Support emitting array in dynamic event

Author: cshung

src/coreclr/gc/gc.cpp

@@ -22342,6 +22342,27 @@ size_t gc_heap::exponential_smoothing (int gen, size_t collection_count, size_t
 //internal part of gc used by the serial and concurrent version
 void gc_heap::gc1()
 {
+#ifdef FEATURE_EVENT_TRACE
+    EventArray<uint8_t> arr1;
+    arr1.Count = 10;
+    arr1.Data = new (nothrow) uint8_t[10];
+    for (uint8_t i = 0; i < 10; i++)
+    {
+        arr1.Data[i] = i * i + i + 1;
+    }
+
+    EventArray<uint16_t> arr2;
+    arr2.Count = 6;
+    arr2.Data = new (nothrow) uint16_t[6];
+    for (uint16_t i = 0; i < 6; i++)
+    {
+        arr2.Data[i] = i * (i + 1);
+    }
+
+    GCEventFireTestArray_V1 (arr1, arr2);
+    delete[] arr1.Data;
+    delete[] arr2.Data;
+#endif //FEATURE_EVENT_TRACE
 #ifdef BACKGROUND_GC
     assert (settings.concurrent == (uint32_t)(bgc_thread_id.IsCurrentThread()));
 #endif //BACKGROUND_GC

src/coreclr/gc/gcevent_serializers.h

@@ -48,15 +48,22 @@
 #define ByteSwap64 __builtin_bswap64
 #endif // MSC_VER
 
-namespace gc_event
+template<class T>
+class EventArray
 {
+public:
+    uint8_t Count;
+    T* Data;
+};
 
+namespace gc_event
+{
 /*
- * `EventSerializatonTraits` is a trait implemented by types that
- * can be serialized to the payload of a dynamic event.
+ * `PrimitiveEventSerializatonTraits` is a trait implemented by types that
+ * can be serialized to the payload of a dynamic event with a fixed size.
  */
 template<class T>
-struct EventSerializationTraits
+struct PrimitiveEventSerializationTraits
 {
     /*
      * Serializes the value `value` to the buffer `buffer`, incrementing
@@ -66,37 +73,36 @@ struct EventSerializationTraits
      * large enough to accommodate the serialized form of T.
      */
     static void Serialize(const T& value, uint8_t** buffer) = delete;
-
     /*
-     * Returns the size of the value `value` if it were to be serialized.
+     * Returns the size required for serializing this type.
      */
-    static size_t SerializedSize(const T& value) = delete;
+    static size_t SerializedSize() = delete;
 };
 
 /*
- * EventSerializationTraits implementation for uint16_t. Other integral types
+ * PrimitiveEventSerializationTraits implementation for uint8_t. Other integral types
  * can follow this pattern.
  *
  * The convention here is that integral types are always serialized as
  * little-endian.
  */
 template<>
-struct EventSerializationTraits<uint8_t>
+struct PrimitiveEventSerializationTraits<uint8_t>
 {
     static void Serialize(const uint8_t& value, uint8_t** buffer)
     {
         **((uint8_t**)buffer) = value;
         *buffer += sizeof(uint8_t);
     }
 
-    static size_t SerializedSize(const uint8_t& value)
+    static size_t SerializedSize()
     {
         return sizeof(uint8_t);
     }
 };
 
 template<>
-struct EventSerializationTraits<uint16_t>
+struct PrimitiveEventSerializationTraits<uint16_t>
 {
     static void Serialize(const uint16_t& value, uint8_t** buffer)
     {
@@ -109,14 +115,14 @@ struct EventSerializationTraits<uint16_t>
         *buffer += sizeof(uint16_t);
     }
 
