Add support for the NetTrace EventPipe file format

Right now the new format is not on by default, but it can be enabled using COMPlus_EventPipeNetTraceFormat = 1 for testing purposes. The plan to have a follow up PR that will add shipping configuration mechanisms and change the default setting.

See the documentation in the PerfView repo for more details about the format. At a glance the goal is to create a format that is more efficient to produce, has a smaller on disk size, and offers enhanced functionality in a few areas:
a) 64 bit thread id support
b) Detection of dropped events via sequence numbers
c) Better support for extracting subsets of the file

Together with the change there was also some refactoring of the EventPipeBufferManager and EventPipeThread.

This change addresses (at least in part) the following issues:
#19688, #23414, #24188, #20751, #20555, #21827, #24852, #25046

src/System.Private.CoreLib/src/System/Diagnostics/Eventing/EventPipeController.cs

@@ -22,6 +22,7 @@ internal static class EventPipeController
         // Miscellaneous constants.
         private const string DefaultAppName = "app";
         private const string NetPerfFileExtension = ".netperf";
+        private const string NetTraceFileExtension = ".nettrace";
         private const uint DefaultCircularBufferMB = 256; // MB (PerfView and dotnet-trace default)
         private const char ProviderConfigDelimiter = ',';
         private const char ConfigComponentDelimiter = ':';
@@ -87,7 +88,8 @@ private static EventPipeConfiguration BuildConfigFromEnvironment()
 
         private static string BuildTraceFileName()
         {
-            return GetAppName() + "." + Interop.GetCurrentProcessId().ToString() + NetPerfFileExtension;
+            return GetAppName() + "." + Interop.GetCurrentProcessId().ToString() +
+              ((Config_NetTraceFormat > 0) ? NetTraceFileExtension : NetPerfFileExtension);
         }
 
         private static string GetAppName()
@@ -180,6 +182,20 @@ private static int Config_EnableEventPipe
             }
         }
 
+        private static int Config_NetTraceFormat
+        {
+            get
+            {
+                string? stringValue = CompatibilitySwitch.GetValueInternal("EventPipeNetTraceFormat");
+                if ((stringValue == null) || (!int.TryParse(stringValue, out int value)))
+                {
+                    value = -1;     // Indicates no value (or is illegal)
+                }
+
+                return value;
+            }
+        }
+
         private static string? Config_EventPipeConfig => CompatibilitySwitch.GetValueInternal("EventPipeConfig");
 
         private static uint Config_EventPipeCircularMB

src/debug/daccess/request.cpp

@@ -759,7 +759,7 @@ ClrDataAccess::GetThreadData(CLRDATA_ADDRESS threadAddr, struct DacpThreadData *
     // initialize our local copy from the marshaled target Thread instance
     ZeroMemory (threadData, sizeof(DacpThreadData));
     threadData->corThreadId = thread->m_ThreadId;
-    threadData->osThreadId = thread->m_OSThreadId;
+    threadData->osThreadId = (DWORD)thread->m_OSThreadId;
     threadData->state = thread->m_State;
     threadData->preemptiveGCDisabled = thread->m_fPreemptiveGCDisabled;
     threadData->allocContextPtr = TO_CDADDR(thread->m_alloc_context.alloc_ptr);

src/inc/clrconfigvalues.h

@@ -718,6 +718,7 @@ RETAIL_CONFIG_DWORD_INFO(EXTERNAL_AllowDComReflection, W("AllowDComReflection"),
 // EventPipe
 //
 RETAIL_CONFIG_DWORD_INFO(INTERNAL_EnableEventPipe, W("EnableEventPipe"), 0, "Enable/disable event pipe.  Non-zero values enable tracing.")
+RETAIL_CONFIG_DWORD_INFO(INTERNAL_EventPipeNetTraceFormat, W("EventPipeNetTraceFormat"), 0, "Enable/disable using the newer nettrace file format.")
 RETAIL_CONFIG_STRING_INFO(INTERNAL_EventPipeOutputPath, W("EventPipeOutputPath"), "The full path excluding file name for the trace file that will be written when COMPlus_EnableEventPipe=1")
 RETAIL_CONFIG_STRING_INFO(INTERNAL_EventPipeConfig, W("EventPipeConfig"), "Configuration for EventPipe.")
 RETAIL_CONFIG_DWORD_INFO(INTERNAL_EventPipeRundown, W("EventPipeRundown"), 1, "Enable/disable eventpipe rundown.")

src/pal/inc/pal.h

@@ -1584,6 +1584,17 @@ CreateThread(
          IN DWORD dwCreationFlags,
          OUT LPDWORD lpThreadId);
 
+PALIMPORT
+HANDLE
+PALAPI
+PAL_CreateThread64(
+    IN LPSECURITY_ATTRIBUTES lpThreadAttributes,
+    IN DWORD dwStackSize,
+    IN LPTHREAD_START_ROUTINE lpStartAddress,
+    IN LPVOID lpParameter,
+    IN DWORD dwCreationFlags,
+    OUT SIZE_T* pThreadId);
+
 PALIMPORT
 PAL_NORETURN
 VOID

src/pal/src/include/pal/thread.hpp

@@ -53,7 +53,7 @@ namespace CorUnix
         LPVOID lpParameter,
         DWORD dwCreationFlags,
         PalThreadType eThreadType,
-        LPDWORD lpThreadId,
+        SIZE_T* pThreadId,
         HANDLE *phThread
         );
 
