Implement TracerProvider Shutdown

src/OpenTelemetry.Api/.publicApi/net452/PublicAPI.Unshipped.txt

@@ -168,6 +168,7 @@ OpenTelemetry.Trace.Tracer.StartSpan(string name, OpenTelemetry.Trace.SpanKind k
 OpenTelemetry.Trace.TracerProvider
 OpenTelemetry.Trace.TracerProvider.Dispose() -> void
 OpenTelemetry.Trace.TracerProvider.GetTracer(string name, string version = null) -> OpenTelemetry.Trace.Tracer
+OpenTelemetry.Trace.TracerProvider.Shutdown(int timeoutMilliseconds = -1) -> bool
 OpenTelemetry.Trace.TracerProvider.TracerProvider() -> void
 abstract OpenTelemetry.Context.RuntimeContextSlot<T>.Get() -> T
 abstract OpenTelemetry.Context.RuntimeContextSlot<T>.Set(T value) -> void
@@ -307,3 +308,4 @@ virtual OpenTelemetry.Metrics.MeterFactoryBase.GetMeter(string name, string vers
 virtual OpenTelemetry.Metrics.MeterProvider.Dispose(bool disposing) -> void
 virtual OpenTelemetry.Metrics.MeterProvider.GetMeter(string name, string version = null) -> OpenTelemetry.Metrics.Meter
 virtual OpenTelemetry.Trace.TracerProvider.Dispose(bool disposing) -> void
+virtual OpenTelemetry.Trace.TracerProvider.OnShutdown(int timeoutMilliseconds) -> bool

src/OpenTelemetry.Api/.publicApi/netstandard2.0/PublicAPI.Unshipped.txt

@@ -168,6 +168,7 @@ OpenTelemetry.Trace.Tracer.StartSpan(string name, OpenTelemetry.Trace.SpanKind k
 OpenTelemetry.Trace.TracerProvider
 OpenTelemetry.Trace.TracerProvider.Dispose() -> void
 OpenTelemetry.Trace.TracerProvider.GetTracer(string name, string version = null) -> OpenTelemetry.Trace.Tracer
+OpenTelemetry.Trace.TracerProvider.Shutdown(int timeoutMilliseconds = -1) -> bool
 OpenTelemetry.Trace.TracerProvider.TracerProvider() -> void
 abstract OpenTelemetry.Context.RuntimeContextSlot<T>.Get() -> T
 abstract OpenTelemetry.Context.RuntimeContextSlot<T>.Set(T value) -> void
@@ -307,3 +308,4 @@ virtual OpenTelemetry.Metrics.MeterFactoryBase.GetMeter(string name, string vers
 virtual OpenTelemetry.Metrics.MeterProvider.Dispose(bool disposing) -> void
 virtual OpenTelemetry.Metrics.MeterProvider.GetMeter(string name, string version = null) -> OpenTelemetry.Metrics.Meter
 virtual OpenTelemetry.Trace.TracerProvider.Dispose(bool disposing) -> void
+virtual OpenTelemetry.Trace.TracerProvider.OnShutdown(int timeoutMilliseconds) -> bool

src/OpenTelemetry.Api/Internal/OpenTelemetryApiEventSource.cs

@@ -55,6 +55,15 @@ public void TracestateExtractException(Exception ex)
             }
         }
 
+        [NonEvent]
+        public void TracerProviderException(string evnt, Exception ex)
+        {
+            if (this.IsEnabled(EventLevel.Warning, (EventKeywords)(-1)))
+            {
+                this.TracerProviderException(evnt, ex.ToInvariantString());
+            }
+        }
+
         [NonEvent]
         public void TracestateKeyIsInvalid(ReadOnlySpan<char> key)
         {
@@ -126,5 +135,11 @@ public void FailedToInjectBaggage(string format, string error)
         {
             this.WriteEvent(11, format, error);
         }
+
+        [Event(12, Message = "Unknown error in TracerProvider '{0}': '{1}'.", Level = EventLevel.Warning)]
+        public void TracerProviderException(string evnt, string ex)
+        {
+            this.WriteEvent(12, evnt, ex);
+        }
     }
 }

src/OpenTelemetry.Api/Trace/TracerProvider.cs

@@ -16,6 +16,8 @@
 
 using System;
 using System.Diagnostics;
+using System.Threading;
+using OpenTelemetry.Internal;
 
 namespace OpenTelemetry.Trace
 {
@@ -24,6 +26,8 @@ namespace OpenTelemetry.Trace
     /// </summary>
     public class TracerProvider : IDisposable
     {
+        private int shutdownCount;
+
         /// <summary>
         /// Initializes a new instance of the <see cref="TracerProvider"/> class.
         /// </summary>
@@ -52,13 +56,75 @@ public Tracer GetTracer(string name, string version = null)
             return new Tracer(new ActivitySource(name, version));
         }
 