-    static size_t SerializedSize(const uint16_t& value)
+    static size_t SerializedSize()
     {
         return sizeof(uint16_t);
     }
 };
 
 template<>
-struct EventSerializationTraits<uint32_t>
+struct PrimitiveEventSerializationTraits<uint32_t>
 {
     static void Serialize(const uint32_t& value, uint8_t** buffer)
     {
@@ -129,14 +135,14 @@ struct EventSerializationTraits<uint32_t>
         *buffer += sizeof(uint32_t);
     }
 
-    static size_t SerializedSize(const uint32_t& value)
+    static size_t SerializedSize()
     {
         return sizeof(uint32_t);
     }
 };
 
 template<>
-struct EventSerializationTraits<uint64_t>
+struct PrimitiveEventSerializationTraits<uint64_t>
 {
     static void Serialize(const uint64_t& value, uint8_t** buffer)
     {
@@ -149,27 +155,76 @@ struct EventSerializationTraits<uint64_t>
         *buffer += sizeof(uint64_t);
     }
 
-    static size_t SerializedSize(const uint64_t& value)
+    static size_t SerializedSize()
     {
         return sizeof(uint64_t);
     }
 };
 
 template<>
-struct EventSerializationTraits<float>
+struct PrimitiveEventSerializationTraits<float>
 {
     static void Serialize(const float& value, uint8_t** buffer)
     {
         memcpy(*buffer, &value, sizeof(float));
         *buffer += sizeof(float);
     }
 
-    static size_t SerializedSize(const float& value)
+    static size_t SerializedSize()
     {
         return sizeof(float);
     }
 };
 
+/*
+ * `EventSerializatonTraits` is a trait implemented by types that
+ * can be serialized to the payload of a dynamic event.
+ */
+template<class T>
+struct EventSerializationTraits
+{
+    /*
+     * Serializes the value `value` to the buffer `buffer`, incrementing
+     * the buffer double-pointer to point to the next byte to be written.
+     *
+     * It is the responsibility of the caller to ensure that the buffer is
+     * large enough to accommodate the serialized form of T.
+     */
+    static void Serialize(const T& value, uint8_t** buffer)
+    {
+        PrimitiveEventSerializationTraits<T>::Serialize(value, buffer);
+    }
+
+    /*
+     * Returns the size of the value `value` if it were to be serialized.
+     */
+    static size_t SerializedSize(const T& value)
+    {
+        return PrimitiveEventSerializationTraits<T>::SerializedSize();
+    }
+};
+
+template<class T>
+struct EventSerializationTraits<EventArray<T>>
+{
+    static void Serialize(const EventArray<T>& value, uint8_t** pBuffer)
+    {
+        uint8_t* buffer = *pBuffer;
+        buffer[0] = value.Count;
+        buffer += 1;
+        for (uint8_t i = 0; i < value.Count; i++)
+        {
+            PrimitiveEventSerializationTraits<T>::Serialize(value.Data[i], &buffer);
+        }
+        *pBuffer = buffer;
+    }
+
+    static size_t SerializedSize(const EventArray<T>& value)
+    {
+        return sizeof(uint8_t)  + PrimitiveEventSerializationTraits<T>::SerializedSize() * value.Count;
+    }
+};
+
 /*
  * Helper routines for serializing lists of arguments.
  */

src/coreclr/gc/gcevents.h

@@ -52,6 +52,7 @@ DYNAMIC_EVENT(CommittedUsage, GCEventLevel_Information, GCEventKeyword_GC, 1)
 DYNAMIC_EVENT(SizeAdaptationTuning, GCEventLevel_Information, GCEventKeyword_GC, 1)
 DYNAMIC_EVENT(SizeAdaptationFullGCTuning, GCEventLevel_Information, GCEventKeyword_GC, 1)
 DYNAMIC_EVENT(SizeAdaptationSample, GCEventLevel_Information, GCEventKeyword_GC, 1)
+DYNAMIC_EVENT(TestArray, GCEventLevel_Information, GCEventKeyword_GC, 1)
 
 #undef KNOWN_EVENT
 #undef DYNAMIC_EVENT