Implement #1156 by having the server send Ping messages

SignalR.sln

@@ -1,6 +1,6 @@
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 15
-VisualStudioVersion = 15.0.26923.0
+VisualStudioVersion = 15.0.27110.0
 MinimumVisualStudioVersion = 15.0.26730.03
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{DA69F624-5398-4884-87E4-B816698CDE65}"
 	ProjectSection(SolutionItems) = preProject
@@ -56,14 +56,6 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Signal
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.SignalR.Client.TS", "client-ts\Microsoft.AspNetCore.SignalR.Client.TS\Microsoft.AspNetCore.SignalR.Client.TS.csproj", "{333526A4-633B-491A-AC45-CC62A0012D1C}"
 EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Common", "Common", "{6CEC3DC2-5B01-45A8-8F0D-8531315DA90B}"
-	ProjectSection(SolutionItems) = preProject
-		test\Common\ChannelExtensions.cs = test\Common\ChannelExtensions.cs
-		test\Common\ServerFixture.cs = test\Common\ServerFixture.cs
-		test\Common\TaskExtensions.cs = test\Common\TaskExtensions.cs
-		test\Common\TestHelpers.cs = test\Common\TestHelpers.cs
-	EndProjectSection
-EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "client-ts", "client-ts", "{3A76C5A2-79ED-49BC-8BDC-6A3A766FFA1B}"
 	ProjectSection(SolutionItems) = preProject
 		client-ts\package.json = client-ts\package.json
@@ -91,7 +83,9 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Signal
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "JwtSample", "samples\JwtSample\JwtSample.csproj", "{6A7491D3-3C97-49BD-A71C-433AED657F30}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "JwtClientSample", "samples\JwtClientSample\JwtClientSample.csproj", "{1A953296-E869-4DE2-A693-FD5FCDE27057}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "JwtClientSample", "samples\JwtClientSample\JwtClientSample.csproj", "{1A953296-E869-4DE2-A693-FD5FCDE27057}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.AspNetCore.SignalR.Tests.Utils", "test\Microsoft.AspNetCore.SignalR.Tests.Utils\Microsoft.AspNetCore.SignalR.Tests.Utils.csproj", "{0A0A6135-EA24-4307-95C2-CE1B7E164A5E}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -207,6 +201,10 @@ Global
 		{1A953296-E869-4DE2-A693-FD5FCDE27057}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{1A953296-E869-4DE2-A693-FD5FCDE27057}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{1A953296-E869-4DE2-A693-FD5FCDE27057}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0A0A6135-EA24-4307-95C2-CE1B7E164A5E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0A0A6135-EA24-4307-95C2-CE1B7E164A5E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0A0A6135-EA24-4307-95C2-CE1B7E164A5E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0A0A6135-EA24-4307-95C2-CE1B7E164A5E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -228,7 +226,6 @@ Global
 		{354335AB-CEE9-4434-A641-78058F6EFE56} = {DA69F624-5398-4884-87E4-B816698CDE65}
 		{455B68D2-C5B6-4BF4-A685-964B07AFAAF8} = {6A35B453-52EC-48AF-89CA-D4A69800F131}
 		{333526A4-633B-491A-AC45-CC62A0012D1C} = {3A76C5A2-79ED-49BC-8BDC-6A3A766FFA1B}
-		{6CEC3DC2-5B01-45A8-8F0D-8531315DA90B} = {6A35B453-52EC-48AF-89CA-D4A69800F131}
 		{96771B3F-4D18-41A7-A75B-FF38E76AAC89} = {8A4582C8-DC59-4B61-BCE7-119FBAA99EFB}
 		{75E342F6-5445-4E7E-9143-6D9AE62C2B1E} = {6A35B453-52EC-48AF-89CA-D4A69800F131}
 		{F2E4FBD6-9AEA-4A82-BAC9-3FAACA677DF8} = {DA69F624-5398-4884-87E4-B816698CDE65}
@@ -240,6 +237,7 @@ Global
 		{0B083AE6-86CA-4E0B-AE02-59154D1FD005} = {6A35B453-52EC-48AF-89CA-D4A69800F131}
 		{6A7491D3-3C97-49BD-A71C-433AED657F30} = {C4BC9889-B49F-41B6-806B-F84941B2549B}
 		{1A953296-E869-4DE2-A693-FD5FCDE27057} = {C4BC9889-B49F-41B6-806B-F84941B2549B}
+		{0A0A6135-EA24-4307-95C2-CE1B7E164A5E} = {6A35B453-52EC-48AF-89CA-D4A69800F131}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {7945A4E4-ACDB-4F6E-95CA-6AC6E7C2CD59}

benchmarks/Microsoft.AspNetCore.SignalR.Microbenchmarks/BroadcastBenchmark.cs

@@ -1,10 +1,12 @@
 using System;
+using System.Threading;
 using System.Threading.Channels;
 using System.Threading.Tasks;
 using BenchmarkDotNet.Attributes;
 using Microsoft.AspNetCore.SignalR.Internal.Protocol;
 using Microsoft.AspNetCore.Sockets;
 using Microsoft.AspNetCore.Sockets.Internal;
+using Microsoft.Extensions.Logging.Abstractions;
 
 namespace Microsoft.AspNetCore.SignalR.Microbenchmarks
 {
@@ -32,7 +34,7 @@ public void GlobalSetup()
                 var transport = ChannelConnection.Create<byte[]>(input: transportToApplication, output: applicationToTransport);
                 var connection = new DefaultConnectionContext(Guid.NewGuid().ToString(), transport, application);
 
