PresentMon Improvements: Memory Leak Fixes, ETW Monitoring & Build Setup

.gitignore

@@ -3,6 +3,13 @@
 
 # Build results
 /build/
+PresentMon/build/
+
+# Claude Code
+.claude/
+
+# Accidental nul file from Windows commands
+PresentMon/nul
 
 # vcpkg dependencies
 /vcpkg_installed/

PresentData/GpuTrace.cpp

@@ -75,6 +75,16 @@ GpuTrace::GpuTrace(PMTraceConsumer* pmConsumer)
 {
 }
 
+GpuTrace::~GpuTrace()
+{
+    for (auto& pair : mContexts) {
+        auto context = pair.second;
+        if (context.mIsHwQueue) {
+            delete context.mNode;
+        }
+    }
+}
+
 void GpuTrace::RegisterDevice(uint64_t hDevice, uint64_t pDxgAdapter)
 {
     // Sometimes there are duplicate start events

PresentData/GpuTrace.hpp

@@ -75,6 +75,7 @@ class GpuTrace {
 
 public:
     explicit GpuTrace(PMTraceConsumer* pmConsumer);
+    ~GpuTrace();
 
     void RegisterDevice(uint64_t hDevice, uint64_t pDxgAdapter);
     void UnregisterDevice(uint64_t hDevice);

PresentData/PresentMonTraceConsumer.cpp

@@ -2365,8 +2365,8 @@ void PMTraceConsumer::CompletePresent(std::shared_ptr<PresentEvent> const& p)
             static_cast<int32_t>(appFrameId - it->second.FrameId) >= 10) {
             // Remove the app frame data if the app frame id is too old
             it = mAppTimingDataByAppFrameId.erase(it); // Erase and move to the next element
-        } else if (appFrameId == 0 && it->second.ProcessId == processId && 
-            it->second.AssignedToPresent == false && it->second.AppPresentStartTime != 0 && 
+        } else if (appFrameId == 0 && it->second.ProcessId == processId &&
+            it->second.AssignedToPresent == false && it->second.AppPresentStartTime != 0 &&
             presentStartTime >= it->second.AppPresentStartTime &&
             presentStartTime - it->second.AppPresentStartTime >= mDeferralTimeLimit) {
             // Remove app frame data if the app present start time is too old
@@ -2376,6 +2376,47 @@ void PMTraceConsumer::CompletePresent(std::shared_ptr<PresentEvent> const& p)
             ++it; // Move to the next element
         }
     }
+
+    // Prune out old PC Latency timing data to prevent memory leaks.
+    // This is critical because PCL data accumulates for every frame and the
+    // PCLStatsShutdown event (the only other cleanup mechanism) is app-controlled.
+    if (mTrackPcLatency) {
+        auto pclFrameId = present->PclFrameId;
+        for (auto it = mPclTimingDataByPclFrameId.begin(); it != mPclTimingDataByPclFrameId.end();) {
+            if (it->first.second == processId) {
+                // For entries from this process:
+                // 1. Remove if assigned and frame ID is too old (10+ frames behind)
+                // 2. Remove if timestamp is too old (stale data - assigned or not)
+                bool shouldRemove = false;
+
+                // Get the best available timestamp for this entry
+                uint64_t timingValue = mUsingOutOfBoundPresentStart
+                    ? it->second.PclOutOfBandPresentStartTime
+                    : it->second.PclPresentStartTime;
+                if (timingValue == 0) {
+                    timingValue = it->second.PclSimStartTime;
+                }
+
+                if (pclFrameId != 0 && it->second.AssignedToPresent &&
+                    static_cast<int32_t>(pclFrameId - it->second.FrameId) >= 10) {
+                    // Remove assigned PCL data if frame id is too old
+                    shouldRemove = true;
+                } else if (timingValue != 0 && presentStartTime >= timingValue &&
+                    presentStartTime - timingValue >= mDeferralTimeLimit) {
+                    // Remove PCL data (assigned or not) if timestamp is too old
+                    shouldRemove = true;
+                }
+
+                if (shouldRemove) {
+                    it = mPclTimingDataByPclFrameId.erase(it);
+                } else {
+                    ++it;
+                }
+            } else {
+                ++it;
+            }
+        }
+    }
 }
 
 void PMTraceConsumer::UpdateReadyCount(bool useLock)
@@ -2708,6 +2749,16 @@ void PMTraceConsumer::HandleProcessEvent(EVENT_RECORD* pEventRecord)
             event.ProcessId    = desc[0].GetData<uint32_t>();
             event.IsStartEvent = false;
 
