[cDAC] implement GetGCHeapDetails and GetGCHeapStaticData (#119119)

* Implement GetGCHeapDetails
* Implement GetGCHeapStaticData
* Expand GC data descriptor

Author: max-charlamb

docs/design/datacontracts/GC.md

@@ -28,10 +28,43 @@ namespace GC_NAMESPACE {
 
 // On non-MSVC builds explicit specializations must be declared in the namespace the template was defined.
 // Due to the gc being built into coreclr, cdac_data must be defined in the global scope.
+
+#ifdef SERVER_GC
+#define GC_HEAP_FIELD(cdacName, fieldName) static constexpr size_t cdacName = offsetof(GC_NAMESPACE::gc_heap, fieldName);
+#else // !SERVER_GC
+#define GC_HEAP_FIELD(cdacName, fieldName) static constexpr decltype(&GC_NAMESPACE::gc_heap::fieldName) cdacName = &GC_NAMESPACE::gc_heap::fieldName;
+#endif // !SERVER_GC
+
 template<>
 struct cdac_data<GC_NAMESPACE::gc_heap>
 {
-#ifdef MULTIPLE_HEAPS
+#ifdef BACKGROUND_GC
+    static constexpr c_gc_state* CurrentGCState = const_cast<c_gc_state*>(&GC_NAMESPACE::gc_heap::current_c_gc_state);
+#endif // BACKGROUND_GC
+#ifdef SERVER_GC
     static constexpr GC_NAMESPACE::gc_heap*** Heaps = &GC_NAMESPACE::gc_heap::g_heaps;
-#endif // MULTIPLE_HEAPS
+#endif // SERVER_GC
+
+    GC_HEAP_FIELD(MarkArray, mark_array)
+    GC_HEAP_FIELD(NextSweepObj, next_sweep_obj)
+    GC_HEAP_FIELD(BackgroundMinSavedAddr, background_saved_lowest_address)
+    GC_HEAP_FIELD(BackgroundMaxSavedAddr, background_saved_highest_address)
+    GC_HEAP_FIELD(AllocAllocated, alloc_allocated)
+    GC_HEAP_FIELD(EphemeralHeapSegment, ephemeral_heap_segment)
+    GC_HEAP_FIELD(CardTable, card_table)
+    GC_HEAP_FIELD(FinalizeQueue, finalize_queue)
+
+    GC_HEAP_FIELD(GenerationTable, generation_table)
+
+#ifndef USE_REGIONS
+    GC_HEAP_FIELD(SavedSweepEphemeralSeg, saved_sweep_ephemeral_seg)
+    GC_HEAP_FIELD(SavedSweepEphemeralStart, saved_sweep_ephemeral_start)
+#endif // !USE_REGIONS
+};
+
+template<>
+struct cdac_data<GC_NAMESPACE::CFinalize>
+{
+    static constexpr size_t FillPointers = offsetof(GC_NAMESPACE::CFinalize, m_FillPointers);
+    static constexpr size_t FillPointersLength = sizeof(GC_NAMESPACE::CFinalize::m_FillPointers) / sizeof(GC_NAMESPACE::CFinalize::m_FillPointers[0]);
 };

src/coreclr/gc/datadescriptor/datadescriptor.h

@@ -10,10 +10,61 @@
 CDAC_BASELINE("empty")
 CDAC_TYPES_BEGIN()
 
