# HG changeset patch
# User cin
# Date 2018-06-14 22:54:09
# Node ID 67ebcfd7d1c81a326b54dc8f57e8ad83895656fa
# Parent  b6924f444abde4539726747bbb3b8c857d7b1088

Working on Implab.Diagnostics

diff --git a/Implab.Playground/Program.cs b/Implab.Playground/Program.cs
--- a/Implab.Playground/Program.cs
+++ b/Implab.Playground/Program.cs
@@ -12,141 +12,24 @@ using Unity.Injection;
 using Unity.Registration;
 
 namespace Implab.Playground {
-
-    public class Foo {
-
-        public class Bar {
-
-        }
-
-        public string Name { get; set; }
-
-        public int IntValue { get; set; }
-
-        public string StringValue { get; set; }
-
-        public void AddRange(Foo[] items) {
-            Console.WriteLine($"AddRange: Foo[]");
-        }
+    using static Trace<Bar>;
+    
+    class Foo {
 
     }
 
-    public class FooFactory : IFactory<Foo>, IFactory<Foo.Bar> {
-
-        public bool UseSsl { get; set; }
-
-        public string Connection { get; set; }
-        
-        public Foo Create() {
-            return new Foo() {
-                Name = "AutoFac"
-            };
-        }
-
-        Foo.Bar IFactory<Foo.Bar>.Create() {
-            return new Foo.Bar(); 
-        }
-    }
-
-    public interface IContainer<T> {
-        T Instance { get; set; }
-    }
-
-    public class Container<T> : IContainer<T> {
-        public class Bar {
-
-        }
+    class Bar : Foo {
 
-        public class Bar<T2> {
-            public class Baz {
-
-            }
-
-        }
-
-        public Container() {
-
-        }
-
-        public Container(T instance) {
-            Instance = instance;
-        }
-
-        public T Instance { get; set; }
-
-        public void SetInstance(T value) {
-            Instance = value;
-        }
-
-        public void AddRange(List<T> items) {
-            Console.WriteLine($"AddRange: {typeof(List<T>)}");
-        }
-
-        public void AddRange(T[] items) {
-            Console.WriteLine($"AddRange: T[] ofType {typeof(T[])}");
-        }
     }
-
     public class Program {
 
         static void Main(string[] args) {
-            var u1 = new Uri("/some/one");
-
-            dynamic obj = new ExpandoObject();
-
-            obj.Name = "Dynamo";
-
-            obj.Hello = new Func<string>(() => { return "Hello"; });
-
-            Console.WriteLine($"{obj.Hello()}");
-
-        }
-
-        static void Main2(string[] args) {
-            var listener = new SimpleTraceListener(Console.Out);
-            var source = Trace<TypeResolver>.TraceSource;
-            source.Switch.Level = SourceLevels.All;
-            source.Listeners.Add(listener);
-
-            var stopwatch = new Stopwatch();
-            stopwatch.Start();
-
-            var container = new UnityContainer();
-
-            Console.WriteLine($"Created: {stopwatch.ElapsedMilliseconds}");
-            stopwatch.Restart();
             
-            container.LoadXmlConfiguration("data/sample.xml");
-
-            Console.WriteLine($"Loaded: {stopwatch.ElapsedMilliseconds}");
-
-            stopwatch.Restart();
-            var instace1 = container.Resolve<IContainer<string>>();
-            Console.WriteLine($"Resolved1: {stopwatch.ElapsedMilliseconds}");
-
-            stopwatch.Restart();
-            var instace2 = container.Resolve<IContainer<Foo>>();
-            Console.WriteLine($"Resolved2: {stopwatch.ElapsedMilliseconds}");
-
-            DisplayContainerRegistrations(container);
-        }
-
-        static void DisplayContainerRegistrations(IUnityContainer theContainer) {
-            string regName, regType, mapTo, lifetime;
-            Console.WriteLine("Container has {0} Registrations:",
-                    theContainer.Registrations.Count());
-            foreach (ContainerRegistration item in theContainer.Registrations) {
-                regType = item.RegisteredType.FullName;
-                mapTo = item.MappedToType.FullName;
-                regName = item.Name ?? "[default]";
-                lifetime = item.LifetimeManager.LifetimeType.Name;
-                if (mapTo != regType) {
-                    mapTo = " -> " + mapTo;
-                } else {
-                    mapTo = string.Empty;
-                }
-                lifetime = lifetime.Substring(0, lifetime.Length - "LifetimeManager".Length);
-                Console.WriteLine("+ {0}{1}  '{2}'  {3}", regType, mapTo, regName, lifetime);
+            using(TraceRegistry.Global.Subscribe(ch => {
+                Console.WriteLine($"{ch.Id}: {ch.Source.Name}");
+            }, true)) {
+                Trace<Foo>.Log("Hi!");
+                Log("Respect!");
             }
         }
 