+        /// <summary>
+        /// Attempts to shutdown the processor, blocks the current thread until
+        /// shutdown completed or timed out.
+        /// </summary>
+        /// <param name="timeoutMilliseconds">
+        /// The number of milliseconds to wait, or <c>Timeout.Infinite</c> to
+        /// wait indefinitely.
+        /// </param>
+        /// <returns>
+        /// Returns <c>true</c> when shutdown succeeded; otherwise, <c>false</c>.
+        /// </returns>
+        /// <exception cref="System.ArgumentOutOfRangeException">
+        /// Thrown when the <c>timeoutMilliseconds</c> is smaller than -1.
+        /// </exception>
+        /// <remarks>
+        /// This function guarantees thread-safety. Only the first call will
+        /// win, subsequent calls will be no-op.
+        /// </remarks>
+        public bool Shutdown(int timeoutMilliseconds = Timeout.Infinite)
+        {
+            if (timeoutMilliseconds < 0 && timeoutMilliseconds != Timeout.Infinite)
+            {
+                throw new ArgumentOutOfRangeException(nameof(timeoutMilliseconds), timeoutMilliseconds, "timeoutMilliseconds should be non-negative.");
+            }
+
+            if (Interlocked.Increment(ref this.shutdownCount) > 1)
+            {
+                return false; // shutdown already called
+            }
+
+            try
+            {
+                return this.OnShutdown(timeoutMilliseconds);
+            }
+            catch (Exception ex)
+            {
+                OpenTelemetryApiEventSource.Log.TracerProviderException(nameof(this.Shutdown), ex);
+                return false;
+            }
+        }
+
         /// <inheritdoc/>
         public void Dispose()
         {
             this.Dispose(true);
             GC.SuppressFinalize(this);
         }
 
+        /// <summary>
+        /// Called by <c>Shutdown</c>. This function should block the current
+        /// thread until shutdown completed or timed out.
+        /// </summary>
+        /// <param name="timeoutMilliseconds">
+        /// The number of milliseconds to wait, or <c>Timeout.Infinite</c> to
+        /// wait indefinitely.
+        /// </param>
+        /// <returns>
+        /// Returns <c>true</c> when shutdown succeeded; otherwise, <c>false</c>.
+        /// </returns>
+        /// <remarks>
+        /// This function is called synchronously on the thread which made the
+        /// first call to <c>Shutdown</c>. This function should not throw
+        /// exceptions.
+        /// </remarks>
+        protected virtual bool OnShutdown(int timeoutMilliseconds)
+        {
+            return true;
+        }
+
         /// <summary>
         /// Releases the unmanaged resources used by this class and optionally releases the managed resources.
         /// </summary>

src/OpenTelemetry/CHANGELOG.md

@@ -2,14 +2,15 @@
 
 ## Unreleased
 
+* Implemented Shutdown for TracerProvider
+  ([#1489](https://github.com/open-telemetry/opentelemetry-dotnet/pull/1489))
+
 ## 0.8.0-beta.1
 
 Released 2020-Nov-5
 
-* TracerProviderBuilder API changes
-  Renamed AddInstrumentation to AddDiagnosticSourceInstrumentation
-  and made internal.
-  Added AddInstrumentation
+* TracerProviderBuilder API changes Renamed AddInstrumentation to
+  AddDiagnosticSourceInstrumentation and made internal. Added AddInstrumentation
   ([#1454](https://github.com/open-telemetry/opentelemetry-dotnet/pull/1454))
 
 * DiagnosticSource subscription helper classes (DiagnosticSourceSubscriber,

src/OpenTelemetry/Trace/TracerProviderSdk.cs

@@ -20,6 +20,7 @@
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Text.RegularExpressions;
+using System.Threading;
 using OpenTelemetry.Internal;
 using OpenTelemetry.Resources;
 
@@ -220,6 +221,14 @@ protected override void Dispose(bool disposing)
             base.Dispose(disposing);
         }
 
+        protected override bool OnShutdown(int timeoutMilliseconds)
+        {
+            bool? result;
+            result = this.processor?.Shutdown(timeoutMilliseconds);
+            this.listener?.Dispose();
+            return result ?? true;
+        }
+
         private static ActivitySamplingResult ComputeActivitySamplingResult(
             in ActivityCreationOptions<ActivityContext> options,
             Sampler sampler)