async multithreading support

src/MiniProfiler.Providers.SqlServer/SqlServerStorage.cs

@@ -85,15 +85,17 @@ public override void Save(MiniProfiler profiler)
                 }
 
                 SaveTimings(timings, conn);
-                if (profiler.ClientTimings != null && profiler.ClientTimings.Timings != null && profiler.ClientTimings.Timings.Any())
+
+                var clientTimings = profiler.ClientTimings?.Timings;
+                if (clientTimings != null && clientTimings.Any())
                 {
                     // set the profilerId (isn't needed unless we are storing it)
-                    profiler.ClientTimings.Timings.ForEach(x =>
+                    foreach(var x in clientTimings)
                     {
                         x.MiniProfilerId = profiler.Id;
                         x.Id = Guid.NewGuid();
-                    });
-                    SaveClientTimings(profiler.ClientTimings.Timings, conn);
+                    }
+                    SaveClientTimings(clientTimings, conn);
                 }
             }
         }
@@ -139,7 +141,7 @@ INSERT INTO MiniProfilerTimings
             }
         }
 
-        private void SaveClientTimings(List<ClientTiming> timings, DbConnection conn)
+        private void SaveClientTimings(IReadOnlyList<ClientTiming> timings, DbConnection conn)
         {
             const string sql = @"
 INSERT INTO MiniProfilerClientTimings

src/MiniProfiler.Providers.SqlServerCe/SqlServerCeStorage.cs

@@ -86,15 +86,16 @@ public override void Save(MiniProfiler profiler)
                 }
 
                 SaveTimings(timings, conn);
-                if (profiler.ClientTimings != null && profiler.ClientTimings.Timings != null && profiler.ClientTimings.Timings.Any())
+                var clientTimings = profiler.ClientTimings?.Timings;
+                if (clientTimings != null && clientTimings.Any())
                 {
                     // set the profilerId (isn't needed unless we are storing it)
-                    profiler.ClientTimings.Timings.ForEach(x =>
+                    foreach (var x in clientTimings)
                     {
                         x.MiniProfilerId = profiler.Id;
                         x.Id = Guid.NewGuid();
-                    });
-                    SaveClientTimings(profiler.ClientTimings.Timings, conn);
+                    }
+                    SaveClientTimings(clientTimings, conn);
                 }
             }
         }
@@ -140,7 +141,7 @@ INSERT INTO MiniProfilerTimings
             }
         }
 
-        private void SaveClientTimings(List<ClientTiming> timings, DbConnection conn)
+        private void SaveClientTimings(IReadOnlyList<ClientTiming> timings, DbConnection conn)
         {
             const string sql = @"
 INSERT INTO MiniProfilerClientTimings

src/MiniProfiler.Shared/ClientTimings.cs

@@ -14,12 +14,26 @@ public class ClientTimings
     {
         private const string TimingPrefix = "clientPerformance[timing][";
         private const string ProbesPrefix = "clientProbes[";
+        private readonly object _lockObject = new object();
+        private List<ClientTiming> _timings;
 
         /// <summary>
         /// Gets or sets the list of client side timings
         /// </summary>
         [DataMember(Order = 2)]
-        public List<ClientTiming> Timings { get; set; }
+        public List<ClientTiming> Timings
+        {
+            get
+            {
+                lock(_lockObject)
+                    return _timings == null ? null : new List<ClientTiming>(_timings);
+            }
+            set
+            {
+                lock (_lockObject)
+                    _timings = value == null ? null : new List<ClientTiming>(value);
+            }
+        }
 
         /// <summary>
         /// Gets or sets the redirect count.

