.NET runtime loader and binder events

Article
09/15/2021

The events described in this article collect information relating to loading and unloading assemblies and modules. For more information about how to use these events for diagnostic purposes, see logging and tracing .NET applications

Keyword for raising the event	Event	Level
`LoaderKeyword` (0x8)	`DomainModuleLoad_V1`	Informational (4)

Event	Event ID	Description
`DomainModuleLoad_V1`	151	Raised when a module is loaded for an application domain.

ModuleLoad_V2 event

Keyword for raising the event	Event	Level
`LoaderKeyword` (0x8)	`DomainModuleLoad_V1`	Informational (4)

Event	Event ID	Description
`ModuleLoad_V2`	152	Raised when a module is loaded during the lifetime of a process.

Field name	Data type	Description
`ModuleID`	`win:UInt64`	Unique ID for the module.
`AssemblyID`	`win:UInt64`	ID of the assembly in which this module resides.
`ModuleFlags`	`win:UInt32`	0x1: Domain neutral module. 0x2: Module has a native image. 0x4: Dynamic module. 0x8: Manifest module.
`Reserved1`	`win:UInt32`	Reserved field.
`ModuleILPath`	`win:UnicodeString`	Path of the Common Intermediate Language (CIL) image for the module, or dynamic module name if it is a dynamic assembly (null-terminated).
`ModuleNativePath`	`win:UnicodeString`	Path of the module native image, if present (null-terminated).
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CLR or CoreCLR.
`ManagedPdbSignature`	`win:GUID`	GUID signature of the managed program database (PDB) that matches this module.
`ManagedPdbAge`	`win:UInt32`	Age number written to the managed PDB that matches this module.
`ManagedPdbBuildPath`	`win:UnicodeString`	Path to the location where the managed PDB that matches this module was built. In some cases, this may just be a file name.
`NativePdbSignature`	`win:GUID`	GUID signature of the Native Image Generator (NGen) PDB that matches this module, if applicable.
`NativePdbAge`	`win:UInt32`	Age number written to the NGen PDB that matches this module, if applicable.
`NativePdbBuildPath`	`win:UnicodeString`	Path to the location where the NGen PDB that matches this module was built, if applicable. In some cases, this may just be a file name.

ModuleUnload_V2 event

Keyword for raising the event	Event	Level
`LoaderKeyword` (0x8)	`DomainModuleLoad_V1`	Informational (4)

Event	Event ID	Description
`ModuleUnload_V2`	153	Raised when a module is unloaded during the lifetime of a process.

Field name	Data type	Description
`ModuleID`	`win:UInt64`	Unique ID for the module.
`AssemblyID`	`win:UInt64`	ID of the assembly in which this module resides.
`ModuleFlags`	`win:UInt32`	0x1: Domain neutral module. 0x2: Module has a native image. 0x4: Dynamic module. 0x8: Manifest module.
`Reserved1`	`win:UInt32`	Reserved field.
`ModuleILPath`	`win:UnicodeString`	Path of the Common Intermediate Language (CIL) image for the module, or dynamic module name if it is a dynamic assembly (null-terminated).
`ModuleNativePath`	`win:UnicodeString`	Path of the module native image, if present (null-terminated).
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CLR or CoreCLR.
`ManagedPdbSignature`	`win:GUID`	GUID signature of the managed program database (PDB) that matches this module.
`ManagedPdbAge`	`win:UInt32`	Age number written to the managed PDB that matches this module.
`ManagedPdbBuildPath`	`win:UnicodeString`	Path to the location where the managed PDB that matches this module was built. In some cases, this may just be a file name.
`NativePdbSignature`	`win:GUID`	GUID signature of the Native Image Generator (NGen) PDB that matches this module, if applicable.
`NativePdbAge`	`win:UInt32`	Age number written to the NGen PDB that matches this module, if applicable.
`NativePdbBuildPath`	`win:UnicodeString`	Path to the location where the NGen PDB that matches this module was built, if applicable. In some cases, this may just be a file name.

