null)
{
sb?.AppendLine(" <tasks>");
var sortedTasks = new List<int>(taskTab.Keys);
sortedTasks.Sort();
foreach (int task in sortedTasks)
{
sb?.Append(" <task");
WriteNameAndMessageAttribs(sb, "task", taskTab[task]);
sb?.Append(" value=\"").Append(task).AppendLine("\"/>");
}
sb?.AppendLine(" </tasks>");
}
// Write out the maps
// Scoping the call to enum GetFields to a local function to limit the trimming suppressions
[UnconditionalSuppressMessage("ReflectionAnalysis", "IL2070:UnrecognizedReflectionPattern",
Justification = "Trimmer does not trim enums")]
static FieldInfo[] GetEnumFields(Type localEnumType)
{
Debug.Assert(localEnumType.IsEnum);
return localEnumType.GetFields(BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.Static);
}
if (mapsTab != null)
{
sb?.AppendLine(" <maps>");
foreach (Type enumType in mapsTab.Values)
{
bool isbitmap = EventSource.IsCustomAttributeDefinedHelper(enumType, typeof(FlagsAttribute), flags);
string mapKind = isbitmap ? "bitMap" : "valueMap";
sb?.Append(" <").Append(mapKind).Append(" name=\"").Append(enumType.Name).AppendLine("\">");
// write out each enum value
FieldInfo[] staticFields = GetEnumFields(enumType);
bool anyValuesWritten = false;
foreach (FieldInfo staticField in staticFields)
{
object? constantValObj = staticField.GetRawConstantValue();
if (constantValObj != null)
{
ulong hexValue;
if (constantValObj is ulong)
hexValue = (ulong)constantValObj; // This is the only integer type that can't be represented by a long.
else
hexValue = (ulong)Convert.ToInt64(constantValObj); // Handles all integer types except ulong.
// ETW requires all bitmap values to be powers of 2. Skip the ones that are not.
// TODO: Warn people about the dropping of values.
if (isbitmap && !BitOperations.IsPow2(hexValue))
continue;
hexValue.TryFormat(ulongHexScratch, out int charsWritten, "x");
Span<char> hexValueFormatted = ulongHexScratch.Slice(0, charsWritten);
sb?.Append(" <map value=\"0x").Append(hexValueFormatted).Append('"');
WriteMessageAttrib(sb, "map", enumType.Name + "." + staticField.Name, staticField.Name);
sb?.AppendLine("/>");
anyValuesWritten = true;
}
}
// the OS requires that bitmaps and valuemaps have at least one value or it reject the whole manifest.
// To avoid that put a 'None' entry if there are no other values.
if (!anyValuesWritten)
{
sb?.Append(" <map value=\"0x0\"");
WriteMessageAttrib(sb, "map", enumType.Name + ".None", "None");
sb?.AppendLine("/>");
}
sb?.Append(" </").Append(mapKind).AppendLine(">");
}
sb?.AppendLine(" </maps>");
}
// Write out the opcodes
sb?.AppendLine(" <opcodes>");
var sortedOpcodes = new List<int>(opcodeTab.Keys);
sortedOpcodes.Sort();
foreach (int opcode in sortedOpcodes)
{
sb?.Append(" <opcode");
WriteNameAndMessageAttribs(sb, "opcode", opcodeTab[opcode]);
sb?.Append(" value=\"").Append(opcode).AppendLine("\"/>");
}
sb?.AppendLine(" </opcodes>");
// Write out the keywords
if (keywordTab != null)
{
sb?.AppendLine(" <keywords>");
var sortedKeywords = new List<ulong>(keywordTab.Keys);
sortedKeywords.Sort();
foreach (ulong keyword in sortedKeywords)
{
sb?.Append(" <keyword");
WriteNameAndMessageAttribs(sb, "keyword", keywordTab[keyword]);
keyword.TryFormat(ulongHexScratch, out int charsWritten, "x");
Span<char> keywordFormatted = ulongHexScratch.Slice(0, charsWritten);
sb?.Append(" mask=\"0x").Append(keywordFormatted).AppendLine("\"/>");
}
sb?.AppendLine(" </keywords>");
}
sb?.AppendLine(" <events>");
sb?.Append(events);
sb?.AppendLine(" </events>");
sb?.AppendLine(" <templates>");
if (templates?.Length > 0)
{
sb?.Append(templates);
}
else
{
// Work around a corner-case ETW issue where a manifest with no templates causes
// ETW events to not get sent to their associated channel.
sb?.AppendLine(" <template tid=\"_empty\"></template>");
}
sb?.AppendLine(" </templates>");
sb?.AppendLine("</provider>");
sb?.AppendLine("</events>");
sb?.AppendLine("</instrumentation>");
// Output the localization information.