+            // Clean up PC Latency tracking data for this process to prevent memory leaks.
+            // This is necessary because PCLStatsShutdown events are application-controlled
+            // and may not be sent if the app crashes or terminates abnormally.
+            if (mTrackPcLatency) {
+                std::erase_if(mPclTimingDataByPclFrameId, [&event](const auto& p) {
+                    return p.first.second == event.ProcessId;
+                });
+                mLatestPingTimestampByProcessId.erase(event.ProcessId);
+            }
+
             break;
         }
         default:
@@ -2734,6 +2785,14 @@ void PMTraceConsumer::HandleProcessEvent(EVENT_RECORD* pEventRecord)
             mMetadata.GetEventData(pEventRecord, desc, _countof(desc));
             event.ProcessId    = desc[0].GetData<uint32_t>();
             event.IsStartEvent = false;
+
+            // Clean up PC Latency tracking data for this process to prevent memory leaks.
+            if (mTrackPcLatency) {
+                std::erase_if(mPclTimingDataByPclFrameId, [&event](const auto& p) {
+                    return p.first.second == event.ProcessId;
+                });
+                mLatestPingTimestampByProcessId.erase(event.ProcessId);
+            }
         } else {
             return;
         }

PresentData/PresentMonTraceSession.cpp

@@ -477,6 +477,9 @@ ULONG PMTraceSession::Start(
         sessionProps.Wnode.Flags = WNODE_FLAG_TRACED_GUID;
         sessionProps.LogFileMode = EVENT_TRACE_REAL_TIME_MODE;      // We have a realtime consumer, not writing to a log file
         sessionProps.LoggerNameOffset = offsetof(TraceProperties, mSessionName);  // Location of session name; will be written by StartTrace()
+        sessionProps.BufferSize = 64;                                // Buffer size in KB
+        sessionProps.MinimumBuffers = 256;                           // Minimum number of buffers allocated for the session's buffer pool
+        sessionProps.MaximumBuffers = 1024;                             // Maximum number of buffers (0 = no limit)
 
         auto status = StartTraceW(&mSessionHandle, sessionName, &sessionProps);
         if (status != ERROR_SUCCESS) {
@@ -656,6 +659,41 @@ void PMTraceSession::TimestampToLocalSystemTime(uint64_t timestamp, SYSTEMTIME*
     *ns = (timestamp % 10000000) * 100;
 }
 
+bool PMTraceSession::QueryEtwStatus(EtwStatus* status) const
+{
+    if (mSessionHandle == 0) {
+        return false;
+    }
+
+    TraceProperties sessionProps = {};
+    sessionProps.Wnode.BufferSize = (ULONG) sizeof(TraceProperties);
+    sessionProps.LoggerNameOffset = offsetof(TraceProperties, mSessionName);
+
+    auto queryStatus = ControlTraceW(mSessionHandle, nullptr, &sessionProps, EVENT_TRACE_CONTROL_QUERY);
+    if (queryStatus != ERROR_SUCCESS) {
+        return false;
+    }
+
+    // Update cached status
+    mCachedEtwStatus.mEtwBuffersInUse = sessionProps.NumberOfBuffers - sessionProps.FreeBuffers;
+    mCachedEtwStatus.mEtwTotalBuffers = sessionProps.NumberOfBuffers;
+    mCachedEtwStatus.mEtwEventsLost = sessionProps.EventsLost;
+    mCachedEtwStatus.mEtwBuffersLost = sessionProps.LogBuffersLost + sessionProps.RealTimeBuffersLost;
+
+    if (sessionProps.NumberOfBuffers > 0) {
+        mCachedEtwStatus.mEtwBufferFillPct = 100.0 * mCachedEtwStatus.mEtwBuffersInUse / sessionProps.NumberOfBuffers;
+    } else {
+        mCachedEtwStatus.mEtwBufferFillPct = 0.0;
+    }
+
+    // Copy to output if provided
+    if (status != nullptr) {
+        *status = mCachedEtwStatus;
+    }
+
+    return true;
+}
+
 ULONG EnableProvidersListing(
     TRACEHANDLE sessionHandle,
     const GUID* pSessionGuid,

