[wasi] Enable EventPipe (FEATURE_PERFTRACING) for CoreCLR WASI

eng/native.wasm.targets

@@ -82,13 +82,13 @@
   </ItemGroup>
   <ItemGroup Condition="'$(TargetsWasi)' == 'true' and '$(RuntimeFlavor)' == 'CoreCLR'">
       <NativeCMakeArg Include="-cmakeargs &quot;-DGEN_PINVOKE=1&quot;" />
-      <!-- Initial WASI bring-up disables EventPipe / diagnostic-server PAL
-           via FEATURE_PERFTRACING=0 in src/coreclr/CMakeLists.txt; the
-           PERFTRACING_DISABLE_* flags are unused while PERFTRACING is off
-           but kept for symmetry with browser-CoreCLR and for when we
-           re-enable PERFTRACING in a follow-up. -->
+      <!-- WASI has no AF_UNIX sockets, so build the TCP flavor of the diagnostic
+           server PAL. Listen and connect ports stay disabled until a WASI
+           transport is validated; EventPipe works in-process only. -->
+      <NativeCMakeArg Include="-cmakeargs &quot;-DFEATURE_PERFTRACING_PAL_TCP=1&quot;" />
       <NativeCMakeArg Include="-cmakeargs &quot;-DFEATURE_PERFTRACING_DISABLE_PERFTRACING_LISTEN_PORTS=1&quot;" />
       <NativeCMakeArg Include="-cmakeargs &quot;-DFEATURE_PERFTRACING_DISABLE_DEFAULT_LISTEN_PORT=1&quot;" />
+      <NativeCMakeArg Include="-cmakeargs &quot;-DFEATURE_PERFTRACING_DISABLE_CONNECT_PORTS=1&quot;" />
   </ItemGroup>
   <ItemGroup Condition="'$(FeatureMultithreading)' != 'true'">
       <NativeCMakeArg Include="-cmakeargs &quot;-DFEATURE_PERFTRACING_DISABLE_THREADS=1&quot;" />

src/coreclr/CMakeLists.txt

@@ -39,10 +39,6 @@ if(CLR_CMAKE_TARGET_WASI)
   add_compile_definitions(_WASI_EMULATED_PROCESS_CLOCKS)
   add_compile_definitions(_WASI_EMULATED_MMAN)
   add_compile_definitions(_WASI_EMULATED_GETPID)
-  # EventPipe / diag-server PAL require sockets we have not validated
-  # for the WASI bring-up; revisit once corerun.wasm runs.
-  set(FEATURE_EVENT_TRACE 0)
-  set(FEATURE_PERFTRACING 0)
   include_directories(BEFORE SYSTEM ${CMAKE_CURRENT_SOURCE_DIR}/pal/src/include/pal/wasi)
   # Cross-compile try_run() answers — wasm32 binaries cannot execute on
   # the build host, so pre-seed the cache.

src/coreclr/clr.featuredefines.props

@@ -32,18 +32,6 @@
         <FeaturePortableThreadPool Condition="'$(WasmEnableThreads)' != 'true'">false</FeaturePortableThreadPool>
     </PropertyGroup>
 
-    <PropertyGroup Condition="'$(TargetsWasi)' == 'true'">
-        <!-- Match the WASI native build (src/coreclr/CMakeLists.txt sets
-             FEATURE_PERFTRACING=0 for CLR_CMAKE_TARGET_WASI). Keeping
-             FEATURE_PERFTRACING on in managed CoreLib while the native
-             side has it off causes EventPipeInternal QCalls (e.g.
-             EventPipeInternal_CreateProvider) to resolve to NULL at
-             runtime; any EventSource activation (e.g. ArrayPoolEventSource
-             via DefaultInterpolatedStringHandler) then traps on a NULL
-             function pointer. -->
-        <FeaturePerfTracing>false</FeaturePerfTracing>
-    </PropertyGroup>
-
     <PropertyGroup Condition="'$(TargetsUnix)' == 'true'">
         <FeatureXplatEventSource Condition="'$(FeatureXplatEventSource)' == '' AND '$(TargetOS)' == 'linux'">true</FeatureXplatEventSource>
         <FeatureComWrappers>true</FeatureComWrappers>