sb?.AppendLine("<localization>");
var sortedStrings = new string[stringTab.Keys.Count];
stringTab.Keys.CopyTo(sortedStrings, 0);
Array.Sort(sortedStrings, StringComparer.Ordinal);
CultureInfo ci = CultureInfo.CurrentUICulture;
sb?.Append(" <resources culture=\"").Append(ci.Name).AppendLine("\">");
sb?.AppendLine(" <stringTable>");
foreach (string stringKey in sortedStrings)
{
string? val = GetLocalizedMessage(stringKey, ci, etwFormat: true);
sb?.Append(" <string id=\"").Append(stringKey).Append("\" value=\"").Append(val).AppendLine("\"/>");
}
sb?.AppendLine(" </stringTable>");
sb?.AppendLine(" </resources>");
sb?.AppendLine("</localization>");
sb?.AppendLine("</instrumentationManifest>");
return sb?.ToString() ?? "";
}
#region private
private void WriteNameAndMessageAttribs(StringBuilder? stringBuilder, string elementName, string name)
{
stringBuilder?.Append(" name=\"").Append(name).Append('"');
WriteMessageAttrib(sb, elementName, name, name);
}
private void WriteMessageAttrib(StringBuilder? stringBuilder, string elementName, string name, string? value)
{
string? key = null;
// See if the user wants things localized.
if (resources != null)
{
// resource fallback: strings in the neutral culture will take precedence over inline strings
key = elementName + "_" + name;
if (resources.GetString(key, CultureInfo.InvariantCulture) is string localizedString)
value = localizedString;
}
if (value == null)
return;
key ??= elementName + "_" + name;
stringBuilder?.Append(" message=\"$(string.").Append(key).Append(")\"");
if (stringTab.TryGetValue(key, out string? prevValue) && !prevValue.Equals(value))
{
ManifestError(SR.Format(SR.EventSource_DuplicateStringKey, key), true);
return;
}
stringTab[key] = value;
}
internal string? GetLocalizedMessage(string key, CultureInfo ci, bool etwFormat)
{
string? value = null;
if (resources != null)
{
string? localizedString = resources.GetString(key, ci);
if (localizedString != null)
{
value = localizedString;
if (etwFormat && key.StartsWith("event_", StringComparison.Ordinal))
{
string evtName = key.Substring("event_".Length);
value = TranslateToManifestConvention(value, evtName);
}
}
}
if (etwFormat && value == null)
stringTab.TryGetValue(key, out value);
return value;
}
private static void AppendLevelName(StringBuilder? sb, EventLevel level)
{
if ((int)level < 16)
{
sb?.Append("win:");
}
sb?.Append(level switch // avoid boxing that comes from level.ToString()
{
EventLevel.LogAlways => nameof(EventLevel.LogAlways),
EventLevel.Critical => nameof(EventLevel.Critical),
EventLevel.Error => nameof(EventLevel.Error),
EventLevel.Warning => nameof(EventLevel.Warning),
EventLevel.Informational => nameof(EventLevel.Informational),
EventLevel.Verbose => nameof(EventLevel.Verbose),
_ => ((int)level).ToString()
});
}
private string? GetChannelName(EventChannel channel, string eventName, string? eventMessage)
{
if (channelTab == null || !channelTab.TryGetValue((int)channel, out ChannelInfo? info))
{
if (channel < EventChannel.Admin) // || channel > EventChannel.Debug)
ManifestError(SR.Format(SR.EventSource_UndefinedChannel, channel, eventName));
// allow channels to be auto-defined. The well known ones get their well known names, and the
// rest get names Channel<N>. This allows users to modify the Manifest if they want more advanced features.
channelTab ??= new Dictionary<int, ChannelInfo>(4);
string channelName = channel.ToString(); // For well know channels this is a nice name, otherwise a number
if (EventChannel.Debug < channel)
channelName = "Channel" + channelName; // Add a 'Channel' prefix for numbers.