diff --git a/Implab.ServiceHost/Unity/ContainerBuilder.cs b/Implab.ServiceHost/Unity/ContainerBuilder.cs
--- a/Implab.ServiceHost/Unity/ContainerBuilder.cs
+++ b/Implab.ServiceHost/Unity/ContainerBuilder.cs
@@ -5,7 +5,7 @@ using Implab.Diagnostics;
 using Unity;
 
 namespace Implab.ServiceHost.Unity {
-    using static Trace<ContainerBuilder>;
+    using Log = Trace<ContainerBuilder>;
 
     public class ContainerBuilder {
 
@@ -33,7 +33,9 @@ namespace Implab.ServiceHost.Unity {
         }
 
         public Type ResolveType(string typeReference) {
-            return string.IsNullOrEmpty(typeReference) ? null : m_resolver.Resolve(typeReference, true);
+            var resolved = string.IsNullOrEmpty(typeReference) ? null : m_resolver.Resolve(typeReference, true);
+            Log.Debug("ResolveType('{0}'): {1}", typeReference, resolved?.FullName);
+            return resolved;
         }
 
         public void Visit(ITypeRegistration registration) {
diff --git a/Implab/Diagnostics/LogicalOperation.cs b/Implab/Diagnostics/LogicalOperation.cs
--- a/Implab/Diagnostics/LogicalOperation.cs
+++ b/Implab/Diagnostics/LogicalOperation.cs
@@ -1,15 +1,25 @@
 using System;
-using System.Diagnostics;
+using Stopwatch = System.Diagnostics.Stopwatch;
 
 namespace Implab.Diagnostics {
     public class LogicalOperation {
-        public Stopwatch OperationStopwatch { get; private set; }
+        readonly Stopwatch m_stopwatch;
 
         public string Name { get; private set; }
 
         internal LogicalOperation(string name) {
             Name = string.IsNullOrEmpty(name) ? "<unnamed>" : name;
-            OperationStopwatch = Stopwatch.StartNew();
+            m_stopwatch = Stopwatch.StartNew();
+        }
+
+        public TimeSpan Elapsed {
+            get {
+                return m_stopwatch.Elapsed;
+            }
+        }
+
+        public void End() {
+            m_stopwatch.Stop();
         }
 
         public override string ToString() => Name;
diff --git a/Implab/Diagnostics/LogicalOperationScope.cs b/Implab/Diagnostics/LogicalOperationScope.cs
--- a/Implab/Diagnostics/LogicalOperationScope.cs
+++ b/Implab/Diagnostics/LogicalOperationScope.cs
@@ -13,7 +13,7 @@ namespace Implab.Diagnostics {
         }
 
         public void Dispose() {
-            m_operation.OperationStopwatch.Stop();
+            m_operation.End();
             Trace.CorrelationManager.StopLogicalOperation();
             m_source.TraceData(TraceEventType.Information, TraceEventCodes.StopLogicalOperation, m_operation);
         }
diff --git a/Implab/Diagnostics/SimpleTraceListener.cs b/Implab/Diagnostics/SimpleTraceListener.cs
--- a/Implab/Diagnostics/SimpleTraceListener.cs
+++ b/Implab/Diagnostics/SimpleTraceListener.cs
@@ -41,7 +41,7 @@ namespace Implab.Diagnostics {
 