src/coreclr/debug/debug-pal/CMakeLists.txt

@@ -27,12 +27,7 @@ if(CLR_CMAKE_HOST_WIN32)
 endif(CLR_CMAKE_HOST_WIN32)
 
 if(CLR_CMAKE_HOST_UNIX)
-    if (NOT CLR_CMAKE_TARGET_WASI)
-        # ds-ipc-pal-socket.c needs UNIX/TCP sockets; re-enable once
-        # WASI PERFTRACING is wired. Tracked by https://github.com/dotnet/runtime/issues/130383
-
-        set(DEBUG_PAL_REFEREENCE_DIAGNOSTICSERVER ON)
-    endif()
+    set(DEBUG_PAL_REFEREENCE_DIAGNOSTICSERVER ON)
 
     add_definitions(-DPAL_IMPLEMENTATION)
     add_definitions(-D_POSIX_C_SOURCE=200809L)

src/coreclr/vm/eventing/eventpipe/ep-rt-coreclr.cpp

@@ -197,4 +197,63 @@ ep_rt_coreclr_session_stopping (void)
 #endif // FEATURE_PGO && PERFTRACING_DISABLE_THREADS
 }
 
+#if defined(TARGET_WASI) && defined(PERFTRACING_DISABLE_THREADS)
+// WASI has no host event loop to schedule EventPipe jobs (session streaming, diagnostic server) on,
+// so they are kept on this list and run by the managed WasiEventLoop (WasiEventPipeJobs.cs).
+// A job returns non-zero when it is done; otherwise it stays queued and runs again on the next pump.
+// Single-threaded by construction, so no locking.
+struct WasiEventPipeJob
+{
+	size_t (*Callback)(void *data);
+	void *Data;
+	WasiEventPipeJob *Next;
+};
+
+static WasiEventPipeJob *s_wasiJobsHead = nullptr;
+static WasiEventPipeJob *s_wasiJobsTail = nullptr;
+
+static void WasiAppendJob(WasiEventPipeJob *job)
+{
+	job->Next = nullptr;
+	if (s_wasiJobsTail != nullptr)
+		s_wasiJobsTail->Next = job;
+	else
+		s_wasiJobsHead = job;
+	s_wasiJobsTail = job;
+}
+
+bool ep_rt_coreclr_wasi_queue_job (size_t (*cb)(void *data), void *data)
+{
+	_ASSERTE (cb != nullptr);
+	WasiEventPipeJob *job = new (nothrow) WasiEventPipeJob();
+	if (job == nullptr)
+		return false;
+
+	job->Callback = cb;
+	job->Data = data;
+	WasiAppendJob (job);
+	return true;
+}
+
+bool ep_rt_coreclr_wasi_run_jobs (void)
+{
+	// Detach the current list so jobs queued while running are picked up on the next pump.
+	WasiEventPipeJob *job = s_wasiJobsHead;
+	s_wasiJobsHead = nullptr;
+	s_wasiJobsTail = nullptr;
+
+	while (job != nullptr)
+	{
+		WasiEventPipeJob *next = job->Next;
+		if (job->Callback (job->Data) != 0)
+			delete job;
+		else
+			WasiAppendJob (job);
+		job = next;
+	}
+
+	return s_wasiJobsHead != nullptr;
+}
+#endif // TARGET_WASI && PERFTRACING_DISABLE_THREADS
+
 #endif /* ENABLE_PERFTRACING */

src/coreclr/vm/eventing/eventpipe/ep-rt-coreclr.h

@@ -314,12 +314,26 @@ ep_rt_init_finish (void)
 	STATIC_CONTRACT_NOTHROW;
 }
 
+#if defined(TARGET_WASI) && defined(PERFTRACING_DISABLE_THREADS)
+// WASI has no host event loop, so jobs are kept on a native list that the managed
+// WASI event loop drains (see ep-rt-coreclr.cpp).
+bool ep_rt_coreclr_wasi_queue_job (size_t (*cb)(void *data), void *data);
+
+// Runs the queued jobs once; returns true if any job is still queued.
+bool ep_rt_coreclr_wasi_run_jobs (void);
+#endif
+
 static
 inline
 void
 ep_rt_shutdown (void)
 {
 	STATIC_CONTRACT_NOTHROW;
+#if defined(TARGET_WASI) && defined(PERFTRACING_DISABLE_THREADS)
+	// The event loop no longer runs, so run the queued jobs once to let the now-disabled streaming
+	// sessions release their references; freeing a session ends its trace file.
+	ep_rt_coreclr_wasi_run_jobs ();
+#endif
 }
 