AddChannel(channelName, (int)channel, GetDefaultChannelAttribute(channel));
if (!channelTab.TryGetValue((int)channel, out info))
ManifestError(SR.Format(SR.EventSource_UndefinedChannel, channel, eventName));
}
// events that specify admin channels *must* have non-null "Message" attributes
if (resources != null)
eventMessage ??= resources.GetString("event_" + eventName, CultureInfo.InvariantCulture);
Debug.Assert(info!.Attribs != null);
if (info.Attribs.EventChannelType == EventChannelType.Admin && eventMessage == null)
ManifestError(SR.Format(SR.EventSource_EventWithAdminChannelMustHaveMessage, eventName, info.Name));
return info.Name;
}
private string GetTaskName(EventTask task, string eventName)
{
if (task == EventTask.None)
return "";
taskTab ??= new Dictionary<int, string>();
if (!taskTab.TryGetValue((int)task, out string? ret))
ret = taskTab[(int)task] = eventName;
return ret;
}
private string? GetOpcodeName(EventOpcode opcode, string eventName)
{
switch (opcode)
{
case EventOpcode.Info:
return "win:Info";
case EventOpcode.Start:
return "win:Start";
case EventOpcode.Stop:
return "win:Stop";
case EventOpcode.DataCollectionStart:
return "win:DC_Start";
case EventOpcode.DataCollectionStop:
return "win:DC_Stop";
case EventOpcode.Extension:
return "win:Extension";
case EventOpcode.Reply:
return "win:Reply";
case EventOpcode.Resume:
return "win:Resume";
case EventOpcode.Suspend:
return "win:Suspend";
case EventOpcode.Send:
return "win:Send";
case EventOpcode.Receive:
return "win:Receive";
}
if (opcodeTab == null || !opcodeTab.TryGetValue((int)opcode, out string? ret))
{
ManifestError(SR.Format(SR.EventSource_UndefinedOpcode, opcode, eventName), true);
ret = null;
}
return ret;
}
private void AppendKeywords(StringBuilder? sb, ulong keywords, string eventName)
{
// ignore keywords associate with channels
// See ValidPredefinedChannelKeywords def for more.
keywords &= ~ValidPredefinedChannelKeywords;
bool appended = false;
for (ulong bit = 1; bit != 0; bit <<= 1)
{
if ((keywords & bit) != 0)
{
string? keyword = null;
if ((keywordTab == null || !keywordTab.TryGetValue(bit, out keyword)) &&
(bit >= (ulong)0x1000000000000))
{
// do not report Windows reserved keywords in the manifest (this allows the code
// to be resilient to potential renaming of these keywords)
keyword = string.Empty;
}
if (keyword == null)
{
ManifestError(SR.Format(SR.EventSource_UndefinedKeyword, "0x" + bit.ToString("x", CultureInfo.CurrentCulture), eventName), true);
keyword = string.Empty;
}
if (keyword.Length != 0)
{
if (appended)
{
sb?.Append(' ');
}
sb?.Append(keyword);
appended = true;
}
}
}
}
private string GetTypeName(Type type)
{
if (type.IsEnum)
{
string typeName = GetTypeName(type.GetEnumUnderlyingType());
return typeName switch // ETW requires enums to be unsigned.
{
"win:Int8" => "win:UInt8",
"win:Int16" => "win:UInt16",
"win:Int32" => "win:UInt32",
"win:Int64" => "win:UInt64",
_ => typeName,
};
}
switch (Type.GetTypeCode(type))
{
case TypeCode.Boolean:
return "win:Boolean";
case TypeCode.Byte:
return "win:UInt8";
case TypeCode.Char:
case TypeCode.UInt16:
return "win:UInt16";
case TypeCode.UInt32:
return "win:UInt32";
case TypeCode.UInt64:
return "win:UInt64";
case TypeCode.SByte:
return "win:Int8";
case TypeCode.Int16:
return "win:Int16";
case TypeCode.Int32:
return "win:Int32";
case TypeCode.Int64:
return "win:Int64";
case TypeCode.String:
return "win:UnicodeString";
case TypeCode.Single:
return "win:Float";
case TypeCode.Double:
return "win:Double";
case TypeCode.DateTime:
return "win:FILETIME";
default:
if (type == typeof(Guid))
return "win:GUID";
else if (type == typeof(IntPtr))
return "win:Pointer";
else if ((type.IsArray || type.IsPointer) && type.GetElementType() == typeof(byte))
return "win:Binary";
ManifestError(SR.Format(SR.EventSource_UnsupportedEventTypeInManifest, type.Name), true);
return string.Empty;
}
}
private static void UpdateStringBuilder([NotNull] ref StringBuilder? stringBuilder, string eventMessage, int startIndex, int count)
{
stringBuilder ??= new StringBuilder();
stringBuilder.Append(eventMessage, startIndex, count);
}
private static readonly string[] s_escapes = { "&", "<", ">", "'", """, "%r", "%n", "%t" };
// Manifest messages use %N conventions for their message substitutions. Translate from
// .NET conventions. We can't use RegEx for this (we are in mscorlib), so we do it 'by hand'
private string TranslateToManifestConvention(string eventMessage, string evtName)
{
StringBuilder? stringBuilder = null; // We lazily create this
int writtenSoFar = 0;
for (int i = 0; ;)
{
if (i >= eventMessage.Length)
{
if (stringBuilder == null)
return eventMessage;
UpdateStringBuilder(ref stringBuilder, eventMessage, writtenSoFar, i - writtenSoFar);
return stringBuilder.ToString();
}
int chIdx;
if (eventMessage[i] == '%')
{
// handle format message escaping character '%' by escaping it
UpdateStringBuilder(ref stringBuilder, eventMessage, writtenSoFar, i - writtenSoFar);
stringBuilder.Append("%%");
i++;
writtenSoFar = i;
}
else if (i < eventMessage.Length - 1 &&
(eventMessage[i] == '{' && eventMessage[i + 1] == '{' || eventMessage[i] == '}' && eventMessage[i + 1] == '}'))
{
// handle C# escaped '{" and '}'
UpdateStringBuilder(ref stringBuilder, eventMessage, writtenSoFar, i - writtenSoFar);
stringBuilder.Append(eventMessage[i]);
i++; i++;
writtenSoFar = i;
}
else if (eventMessage[i] == '{')
{
int leftBracket = i;
i++;
int argNum = 0;
while (i < eventMessage.Length && char.IsDigit(eventMessage[i]))
{
argNum = argNum * 10 + eventMessage[i] - '0';
i++;
}
if (i < eventMessage.Length && eventMessage[i] == '}')
{
i++;
UpdateStringBuilder(ref stringBuilder, eventMessage, writtenSoFar, leftBracket - writtenSoFar);
int manIndex = TranslateIndexToManifestConvention(argNum, evtName);
stringBuilder.Append('%').Append(manIndex);
// An '!' after the insert specifier {n} will be interpreted as a literal.