PresentData/PresentMonTraceSession.hpp

@@ -6,6 +6,14 @@
 
 struct PMTraceConsumer;
 
+struct EtwStatus {
+    double mEtwBufferFillPct;
+    ULONG mEtwBuffersInUse;
+    ULONG mEtwTotalBuffers;
+    ULONG mEtwEventsLost;
+    ULONG mEtwBuffersLost;
+};
+
 struct PMTraceSession {
     enum TimestampType {
         TIMESTAMP_TYPE_QPC = 1,
@@ -38,6 +46,9 @@ struct PMTraceSession {
 
     bool mIsRealtimeSession = false;
 
+    // Cached ETW status for CSV output (updated periodically via QueryEtwStatus)
+    mutable EtwStatus mCachedEtwStatus = {};
+
     ULONG Start(wchar_t const* etlPath,      // If nullptr, start a live/realtime tracing session
                 wchar_t const* sessionName); // Required session name
     void Stop();
@@ -48,6 +59,8 @@ struct PMTraceSession {
     double TimestampToMilliSeconds(uint64_t timestamp) const;
     void TimestampToLocalSystemTime(uint64_t timestamp, SYSTEMTIME* st, uint64_t* ns) const;
     uint64_t MilliSecondsDeltaToTimestamp(double millisecondsDelta) const;
+
+    bool QueryEtwStatus(EtwStatus* status) const;
 };
 
 ULONG StopNamedTraceSession(wchar_t const* sessionName);

PresentMon/CommandLine.cpp

@@ -411,6 +411,7 @@ bool ParseCommandLine(int argc, wchar_t** argv)
     args->mWriteFrameId = false;
     args->mWriteDisplayTime = false;
     args->mDisableOfflineBackpressure = false;
+    args->mTrackEtwStatus = false;
 
     bool sessionNameSet  = false;
     bool csvOutputStdout = false;
@@ -479,6 +480,7 @@ bool ParseCommandLine(int argc, wchar_t** argv)
         else if (ParseArg(argv[i], L"write_frame_id")) { args->mWriteFrameId = true; continue; }
         else if (ParseArg(argv[i], L"write_display_time")) { args->mWriteDisplayTime = true; continue; }
         else if (ParseArg(argv[i], L"disable_offline_backpressure")) { args->mDisableOfflineBackpressure = true; continue; }
+        else if (ParseArg(argv[i], L"track_etw_status")) { args->mTrackEtwStatus = true; continue; }
 
         // Provided argument wasn't recognized
         else if (!(ParseArg(argv[i], L"?") || ParseArg(argv[i], L"h") || ParseArg(argv[i], L"help"))) {

