[NativeAOT] GC events don't get logged on Linux

[elinor-fung]

The event firing in Native AOT is under a mix of FEATURE_EVENT_TRACE and FEATURE_ETW.

Some things don't even attempt to fire:

runtime/src/coreclr/nativeaot/Runtime/gctoclreventsink.cpp

Lines 30 to 37 in eb65022

	#ifdef FEATURE_ETW
	ETW::GCLog::ETW_GC_INFO gcStartInfo;
	gcStartInfo.GCStart.Count = count;
	gcStartInfo.GCStart.Depth = depth;
	gcStartInfo.GCStart.Reason = static_cast<ETW::GCLog::ETW_GC_INFO::GC_REASON>(reason);
	gcStartInfo.GCStart.Type = static_cast<ETW::GCLog::ETW_GC_INFO::GC_TYPE>(type);
	ETW::GCLog::FireGcStart(&gcStartInfo);
	#endif // FEATURE_ETW

Implementation of ETW::GCLog is in eventtrace.cpp, which is only included on Windows:

runtime/src/coreclr/nativeaot/Runtime/CMakeLists.txt

Lines 110 to 115 in c32bee1

	list(APPEND COMMON_RUNTIME_SOURCES
	windows/PalRedhawkCommon.cpp
	windows/PalRedhawkMinWin.cpp
	${GC_DIR}/windows/gcenv.windows.cpp
	eventtrace.cpp
	rheventtrace.cpp

(There's a bunch of stuff in there, so it's not quite as simple as including it on non-Windows)

Related (but more involved than): #87325

cc @LakshanF

Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas
See info in area-owners.md if you want to be subscribed.

Issue Details

---

The event firing in Native AOT is under a mix of FEATURE_EVENT_TRACE and FEATURE_ETW.

Some things don't even attempt to fire:

runtime/src/coreclr/nativeaot/Runtime/gctoclreventsink.cpp

Lines 30 to 37 in eb65022

	#ifdef FEATURE_ETW
	ETW::GCLog::ETW_GC_INFO gcStartInfo;
	gcStartInfo.GCStart.Count = count;
	gcStartInfo.GCStart.Depth = depth;
	gcStartInfo.GCStart.Reason = static_cast<ETW::GCLog::ETW_GC_INFO::GC_REASON>(reason);
	gcStartInfo.GCStart.Type = static_cast<ETW::GCLog::ETW_GC_INFO::GC_TYPE>(type);
	ETW::GCLog::FireGcStart(&gcStartInfo);
	#endif // FEATURE_ETW

Implementation of ETW::GCLog is in eventtrace.cpp, which is only included on Windows:

runtime/src/coreclr/nativeaot/Runtime/CMakeLists.txt

Lines 110 to 115 in c32bee1

	list(APPEND COMMON_RUNTIME_SOURCES
	windows/PalRedhawkCommon.cpp
	windows/PalRedhawkMinWin.cpp
	${GC_DIR}/windows/gcenv.windows.cpp
	eventtrace.cpp
	rheventtrace.cpp

(There's a bunch of stuff in there, so it's not quite as simple as including it on non-Windows)

Related (but more involved than): #87325

cc @LakshanF

Author:	elinor-fung
Assignees:	-
Labels:	area-NativeAOT-coreclr
Milestone:	-

[elinor-fung]

(There's a bunch of stuff in there, so it's not quite as simple as including it on non-Windows)

More details - the tracking of whether the runtime provider is enabled for ETW vs event pipe is happening/stored in different places.

Event pipe is tracked in MICROSOFT_WINDOWS_DOTNETRUNTIME_PROVIDER_DOTNET_Context

runtime/src/coreclr/nativeaot/Runtime/eventpipe/dotnetruntime.cpp

Line 1890 in 39bbff8

DOTNET_TRACE_CONTEXT MICROSOFT_WINDOWS_DOTNETRUNTIME_PROVIDER_DOTNET_Context;

And updated in EtwCallbackCommon (called by EventPipeEtwCallbackDotNETRuntime, isn't registered as an ETW callback):

runtime/src/coreclr/nativeaot/Runtime/eventpipe/dotnetruntime.cpp

Lines 1924 to 1926 in 39bbff8

	ctxToUpdate->EventPipeProvider.Level = Level;
	ctxToUpdate->EventPipeProvider.EnabledKeywordsBitmask = MatchAnyKeyword;
	ctxToUpdate->EventPipeProvider.IsEnabled = ControlCode;

