get rid of explicit GrpcEnvironment.Shutdown()

src/csharp/Grpc.Core.Tests/ChannelTest.cs

@@ -41,12 +41,6 @@ namespace Grpc.Core.Tests
 {
     public class ChannelTest
     {
-        [TestFixtureTearDown]
-        public void CleanupClass()
-        {
-            GrpcEnvironment.Shutdown();
-        }
-
         [Test]
         public void Constructor_RejectsInvalidParams()
         {
@@ -56,36 +50,33 @@ namespace Grpc.Core.Tests
         [Test]
         public void State_IdleAfterCreation()
         {
-            using (var channel = new Channel("localhost", Credentials.Insecure))
+            var channel = new Channel("localhost", Credentials.Insecure);
-            {
             Assert.AreEqual(ChannelState.Idle, channel.State);
-            }
+            channel.ShutdownAsync().Wait();
         }
 
         [Test]
         public void WaitForStateChangedAsync_InvalidArgument()
         {
-            using (var channel = new Channel("localhost", Credentials.Insecure))
+            var channel = new Channel("localhost", Credentials.Insecure);
-            {
             Assert.Throws(typeof(ArgumentException), () => channel.WaitForStateChangedAsync(ChannelState.FatalFailure));
-            }
+            channel.ShutdownAsync().Wait();
         }
 
         [Test]
         public void ResolvedTarget()
         {
-            using (var channel = new Channel("127.0.0.1", Credentials.Insecure))
+            var channel = new Channel("127.0.0.1", Credentials.Insecure);
-            {
             Assert.IsTrue(channel.ResolvedTarget.Contains("127.0.0.1"));
-            }
+            channel.ShutdownAsync().Wait();
         }
 
         [Test]
-        public void Dispose_IsIdempotent()
+        public void Shutdown_AllowedOnlyOnce()
         {
             var channel = new Channel("localhost", Credentials.Insecure);
-            channel.Dispose();
+            channel.ShutdownAsync().Wait();
-            channel.Dispose();
+            Assert.Throws(typeof(InvalidOperationException), () => channel.ShutdownAsync().GetAwaiter().GetResult());
         }
     }
 }

src/csharp/Grpc.Core.Tests/ClientServerTest.cs

@@ -63,16 +63,10 @@ namespace Grpc.Core.Tests
         [TearDown]
         public void Cleanup()
         {
-            channel.Dispose();
+            channel.ShutdownAsync().Wait();
             server.ShutdownAsync().Wait();
         }
 
-        [TestFixtureTearDown]
-        public void CleanupClass()
-        {
-            GrpcEnvironment.Shutdown();
-        }
-
         [Test]
         public async Task UnaryCall()
         {
@@ -207,13 +201,6 @@ namespace Grpc.Core.Tests
             CollectionAssert.AreEqual(headers[1].ValueBytes, trailers[1].ValueBytes);
         }
 
-        [Test]
-        public void UnaryCall_DisposedChannel()
-        {
-            channel.Dispose();
-            Assert.Throws(typeof(ObjectDisposedException), () => Calls.BlockingUnaryCall(helper.CreateUnaryCall(), "ABC"));
-        }
-
         [Test]
         public void UnaryCallPerformance()
         {

src/csharp/Grpc.Core.Tests/CompressionTest.cs

@@ -62,16 +62,10 @@ namespace Grpc.Core.Tests
         [TearDown]
         public void Cleanup()
         {
-            channel.Dispose();
+            channel.ShutdownAsync().Wait();
             server.ShutdownAsync().Wait();
         }
 
-        [TestFixtureTearDown]
-        public void CleanupClass()
-        {
-            GrpcEnvironment.Shutdown();
-        }
-
         [Test]
         public void WriteOptions_Unary()
         {

src/csharp/Grpc.Core.Tests/ContextPropagationTest.cs

@@ -62,16 +62,10 @@ namespace Grpc.Core.Tests
         [TearDown]
         public void Cleanup()
         {
-            channel.Dispose();
+            channel.ShutdownAsync().Wait();
             server.ShutdownAsync().Wait();
         }
 