PresentMon/ConsoleApplication.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 17
-VisualStudioVersion = 17.6.33723.286
+# Visual Studio Version 18
+VisualStudioVersion = 18.1.11312.151 d18.0
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "PresentData", "..\PresentData\PresentData.vcxproj", "{892028E5-32F6-45FC-8AB2-90FCBCAC4BF6}"
 EndProject
@@ -10,6 +10,8 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "PresentMon", "PresentMon.vc
 		{892028E5-32F6-45FC-8AB2-90FCBCAC4BF6} = {892028E5-32F6-45FC-8AB2-90FCBCAC4BF6}
 	EndProjectSection
 EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "CommonUtilities", "..\IntelPresentMon\CommonUtilities\CommonUtilities.vcxproj", "{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|ARM = Debug|ARM
@@ -54,6 +56,22 @@ Global
 		{4EB9794B-1F12-48CE-ADC1-917E9810F29E}.Release|x64.Build.0 = Release|x64
 		{4EB9794B-1F12-48CE-ADC1-917E9810F29E}.Release|x86.ActiveCfg = Release|Win32
 		{4EB9794B-1F12-48CE-ADC1-917E9810F29E}.Release|x86.Build.0 = Release|Win32
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Debug|ARM.ActiveCfg = Debug|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Debug|ARM.Build.0 = Debug|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Debug|ARM64.ActiveCfg = Debug|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Debug|ARM64.Build.0 = Debug|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Debug|x64.ActiveCfg = Debug|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Debug|x64.Build.0 = Debug|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Debug|x86.ActiveCfg = Debug|Win32
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Debug|x86.Build.0 = Debug|Win32
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Release|ARM.ActiveCfg = Release|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Release|ARM.Build.0 = Release|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Release|ARM64.ActiveCfg = Release|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Release|ARM64.Build.0 = Release|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Release|x64.ActiveCfg = Release|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Release|x64.Build.0 = Release|x64
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Release|x86.ActiveCfg = Release|Win32
+		{08A704D8-CA1C-45E9-8EDE-542A1A43B53E}.Release|x86.Build.0 = Release|Win32
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

PresentMon/CsvOutput.cpp

@@ -179,6 +179,13 @@ void WriteCsvHeader<FrameMetrics1>(FILE* fp)
     if (args.mWriteFrameId) {
         fwprintf(fp, L",FrameId");
     }
+    if (args.mTrackEtwStatus) {
+        fwprintf(fp, L",EtwBufferFillPct"
+                     L",EtwBuffersInUse"
+                     L",EtwTotalBuffers"
+                     L",EtwEventsLost"
+                     L",EtwBuffersLost");
+    }
     fwprintf(fp, L"\n");
 
     if (args.mCSVOutput == CSVOutput::Stdout) {
@@ -259,6 +266,14 @@ void WriteCsvRow<FrameMetrics1>(
     if (args.mWriteFrameId) {
         fwprintf(fp, L",%u", p.FrameId);
     }
+    if (args.mTrackEtwStatus) {
+        fwprintf(fp, L",%.1lf,%lu,%lu,%lu,%lu",
+            pmSession.mCachedEtwStatus.mEtwBufferFillPct,
+            pmSession.mCachedEtwStatus.mEtwBuffersInUse,
+            pmSession.mCachedEtwStatus.mEtwTotalBuffers,
+            pmSession.mCachedEtwStatus.mEtwEventsLost,
+            pmSession.mCachedEtwStatus.mEtwBuffersLost);
+    }
     fwprintf(fp, L"\n");
 
     if (args.mCSVOutput == CSVOutput::Stdout) {
@@ -393,6 +408,13 @@ void WriteCsvHeader<FrameMetrics>(FILE* fp)
             fwprintf(fp, L",PCLFrameId");
         }
     }
+    if (args.mTrackEtwStatus) {
+        fwprintf(fp, L",EtwBufferFillPct"
+                     L",EtwBuffersInUse"
+                     L",EtwTotalBuffers"
+                     L",EtwEventsLost"
+                     L",EtwBuffersLost");
+    }
     fwprintf(fp, L"\n");
 
     if (args.mCSVOutput == CSVOutput::Stdout) {
@@ -606,6 +628,14 @@ void WriteCsvRow<FrameMetrics>(
             fwprintf(fp, L",%u", p.PclFrameId);
         }
     }
+    if (args.mTrackEtwStatus) {
+        fwprintf(fp, L",%.1lf,%lu,%lu,%lu,%lu",
+            pmSession.mCachedEtwStatus.mEtwBufferFillPct,
+            pmSession.mCachedEtwStatus.mEtwBuffersInUse,
+            pmSession.mCachedEtwStatus.mEtwTotalBuffers,
+            pmSession.mCachedEtwStatus.mEtwEventsLost,
+            pmSession.mCachedEtwStatus.mEtwBuffersLost);
+    }
     fwprintf(fp, L"\n");
 
     if (args.mCSVOutput == CSVOutput::Stdout) {