src/MiniProfiler.Shared/Helpers/Net45/AsyncLocal.cs

@@ -0,0 +1,78 @@
+#if NET45
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Runtime.Remoting.Messaging;
+using System.Runtime.Serialization;
+
+namespace StackExchange.Profiling.Helpers.Net45
+{
+    /// <summary>
+    /// Implements interface similar to AsyncLocal which is not available until .Net 4.6.
+    /// 
+    /// The implementation is inspired by Ambient Context Logic from here: 
+    /// https://github.com/mehdime/DbContextScope/blob/master/Mehdime.Entity/Implementations/DbContextScope.cs
+    /// Unlike DbContextScope's implementation this implementation doesn't support serialization/deserialization 
+    /// ths not allowing to cross app domain barrier.
+    /// </summary>
+    internal class AsyncLocal<T>
+    where T : class
+    {
+        public AsyncLocal()
+        {
+        }
+
+        public AsyncLocal(
+            T obj
+            )
+        {
+            Value = obj;
+        }
+
+        /// <summary>
+        /// Gets or Sets the value.
+        /// </summary>
+        public T Value
+        {
+            get
+            {
+                return (CallContext.LogicalGetData(_id) as ObjectRef)?.Ref;
+            }
+
+            set
+            {
+                CallContext.LogicalSetData(_id, new ObjectRef { Ref = value });
+            }
+        }
+
+        /// <summary>
+        /// Identifies this instance of <see cref="AsyncLocal"/> in CallContext.
+        /// </summary>
+        private readonly string _id = Guid.NewGuid().ToString();
+
+        [Serializable]
+        private class ObjectRef : MarshalByRefObject, ISerializable
+        {
+            // The special constructor is used to deserialize values.
+            public ObjectRef()
+            {
+            }
+
+            // The special constructor is used to deserialize values.
+            public ObjectRef(
+                SerializationInfo info,
+                StreamingContext context
+                )
+            {
+            }
+
+            public void GetObjectData(SerializationInfo info, StreamingContext context)
+            {
+            }
+
+            public T Ref { get; set; }
+        }
+    }
+}
+#endif

src/MiniProfiler.Shared/MiniProfiler.Shared.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
+<Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
     <TargetFrameworks>net45;netstandard1.5</TargetFrameworks>
     <AssemblyName>MiniProfiler.Shared</AssemblyName>
@@ -22,6 +22,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="NETStandard.Library" Version="1.6.1" />
+    <PackageReference Include="System.Collections.Immutable" Version="1.3.0" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard1.5'">
     <PackageReference Include="System.ComponentModel.Primitives" Version="4.3.0" />

src/MiniProfiler.Shared/MiniProfiler.cs

@@ -135,10 +135,9 @@ public Timing Root
                     {
                         var timing = timings.Pop();
 
-                        if (timing.HasChildren)
+                        var children = timing.Children;
+                        if (children?.Count > 0)
                         {
-                            var children = timing.Children;
-
                             for (int i = children.Count - 1; i >= 0; i--)
                             {
                                 children[i].ParentTiming = timing;
@@ -189,7 +188,19 @@ public Timing Root
         /// <summary>
         /// Gets or sets points to the currently executing Timing. 
         /// </summary>
-        public Timing Head { get; set; }
+        public Timing Head
+        {
+            get
+            {
+                Settings.EnsureProfilerProvider();
+                return Settings.ProfilerProvider.CurrentHead;
+            }
+            set
+            {
+                Settings.EnsureProfilerProvider();
+                Settings.ProfilerProvider.CurrentHead = value;
+            }
+        }
 
         /// <summary>
         /// Gets the ticks since this MiniProfiler was started.
@@ -329,9 +340,9 @@ public IEnumerable<Timing> GetTimingHierarchy()
 
                 yield return timing;
 
-                if (timing.HasChildren)
+                var children = timing.Children;
+                if (children?.Count > 0)
                 {
-                    var children = timing.Children;
                     for (int i = children.Count - 1; i >= 0; i--) timings.Push(children[i]);
                 }
             }

src/MiniProfiler.Shared/ProfileProviders/BaseProfilerProvider.cs

@@ -28,6 +28,11 @@ public abstract class BaseProfilerProvider : IProfilerProvider
         /// </summary>
         public abstract MiniProfiler GetCurrentProfiler();
 
+        /// <summary>
+        /// GEts or sets the current head timing. This is used by <see cref="MiniProfiler.Head"/>.
+        /// </summary>
+        public abstract Timing CurrentHead { get; set; }
+
         /// <summary>
         /// Sets <paramref name="profiler"/> to be active (read to start profiling)
         /// This should be called once a new MiniProfiler has been created.