-        [TestFixtureTearDown]
-        public void CleanupClass()
-        {
-            GrpcEnvironment.Shutdown();
-        }
-
         [Test]
         public async Task PropagateCancellation()
         {

src/csharp/Grpc.Core.Tests/Grpc.Core.Tests.csproj

@@ -64,6 +64,7 @@
       <Link>Version.cs</Link>
     </Compile>
     <Compile Include="ClientBaseTest.cs" />
+    <Compile Include="ShutdownTest.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ClientServerTest.cs" />
     <Compile Include="ServerTest.cs" />

src/csharp/Grpc.Core.Tests/GrpcEnvironmentTest.cs

@@ -43,33 +43,39 @@ namespace Grpc.Core.Tests
         [Test]
         public void InitializeAndShutdownGrpcEnvironment()
         {
-            var env = GrpcEnvironment.GetInstance();
+            var env = GrpcEnvironment.AddRef();
             Assert.IsNotNull(env.CompletionQueue);
-            GrpcEnvironment.Shutdown();
+            GrpcEnvironment.Release();
         }
 
         [Test]
         public void SubsequentInvocations()
         {
-            var env1 = GrpcEnvironment.GetInstance();
+            var env1 = GrpcEnvironment.AddRef();
-            var env2 = GrpcEnvironment.GetInstance();
+            var env2 = GrpcEnvironment.AddRef();
             Assert.IsTrue(object.ReferenceEquals(env1, env2));
-            GrpcEnvironment.Shutdown();
+            GrpcEnvironment.Release();
-            GrpcEnvironment.Shutdown();
+            GrpcEnvironment.Release();
         }
 
         [Test]
         public void InitializeAfterShutdown()
         {
-            var env1 = GrpcEnvironment.GetInstance();
+            var env1 = GrpcEnvironment.AddRef();
-            GrpcEnvironment.Shutdown();
+            GrpcEnvironment.Release();
 
-            var env2 = GrpcEnvironment.GetInstance();
+            var env2 = GrpcEnvironment.AddRef();
-            GrpcEnvironment.Shutdown();
+            GrpcEnvironment.Release();
 
             Assert.IsFalse(object.ReferenceEquals(env1, env2));
         }
 
+        [Test]
+        public void ReleaseWithoutAddRef()
+        {
+            Assert.Throws(typeof(InvalidOperationException), () => GrpcEnvironment.Release());
+        }
+
         [Test]
         public void GetCoreVersionString()
         {

src/csharp/Grpc.Core.Tests/ResponseHeadersTest.cs

@@ -69,16 +69,10 @@ namespace Grpc.Core.Tests
         [TearDown]
         public void Cleanup()
         {
-            channel.Dispose();
+            channel.ShutdownAsync().Wait();
             server.ShutdownAsync().Wait();
         }
 
-        [TestFixtureTearDown]
-        public void CleanupClass()
-        {
-            GrpcEnvironment.Shutdown();
-        }
-
         [Test]
         public void WriteResponseHeaders_NullNotAllowed()
         {

src/csharp/Grpc.Core.Tests/ServerTest.cs

@@ -51,7 +51,6 @@ namespace Grpc.Core.Tests
             };
             server.Start();
             server.ShutdownAsync().Wait();
-            GrpcEnvironment.Shutdown();
         }
 
         [Test]
@@ -67,8 +66,7 @@ namespace Grpc.Core.Tests
             Assert.Greater(boundPort.BoundPort, 0);
 
             server.Start();
-            server.ShutdownAsync();
+            server.ShutdownAsync().Wait();
-            GrpcEnvironment.Shutdown();
         }
 
         [Test]
@@ -83,7 +81,6 @@ namespace Grpc.Core.Tests
             Assert.Throws(typeof(InvalidOperationException), () => server.Services.Add(ServerServiceDefinition.CreateBuilder("serviceName").Build()));
 
             server.ShutdownAsync().Wait();
-            GrpcEnvironment.Shutdown();
         }
     }
 }