@@ -215,7 +215,7 @@ namespace CorUnix
                 LPVOID,
                 DWORD,
                 PalThreadType,
-                LPDWORD,
+                SIZE_T*,
                 HANDLE*
                 );
 

src/pal/src/synchmgr/synchmanager.cpp

@@ -1486,18 +1486,20 @@ namespace CorUnix
         }
 
         HANDLE hWorkerThread = NULL;
+        SIZE_T osThreadId = 0;
         palErr = InternalCreateThread(pthrCurrent,
                                       NULL,
                                       0,
                                       &WorkerThread,
                                       (PVOID)pSynchManager,
                                       0,
                                       PalWorkerThread,
-                                      &pSynchManager->m_dwWorkerThreadTid,
+                                      &osThreadId,
                                       &hWorkerThread);
 
         if (NO_ERROR == palErr)
         {
+            pSynchManager->m_dwWorkerThreadTid = (DWORD)osThreadId;
             palErr = InternalGetThreadDataFromHandle(pthrCurrent,
                                                      hWorkerThread,
                                                      0,

src/pal/src/thread/process.cpp

@@ -1674,6 +1674,7 @@ class PAL_RuntimeStartupHelper
         PAL_ERROR pe = NO_ERROR;
         BOOL ret;
         UnambiguousProcessDescriptor unambiguousProcessDescriptor;
+        SIZE_T osThreadId = 0;
 
 #ifdef __APPLE__
         if (lpApplicationGroupId != NULL)
@@ -1734,7 +1735,6 @@ class PAL_RuntimeStartupHelper
 
         // Add a reference for the thread handler
         AddRef();
-
         pe = InternalCreateThread(
             pThread,
             NULL,
@@ -1743,7 +1743,7 @@ class PAL_RuntimeStartupHelper
             this,
             0,
             UserCreatedThread,
-            &m_threadId,
+            &osThreadId,
             &m_threadHandle);
 
         if (NO_ERROR != pe)
@@ -1752,7 +1752,7 @@ class PAL_RuntimeStartupHelper
             Release();
             goto exit;
         }
-
+        m_threadId = (DWORD)osThreadId;
     exit:
         return pe;
     }

src/pal/src/thread/thread.cpp

@@ -510,7 +510,7 @@ CreateThread(
           dwCreationFlags, lpThreadId);
 
     pThread = InternalGetCurrentThread();
-
+    SIZE_T osThreadId = 0;
     palError = InternalCreateThread(
         pThread,
         lpThreadAttributes,
@@ -519,21 +519,79 @@ CreateThread(
         lpParameter,
         dwCreationFlags,
         UserCreatedThread,
-        lpThreadId,
+        &osThreadId,
         &hNewThread
         );
 
     if (NO_ERROR != palError)
     {
         pThread->SetLastError(palError);
     }
-
+    if(lpThreadId != nullptr)
+    {
+        *lpThreadId = (DWORD)osThreadId;
+    }
     LOGEXIT("CreateThread returns HANDLE %p\n", hNewThread);
     PERF_EXIT(CreateThread);
 
     return hNewThread;
 }
 
+/*++
+Function:
+  PAL_CreateThread64
+  Similar to CreateThread but passes out a 64 bit thread id on platforms which use one.
+
+Note:
+  lpThreadAttributes could be ignored.
+
+See MSDN doc.
+
+--*/
+HANDLE
+PALAPI
+PAL_CreateThread64(
+    IN LPSECURITY_ATTRIBUTES lpThreadAttributes,
+    IN DWORD dwStackSize,
+    IN LPTHREAD_START_ROUTINE lpStartAddress,
+    IN LPVOID lpParameter,
+    IN DWORD dwCreationFlags,
+    OUT SIZE_T* pThreadId)
+{
+    PAL_ERROR palError;
+    CPalThread *pThread;
+    HANDLE hNewThread = NULL;
+
+    PERF_ENTRY(PAL_CreateThread64);
+    ENTRY("PAL_CreateThread64(lpThreadAttr=%p, dwStackSize=%u, lpStartAddress=%p, "
+        "lpParameter=%p, dwFlags=%#x, pThreadId=%p)\n",
+        lpThreadAttributes, dwStackSize, lpStartAddress, lpParameter,
+        dwCreationFlags, pThreadId);
+
+    pThread = InternalGetCurrentThread();
+    palError = InternalCreateThread(
+        pThread,
+        lpThreadAttributes,
+        dwStackSize,
+        lpStartAddress,
+        lpParameter,
+        dwCreationFlags,
+        UserCreatedThread,
+        pThreadId,
+        &hNewThread
+    );
+
+    if (NO_ERROR != palError)
+    {
+        pThread->SetLastError(palError);
+    }
+
+    LOGEXIT("PAL_CreateThread64 returns HANDLE %p\n", hNewThread);
+    PERF_EXIT(PAL_CreateThread64);
+
+    return hNewThread;
+}
+
 PAL_ERROR
 CorUnix::InternalCreateThread(
     CPalThread *pThread,
@@ -543,7 +601,7 @@ CorUnix::InternalCreateThread(
     LPVOID lpParameter,
     DWORD dwCreationFlags,
     PalThreadType eThreadType,
-    LPDWORD lpThreadId,
+    SIZE_T* pThreadId,
     HANDLE *phThread
     )
 {
@@ -825,9 +883,9 @@ CorUnix::InternalCreateThread(
         //
         *phThread = hNewThread;
 
