Use IHostLifetime to handle restarting and shutting down

3 files changed, 72 insertions, 191 deletions

diff --git a/Emby.Server.Implementations/ApplicationHost.cs b/Emby.Server.Implementations/ApplicationHost.cs
index 8b13ccadab..86721ace61 100644
--- a/Emby.Server.Implementations/ApplicationHost.cs
+++ b/Emby.Server.Implementations/ApplicationHost.cs
@@ -12,7 +12,6 @@ using System.Linq;
 using System.Net;
 using System.Reflection;
 using System.Security.Cryptography.X509Certificates;
-using System.Threading;
 using System.Threading.Tasks;
 using Emby.Dlna;
 using Emby.Dlna.Main;
@@ -112,7 +111,7 @@ namespace Emby.Server.Implementations
     /// <summary>
     /// Class CompositionRoot.
     /// </summary>
-    public abstract class ApplicationHost : IServerApplicationHost, IAsyncDisposable, IDisposable
+    public abstract class ApplicationHost : IServerApplicationHost, IDisposable
     {
         /// <summary>
         /// The disposable parts.
@@ -127,7 +126,6 @@ namespace Emby.Server.Implementations
         private readonly IPluginManager _pluginManager;
 
         private List<Type> _creatingInstances;
-        private ISessionManager _sessionManager;
 
         /// <summary>
         /// Gets or sets all concrete types.
@@ -172,6 +170,8 @@ namespace Emby.Server.Implementations
                 ConfigurationManager.Configuration,
                 ApplicationPaths.PluginsPath,
                 ApplicationVersion);
+
+            _disposableParts.TryAdd((PluginManager)_pluginManager, byte.MinValue);
         }
 
         /// <summary>
@@ -202,7 +202,10 @@ namespace Emby.Server.Implementations
         public bool HasPendingRestart { get; private set; }
 
         /// <inheritdoc />
-        public bool IsShuttingDown { get; private set; }
+        public bool IsShuttingDown { get; set; }
+
+        /// <inheritdoc />
+        public bool ShouldRestart { get; set; }
 
         /// <summary>
         /// Gets the logger.
@@ -406,11 +409,9 @@ namespace Emby.Server.Implementations
         /// <summary>
         /// Runs the startup tasks.
         /// </summary>
-        /// <param name="cancellationToken">The cancellation token.</param>
         /// <returns><see cref="Task" />.</returns>
-        public async Task RunStartupTasksAsync(CancellationToken cancellationToken)
+        public async Task RunStartupTasksAsync()
         {
-            cancellationToken.ThrowIfCancellationRequested();
             Logger.LogInformation("Running startup tasks");
 
             Resolve<ITaskManager>().AddTasks(GetExports<IScheduledTask>(false));
@@ -424,8 +425,6 @@ namespace Emby.Server.Implementations
 
             var entryPoints = GetExports<IServerEntryPoint>();
 
-            cancellationToken.ThrowIfCancellationRequested();
-
             var stopWatch = new Stopwatch();
             stopWatch.Start();
 
@@ -435,8 +434,6 @@ namespace Emby.Server.Implementations
             Logger.LogInformation("Core startup complete");
             CoreStartupHasCompleted = true;
 
-            cancellationToken.ThrowIfCancellationRequested();
-
             stopWatch.Restart();
 
             await Task.WhenAll(StartEntryPoints(entryPoints, false)).ConfigureAwait(false);
@@ -633,8 +630,6 @@ namespace Emby.Server.Implementations
             var localizationManager = (LocalizationManager)Resolve<ILocalizationManager>();
             await localizationManager.LoadAll().ConfigureAwait(false);
 
-            _sessionManager = Resolve<ISessionManager>();
-
             SetStaticProperties();
 
             FindParts();
@@ -856,38 +851,6 @@ namespace Emby.Server.Implementations
         }
 