src/csharp/Grpc.Core.Tests/ShutdownTest.cs

@@ -0,0 +1,77 @@
+#region Copyright notice and license
+
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#endregion
+
+using System;
+using System.Diagnostics;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Grpc.Core;
+using Grpc.Core.Internal;
+using Grpc.Core.Utils;
+using NUnit.Framework;
+
+namespace Grpc.Core.Tests
+{
+    public class ShutdownTest
+    {
+        const string Host = "127.0.0.1";
+
+        MockServiceHelper helper;
+        Server server;
+        Channel channel;
+
+        [SetUp]
+        public void Init()
+        {
+            helper = new MockServiceHelper(Host);
+            server = helper.GetServer();
+            server.Start();
+            channel = helper.GetChannel();
+        }
+
+        [Test]
+        public async Task AbandonedCall()
+        {
+            helper.DuplexStreamingHandler = new DuplexStreamingServerMethod<string, string>(async (requestStream, responseStream, context) =>
+            {
+                await requestStream.ToListAsync();
+            });
+
+            var call = Calls.AsyncDuplexStreamingCall(helper.CreateDuplexStreamingCall(new CallOptions(deadline: DateTime.UtcNow.AddMilliseconds(1))));
+
+            channel.ShutdownAsync().Wait();
+            server.ShutdownAsync().Wait();
+        }
+    }
+}

src/csharp/Grpc.Core.Tests/TimeoutsTest.cs

@@ -65,16 +65,10 @@ namespace Grpc.Core.Tests
         [TearDown]
         public void Cleanup()
         {
-            channel.Dispose();
+            channel.ShutdownAsync().Wait();
             server.ShutdownAsync().Wait();
         }
 
-        [TestFixtureTearDown]
-        public void CleanupClass()
-        {
-            GrpcEnvironment.Shutdown();
-        }
-
         [Test]
         public void InfiniteDeadline()
         {

src/csharp/Grpc.Core/Channel.cs

@@ -45,14 +45,19 @@ namespace Grpc.Core
     /// <summary>
     /// gRPC Channel
     /// </summary>
-    public class Channel : IDisposable
+    public class Channel
     {
         static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<Channel>();
 
+        readonly object myLock = new object();
+        readonly AtomicCounter activeCallCounter = new AtomicCounter();
+
         readonly string target;
         readonly GrpcEnvironment environment;
         readonly ChannelSafeHandle handle;
         readonly List<ChannelOption> options;
+
+        bool shutdownRequested;
         bool disposed;
 
         /// <summary>
@@ -65,7 +70,7 @@ namespace Grpc.Core
         public Channel(string target, Credentials credentials, IEnumerable<ChannelOption> options = null)
         {
             this.target = Preconditions.CheckNotNull(target, "target");
-            this.environment = GrpcEnvironment.GetInstance();
+            this.environment = GrpcEnvironment.AddRef();
             this.options = options != null ? new List<ChannelOption>(options) : new List<ChannelOption>();
 
             EnsureUserAgentChannelOption(this.options);
@@ -172,12 +177,26 @@ namespace Grpc.Core
         }
 
         /// <summary>
-        /// Destroys the underlying channel.
+        /// Waits until there are no more active calls for this channel and then cleans up
+        /// resources used by this channel.
         /// </summary>
-        public void Dispose()
+        public async Task ShutdownAsync()
+        {
+            lock (myLock)
+            {
+                Preconditions.CheckState(!shutdownRequested);
+                shutdownRequested = true;
+            }
+
+            var activeCallCount = activeCallCounter.Count;
+            if (activeCallCount > 0)
             {
-            Dispose(true);
+                Logger.Warning("Channel shutdown was called but there are still {0} active calls for that channel.", activeCallCount);
-            GC.SuppressFinalize(this);
+            }
+
+            handle.Dispose();
+
+            await Task.Run(() => GrpcEnvironment.Release());
         }
 
         internal ChannelSafeHandle Handle
@@ -196,13 +215,20 @@ namespace Grpc.Core
             }
         }
 
-        protected virtual void Dispose(bool disposing)
+        internal void AddCallReference(object call)
         {
-            if (disposing && handle != null && !disposed)
+            activeCallCounter.Increment();
-            {
+
-                disposed = true;
+            bool success = false;
-                handle.Dispose();
+            handle.DangerousAddRef(ref success);
+            Preconditions.CheckState(success);
         }
+
+        internal void RemoveCallReference(object call)
+        {
+            handle.DangerousRelease();
+
+            activeCallCounter.Decrement();
         }
 
         private static void EnsureUserAgentChannelOption(List<ChannelOption> options)

src/csharp/Grpc.Core/GrpcEnvironment.cs

@@ -58,6 +58,7 @@ namespace Grpc.Core
 
         static object staticLock = new object();
         static GrpcEnvironment instance;
+        static int refCount;
 
         static ILogger logger = new ConsoleLogger();
 