ModuleDCStart_V2 event

Keyword for raising the event	Event	Level
`LoaderKeyword` (0x8)	`DomainModuleLoad_V1`	Informational (4)

Event	Event ID	Description
`ModuleDCStart_V2`	153	Enumerates modules during a start rundown.

Field name	Data type	Description
`ModuleID`	`win:UInt64`	Unique ID for the module.
`AssemblyID`	`win:UInt64`	ID of the assembly in which this module resides.
`ModuleFlags`	`win:UInt32`	0x1: Domain neutral module. 0x2: Module has a native image. 0x4: Dynamic module. 0x8: Manifest module.
`Reserved1`	`win:UInt32`	Reserved field.
`ModuleILPath`	`win:UnicodeString`	Path of the Common Intermediate Language (CIL) image for the module, or dynamic module name if it is a dynamic assembly (null-terminated).
`ModuleNativePath`	`win:UnicodeString`	Path of the module native image, if present (null-terminated).
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CLR or CoreCLR.
`ManagedPdbSignature`	`win:GUID`	GUID signature of the managed program database (PDB) that matches this module.
`ManagedPdbAge`	`win:UInt32`	Age number written to the managed PDB that matches this module.
`ManagedPdbBuildPath`	`win:UnicodeString`	Path to the location where the managed PDB that matches this module was built. In some cases, this may just be a file name.
`NativePdbSignature`	`win:GUID`	GUID signature of the Native Image Generator (NGen) PDB that matches this module, if applicable.
`NativePdbAge`	`win:UInt32`	Age number written to the NGen PDB that matches this module, if applicable.
`NativePdbBuildPath`	`win:UnicodeString`	Path to the location where the NGen PDB that matches this module was built, if applicable. In some cases, this may just be a file name.

ModuleDCEnd_V2 event

Keyword for raising the event	Event	Level
`LoaderKeyword` (0x8)	`DomainModuleLoad_V1`	Informational (4)

Event	Event ID	Description
`ModuleDCEnd_V2`	154	Enumerates modules during an end rundown.

Field name	Data type	Description
`ModuleID`	`win:UInt64`	Unique ID for the module.
`AssemblyID`	`win:UInt64`	ID of the assembly in which this module resides.
`ModuleFlags`	`win:UInt32`	0x1: Domain neutral module. 0x2: Module has a native image. 0x4: Dynamic module. 0x8: Manifest module.
`Reserved1`	`win:UInt32`	Reserved field.
`ModuleILPath`	`win:UnicodeString`	Path of the Common Intermediate Language (CIL) image for the module, or dynamic module name if it is a dynamic assembly (null-terminated).
`ModuleNativePath`	`win:UnicodeString`	Path of the module native image, if present (null-terminated).
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CLR or CoreCLR.
`ManagedPdbSignature`	`win:GUID`	GUID signature of the managed program database (PDB) that matches this module.
`ManagedPdbAge`	`win:UInt32`	Age number written to the managed PDB that matches this module.
`ManagedPdbBuildPath`	`win:UnicodeString`	Path to the location where the managed PDB that matches this module was built. In some cases, this may just be a file name.
`NativePdbSignature`	`win:GUID`	GUID signature of the Native Image Generator (NGen) PDB that matches this module, if applicable.
`NativePdbAge`	`win:UInt32`	Age number written to the NGen PDB that matches this module, if applicable.
`NativePdbBuildPath`	`win:UnicodeString`	Path to the location where the NGen PDB that matches this module was built, if applicable. In some cases, this may just be a file name.

AssemblyLoad_V1 event

Keyword for raising the event	Event	Level
`LoaderKeyword` (0x8)	`DomainModuleLoad_V1`	Informational (4)

Event	Event ID	Description
`AssemblyLoad_V1`	154	Raised when an assembly is loaded.