ETW is tracked in MICROSOFT_WINDOWS_NATIVEAOT_GC_PUBLIC_PROVIDER_Context:

runtime/src/coreclr/nativeaot/Runtime/gcrhenv.cpp

Lines 154 to 164 in 39bbff8

	#ifdef FEATURE_ETW
	MICROSOFT_WINDOWS_NATIVEAOT_GC_PRIVATE_PROVIDER_Context.IsEnabled = FALSE;
	MICROSOFT_WINDOWS_NATIVEAOT_GC_PUBLIC_PROVIDER_Context.IsEnabled = FALSE;
	// Register the Redhawk event provider with the system.
	RH_ETW_REGISTER_Microsoft_Windows_Redhawk_GC_Private();
	RH_ETW_REGISTER_Microsoft_Windows_Redhawk_GC_Public();
	MICROSOFT_WINDOWS_NATIVEAOT_GC_PRIVATE_PROVIDER_Context.RegistrationHandle = Microsoft_Windows_Redhawk_GC_PrivateHandle;
	MICROSOFT_WINDOWS_NATIVEAOT_GC_PUBLIC_PROVIDER_Context.RegistrationHandle = Microsoft_Windows_Redhawk_GC_PublicHandle;
	#endif // FEATURE_ETW

And updated in RhEtwControlCallback:

runtime/src/coreclr/nativeaot/Runtime/EtwEvents.h

Lines 42 to 53 in 39bbff8

	RhEtwControlCallback(GUID * /*SourceId*/, uint32_t IsEnabled, uint8_t Level, uint64_t MatchAnyKeyword, uint64_t MatchAllKeyword, EVENT_FILTER_DESCRIPTOR * FilterData, void * CallbackContext)
	{
	RH_ETW_CONTEXT * Ctx = (RH_ETW_CONTEXT*)CallbackContext;
	if (Ctx == NULL)
	return;
	Ctx->Level = Level;
	Ctx->MatchAnyKeyword = MatchAnyKeyword;
	Ctx->MatchAllKeyword = MatchAllKeyword;
	Ctx->FilterData = FilterData;
	Ctx->IsEnabled = IsEnabled;
	EtwCallback(IsEnabled, (RH_ETW_CONTEXT*)CallbackContext);
	}

The ETW::GCLog implementations use macros that are ETW-specific:

runtime/src/coreclr/nativeaot/Runtime/rheventtrace.h

Lines 18 to 21 in 39bbff8

	// Map the CLR private provider to our version so we can avoid inserting more #ifdef's in the code.
	#define MICROSOFT_WINDOWS_DOTNETRUNTIME_PRIVATE_PROVIDER_Context MICROSOFT_WINDOWS_NATIVEAOT_GC_PRIVATE_PROVIDER_Context
	#define MICROSOFT_WINDOWS_DOTNETRUNTIME_PROVIDER_Context MICROSOFT_WINDOWS_NATIVEAOT_GC_PUBLIC_PROVIDER_Context
	#define Microsoft_Windows_DotNETRuntimeHandle Microsoft_Windows_Redhawk_GC_PublicHandle

runtime/src/coreclr/nativeaot/Runtime/eventtracebase.h

Lines 106 to 107 in 39bbff8

	#define ETW_TRACING_CATEGORY_ENABLED(Context, Level, Keyword) \
	(ETW_TRACING_INITIALIZED(Context.RegistrationHandle) && ETW_CATEGORY_ENABLED(Context, Level, Keyword))

Implementation of GCLog::FireGcStart also checks EventPipeAdapter_Enabled() - but the other defines still only exist under FEATURE_ETW right now. The event pipe enabled check does also mean that it is doing the added work as long as event pipe is enabled, regardless of whether the actual provider and keyword are enabled.

runtime/src/coreclr/nativeaot/Runtime/eventtrace.cpp

Lines 902 to 905 in 39bbff8

	if (EventPipeAdapter_Enabled() || ETW_TRACING_CATEGORY_ENABLED(
	MICROSOFT_WINDOWS_DOTNETRUNTIME_PROVIDER_Context,
	TRACE_LEVEL_INFORMATION,
	CLR_GC_KEYWORD))