@@ -67,13 +68,14 @@ namespace Grpc.Core
         bool isClosed;
 
         /// <summary>
-        /// Returns an instance of initialized gRPC environment.
+        /// Returns a reference-counted instance of initialized gRPC environment.
-        /// Subsequent invocations return the same instance unless Shutdown has been called first.
+        /// Subsequent invocations return the same instance unless reference count has dropped to zero previously.
         /// </summary>
-        internal static GrpcEnvironment GetInstance()
+        internal static GrpcEnvironment AddRef()
         {
             lock (staticLock)
             {
+                refCount++;
                 if (instance == null)
                 {
                     instance = new GrpcEnvironment();
@@ -83,14 +85,16 @@ namespace Grpc.Core
         }
 
         /// <summary>
-        /// Shuts down the gRPC environment if it was initialized before.
+        /// Decrements the reference count for currently active environment and shuts down the gRPC environment if reference count drops to zero.
-        /// Blocks until the environment has been fully shutdown.
+        /// (and blocks until the environment has been fully shutdown).
         /// </summary>
-        public static void Shutdown()
+        internal static void Release()
         {
             lock (staticLock)
             {
-                if (instance != null)
+                Preconditions.CheckState(refCount > 0);
+                refCount--;
+                if (refCount == 0)
                 {
                     instance.Close();
                     instance = null;
@@ -125,12 +129,10 @@ namespace Grpc.Core
         private GrpcEnvironment()
         {
             NativeLogRedirector.Redirect();
-            grpcsharp_init();
+            GrpcNativeInit();
             completionRegistry = new CompletionRegistry(this);
             threadPool = new GrpcThreadPool(this, THREAD_POOL_SIZE);
             threadPool.Start();
-            // TODO: use proper logging here
-            Logger.Info("gRPC initialized.");
         }
 
         /// <summary>
@@ -175,6 +177,17 @@ namespace Grpc.Core
             return Marshal.PtrToStringAnsi(ptr);
         }
 
+
+        internal static void GrpcNativeInit()
+        {
+            grpcsharp_init();
+        }
+
+        internal static void GrpcNativeShutdown()
+        {
+            grpcsharp_shutdown();
+        }
+
         /// <summary>
         /// Shuts down this environment.
         /// </summary>
@@ -185,12 +198,10 @@ namespace Grpc.Core
                 throw new InvalidOperationException("Close has already been called");
             }
             threadPool.Stop();
-            grpcsharp_shutdown();
+            GrpcNativeShutdown();
             isClosed = true;
 
             debugStats.CheckOK();
-
-            Logger.Info("gRPC shutdown.");
         }
     }
 }

src/csharp/Grpc.Core/Internal/AsyncCall.cs

@@ -311,9 +311,9 @@ namespace Grpc.Core.Internal
             }
         }
 
-        protected override void OnReleaseResources()
+        protected override void OnAfterReleaseResources()
         {
-            details.Channel.Environment.DebugStats.ActiveClientCalls.Decrement();
+            details.Channel.RemoveCallReference(this);
         }
 
         private void Initialize(CompletionQueueSafeHandle cq)
@@ -323,7 +323,9 @@ namespace Grpc.Core.Internal
             var call = details.Channel.Handle.CreateCall(details.Channel.Environment.CompletionRegistry,
                 parentCall, ContextPropagationToken.DefaultMask, cq,
                 details.Method, details.Host, Timespec.FromDateTime(details.Options.Deadline.Value));
-            details.Channel.Environment.DebugStats.ActiveClientCalls.Increment();
+
+            details.Channel.AddCallReference(this);
+
             InitializeInternal(call);
             RegisterCancellationCallback();
         }

src/csharp/Grpc.Core/Internal/AsyncCallBase.cs

@@ -189,15 +189,15 @@ namespace Grpc.Core.Internal
 
         private void ReleaseResources()
         {
-            OnReleaseResources();
             if (call != null)
             {
                 call.Dispose();
             }
             disposed = true;
+            OnAfterReleaseResources();
         }
 
-        protected virtual void OnReleaseResources()
+        protected virtual void OnAfterReleaseResources()
         {
         }
 
@@ -212,7 +212,7 @@ namespace Grpc.Core.Internal
             Preconditions.CheckState(sendCompletionDelegate == null, "Only one write can be pending at a time");
         }
 
