Misc generic host pr feedback (#1222)

samples/GenericHostSample/ServiceBaseLifetime.cs

@@ -31,7 +31,7 @@ namespace GenericHostSample
         public void RegisterDelayStartCallback(Action<object> callback, object state)
         {
             _startCallback = callback ?? throw new ArgumentNullException(nameof(callback));
-            _startState = state ?? throw new ArgumentNullException(nameof(state));
+            _startState = state;
 
             Run(this);
         }
@@ -39,7 +39,7 @@ namespace GenericHostSample
         public void RegisterStopCallback(Action<object> callback, object state)
         {
             _stopCallback = callback ?? throw new ArgumentNullException(nameof(callback));
-            _stopState = state ?? throw new ArgumentNullException(nameof(state));
+            _stopState = state;
         }
 
         public Task StopAsync(CancellationToken cancellationToken)

src/Microsoft.AspNetCore.Hosting.Abstractions/IWebHost.cs

@@ -31,13 +31,13 @@ namespace Microsoft.AspNetCore.Hosting
         /// <summary>
         /// Starts listening on the configured addresses.
         /// </summary>
-        Task StartAsync(CancellationToken cancellationToken = default(CancellationToken));
+        Task StartAsync(CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Attempt to gracefully stop the host.
         /// </summary>
         /// <param name="cancellationToken"></param>
         /// <returns></returns>
-        Task StopAsync(CancellationToken cancellationToken = default(CancellationToken));
+        Task StopAsync(CancellationToken cancellationToken = default);
     }
 }

src/Microsoft.AspNetCore.Hosting/Internal/WebHost.cs

@@ -109,7 +109,7 @@ namespace Microsoft.AspNetCore.Hosting.Internal
             StartAsync().GetAwaiter().GetResult();
         }
 
-        public virtual async Task StartAsync(CancellationToken cancellationToken = default(CancellationToken))
+        public virtual async Task StartAsync(CancellationToken cancellationToken = default)
         {
             HostingEventSource.Log.HostStart();
             _logger = _applicationServices.GetRequiredService<ILogger<WebHost>>();
@@ -282,7 +282,7 @@ namespace Microsoft.AspNetCore.Hosting.Internal
             }
         }
 
-        public async Task StopAsync(CancellationToken cancellationToken = default(CancellationToken))
+        public async Task StopAsync(CancellationToken cancellationToken = default)
         {
             if (_stopped)
             {

src/Microsoft.AspNetCore.Hosting/WebHostExtensions.cs

@@ -37,7 +37,7 @@ namespace Microsoft.AspNetCore.Hosting
         /// </summary>
         /// <param name="host">The running <see cref="IWebHost"/>.</param>
         /// <param name="token">The token to trigger shutdown.</param>
-        public static async Task WaitForShutdownAsync(this IWebHost host, CancellationToken token = default(CancellationToken))
+        public static async Task WaitForShutdownAsync(this IWebHost host, CancellationToken token = default)
         {
             var done = new ManualResetEventSlim(false);
             using (var cts = CancellationTokenSource.CreateLinkedTokenSource(token))
@@ -63,7 +63,7 @@ namespace Microsoft.AspNetCore.Hosting
         /// </summary>
         /// <param name="host">The <see cref="IWebHost"/> to run.</param>
         /// <param name="token">The token to trigger shutdown.</param>
-        public static async Task RunAsync(this IWebHost host, CancellationToken token = default(CancellationToken))
+        public static async Task RunAsync(this IWebHost host, CancellationToken token = default)
         {
             // Wait for token shutdown if it can be canceled
             if (token.CanBeCanceled)

src/Microsoft.AspNetCore.Server.IntegrationTesting/Common/RetryHelper.cs

@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Server.IntegrationTesting
         public static async Task<HttpResponseMessage> RetryRequest(
             Func<Task<HttpResponseMessage>> retryBlock,
             ILogger logger,
-            CancellationToken cancellationToken = default(CancellationToken),
+            CancellationToken cancellationToken = default,
             int retryCount = 60)
         {
             for (var retry = 0; retry < retryCount; retry++)

src/Microsoft.Extensions.Hosting.Abstractions/HostingAbstractionsHostBuilderExtensions.cs

@@ -8,7 +8,7 @@ namespace Microsoft.Extensions.Hosting
     public static class HostingAbstractionsHostBuilderExtensions
     {
         /// <summary>
-        /// Start the web host and listen on the specified urls.
+        /// Start the host and listen on the specified urls.
         /// </summary>
         /// <param name="hostBuilder">The <see cref="IHostBuilder"/> to start.</param>
         /// <returns>The <see cref="IHostBuilder"/>.</returns>

src/Microsoft.Extensions.Hosting.Abstractions/HostingAbstractionsHostExtensions.cs

@@ -41,7 +41,7 @@ namespace Microsoft.Extensions.Hosting
         }
 
         /// <summary>
-        /// Runs a web application and block the calling thread until host shutdown.
+        /// Runs an application and block the calling thread until host shutdown.
         /// </summary>
         /// <param name="host">The <see cref="IHost"/> to run.</param>
         public static void Run(this IHost host)
@@ -50,11 +50,11 @@ namespace Microsoft.Extensions.Hosting
         }
 