-        if (NULL != lpThreadId)
+        if (NULL != pThreadId)
         {
-            *lpThreadId = pNewThread->GetThreadId();
+            *pThreadId = pNewThread->GetThreadId();
         }
     }
     else

src/vm/CMakeLists.txt

@@ -331,6 +331,7 @@ set(VM_SOURCES_WKS
     eventpipemetadatagenerator.cpp
     eventpipeprotocolhelper.cpp
     eventpipeprovider.cpp
+    eventpipethread.cpp
     eventpipebuffer.cpp
     eventpipebuffermanager.cpp
     eventpipesession.cpp

src/vm/eventpipe.cpp

@@ -268,13 +268,15 @@ EventPipeSessionID EventPipe::Enable(
     const EventPipeProviderConfiguration *pProviders,
     uint32_t numProviders,
     EventPipeSessionType sessionType,
+    EventPipeSerializationFormat format,
     IpcStream *const pStream)
 {
     CONTRACTL
     {
         THROWS;
         GC_TRIGGERS;
         MODE_PREEMPTIVE;
+        PRECONDITION(format < EventPipeSerializationFormat::Count);
         PRECONDITION(circularBufferSizeInMB > 0);
         PRECONDITION(numProviders > 0 && pProviders != nullptr);
     }
@@ -295,6 +297,7 @@ EventPipeSessionID EventPipe::Enable(
             strOutputPath,
             pStream,
             sessionType,
+            format,
             circularBufferSizeInMB,
             pProviders,
             numProviders);
@@ -478,6 +481,10 @@ void EventPipe::DisableInternal(EventPipeSessionID id, EventPipeProviderCallback
         return;
     }
 
+    // Write a final sequence point to the file now that all events have
+    // been emitted
+    pSession->WriteSequencePointUnbuffered();
+
     // Remove the session.
     s_config.DeleteSession(pSession);
 
@@ -699,7 +706,7 @@ void EventPipe::WriteEventInternal(
             //    as opposed a a buffer copy here
             EventPipeEventInstance instance(
                 event,
-                pThread->GetOSThreadId(),
+                pEventPipeThread->GetOSThreadId(),
                 pData,
                 payload.GetSize(),
                 pActivityId,
@@ -713,7 +720,7 @@ void EventPipe::WriteEventInternal(
             {
                 _ASSERTE(pRundownSession != nullptr);
                 if (pRundownSession != nullptr)
-                    pRundownSession->WriteEvent(instance);
+                    pRundownSession->WriteEventUnbuffered(instance, pEventPipeThread);
             }
             EX_CATCH {}
             EX_END_CATCH(SwallowAllExceptions);
@@ -742,7 +749,7 @@ void EventPipe::WriteEventInternal(
                 // allowed to set s_pSessions[i] = NULL at any time and that may have occured in between
                 // the check and the load
                 if (pSession != nullptr)
-                    pSession->WriteEvent(
+                    pSession->WriteEventBuffered(
                         pThread,
                         event,
                         payload,

src/vm/eventpipe.h

@@ -22,6 +22,7 @@ struct EventPipeProviderConfiguration;
 class EventPipeSession;
 class IpcStream;
 enum class EventPipeSessionType;
+enum class EventPipeSerializationFormat;
 
 enum class EventPipeEventLevel
 {
@@ -272,6 +273,8 @@ class EventPipe
     friend class EventPipeProvider;
 
 public:
+    static const uint32_t MaxNumberOfSessions = 64;
+
     // Initialize the event pipe.
     static void Initialize();
 
@@ -285,6 +288,7 @@ class EventPipe
         const EventPipeProviderConfiguration *pProviders,
         uint32_t numProviders,
         EventPipeSessionType sessionType,
+        EventPipeSerializationFormat format,
         IpcStream *const pStream);
 
     // Disable tracing via the event pipe.
@@ -406,7 +410,6 @@ class EventPipe
     static CrstStatic s_configCrst;
     static Volatile<bool> s_tracingInitialized;
     static EventPipeConfiguration s_config;
-    static const uint32_t MaxNumberOfSessions = 64;
     static VolatilePtr<EventPipeSession> s_pSessions[MaxNumberOfSessions];
     static EventPipeEventSource *s_pEventSource;
     static HANDLE s_fileSwitchTimerHandle;