-        protected void CheckReadingAllowed()
+        protected virtual void CheckReadingAllowed()
         {
             Preconditions.CheckState(started);
             Preconditions.CheckState(!disposed);

src/csharp/Grpc.Core/Internal/AsyncCallServer.cs

@@ -50,16 +50,19 @@ namespace Grpc.Core.Internal
         readonly TaskCompletionSource<object> finishedServersideTcs = new TaskCompletionSource<object>();
         readonly CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
         readonly GrpcEnvironment environment;
+        readonly Server server;
 
-        public AsyncCallServer(Func<TResponse, byte[]> serializer, Func<byte[], TRequest> deserializer, GrpcEnvironment environment) : base(serializer, deserializer)
+        public AsyncCallServer(Func<TResponse, byte[]> serializer, Func<byte[], TRequest> deserializer, GrpcEnvironment environment, Server server) : base(serializer, deserializer)
         {
             this.environment = Preconditions.CheckNotNull(environment);
+            this.server = Preconditions.CheckNotNull(server);
         }
 
         public void Initialize(CallSafeHandle call)
         {
             call.SetCompletionRegistry(environment.CompletionRegistry);
-            environment.DebugStats.ActiveServerCalls.Increment();
+
+            server.AddCallReference(this);
             InitializeInternal(call);
         }
 
@@ -168,9 +171,15 @@ namespace Grpc.Core.Internal
             }
         }
 
-        protected override void OnReleaseResources()
+        protected override void CheckReadingAllowed()
+        {
+            base.CheckReadingAllowed();
+            Preconditions.CheckArgument(!cancelRequested);
+        }
+
+        protected override void OnAfterReleaseResources()
         {
-            environment.DebugStats.ActiveServerCalls.Decrement();
+            server.RemoveCallReference(this);
         }
 
         /// <summary>

src/csharp/Grpc.Core/Internal/BatchContextSafeHandle.cs

@@ -134,7 +134,7 @@ namespace Grpc.Core.Internal
         }
 
         // Gets data of server_rpc_new completion.
-        public ServerRpcNew GetServerRpcNew()
+        public ServerRpcNew GetServerRpcNew(Server server)
         {
             var call = grpcsharp_batch_context_server_rpc_new_call(this);
 
@@ -145,7 +145,7 @@ namespace Grpc.Core.Internal
             IntPtr metadataArrayPtr = grpcsharp_batch_context_server_rpc_new_request_metadata(this);
             var metadata = MetadataArraySafeHandle.ReadMetadataFromPtrUnsafe(metadataArrayPtr);
 
-            return new ServerRpcNew(call, method, host, deadline, metadata);
+            return new ServerRpcNew(server, call, method, host, deadline, metadata);
         }
 
         // Gets data of receive_close_on_server completion.
@@ -198,14 +198,16 @@ namespace Grpc.Core.Internal
     /// </summary>
     internal struct ServerRpcNew
     {
+        readonly Server server;
         readonly CallSafeHandle call;
         readonly string method;
         readonly string host;
         readonly Timespec deadline;
         readonly Metadata requestMetadata;
 
-        public ServerRpcNew(CallSafeHandle call, string method, string host, Timespec deadline, Metadata requestMetadata)
+        public ServerRpcNew(Server server, CallSafeHandle call, string method, string host, Timespec deadline, Metadata requestMetadata)
         {
+            this.server = server;
             this.call = call;
             this.method = method;
             this.host = host;
@@ -213,6 +215,14 @@ namespace Grpc.Core.Internal
             this.requestMetadata = requestMetadata;
         }
 
+        public Server Server
+        {
+            get
+            {
+                return this.server;
+            }
+        }
+
         public CallSafeHandle Call
         {
             get

src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs

@@ -68,11 +68,17 @@ namespace Grpc.Core.Internal
 
         public static ChannelSafeHandle CreateInsecure(string target, ChannelArgsSafeHandle channelArgs)
         {
+            // Increment reference count for the native gRPC environment to make sure we don't do grpc_shutdown() before destroying the server handle.
+            // Doing so would make object finalizer crash if we end up abandoning the handle.
+            GrpcEnvironment.GrpcNativeInit();
             return grpcsharp_insecure_channel_create(target, channelArgs);
         }
 
         public static ChannelSafeHandle CreateSecure(CredentialsSafeHandle credentials, string target, ChannelArgsSafeHandle channelArgs)
         {
+            // Increment reference count for the native gRPC environment to make sure we don't do grpc_shutdown() before destroying the server handle.
+            // Doing so would make object finalizer crash if we end up abandoning the handle.
+            GrpcEnvironment.GrpcNativeInit();
             return grpcsharp_secure_channel_create(credentials, target, channelArgs);
         }
 