         string FormatStopLogicalOperation(object data) {
             if (data is LogicalOperation op) {
-                return string.Format("-{0} ({1})", op, FormatTimespan(op.OperationStopwatch.Elapsed));
+                return string.Format("-{0} ({1})", op, FormatTimespan(op.Elapsed));
             } else {
                 return data?.ToString();
             }
@@ -90,7 +90,7 @@ namespace Implab.Diagnostics {
                     operation = eventCache.LogicalOperationStack.Peek() as LogicalOperation;
 
                 if (operation != null) {
-                    base.TraceData(eventCache, source, eventType, id, FormatTimespan(operation.OperationStopwatch.Elapsed) + ": " + message);
+                    base.TraceData(eventCache, source, eventType, id, FormatTimespan(operation.Elapsed) + ": " + message);
                 } else {
                     base.TraceData(eventCache, source, eventType, id, message);
                 }
diff --git a/Implab/Diagnostics/Trace.cs b/Implab/Diagnostics/Trace.cs
--- a/Implab/Diagnostics/Trace.cs
+++ b/Implab/Diagnostics/Trace.cs
@@ -10,35 +10,50 @@ using System.Threading;
 using System.Threading.Tasks;
 
 namespace Implab.Diagnostics {
+    /// <summary>
+    /// Static class which creates an individual <see cref="TraceSource"/> for
+    /// the type specified in the parameter <typeparamref name="T"/>.
+    /// </summary>
+    /// <typeparam name="T">The type for which tracing is demanded.</typeparam>
     public static class Trace<T> {
 
-        static Lazy<TraceSource> _traceSource = new Lazy<TraceSource>(CreateChannel, LazyThreadSafetyMode.ExecutionAndPublication);
-
-        static int _nextId;
+        readonly static Lazy<TraceSource> _trace = new Lazy<TraceSource>(() => TraceSourceChannel<T>.Default.Source);
 
-        static TraceSource CreateChannel() {
-            var id = Interlocked.Increment(ref _nextId);
-            var trs = new TraceSource(typeof(T).Name);
-
-            TraceChannelRegistry.AllCannels.NotifyChannelCreated(new ChannelInfo(typeof(T), trs));
-            
-            return trs;
-        }
-
-        public static TraceSource TraceSource { get { return _traceSource.Value; } }
+        public static TraceSource TraceSource { get { return _trace.Value; } }
 
 #if NETFX_TRACE_BUG
         readonly static AsyncLocal<object> m_currentOperation = new AsyncLocal<object>();
 #endif 
 
         /// <summary>
-        /// Starts the logical operation nested to the current operation nested to the current one.
+        /// If this property is set then <see cref="Debug(string, object[])"/> will produce output.
+        /// </summary>
+        public static bool TraceVerbose {
+            get {
+                return TraceSource.Switch.ShouldTrace(TraceEventType.Verbose);
+            }
+        }
+
+        /// <summary>
+        /// If this property is set then <see cref="Log(string, object[])"/> will produce output.
         /// </summary>
-        public static void StartLogicalOperation() {
-            Trace.CorrelationManager.StartLogicalOperation();
+        public static bool TraceInformation {
+            get {
+                return TraceSource.Switch.ShouldTrace(TraceEventType.Information);
+            }
+        }
 
+        /// <summary>
+        /// If this property is set then <see cref="Warn(string, object[])"/> will produce output.
+        /// </summary>
+        public static bool TraceWarnings {
+            get {
+                return TraceSource.Switch.ShouldTrace(TraceEventType.Warning);
+            }
         }
 