         /// <summary>
-        /// Runs a web application and returns a Task that only completes when the token is triggered or shutdown is triggered.
+        /// Runs an application and returns a Task that only completes when the token is triggered or shutdown is triggered.
         /// </summary>
         /// <param name="host">The <see cref="IHost"/> to run.</param>
         /// <param name="token">The token to trigger shutdown.</param>
-        public static async Task RunAsync(this IHost host, CancellationToken token = default(CancellationToken))
+        public static async Task RunAsync(this IHost host, CancellationToken token = default)
         {
             using (host)
             {
@@ -69,7 +69,7 @@ namespace Microsoft.Extensions.Hosting
         /// </summary>
         /// <param name="host">The running <see cref="IHost"/>.</param>
         /// <param name="token">The token to trigger shutdown.</param>
-        public static async Task WaitForShutdownAsync(this IHost host, CancellationToken token = default(CancellationToken))
+        public static async Task WaitForShutdownAsync(this IHost host, CancellationToken token = default)
         {
             var applicationLifetime = host.Services.GetService<IApplicationLifetime>();
 
@@ -88,7 +88,7 @@ namespace Microsoft.Extensions.Hosting
 
             await waitForStop.Task;
 
-            // WebHost will use its default ShutdownTimeout if none is specified.
+            // Host will use its default ShutdownTimeout if none is specified.
             await host.StopAsync();
         }
     }

src/Microsoft.Extensions.Hosting.Abstractions/IHost.cs

@@ -22,13 +22,13 @@ namespace Microsoft.Extensions.Hosting
         /// </summary>
         /// <param name="cancellationToken">Used to abort program start.</param>
         /// <returns></returns>
-        Task StartAsync(CancellationToken cancellationToken = default(CancellationToken));
+        Task StartAsync(CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Attempts to gracefully stop the program.
         /// </summary>
         /// <param name="cancellationToken">Used to indicate when stop should no longer be graceful.</param>
         /// <returns></returns>
-        Task StopAsync(CancellationToken cancellationToken = default(CancellationToken));
+        Task StopAsync(CancellationToken cancellationToken = default);
     }
 }

src/Microsoft.Extensions.Hosting.Abstractions/IHostingEnvironment.cs

@@ -1,13 +1,12 @@
 // 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.Collections.Generic;
 using Microsoft.Extensions.FileProviders;
 
 namespace Microsoft.Extensions.Hosting
 {
     /// <summary>
-    /// Provides information about the web hosting environment an application is running in.
+    /// Provides information about the hosting environment an application is running in.
     /// </summary>
     public interface IHostingEnvironment
     {

src/Microsoft.Extensions.Hosting/HostBuilder.cs

@@ -178,7 +178,7 @@ namespace Microsoft.Extensions.Hosting
             services.AddSingleton(_hostBuilderContext);
             services.AddSingleton(_appConfiguration);
             services.AddSingleton<IApplicationLifetime, ApplicationLifetime>();
-            services.AddSingleton<IHostLifetime, HostProcessLifetime>();
+            services.AddSingleton<IHostLifetime, ProcessLifetime>();
             services.AddOptions();
             services.AddLogging();
             

src/Microsoft.Extensions.Hosting/HostingHostBuilderExtensions.cs

@@ -15,7 +15,7 @@ namespace Microsoft.Extensions.Hosting
     public static class HostingHostBuilderExtensions
     {
         /// <summary>
-        /// Specify the environment to be used by the web host.
+        /// Specify the environment to be used by the host.
         /// </summary>
         /// <param name="hostBuilder">The <see cref="IHostBuilder"/> to configure.</param>
         /// <param name="environment">The environment to host the application in.</param>
@@ -33,7 +33,7 @@ namespace Microsoft.Extensions.Hosting
         }
 
         /// <summary>
-        /// Specify the content root directory to be used by the web host.
+        /// Specify the content root directory to be used by the host.
         /// </summary>
         /// <param name="hostBuilder">The <see cref="IHostBuilder"/> to configure.</param>
         /// <param name="contentRoot">Path to root directory of the application.</param>
@@ -125,7 +125,7 @@ namespace Microsoft.Extensions.Hosting
         /// <param name="hostBuilder">The <see cref="IHostBuilder" /> to configure.</param>
         /// <param name="cancellationToken"></param>
         /// <returns></returns>
-        public static Task RunConsoleAsync(this IHostBuilder hostBuilder, CancellationToken cancellationToken = default(CancellationToken))
+        public static Task RunConsoleAsync(this IHostBuilder hostBuilder, CancellationToken cancellationToken = default)
         {
             return hostBuilder.UseConsoleLifetime().Build().RunAsync(cancellationToken);
         }

src/Microsoft.Extensions.Hosting/Internal/Host.cs

@@ -28,7 +28,7 @@ namespace Microsoft.Extensions.Hosting.Internal
 
         public IServiceProvider Services { get; }
 
-        public async Task StartAsync(CancellationToken cancellationToken = default(CancellationToken))
+        public async Task StartAsync(CancellationToken cancellationToken = default)
         {
             _logger.Starting();
 
@@ -53,7 +53,7 @@ namespace Microsoft.Extensions.Hosting.Internal
             _logger.Started();
         }
 
-        public async Task StopAsync(CancellationToken cancellationToken = default(CancellationToken))
+        public async Task StopAsync(CancellationToken cancellationToken = default)
         {
             _logger.Stopping();
             

src/Microsoft.Extensions.Hosting/Internal/ProcessLifetime.cs

@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 
 namespace Microsoft.Extensions.Hosting.Internal
 {
-    public class HostProcessLifetime : IHostLifetime
+    public class ProcessLifetime : IHostLifetime
     {
         public void RegisterDelayStartCallback(Action<object> callback, object state)
         {