@@ -107,6 +113,7 @@ namespace Grpc.Core.Internal
         protected override bool ReleaseHandle()
         {
             grpcsharp_channel_destroy(handle);
+            GrpcEnvironment.GrpcNativeShutdown();
             return true;
         }
     }

src/csharp/Grpc.Core/Internal/DebugStats.cs

@@ -38,10 +38,6 @@ namespace Grpc.Core.Internal
 {
     internal class DebugStats
     {
-        public readonly AtomicCounter ActiveClientCalls = new AtomicCounter();
-
-        public readonly AtomicCounter ActiveServerCalls = new AtomicCounter();
-
         public readonly AtomicCounter PendingBatchCompletions = new AtomicCounter();
 
         /// <summary>
@@ -49,16 +45,6 @@ namespace Grpc.Core.Internal
         /// </summary>
         public void CheckOK()
         {
-            var remainingClientCalls = ActiveClientCalls.Count;
-            if (remainingClientCalls != 0)
-            {                
-                DebugWarning(string.Format("Detected {0} client calls that weren't disposed properly.", remainingClientCalls));
-            }
-            var remainingServerCalls = ActiveServerCalls.Count;
-            if (remainingServerCalls != 0)
-            {
-                DebugWarning(string.Format("Detected {0} server calls that weren't disposed properly.", remainingServerCalls));
-            }
             var pendingBatchCompletions = PendingBatchCompletions.Count;
             if (pendingBatchCompletions != 0)
             {

src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs

@@ -83,8 +83,6 @@ namespace Grpc.Core.Internal
             lock (myLock)
             {
                 cq.Shutdown();
-
-                Logger.Info("Waiting for GRPC threads to finish.");
                 foreach (var thread in threads)
                 {
                     thread.Join();
@@ -136,7 +134,6 @@ namespace Grpc.Core.Internal
                 }
             }
             while (ev.type != GRPCCompletionType.Shutdown);
-            Logger.Info("Completion queue has shutdown successfully, thread {0} exiting.", Thread.CurrentThread.Name);
         }
     }
 }

src/csharp/Grpc.Core/Internal/ServerCallHandler.cs

@@ -67,7 +67,7 @@ namespace Grpc.Core.Internal
             var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                 method.ResponseMarshaller.Serializer,
                 method.RequestMarshaller.Deserializer,
-                environment);
+                environment, newRpc.Server);
 
             asyncCall.Initialize(newRpc.Call);
             var finishedTask = asyncCall.ServerSideCallAsync();
@@ -123,7 +123,7 @@ namespace Grpc.Core.Internal
             var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                 method.ResponseMarshaller.Serializer,
                 method.RequestMarshaller.Deserializer,
-                environment);
+                environment, newRpc.Server);
 
             asyncCall.Initialize(newRpc.Call);
             var finishedTask = asyncCall.ServerSideCallAsync();
@@ -179,7 +179,7 @@ namespace Grpc.Core.Internal
             var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                 method.ResponseMarshaller.Serializer,
                 method.RequestMarshaller.Deserializer,
-                environment);
+                environment, newRpc.Server);
 
             asyncCall.Initialize(newRpc.Call);
             var finishedTask = asyncCall.ServerSideCallAsync();
@@ -239,7 +239,7 @@ namespace Grpc.Core.Internal
             var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                 method.ResponseMarshaller.Serializer,
                 method.RequestMarshaller.Deserializer,
-                environment);
+                environment, newRpc.Server);
 
             asyncCall.Initialize(newRpc.Call);
             var finishedTask = asyncCall.ServerSideCallAsync();
@@ -278,7 +278,7 @@ namespace Grpc.Core.Internal
         {
             // We don't care about the payload type here.
             var asyncCall = new AsyncCallServer<byte[], byte[]>(
-                (payload) => payload, (payload) => payload, environment);
+                (payload) => payload, (payload) => payload, environment, newRpc.Server);
             
             asyncCall.Initialize(newRpc.Call);
             var finishedTask = asyncCall.ServerSideCallAsync();

src/csharp/Grpc.Core/Internal/ServerSafeHandle.cs

@@ -74,6 +74,9 @@ namespace Grpc.Core.Internal
 
         public static ServerSafeHandle NewServer(CompletionQueueSafeHandle cq, ChannelArgsSafeHandle args)
         {
+            // Increment reference count for the native gRPC environment to make sure we don't do grpc_shutdown() before destroying the server handle.
+            // Doing so would make object finalizer crash if we end up abandoning the handle.
+            GrpcEnvironment.GrpcNativeInit();
             return grpcsharp_server_create(cq, args);
         }
 