+#ifdef SERVER_GC
+CDAC_TYPE_BEGIN(GCHeap)
+CDAC_TYPE_INDETERMINATE(GCHeap)
+CDAC_TYPE_FIELD(GCHeap, /*pointer*/, MarkArray, cdac_data<GC_NAMESPACE::gc_heap>::MarkArray)
+CDAC_TYPE_FIELD(GCHeap, /*pointer*/, NextSweepObj, cdac_data<GC_NAMESPACE::gc_heap>::NextSweepObj)
+CDAC_TYPE_FIELD(GCHeap, /*pointer*/, BackgroundMinSavedAddr, cdac_data<GC_NAMESPACE::gc_heap>::BackgroundMinSavedAddr)
+CDAC_TYPE_FIELD(GCHeap, /*pointer*/, BackgroundMaxSavedAddr, cdac_data<GC_NAMESPACE::gc_heap>::BackgroundMaxSavedAddr)
+CDAC_TYPE_FIELD(GCHeap, /*pointer*/, AllocAllocated, cdac_data<GC_NAMESPACE::gc_heap>::AllocAllocated)
+CDAC_TYPE_FIELD(GCHeap, /*pointer*/, EphemeralHeapSegment, cdac_data<GC_NAMESPACE::gc_heap>::EphemeralHeapSegment)
+CDAC_TYPE_FIELD(GCHeap, /*pointer*/, CardTable, cdac_data<GC_NAMESPACE::gc_heap>::CardTable)
+CDAC_TYPE_FIELD(GCHeap, /*pointer*/, FinalizeQueue, cdac_data<GC_NAMESPACE::gc_heap>::FinalizeQueue)
+CDAC_TYPE_FIELD(GCHeap, /*pointer*/, GenerationTable, cdac_data<GC_NAMESPACE::gc_heap>::GenerationTable)
+#ifndef USE_REGIONS
+CDAC_TYPE_FIELD(GCHeap, /*pointer*/, SavedSweepEphemeralSeg, cdac_data<GC_NAMESPACE::gc_heap>::SavedSweepEphemeralSeg)
+CDAC_TYPE_FIELD(GCHeap, /*pointer*/, SavedSweepEphemeralStart, cdac_data<GC_NAMESPACE::gc_heap>::SavedSweepEphemeralStart)
+#endif // !USE_REGIONS
+CDAC_TYPE_END(GCHeap)
+#endif // SERVER_GC
+
+CDAC_TYPE_BEGIN(Generation)
+CDAC_TYPE_SIZE(sizeof(GC_NAMESPACE::generation))
+CDAC_TYPE_FIELD(Generation, /*AllocContext*/, AllocationContext, offsetof(GC_NAMESPACE::generation, allocation_context))
+CDAC_TYPE_FIELD(Generation, /*pointer*/, StartSegment, offsetof(GC_NAMESPACE::generation, start_segment))
+#ifndef USE_REGIONS
+CDAC_TYPE_FIELD(Generation, /*pointer*/, AllocationStart, offsetof(GC_NAMESPACE::generation, allocation_start))
+#endif // !USE_REGIONS
+CDAC_TYPE_END(Generation)
+
+CDAC_TYPE_BEGIN(CFinalize)
+CDAC_TYPE_INDETERMINATE(CFinalize)
+CDAC_TYPE_FIELD(CFinalize, /*pointer*/, FillPointers, cdac_data<GC_NAMESPACE::CFinalize>::FillPointers)
+CDAC_TYPE_END(CFinalize)
+
 CDAC_TYPES_END()
 
 CDAC_GLOBALS_BEGIN()
 
+CDAC_GLOBAL(TotalGenerationCount, /*uint32*/, (uint32_t)total_generation_count)
+CDAC_GLOBAL(CFinalizeFillPointersLength, /*uint32*/, (uint32_t)cdac_data<GC_NAMESPACE::CFinalize>::FillPointersLength)
+
+#ifndef SERVER_GC
+CDAC_GLOBAL_POINTER(GCHeapMarkArray, cdac_data<GC_NAMESPACE::gc_heap>::MarkArray)
+CDAC_GLOBAL_POINTER(GCHeapNextSweepObj, cdac_data<GC_NAMESPACE::gc_heap>::NextSweepObj)
+CDAC_GLOBAL_POINTER(GCHeapBackgroundMinSavedAddr, cdac_data<GC_NAMESPACE::gc_heap>::BackgroundMinSavedAddr)
+CDAC_GLOBAL_POINTER(GCHeapBackgroundMaxSavedAddr, cdac_data<GC_NAMESPACE::gc_heap>::BackgroundMaxSavedAddr)
+CDAC_GLOBAL_POINTER(GCHeapAllocAllocated, cdac_data<GC_NAMESPACE::gc_heap>::AllocAllocated)
+CDAC_GLOBAL_POINTER(GCHeapEphemeralHeapSegment, cdac_data<GC_NAMESPACE::gc_heap>::EphemeralHeapSegment)
+CDAC_GLOBAL_POINTER(GCHeapCardTable, cdac_data<GC_NAMESPACE::gc_heap>::CardTable)
+CDAC_GLOBAL_POINTER(GCHeapFinalizeQueue, cdac_data<GC_NAMESPACE::gc_heap>::FinalizeQueue)
+CDAC_GLOBAL_POINTER(GCHeapGenerationTable, cdac_data<GC_NAMESPACE::gc_heap>::GenerationTable)
+#ifndef USE_REGIONS
+CDAC_GLOBAL_POINTER(GCHeapSavedSweepEphemeralSeg, cdac_data<GC_NAMESPACE::gc_heap>::SavedSweepEphemeralSeg)
+CDAC_GLOBAL_POINTER(GCHeapSavedSweepEphemeralStart, cdac_data<GC_NAMESPACE::gc_heap>::SavedSweepEphemeralStart)
+#endif // !USE_REGIONS
+#endif // !SERVER_GC
 