 static
@@ -1111,6 +1125,8 @@ ep_rt_queue_job (
 	if (!cb (params))
 		SystemJS_DiagnosticServerQueueJob (cb, params);
 	return true;
+#elif defined(TARGET_WASI)
+	return ep_rt_coreclr_wasi_queue_job ((size_t (*)(void *))job_func, params);
 #else
 	EP_UNREACHABLE ("Not implemented on this platform");
 	return false;

src/coreclr/vm/eventpipeadapter.h

@@ -285,6 +285,15 @@ class EventPipeAdapter final
 		return !ep_rt_wait_event_wait (ep_session_get_wait_event (session), (uint32_t)timeoutMs, false) ? true : false;
 	}
 
+#if defined(TARGET_WASI) && defined(PERFTRACING_DISABLE_THREADS)
+	// Runs the queued EventPipe jobs; returns true if any remain queued.
+	static inline bool RunWasiJobs()
+	{
+		STATIC_CONTRACT_NOTHROW;
+		return ep_rt_coreclr_wasi_run_jobs ();
+	}
+#endif // TARGET_WASI && PERFTRACING_DISABLE_THREADS
+
 	static inline FILETIME GetSessionStartTime(EventPipeSession *session)
 	{
 		STATIC_CONTRACT_NOTHROW;

src/coreclr/vm/eventpipeinternal.cpp

@@ -296,4 +296,21 @@ extern "C" BOOL QCALLTYPE EventPipeInternal_WaitForSessionSignal(UINT64 sessionI
     return result;
 }
 
+#if defined(TARGET_WASI) && defined(PERFTRACING_DISABLE_THREADS)
+// Runs the queued EventPipe jobs and returns whether any are still queued, so the caller knows to run again.
+extern "C" CLR_BOOL QCALLTYPE EventPipeInternal_WasiRunJobs(QCallExceptionStatus* qcallError)
+{
+    QCALL_CONTRACT;
+
+    bool pending = false;
+
+    BEGIN_QCALL;
+
+    pending = EventPipeAdapter::RunWasiJobs();
+
+    END_QCALL;
+    return pending ? TRUE : FALSE;
+}
+#endif // TARGET_WASI && PERFTRACING_DISABLE_THREADS
+
 #endif // FEATURE_PERFTRACING

src/coreclr/vm/eventpipeinternal.h

@@ -104,6 +104,10 @@ extern "C" BOOL QCALLTYPE EventPipeInternal_WaitForSessionSignal(
     INT32 timeoutMs,
     QCallExceptionStatus* qcallError);
 
+#if defined(TARGET_WASI) && defined(PERFTRACING_DISABLE_THREADS)
+extern "C" CLR_BOOL QCALLTYPE EventPipeInternal_WasiRunJobs(QCallExceptionStatus* qcallError);
+#endif // TARGET_WASI && PERFTRACING_DISABLE_THREADS
+
 #endif // FEATURE_PERFTRACING
 
 #endif // __EVENTPIPEINTERNAL_H__

src/coreclr/vm/qcallentrypoints.cpp

@@ -492,6 +492,9 @@ static const Entry s_QCall[] =
     DllImportEntry(EventPipeInternal_GetNextEvent)
     DllImportEntry(EventPipeInternal_SignalSession)
     DllImportEntry(EventPipeInternal_WaitForSessionSignal)
+#if defined(TARGET_WASI) && defined(PERFTRACING_DISABLE_THREADS)
+    DllImportEntry(EventPipeInternal_WasiRunJobs)
+#endif // TARGET_WASI && PERFTRACING_DISABLE_THREADS
 #endif // FEATURE_PERFTRACING
 #if defined(TARGET_UNIX)
     DllImportEntry(FreeEnvironmentStringsW)