         /// <summary>
-        /// Restarts this instance.
-        /// </summary>
-        public void Restart()
-        {
-            if (IsShuttingDown)
-            {
-                return;
-            }
-
-            IsShuttingDown = true;
-            _pluginManager.UnloadAssemblies();
-
-            Task.Run(async () =>
-            {
-                try
-                {
-                    await _sessionManager.SendServerRestartNotification(CancellationToken.None).ConfigureAwait(false);
-                }
-                catch (Exception ex)
-                {
-                    Logger.LogError(ex, "Error sending server restart notification");
-                }
-
-                Logger.LogInformation("Calling RestartInternal");
-
-                RestartInternal();
-            });
-        }
-
-        protected abstract void RestartInternal();
-
-        /// <summary>
         /// Gets the composable part assemblies.
         /// </summary>
         /// <returns>IEnumerable{Assembly}.</returns>
@@ -1065,30 +1028,6 @@ namespace Emby.Server.Implementations
             }.ToString().TrimEnd('/');
         }
 
-        /// <inheritdoc />
-        public async Task Shutdown()
-        {
-            if (IsShuttingDown)
-            {
-                return;
-            }
-
-            IsShuttingDown = true;
-
-            try
-            {
-                await _sessionManager.SendServerShutdownNotification(CancellationToken.None).ConfigureAwait(false);
-            }
-            catch (Exception ex)
-            {
-                Logger.LogError(ex, "Error sending server shutdown notification");
-            }
-
-            ShutdownInternal();
-        }
-
-        protected abstract void ShutdownInternal();
-
         public IEnumerable<Assembly> GetApiPluginAssemblies()
         {
             var assemblies = _allConcreteTypes
@@ -1152,52 +1091,5 @@ namespace Emby.Server.Implementations
 
             _disposed = true;
         }
-
-        public async ValueTask DisposeAsync()
-        {
-            await DisposeAsyncCore().ConfigureAwait(false);
-            Dispose(false);
-            GC.SuppressFinalize(this);
-        }
-
-        /// <summary>
-        /// Used to perform asynchronous cleanup of managed resources or for cascading calls to <see cref="DisposeAsync"/>.
-        /// </summary>
-        /// <returns>A ValueTask.</returns>
-        protected virtual async ValueTask DisposeAsyncCore()
-        {
-            var type = GetType();
-
-            Logger.LogInformation("Disposing {Type}", type.Name);
-
-            foreach (var (part, _) in _disposableParts)
-            {
-                var partType = part.GetType();
-                if (partType == type)
-                {
-                    continue;
-                }
-
-                Logger.LogInformation("Disposing {Type}", partType.Name);
-
-                try
-                {
-                    part.Dispose();
-                }
-                catch (Exception ex)
-                {
-                    Logger.LogError(ex, "Error disposing {Type}", partType.Name);
-                }
-            }
-
-            if (_sessionManager is not null)
-            {
-                // used for closing websockets
-                foreach (var session in _sessionManager.Sessions)
-                {
-                    await session.DisposeAsync().ConfigureAwait(false);
-                }
-            }
-        }
     }
 }
diff --git a/Emby.Server.Implementations/Plugins/PluginManager.cs b/Emby.Server.Implementations/Plugins/PluginManager.cs
index 1303012e1a..d7189ef0ca 100644
--- a/Emby.Server.Implementations/Plugins/PluginManager.cs
+++ b/Emby.Server.Implementations/Plugins/PluginManager.cs
@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Data;
 using System.Globalization;
 using System.IO;
 using System.Linq;
@@ -11,7 +10,6 @@ using System.Text;
 using System.Text.Json;
 using System.Threading.Tasks;
 using Emby.Server.Implementations.Library;
-using Jellyfin.Extensions;
 using Jellyfin.Extensions.Json;
 using Jellyfin.Extensions.Json.Converters;
 using MediaBrowser.Common;
@@ -30,7 +28,7 @@ namespace Emby.Server.Implementations.Plugins
     /// <summary>
     /// Defines the <see cref="PluginManager" />.
     /// </summary>
-    public class PluginManager : IPluginManager
+    public sealed class PluginManager : IPluginManager, IDisposable
     {
         private const string MetafileName = "meta.json";
 