@@ -109,6 +112,7 @@ namespace Grpc.Core.Internal
         protected override bool ReleaseHandle()
         {
             grpcsharp_server_destroy(handle);
+            GrpcEnvironment.GrpcNativeShutdown();
             return true;
         }
             

src/csharp/Grpc.Core/Logging/ConsoleLogger.cs

@@ -51,7 +51,19 @@ namespace Grpc.Core.Logging
         private ConsoleLogger(Type forType)
         {
             this.forType = forType;
-            this.forTypeString = forType != null ? forType.FullName + " " : "";
+            if (forType != null)
+            {
+                var namespaceStr = forType.Namespace ?? "";
+                if (namespaceStr.Length > 0)
+                {
+                     namespaceStr += ".";
+                }
+                this.forTypeString = namespaceStr + forType.Name + " ";
+            }
+            else
+            {
+                this.forTypeString = "";
+            }
         }
  
         /// <summary>

src/csharp/Grpc.Core/Server.cs

@@ -50,6 +50,8 @@ namespace Grpc.Core
     {
         static readonly ILogger Logger = GrpcEnvironment.Logger.ForType<Server>();
 
+        readonly AtomicCounter activeCallCounter = new AtomicCounter();
+
         readonly ServiceDefinitionCollection serviceDefinitions;
         readonly ServerPortCollection ports;
         readonly GrpcEnvironment environment;
@@ -73,7 +75,7 @@ namespace Grpc.Core
         {
             this.serviceDefinitions = new ServiceDefinitionCollection(this);
             this.ports = new ServerPortCollection(this);
-            this.environment = GrpcEnvironment.GetInstance();
+            this.environment = GrpcEnvironment.AddRef();
             this.options = options != null ? new List<ChannelOption>(options) : new List<ChannelOption>();
             using (var channelArgs = ChannelOptions.CreateChannelArgs(this.options))
             {
@@ -105,6 +107,17 @@ namespace Grpc.Core
             }
         }
 
+        /// <summary>
+        /// To allow awaiting termination of the server.
+        /// </summary>
+        public Task ShutdownTask
+        {
+            get
+            {
+                return shutdownTcs.Task;
+            }
+        }
+
         /// <summary>
         /// Starts the server.
         /// </summary>
@@ -136,18 +149,9 @@ namespace Grpc.Core
 
             handle.ShutdownAndNotify(HandleServerShutdown, environment);
             await shutdownTcs.Task;
-            handle.Dispose();
+            DisposeHandle();
-        }
 
-        /// <summary>
+            await Task.Run(() => GrpcEnvironment.Release());
-        /// To allow awaiting termination of the server.
-        /// </summary>
-        public Task ShutdownTask
-        {
-            get
-            {
-                return shutdownTcs.Task;
-            }
         }
 
         /// <summary>
@@ -166,7 +170,22 @@ namespace Grpc.Core
             handle.ShutdownAndNotify(HandleServerShutdown, environment);
             handle.CancelAllCalls();
             await shutdownTcs.Task;
-            handle.Dispose();
+            DisposeHandle();
+        }
+
+        internal void AddCallReference(object call)
+        {
+            activeCallCounter.Increment();
+
+            bool success = false;
+            handle.DangerousAddRef(ref success);
+            Preconditions.CheckState(success);
+        }
+
+        internal void RemoveCallReference(object call)
+        {
+            handle.DangerousRelease();
+            activeCallCounter.Decrement();
         }
 