+
+
         /// <summary>
         /// Starts the logical operation with the specified name, this name is usefull in logs.
         /// </summary>
@@ -48,10 +63,27 @@ namespace Implab.Diagnostics {
             m_currentOperation.Value = name;
             Trace.CorrelationManager.StartLogicalOperation(name);
         }
+
+        /// <summary>
+        /// Starts the logical operation nested to the current operation nested to the current one.
+        /// </summary>
+        public static void StartLogicalOperation() {
+            m_currentOperation.Value = new object();
+            Trace.CorrelationManager.StartLogicalOperation();
+
+        }
 #else
         public static void StartLogicalOperation(object name) {
             Trace.CorrelationManager.StartLogicalOperation(name);
         }
+
+        /// <summary>
+        /// Starts the logical operation nested to the current operation nested to the current one.
+        /// </summary>
+        public static void StartLogicalOperation() {
+            Trace.CorrelationManager.StartLogicalOperation();
+
+        }
 #endif
 
         /// <summary>
@@ -68,7 +100,7 @@ namespace Implab.Diagnostics {
         /// <param name="arguments">Arguments.</param>
         [Conditional("DEBUG")]
         public static void Debug(string format, params object[] arguments) {
-
+            TraceSource.TraceEvent(TraceEventType.Verbose, 0, format, arguments);
         }
 
         /// <summary>
@@ -135,7 +167,7 @@ namespace Implab.Diagnostics {
                 Trace.CorrelationManager.ActivityId = Guid.NewGuid();
 
