Perf: Reduce tracing related allocations (#479)

Author: Wraith2

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/Common/ActivityCorrelator.cs

@@ -14,30 +14,15 @@ namespace Microsoft.Data.Common
 
     internal static class ActivityCorrelator
     {
-        internal class ActivityId
+        internal sealed class ActivityId
         {
-            internal Guid Id { get; private set; }
-            internal uint Sequence { get; private set; }
+            internal readonly Guid Id;
+            internal readonly uint Sequence;
 
-            internal ActivityId()
+            internal ActivityId(uint sequence)
             {
                 this.Id = Guid.NewGuid();
-                this.Sequence = 0; // the first event will start 1
-            }
-
-            // copy-constructor
-            internal ActivityId(ActivityId activity)
-            {
-                this.Id = activity.Id;
-                this.Sequence = activity.Sequence;
-            }
-
-            internal void Increment()
-            {
-                unchecked
-                {
-                    ++this.Sequence;
-                }
+                this.Sequence = sequence;
             }
 
             public override string ToString()
@@ -61,10 +46,9 @@ internal static ActivityId Current
             {
                 if (t_tlsActivity == null)
                 {
-                    t_tlsActivity = new ActivityId();
+                    t_tlsActivity = new ActivityId(1);
                 }
-
-                return new ActivityId(t_tlsActivity);
+                return t_tlsActivity;
             }
         }
 
@@ -74,14 +58,9 @@ internal static ActivityId Current
         /// <returns>ActivityId</returns>
         internal static ActivityId Next()
         {
-            if (t_tlsActivity == null)
-            {
-                t_tlsActivity = new ActivityId();
-            }
-
-            t_tlsActivity.Increment();
+            t_tlsActivity = new ActivityId( (t_tlsActivity?.Sequence ?? 0) + 1);
 
-            return new ActivityId(t_tlsActivity);
+            return t_tlsActivity;
         }
     }
 }

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParser.cs

@@ -979,7 +979,10 @@ internal void Deactivate(bool connectionIsDoomed)
         {
             // Called when the connection that owns us is deactivated.
             SqlClientEventSource.Log.AdvanceTrace("<sc.TdsParser.Deactivate|ADV> {0}# deactivating", ObjectID);
-            SqlClientEventSource.Log.StateDumpEvent("<sc.TdsParser.Deactivate|STATE> {0}# {1}", ObjectID, TraceString());
+            if (SqlClientEventSource.Log.IsStateDumpEnabled())
+            {
+                SqlClientEventSource.Log.StateDumpEvent("<sc.TdsParser.Deactivate|STATE> {0}# {1}", ObjectID, TraceString());
+            }
 
             if (MARSOn)
             {
@@ -12631,13 +12634,13 @@ private bool TryProcessUDTMetaData(SqlMetaDataPriv metaData, TdsParserStateObjec
                                        ;
         internal string TraceString()
         {
-            return String.Format(/*IFormatProvider*/ null,
+            return string.Format(/*IFormatProvider*/ null,
                            StateTraceFormatString,
-                           null == _physicalStateObj,
-                           null == _pMarsPhysicalConObj,
+                           null == _physicalStateObj ? bool.TrueString : bool.FalseString,
+                           null == _pMarsPhysicalConObj ? bool.TrueString : bool.FalseString,
                            _state,
                            _server,
-                           _fResetConnection,
+                           _fResetConnection ? bool.TrueString : bool.FalseString,
                            null == _defaultCollation ? "(null)" : _defaultCollation.TraceString(),
                            _defaultCodePage,
                            _defaultLCID,
@@ -12649,17 +12652,17 @@ internal string TraceString()
                            _retainedTransactionId,
                            _nonTransactedOpenResultCount,
                            null == _connHandler ? "(null)" : _connHandler.ObjectID.ToString((IFormatProvider)null),
-                           _fMARS,
+                           _fMARS ? bool.TrueString : bool.FalseString,
                            null == _sessionPool ? "(null)" : _sessionPool.TraceString(),
-                           _isYukon,
+                           _isYukon ? bool.TrueString : bool.FalseString,
                            null == _sniSpnBuffer ? "(null)" : _sniSpnBuffer.Length.ToString((IFormatProvider)null),
                            _physicalStateObj != null ? "(null)" : _physicalStateObj.ErrorCount.ToString((IFormatProvider)null),
                            _physicalStateObj != null ? "(null)" : _physicalStateObj.WarningCount.ToString((IFormatProvider)null),
                            _physicalStateObj != null ? "(null)" : _physicalStateObj.PreAttentionErrorCount.ToString((IFormatProvider)null),
                            _physicalStateObj != null ? "(null)" : _physicalStateObj.PreAttentionWarningCount.ToString((IFormatProvider)null),
-                           null == _statistics,
-                           _statisticsIsInTransaction,
-                           _fPreserveTransaction,
+                           null == _statistics ? bool.TrueString : bool.FalseString,
+                           _statisticsIsInTransaction ? bool.TrueString : bool.FalseString,
+                           _fPreserveTransaction ? bool.TrueString : bool.FalseString,
                            null == _connHandler ? "(null)" : _connHandler.ConnectionOptions.MultiSubnetFailover.ToString((IFormatProvider)null));
         }