 #ifdef SERVER_GC
 #define GC_TYPE server
@@ -30,7 +81,12 @@ CDAC_GLOBALS_BEGIN()
 // CDAC_GLOBAL_STRING takes a single value argument.
 // To avoid issues with commas in the string we wrap the input string in a macro.
 #define GC_IDENTIFIER(...) __VA_ARGS__ // GC_IDENTIFIER(gc, heap) expands to: gc, heap
+
+#ifdef BACKGROUND_GC
+CDAC_GLOBAL_STRING(GCIdentifiers, GC_IDENTIFIER(GC_TYPE, HEAP_TYPE, background))
+#else
 CDAC_GLOBAL_STRING(GCIdentifiers, GC_IDENTIFIER(GC_TYPE, HEAP_TYPE))
+#endif // BACKGROUND_GC
 
 CDAC_GLOBAL_POINTER(MaxGeneration, &::g_max_generation)
 CDAC_GLOBAL_POINTER(StructureInvalidCount, &GCScan::m_GcStructuresInvalidCnt)
@@ -40,4 +96,8 @@ CDAC_GLOBAL_POINTER(NumHeaps, &GC_NAMESPACE::gc_heap::n_heaps)
 CDAC_GLOBAL_POINTER(Heaps, cdac_data<GC_NAMESPACE::gc_heap>::Heaps)
 #endif // SERVER_GC
 
+#ifdef BACKGROUND_GC
+CDAC_GLOBAL_POINTER(CurrentGCState, cdac_data<GC_NAMESPACE::gc_heap>::CurrentGCState)
+#endif // BACKGROUND_GC
+
 CDAC_GLOBALS_END()

src/coreclr/gc/datadescriptor/datadescriptor.inc

@@ -5680,6 +5680,7 @@ class CFinalize
 {
 
     friend class CFinalizeStaticAsserts;
+    friend struct ::cdac_data<CFinalize>;
 
 private:
 

src/coreclr/gc/gcpriv.h

@@ -1005,6 +1005,9 @@ CDAC_GLOBAL_POINTER(PlatformMetadata, &::g_cdacPlatformMetadata)
 CDAC_GLOBAL_POINTER(ProfilerControlBlock, &::g_profControlBlock)
 CDAC_GLOBAL_POINTER(MethodDescSizeTable, &MethodDesc::s_ClassificationSizeTable)
 
+CDAC_GLOBAL_POINTER(GCLowestAddress, &g_lowest_address)
+CDAC_GLOBAL_POINTER(GCHighestAddress, &g_highest_address)
+
 CDAC_GLOBAL_SUB_DESCRIPTOR(GC, &(g_gc_dac_vars.gc_descriptor))
 
 CDAC_GLOBALS_END()

src/coreclr/vm/datadescriptor/datadescriptor.inc

@@ -6,24 +6,62 @@
 
 namespace Microsoft.Diagnostics.DataContractReader.Contracts;
 
-public class GCIdentifiers
+public static class GCIdentifiers
 {
     public const string Server = "server";
     public const string Workstation = "workstation";
 