             var prev = Trace.CorrelationManager.ActivityId;
-            
+
             TraceSource.TraceEvent(TraceEventType.Start, 0, activityName);
             return new ActivityScope(TraceSource, prev, 0, activityName);
         }
diff --git a/Implab/Diagnostics/TraceChannel.cs b/Implab/Diagnostics/TraceChannel.cs
new file mode 100644
--- /dev/null
+++ b/Implab/Diagnostics/TraceChannel.cs
@@ -0,0 +1,17 @@
+namespace Implab.Diagnostics
+{
+    public abstract class TraceChannel {
+        readonly object m_id;
+
+        public object Id {
+            get {
+                return m_id;
+            }
+        }
+
+        protected TraceChannel(object id) {
+            m_id = id ?? new object();
+        }
+        
+    }
+}
\ No newline at end of file
diff --git a/Implab/Diagnostics/TraceRegistry.cs b/Implab/Diagnostics/TraceRegistry.cs
new file mode 100644
--- /dev/null
+++ b/Implab/Diagnostics/TraceRegistry.cs
@@ -0,0 +1,83 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using Implab.Parallels;
+
+namespace Implab.Diagnostics {
+    public class TraceRegistry {
+
+        class Subscription : IDisposable {
+            readonly WeakReference<TraceRegistry> m_registry;
+            readonly Action<object> m_unsubscribe;
+
+            public Subscription(TraceRegistry registry) {
+                m_registry = new WeakReference<TraceRegistry>(registry);
+            }
+
+            public void Dispose() {
+                TraceRegistry t;
+                if (m_registry.TryGetTarget(out t))
+                    t.RemoveSubscription(this);
+            }
+        }
+
+        public static TraceRegistry Global { get; } = new TraceRegistry();
+
+        readonly object m_lock = new object();
+
+        readonly Dictionary<object, Action<TraceChannel>> m_subscriptions = new Dictionary<object, Action<TraceChannel>>();
+        readonly SimpleAsyncQueue<TraceChannel> m_channels = new SimpleAsyncQueue<TraceChannel>();
+
+        internal void Register(TraceChannel channel) {
+            // notifications can run in parallel
+            Action<TraceChannel>[] handlers = null;
+            
+            lock(m_lock) {
+                m_channels.Enqueue(channel);
+                if (m_subscriptions.Count > 0) {
+                    handlers = new Action<TraceChannel>[m_subscriptions.Count];
+                    m_subscriptions.Values.CopyTo(handlers, 0);
+                }           
+            }
+
+            if (handlers != null)
+                foreach(var h in handlers)
+                    h(channel);
+        }
+
+        /// <summary>
+        /// Subscribes the specified handler to notifications about new trace
+        /// channels
+        /// </summary>
+        /// <param name="handler"></param>
+        /// <returns></returns>
+        public IDisposable Subscribe(Action<TraceChannel> handler, bool existing) {
+            Safe.ArgumentNotNull(handler, nameof(handler));
+
+            var cookie = new Subscription(this);
+
+            IEnumerable<TraceChannel> snap;
+
+            // lock to ensure that no new channels will be added
+            // while the subscription is added
+            lock(m_lock) {
+                m_subscriptions.Add(cookie, handler);
+                snap = m_channels.Snapshot();
+            }
+
+            // announce previously declared channels if required
+            if (existing) {
+                foreach(var c in snap)
+                    handler(c);
+            }
+
+            // return the subscription            
+            return cookie;
+        }
+
+        void RemoveSubscription(object cookie) {
+            lock(m_lock)
+                m_subscriptions.Remove(cookie);
+        }
+    }
+}
\ No newline at end of file
diff --git a/Implab/Diagnostics/TraceSourceAttribute.cs b/Implab/Diagnostics/TraceSourceAttribute.cs
--- a/Implab/Diagnostics/TraceSourceAttribute.cs
+++ b/Implab/Diagnostics/TraceSourceAttribute.cs
@@ -5,6 +5,7 @@ namespace Implab.Diagnostics {
     /// Used to mark class which uses <see cref="Trace{T}"/> class to trace it's events
     /// </summary>
     [AttributeUsage(AttributeTargets.Class)]
+    [Obsolete("Use TraceRegistry to monitor trace sources")]
     public class TraceSourceAttribute : Attribute {
     }
 }
diff --git a/Implab/Diagnostics/TraceSourceChannel.cs b/Implab/Diagnostics/TraceSourceChannel.cs
new file mode 100644
--- /dev/null
+++ b/Implab/Diagnostics/TraceSourceChannel.cs
@@ -0,0 +1,27 @@
+using TraceSource = System.Diagnostics.TraceSource;
+
+namespace Implab.Diagnostics {
+
+    /// <summary>
+    /// Trace channel which incapsulates <see cref="System.Diagnostics.TraceSource"/> instance.
+    /// </summary>
+    public class TraceSourceChannel : TraceChannel {
+        readonly TraceSource m_trace;
+
+        public TraceSourceChannel() : base(new object()) {
+        }
+
+        public TraceSourceChannel(object id) : base(id) {
+        }
+
+        public TraceSourceChannel(object id, string name) : base(id) {
+            m_trace = new TraceSource(name);
+        }
+
+        public TraceSource Source {
+            get {
+                return m_trace;
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/Implab/Diagnostics/TraceSourceChannel`1.cs b/Implab/Diagnostics/TraceSourceChannel`1.cs
new file mode 100644
--- /dev/null
+++ b/Implab/Diagnostics/TraceSourceChannel`1.cs
@@ -0,0 +1,33 @@
+using System;
+using System.Threading;
+using TraceSource = System.Diagnostics.TraceSource;
+
+namespace Implab.Diagnostics {
+    /// <summary>
+    /// This class is used to provide a single <see cref="TraceSourceChannel"/> 
+    /// instance for the specified class in <typeparamref name="T"/> parameter.
+    /// </summary>
+    /// <typeparam name="T">
+    /// The class for which <see cref="TraceSourceChannel"/> is required.
+    /// </typeparam>
+    /// <remarks>
+    /// The <see cref="TraceSourceChannel"/> instance will be created on demand
+    /// and automatically registered in <see cref="TraceRegistry.Global"/>.
+    /// </remarks>
+    public static class TraceSourceChannel<T> {
+        static Lazy<TraceSourceChannel> _traceSource = new Lazy<TraceSourceChannel>(CreateChannel, LazyThreadSafetyMode.ExecutionAndPublication);
+
+        /// <summary>
+        /// The default <see cref="TraceSourceChannel"/> instance.
+        /// </summary>
+        public static TraceSourceChannel Default { get { return _traceSource.Value; } }
+
+        static TraceSourceChannel CreateChannel() {
+            var channel = new TraceSourceChannel(typeof(T), typeof(T).Name);
+
+            TraceRegistry.Global.Register(channel);
+
+            return channel;
+        }
+    }
+}
\ No newline at end of file