src/MiniProfiler.Shared/ProfileProviders/DefaultProfilerProvider.cs

@@ -1,7 +1,8 @@
 #if NET45
 using System;
 using System.Runtime.Remoting.Messaging;
-using System.Web;
+using System.Web; 
+using StackExchange.Profiling.Helpers.Net45;
 #else
 using System.Threading;
 #endif
@@ -13,43 +14,23 @@ namespace StackExchange.Profiling
     /// </summary>
     public class DefaultProfilerProvider : BaseProfilerProvider
     {
-#if NET45
-        const string ContextKey = ":miniprofiler:";
+        private readonly AsyncLocal<MiniProfiler> _profiler = new AsyncLocal<MiniProfiler>();
+        private readonly AsyncLocal<Timing> _currentTiming = new AsyncLocal<Timing>();
 
         private MiniProfiler Profiler
         {
-            get
-            {
-                if (HttpContext.Current != null)
-                {
-                    return HttpContext.Current?.Items[ContextKey] as MiniProfiler;
-                }
-                else
-                {
-                    return CallContext.LogicalGetData(ContextKey) as MiniProfiler;
-                }
-            }
-            set
-            {
-                if (HttpContext.Current != null)
-                {
-                    HttpContext.Current.Items[ContextKey] = value;
-                }
-                else
-                {
-                    CallContext.LogicalSetData(ContextKey, value);
-                }
-            }
+            get { return _profiler.Value; }
+            set { _profiler.Value = value; }
         }
-#else
-        private AsyncLocal<MiniProfiler> _profiler = new AsyncLocal<MiniProfiler>();
 
-        private MiniProfiler Profiler
+        /// <summary>
+        /// Current head timing.
+        /// </summary>
+        public override Timing CurrentHead
         {
-            get { return _profiler.Value; }
-            set { _profiler.Value = value; }
+            get { return _currentTiming.Value; }
+            set { _currentTiming.Value = value; }
         }
-#endif
 
         /// <summary>
         /// The name says it all.

src/MiniProfiler.Shared/ProfileProviders/IProfilerProvider.cs

@@ -30,5 +30,10 @@ public interface IProfilerProvider
         /// Returns the current MiniProfiler.  This is used by <see cref="MiniProfiler.Current"/>.
         /// </summary>
         MiniProfiler GetCurrentProfiler();
+
+        /// <summary>
+        /// Current head <see cref="Timing"/>. Used by <see cref="MiniProfiler.Head"/>
+        /// </summary>
+        Timing CurrentHead { get; set; }
     }
 }

src/MiniProfiler.Shared/ProfileProviders/SingletonProfilerProvider.cs

@@ -9,12 +9,22 @@ namespace StackExchange.Profiling
     public class SingletonProfilerProvider : IProfilerProvider
     {
         private MiniProfiler _profiler;
+        private Timing _timing;
 
         /// <summary>
         /// The name says it all
         /// </summary>
         public MiniProfiler GetCurrentProfiler() => _profiler;
 
+        /// <summary>
+        /// Current head timing.
+        /// </summary>
+        public Timing CurrentHead
+        {
+            get { return _timing; }
+            set { _timing = value; }
+        }
+
         /// <summary>
         /// Starts a new profiling session.
         /// </summary>

src/MiniProfiler.Shared/Storage/DatabaseStorageBase.cs

@@ -132,9 +132,13 @@ private void PopulateChildTimings(Timing parent, ILookup<Guid, Timing> timingsLo
         protected void FlattenTimings(Timing timing, List<Timing> timingsCollection)
         {
             timingsCollection.Add(timing);
-            if (timing.HasChildren)
+            var children = timing.Children;
+            if (children?.Count > 0)
             {
-                timing.Children.ForEach(x => FlattenTimings(x, timingsCollection));
+                foreach (var child in children)
+                {
+                    FlattenTimings(child, timingsCollection);
+                }
             }
         }
     }