         /// <summary>
@@ -227,6 +246,16 @@ namespace Grpc.Core
             }
         }
 
+        private void DisposeHandle()
+        {
+            var activeCallCount = activeCallCounter.Count;
+            if (activeCallCount > 0)
+            {
+                Logger.Warning("Server shutdown has finished but there are still {0} active calls for that server.", activeCallCount);
+            }
+            handle.Dispose();
+        }
+
         /// <summary>
         /// Selects corresponding handler for given call and handles the call.
         /// </summary>
@@ -254,7 +283,7 @@ namespace Grpc.Core
         {
             if (success)
             {
-                ServerRpcNew newRpc = ctx.GetServerRpcNew();
+                ServerRpcNew newRpc = ctx.GetServerRpcNew(this);
 
                 // after server shutdown, the callback returns with null call
                 if (!newRpc.Call.IsInvalid)

src/csharp/Grpc.Examples.MathClient/MathClient.cs

@@ -39,8 +39,7 @@ namespace math
     {
         public static void Main(string[] args)
         {
-            using (Channel channel = new Channel("127.0.0.1", 23456, Credentials.Insecure))
+            var channel = new Channel("127.0.0.1", 23456, Credentials.Insecure);
-            {
             Math.IMathClient client = new Math.MathClient(channel);
             MathExamples.DivExample(client);
 
@@ -53,9 +52,8 @@ namespace math
             MathExamples.DivManyExample(client).Wait();
 
             MathExamples.DependendRequestsExample(client).Wait();
-            }
 
-            GrpcEnvironment.Shutdown();
+            channel.ShutdownAsync().Wait();
         }
     }
 }

src/csharp/Grpc.Examples.MathServer/MathServer.cs

@@ -56,7 +56,6 @@ namespace math
             Console.ReadKey();
 
             server.ShutdownAsync().Wait();
-            GrpcEnvironment.Shutdown();
         }
     }
 }

src/csharp/Grpc.Examples.Tests/MathClientServerTests.cs

@@ -68,9 +68,8 @@ namespace math.Tests
         [TestFixtureTearDown]
         public void Cleanup()
         {
-            channel.Dispose();
+            channel.ShutdownAsync().Wait();
             server.ShutdownAsync().Wait();
-            GrpcEnvironment.Shutdown();
         }
 
         [Test]

src/csharp/Grpc.HealthCheck.Tests/HealthClientServerTest.cs

@@ -71,10 +71,9 @@ namespace Grpc.HealthCheck.Tests
         [TestFixtureTearDown]
         public void Cleanup()
         {
-            channel.Dispose();
+            channel.ShutdownAsync().Wait();
 
             server.ShutdownAsync().Wait();
-            GrpcEnvironment.Shutdown();
         }
 
         [Test]

src/csharp/Grpc.IntegrationTesting/InteropClient.cs

@@ -120,12 +120,10 @@ namespace Grpc.IntegrationTesting
                 };
             }
 
-            using (Channel channel = new Channel(options.serverHost, options.serverPort.Value, credentials, channelOptions))
+            var channel = new Channel(options.serverHost, options.serverPort.Value, credentials, channelOptions);
-            {
             TestService.TestServiceClient client = new TestService.TestServiceClient(channel);
             await RunTestCaseAsync(options.testCase, client);
-            }
+            channel.ShutdownAsync().Wait();
-            GrpcEnvironment.Shutdown();
         }
 
         private async Task RunTestCaseAsync(string testCase, TestService.TestServiceClient client)

src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs

@@ -75,9 +75,8 @@ namespace Grpc.IntegrationTesting
         [TestFixtureTearDown]
         public void Cleanup()
         {
-            channel.Dispose();
+            channel.ShutdownAsync().Wait();
             server.ShutdownAsync().Wait();
-            GrpcEnvironment.Shutdown();
         }
 
         [Test]

src/csharp/Grpc.IntegrationTesting/InteropServer.cs

@@ -107,8 +107,6 @@ namespace Grpc.IntegrationTesting
             server.Start();
 
             server.ShutdownTask.Wait();
-
-            GrpcEnvironment.Shutdown();
         }
 
         private static ServerOptions ParseArguments(string[] args)

src/csharp/Grpc.IntegrationTesting/SslCredentialsTest.cs

@@ -85,9 +85,8 @@ namespace Grpc.IntegrationTesting
         [TestFixtureTearDown]
         public void Cleanup()
         {
-            channel.Dispose();
+            channel.ShutdownAsync().Wait();
             server.ShutdownAsync().Wait();
-            GrpcEnvironment.Shutdown();
         }
 
         [Test]