// We'll escape it so that mc.exe does not attempt to consider it the
// beginning of a format string.
if (i < eventMessage.Length && eventMessage[i] == '!')
{
i++;
stringBuilder.Append("%!");
}
writtenSoFar = i;
}
else
{
ManifestError(SR.Format(SR.EventSource_UnsupportedMessageProperty, evtName, eventMessage));
}
}
else if ((chIdx = "&<>'\"\r\n\t".IndexOf(eventMessage[i])) >= 0)
{
UpdateStringBuilder(ref stringBuilder, eventMessage, writtenSoFar, i - writtenSoFar);
i++;
stringBuilder.Append(s_escapes[chIdx]);
writtenSoFar = i;
}
else
i++;
}
}
private int TranslateIndexToManifestConvention(int idx, string evtName)
{
if (perEventByteArrayArgIndices.TryGetValue(evtName, out List<int>? byteArrArgIndices))
{
foreach (int byArrIdx in byteArrArgIndices)
{
if (idx >= byArrIdx)
++idx;
else
break;
}
}
return idx + 1;
}
private sealed class ChannelInfo
{
public string? Name;
public ulong Keywords;
public EventChannelAttribute? Attribs;
}
private readonly Dictionary<int, string> opcodeTab;
private Dictionary<int, string>? taskTab;
private Dictionary<int, ChannelInfo>? channelTab;
private Dictionary<ulong, string>? keywordTab;
private Dictionary<string, Type>? mapsTab;
private readonly Dictionary<string, string> stringTab; // Maps unlocalized strings to localized ones
// WCF used EventSource to mimic a existing ETW manifest. To support this
// in just their case, we allowed them to specify the keywords associated
// with their channels explicitly. ValidPredefinedChannelKeywords is
// this set of channel keywords that we allow to be explicitly set. You
// can ignore these bits otherwise.
internal const ulong ValidPredefinedChannelKeywords = 0xF000000000000000;
private ulong nextChannelKeywordBit = 0x8000000000000000; // available Keyword bit to be used for next channel definition, grows down
private const int MaxCountChannels = 8; // a manifest can defined at most 8 ETW channels
private readonly StringBuilder? sb; // Holds the provider information.
private readonly StringBuilder? events; // Holds the events.
private readonly StringBuilder? templates;
private readonly string providerName;
private readonly ResourceManager? resources; // Look up localized strings here.
private readonly EventManifestOptions flags;
private readonly List<string> errors; // list of currently encountered errors
private readonly Dictionary<string, List<int>> perEventByteArrayArgIndices; // "event_name" -> List_of_Indices_of_Byte[]_Arg
// State we track between StartEvent and EndEvent.
private string? eventName; // Name of the event currently being processed.
private int numParams; // keeps track of the number of args the event has.
private List<int>? byteArrArgIndices; // keeps track of the index of each byte[] argument
#endregion
}
/// <summary>
/// Used to send the m_rawManifest into the event dispatcher as a series of events.
/// </summary>
internal struct ManifestEnvelope
{
public const int MaxChunkSize = 0xF700;
public enum ManifestFormats : byte
{
SimpleXmlFormat = 1, // simply dump the XML manifest as UTF8
}
public ManifestFormats Format;
public byte MajorVersion;
public byte MinorVersion;
public byte Magic;
public ushort TotalChunks;
public ushort ChunkNumber;
}
#endregion
}
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