Field name	Data type	Description
`AssemblyID`	`win:UInt64`	Unique ID for the assembly.
`AppDomainID`	`win:UInt64`	ID of the domain of this assembly.
`BindingID`	`win:UInt64`	ID that uniquely identifies the assembly binding.
`AssemblyFlags`	`win:UInt32`	0x1: Domain neutral assembly. 0x2: Dynamic assembly. 0x4: Assembly has a native image. 0x8: Collectible assembly.
`AssemblyName`	`win:UnicodeString`	Fully qualified assembly name.
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CoreCLR.

AssemblyUnload_V1 event

Keyword for raising the event	Event	Level
`LoaderKeyword` (0x8)	`DomainModuleLoad_V1`	Informational (4)

Event	Event ID	Description
`FireAssemblyUnload_V1`	155	Raised when an assembly is loaded.

Field name	Data type	Description
`AssemblyID`	`win:UInt64`	Unique ID for the assembly.
`AppDomainID`	`win:UInt64`	ID of the domain of this assembly.
`BindingID`	`win:UInt64`	ID that uniquely identifies the assembly binding.
`AssemblyFlags`	`win:UInt32`	0x1: Domain neutral assembly. 0x2: Dynamic assembly. 0x4: Assembly has a native image. 0x8: Collectible assembly.
`AssemblyName`	`win:UnicodeString`	Fully qualified assembly name.
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CoreCLR.

AssemblyDCStart_V1 event

Keyword for raising the event	Event	Level
`LoaderKeyword` (0x8)	`DomainModuleLoad_V1`	Informational (4)

Event	Event ID	Description
`AssemblyDCStart_V1`	155	Enumerates assemblies during a start rundown.

Field name	Data type	Description
`AssemblyID`	`win:UInt64`	Unique ID for the assembly.
`AppDomainID`	`win:UInt64`	ID of the domain of this assembly.
`BindingID`	`win:UInt64`	ID that uniquely identifies the assembly binding.
`AssemblyFlags`	`win:UInt32`	0x1: Domain neutral assembly. 0x2: Dynamic assembly. 0x4: Assembly has a native image. 0x8: Collectible assembly.
`AssemblyName`	`win:UnicodeString`	Fully qualified assembly name.
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CoreCLR.

AssemblyLoadStart event

Keyword for raising the event	Event	Level
`Binder` (0x4)	`AssemblyLoadStart`	Informational (4)

Event	Event ID	Description
`AssemblyLoadStart`	290	An assembly load has been requested.

Field name	Data type	Description
`AssemblyName`	`win:UnicodeString`	Name of assembly name.
`AssemblyPath`	`win:UnicodeString`	Path of assembly name.
`RequestingAssembly`	`win:UnicodeString`	Name of the requesting ("parent") assembly.
`AssemblyLoadContext`	`win:UnicodeString`	Load context of the assembly.
`RequestingAssemblyLoadContext`	`win:UnicodeString`	Load context of the requesting ("parent") assembly.
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CoreCLR.

AssemblyLoadStop event

Keyword for raising the event	Event	Level
`Binder` (0x4)	`AssemblyLoadStart`	Informational (4)

Event	Event ID	Description
`AssemblyLoadStart`	291	An assembly load has been requested.

Field name	Data type	Description
`AssemblyName`	`win:UnicodeString`	Name of assembly name.
`AssemblyPath`	`win:UnicodeString`	Path of assembly name.
`RequestingAssembly`	`win:UnicodeString`	Name of the requesting ("parent") assembly.
`AssemblyLoadContext`	`win:UnicodeString`	Load context of the assembly.
`RequestingAssemblyLoadContext`	`win:UnicodeString`	Load context of the requesting ("parent") assembly.
`Success`	`win:Boolean`	Whether the assembly load succeeded.
`ResultAssemblyName`	`win:UnicodeString`	The name of assembly that was loaded.
`ResultAssemblyPath`	`win:UnicodeString`	The path of the assembly that was loaded from.
`Cached`	`win:UnicodeString`	Whether the load was cached.
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CoreCLR.