-                _hubLifetimeManager.OnConnectedAsync(new HubConnectionContext(Channel.CreateUnbounded<HubMessage>(), connection)).Wait();
+                _hubLifetimeManager.OnConnectedAsync(new HubConnectionContext(connection, Timeout.InfiniteTimeSpan, NullLoggerFactory.Instance)).Wait();
             }
 
             _hubContext = new HubContext<Hub>(_hubLifetimeManager);

samples/SocketsSample/Startup.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.DependencyInjection;
@@ -17,7 +18,11 @@ public void ConfigureServices(IServiceCollection services)
         {
             services.AddSockets();
 
-            services.AddSignalR();
+            services.AddSignalR(options =>
+            {
+                // Faster pings for testing
+                options.KeepAliveInterval = TimeSpan.FromSeconds(5);
+            });
             // .AddRedis();
 
             services.AddCors(o =>

samples/SocketsSample/wwwroot/hubs.html

@@ -1,4 +1,4 @@
-<!DOCTYPE html>
+<!DOCTYPE html>
 <html>
 <head>
     <meta charset="utf-8" />

samples/SocketsSample/wwwroot/sockets.html

@@ -1,4 +1,4 @@
-<!DOCTYPE html>
+<!DOCTYPE html>
 <html>
 <head>
     <meta charset="utf-8" />
@@ -31,7 +31,7 @@ <h1 id="transportName">Unknown Transport</h1>
             document.getElementById('transportName').innerHTML = signalR.TransportType[transportType];
 
             let url = 'http://' + document.location.host + '/chat';
-            let connection = new signalR.HttpConnection(url, { transport: transportType, logger: new signalR.ConsoleLogger(signalR.LogLevel.Information) });
+            let connection = new signalR.HttpConnection(url, { transport: transportType, logging: new signalR.ConsoleLogger(signalR.LogLevel.Information) });
 
             connection.onreceive =  function(data) {
                 let child = document.createElement('li');

samples/SocketsSample/wwwroot/streaming.html

@@ -1,4 +1,4 @@
-<!DOCTYPE html>
+<!DOCTYPE html>
 <html>
 <head>
     <meta charset="utf-8" />
@@ -65,7 +65,7 @@ <h2>Results</h2>
             });
 
             click('connectButton', function () {
-                connection = new signalR.HubConnection('/streaming', { transport: transportType, logger: logger });
+                connection = new signalR.HubConnection('/streaming', { transport: transportType, logging: logger });
 
                 connection.onclose(function () {
                     channelButton.disabled = true;

specs/HubProtocol.md

@@ -109,6 +109,8 @@ Keep alive behavior is achieved via the `Ping` message type. **Either endpoint**
 
 Ping messages do not have any payload, they are completely empty messages (aside from the encoding necessary to identify the message as a `Ping` message).
 
+It is up to the server implementation to decide how frequently (if at all) `Ping` frames are sent. The ASP.NET Core implementation sends `Ping` frames only when using the Server Sent Events and WebSockets transports, at a default interval of 15 seconds (configurable). However, a `Ping` frame is only sent if 15 seconds elapses since the last message was sent. Clients may choose to use the "Ping rate" to provide a timeout for the server connection. Since the Client can expect the server to send `Ping` frames at regular intervals, even when the connection is idle, it can use that to determine if the server has left without closing the connection. The ASP.NET Core implementation (both JavaScript and C#) use a default timeout window of 30 seconds, which is twice the server ping rate interval.
+
 ## Example
 
 Consider the following C# methods

src/Microsoft.AspNetCore.SignalR.Core/DefaultHubLifetimeManager.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
@@ -86,7 +86,7 @@ private Task InvokeAllWhere(string methodName, object[] args, Func<HubConnection
                     continue;
                 }
 
-                tasks.Add(WriteAsync(connection, message));
+                tasks.Add(connection.WriteAsync(message));
             }
 
             return Task.WhenAll(tasks);
@@ -108,7 +108,7 @@ public override Task InvokeConnectionAsync(string connectionId, string methodNam
 
             var message = CreateInvocationMessage(methodName, args);
 
-            return WriteAsync(connection, message);
+            return connection.WriteAsync(message);
         }
 
         public override Task InvokeGroupAsync(string groupName, string methodName, object[] args)
@@ -122,7 +122,7 @@ public override Task InvokeGroupAsync(string groupName, string methodName, objec
             if (group != null)
             {
                 var message = CreateInvocationMessage(methodName, args);
-                var tasks = group.Values.Select(c => WriteAsync(c, message));
+                var tasks = group.Values.Select(c => c.WriteAsync(message));
                 return Task.WhenAll(tasks);
             }
 
@@ -153,17 +153,6 @@ public override Task OnDisconnectedAsync(HubConnectionContext connection)
             return Task.CompletedTask;
         }
 
-        private async Task WriteAsync(HubConnectionContext connection, HubInvocationMessage hubMessage)
-        {
-            while (await connection.Output.WaitToWriteAsync())
-            {
-                if (connection.Output.TryWrite(hubMessage))
-                {
-                    break;
-                }
-            }
-        }
-
         private string GetInvocationId()
         {
             var invocationId = Interlocked.Increment(ref _nextInvocationId);