Fix Etw test in System.Collections.Concurrent.tests on ILC (#3621)

Hopefully, this will fix the other Etw-related test failures
I've seen among various projects. ETW propagation to EventListeners
was dying internally with a NullReferenceException on
EventMetadata.Parameters.

EventMetadata.Parameters and EventMetadata.ParameterTypes
represent the same data with EventMetadata.Parameters always
being null on the toolchain-based path and a comment attached to
it saying "Would you hurry up and die already?"

The EventSource rules of the code seems to be to check
before using Parameters and fallback to using ParameterTypes
if necessary but it was forgetting that in a few places.

1 files changed, 12 insertions, 18 deletions

diff --git a/src/System.Private.CoreLib/shared/System/Diagnostics/Tracing/EventSource.cs b/src/System.Private.CoreLib/shared/System/Diagnostics/Tracing/EventSource.cs
index 440e758f2..ed840a2e0 100644
--- a/src/System.Private.CoreLib/shared/System/Diagnostics/Tracing/EventSource.cs
+++ b/src/System.Private.CoreLib/shared/System/Diagnostics/Tracing/EventSource.cs
@@ -2096,32 +2096,26 @@ namespace System.Diagnostics.Tracing
 #endif //!ES_BUILD_PCL
         }
 
-        private int GetParamLenghtIncludingByteArray(ParameterInfo[] parameters)
+        unsafe private void WriteToAllListeners(int eventId, Guid* childActivityID, int eventDataCount, EventSource.EventData* data)
         {
-            int sum = 0;
-            foreach (ParameterInfo info in parameters)
+            // We represent a byte[] as a integer denoting the length  and then a blob of bytes in the data pointer. This causes a spurious
+            // warning because eventDataCount is off by one for the byte[] case since a byte[] has 2 items associated it. So we want to check
+            // that the number of parameters is correct against the byte[] case, but also we the args array would be one too long if
+            // we just used the modifiedParamCount here -- so we need both.
+            int paramCount = GetParameterCount(m_eventData[eventId]);
+            int modifiedParamCount = 0;
+            for (int i = 0; i < paramCount; i++)
             {
-                if (info.ParameterType == typeof(byte[]))
+                Type parameterType = GetDataType(m_eventData[eventId], i);
+                if (parameterType == typeof(byte[]))
                 {
-                    sum += 2;
+                    modifiedParamCount += 2;
                 }
                 else
                 {
-                    sum++;
+                    modifiedParamCount++;
                 }
             }
-
-            return sum;
-        }
-
-        unsafe private void WriteToAllListeners(int eventId, Guid* childActivityID, int eventDataCount, EventSource.EventData* data)
-        {
-            // We represent a byte[] as a integer denoting the length  and then a blob of bytes in the data pointer. This causes a spurious
-            // warning because eventDataCount is off by one for the byte[] case since a byte[] has 2 items associated it. So we want to check
-            // that the number of parameters is correct against the byte[] case, but also we the args array would be one too long if
-            // we just used the modifiedParamCount here -- so we need both.
-            int paramCount = m_eventData[eventId].Parameters.Length;
-            int modifiedParamCount = GetParamLenghtIncludingByteArray(m_eventData[eventId].Parameters);
             if (eventDataCount != modifiedParamCount)
             {
                 ReportOutOfBandMessage(Resources.GetResourceString("EventSource_EventParametersMismatch", eventId, eventDataCount, paramCount), true);