     public const string Regions = "regions";
     public const string Segments = "segments";
+
+    public const string Background = "background";
+}
+
+public readonly struct GCHeapData
+{
+    public TargetPointer MarkArray { get; init; }
+    public TargetPointer NextSweepObject { get; init; }
+    public TargetPointer BackGroundSavedMinAddress { get; init; }
+    public TargetPointer BackGroundSavedMaxAddress { get; init; }
+
+    public TargetPointer AllocAllocated { get; init; }
+    public TargetPointer EphemeralHeapSegment { get; init; }
+    public TargetPointer CardTable { get; init; }
+    public IReadOnlyList<GCGenerationData> GenerationTable { get; init; }
+
+    public IReadOnlyList<TargetPointer> FillPointers { get; init; }
+
+    // Fields only valid in segment GC builds
+    public TargetPointer SavedSweepEphemeralSegment { get; init; }
+    public TargetPointer SavedSweepEphemeralStart { get; init; }
+}
+
+public readonly struct GCGenerationData
+{
+    public TargetPointer StartSegment { get; init; }
+    public TargetPointer AllocationStart { get; init; }
+    public TargetPointer AllocationContextPointer { get; init; }
+    public TargetPointer AllocationContextLimit { get; init; }
 }
 
 public interface IGC : IContract
 {
     static string IContract.Name { get; } = nameof(GC);
 
     string[] GetGCIdentifiers() => throw new NotImplementedException();
+
     uint GetGCHeapCount() => throw new NotImplementedException();
     bool GetGCStructuresValid() => throw new NotImplementedException();
     uint GetMaxGeneration() => throw new NotImplementedException();
+    void GetGCBounds(out TargetPointer minAddr, out TargetPointer maxAddr) => throw new NotImplementedException();
+    uint GetCurrentGCState() => throw new NotImplementedException();
     IEnumerable<TargetPointer> GetGCHeaps() => throw new NotImplementedException();
+
+    /* WKS only APIs */
+    GCHeapData WKSGetHeapData() => throw new NotImplementedException();
+
+    /* SVR only APIs */
+    GCHeapData SVRGetHeapData(TargetPointer heapAddress) => throw new NotImplementedException();
 }
 
 public readonly struct GC : IGC

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/Contracts/IGC.cs

@@ -19,6 +19,8 @@ public enum DataType
     nuint,
     pointer,
 
+    /* VM Data Types */
+
     GCHandle,
     CodePointer,
     Thread,
@@ -129,4 +131,11 @@ public enum DataType
     HijackFrame,
     TailCallFrame,
     StubDispatchFrame,
+
+
+    /* GC Data Types */
+
+    GCHeap,
+    Generation,
+    CFinalize,
 }

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/DataType.cs

@@ -74,6 +74,8 @@ public static class Globals
         public const string OperatingSystem = nameof(OperatingSystem);
 
         public const string GCInfoVersion = nameof(GCInfoVersion);
+        public const string GCLowestAddress = nameof(GCLowestAddress);
+        public const string GCHighestAddress = nameof(GCHighestAddress);
 
         // Globals found on GCDescriptor
         // see src/coreclr/gc/datadescriptors/datadescriptor.inc
@@ -82,6 +84,21 @@ public static class Globals
         public const string StructureInvalidCount = nameof(StructureInvalidCount);
         public const string NumHeaps = nameof(NumHeaps);
         public const string Heaps = nameof(Heaps);
+        public const string CurrentGCState = nameof(CurrentGCState);
+        public const string CFinalizeFillPointersLength = nameof(CFinalizeFillPointersLength);
+        public const string TotalGenerationCount = nameof(TotalGenerationCount);
+
+        public const string GCHeapMarkArray = nameof(GCHeapMarkArray);
+        public const string GCHeapNextSweepObj = nameof(GCHeapNextSweepObj);
+        public const string GCHeapBackgroundMinSavedAddr = nameof(GCHeapBackgroundMinSavedAddr);
+        public const string GCHeapBackgroundMaxSavedAddr = nameof(GCHeapBackgroundMaxSavedAddr);
+        public const string GCHeapAllocAllocated = nameof(GCHeapAllocAllocated);
+        public const string GCHeapEphemeralHeapSegment = nameof(GCHeapEphemeralHeapSegment);
+        public const string GCHeapCardTable = nameof(GCHeapCardTable);
+        public const string GCHeapFinalizeQueue = nameof(GCHeapFinalizeQueue);
+        public const string GCHeapGenerationTable = nameof(GCHeapGenerationTable);
+        public const string GCHeapSavedSweepEphemeralSeg = nameof(GCHeapSavedSweepEphemeralSeg);
+        public const string GCHeapSavedSweepEphemeralStart = nameof(GCHeapSavedSweepEphemeralStart);
     }
     public static class FieldNames
     {