ResolutionAttempted event

Keyword for raising the event	Level
`Binder` (0x4)	Informational (4)

Event	Event ID	Description
`ResolutionAttempted`	292	An assembly load has been requested.

Field name	Data type	Description
`AssemblyName`	`win:UnicodeString`	Name of assembly name.
`Stage`	`win:UInt16`	The resolution stage. 0: Find in load. 1: Assembly Load Context 2: Application assemblies. 3: Default assembly load context fallback. 4: Resolve satellite assembly. 5: Assembly load context resolving. 6: AppDomain assembly resolving.
`AssemblyLoadContext`	`win:UnicodeString`	Load context of the assembly.
`Result`	`win:UInt16`	The result of resolution attempt. 0: Success 1: Assembly NotFound 2: Incompatible Version 3: Mismatched Assembly Name 4: Failure 5: Exception
`ResultAssemblyName`	`win:UnicodeString`	The name of assembly that was resolved.
`ResultAssemblyPath`	`win:UnicodeString`	The path of the assembly that was resolved from.
`ErrorMessage`	`win:UnicodeString`	Error message if there is an exception.
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CoreCLR.

AssemblyLoadContextResolvingHandlerInvoked event

Keyword for raising the event	Level
`Binder` (0x4)	Informational (4)

Event	Event ID	Description
`AssemblyLoadContextResolvingHandlerInvoked`	293	An AssemblyLoadContext.Resolving handler has been invoked.

Field name	Data type	Description
`AssemblyName`	`win:UnicodeString`	Name of assembly name.
`HandlerName`	`win:UnicodeString`	Name of the handler invoked.
`AssemblyLoadContext`	`win:UnicodeString`	Load context of the assembly.
`ResultAssemblyName`	`win:UnicodeString`	The name of assembly that was resolved.
`ResultAssemblyPath`	`win:UnicodeString`	The path of the assembly that was resolved from.
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CoreCLR.

AppDomainAssemblyResolveHandlerInvoked event

Keyword for raising the event	Level
`Binder` (0x4)	Informational (4)

Event	Event ID	Description
`AppDomainAssemblyResolveHandlerInvoked`	294	An AppDomain.AssemblyResolve handler has been invoked.

Field name	Data type	Description
`AssemblyName`	`win:UnicodeString`	Name of assembly name.
`HandlerName`	`win:UnicodeString`	Name of the handler invoked.
`ResultAssemblyName`	`win:UnicodeString`	The name of assembly that was resolved.
`ResultAssemblyPath`	`win:UnicodeString`	The path of the assembly that was resolved from.
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CoreCLR.

AssemblyLoadFromResolveHandlerInvoked event

Keyword for raising the event	Level
`Binder` (0x4)	Informational (4)

Event	Event ID	Description
`AssemblyLoadFromResolveHandlerInvoked`	295	An Assembly.LoadFrom handler has been invoked.

Field name	Data type	Description
`AssemblyName`	`win:UnicodeString`	Name of assembly name.
`IsTrackedLoad`	`win:Boolean`	Whether the assembly load is tracked.
`RequestingAssemblyPath`	`win:UnicodeString`	The path of the requesting assembly.
`ComputedRequestedAssemblyPath`	`win:UnicodeString`	The path of the assembly that was requested.
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CoreCLR.

KnownPathProbed event

Keyword for raising the event	Level
`Binder` (0x4)	Informational (4)

Event	Event ID	Description
`KnownPathProbed`	296	A known path was probed for an assembly.

Field Name	Data Type	Description
`FilePath`	`win:UnicodeString`	Path probed.
`Source`	`win:UInt16`	Source of the path probed. 0x0:Application Assemblies. 0x1:App native image path. 0x2:App path. 0x3:Platform resource roots. 0x4:Satellite Subdirectory.
`Result`	`win:UInt32`	HRESULT for the probe.
`ClrInstanceID`	`win:UInt16`	Unique ID for the instance of CoreCLR.

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