@@ -191,15 +189,6 @@ namespace Emby.Server.Implementations.Plugins
             }
         }
 
-        /// <inheritdoc />
-        public void UnloadAssemblies()
-        {
-            foreach (var assemblyLoadContext in _assemblyLoadContexts)
-            {
-                assemblyLoadContext.Unload();
-            }
-        }
-
         /// <summary>
         /// Creates all the plugin instances.
         /// </summary>
@@ -441,6 +430,15 @@ namespace Emby.Server.Implementations.Plugins
             return SaveManifest(manifest, path);
         }
 
+        /// <inheritdoc />
+        public void Dispose()
+        {
+            foreach (var assemblyLoadContext in _assemblyLoadContexts)
+            {
+                assemblyLoadContext.Unload();
+            }
+        }
+
         /// <summary>
         /// Reconciles the manifest against any properties that exist locally in a pre-packaged meta.json found at the path.
         /// If no file is found, no reconciliation occurs.
diff --git a/Emby.Server.Implementations/Session/SessionManager.cs b/Emby.Server.Implementations/Session/SessionManager.cs
index b4a622ccf4..902d46a906 100644
--- a/Emby.Server.Implementations/Session/SessionManager.cs
+++ b/Emby.Server.Implementations/Session/SessionManager.cs
@@ -36,6 +36,7 @@ using MediaBrowser.Model.Querying;
 using MediaBrowser.Model.Session;
 using MediaBrowser.Model.SyncPlay;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 using Episode = MediaBrowser.Controller.Entities.TV.Episode;
 
@@ -44,7 +45,7 @@ namespace Emby.Server.Implementations.Session
     /// <summary>
     /// Class SessionManager.
     /// </summary>
-    public class SessionManager : ISessionManager, IDisposable
+    public sealed class SessionManager : ISessionManager, IAsyncDisposable
     {
         private readonly IUserDataManager _userDataManager;
         private readonly ILogger<SessionManager> _logger;
@@ -57,11 +58,9 @@ namespace Emby.Server.Implementations.Session
         private readonly IMediaSourceManager _mediaSourceManager;
         private readonly IServerApplicationHost _appHost;
         private readonly IDeviceManager _deviceManager;
-
-        /// <summary>
-        /// The active connections.
-        /// </summary>
-        private readonly ConcurrentDictionary<string, SessionInfo> _activeConnections = new(StringComparer.OrdinalIgnoreCase);
+        private readonly CancellationTokenRegistration _shutdownCallback;
+        private readonly ConcurrentDictionary<string, SessionInfo> _activeConnections
+            = new(StringComparer.OrdinalIgnoreCase);
 
         private Timer _idleTimer;
 
@@ -79,7 +78,8 @@ namespace Emby.Server.Implementations.Session
             IImageProcessor imageProcessor,
             IServerApplicationHost appHost,
             IDeviceManager deviceManager,
-            IMediaSourceManager mediaSourceManager)
+            IMediaSourceManager mediaSourceManager,
+            IHostApplicationLifetime hostApplicationLifetime)
         {
             _logger = logger;
             _eventManager = eventManager;
@@ -92,6 +92,7 @@ namespace Emby.Server.Implementations.Session
             _appHost = appHost;
             _deviceManager = deviceManager;
             _mediaSourceManager = mediaSourceManager;
+            _shutdownCallback = hostApplicationLifetime.ApplicationStopping.Register(OnApplicationStopping);
 
             _deviceManager.DeviceOptionsUpdated += OnDeviceManagerDeviceOptionsUpdated;
         }
@@ -151,36 +152,6 @@ namespace Emby.Server.Implementations.Session
             }
         }
 
-        /// <inheritdoc />
-        public void Dispose()
-        {
-            Dispose(true);
-            GC.SuppressFinalize(this);
-        }
-
-        /// <summary>
-        /// Releases unmanaged and optionally managed resources.
-        /// </summary>
-        /// <param name="disposing"><c>true</c> to release both managed and unmanaged resources; <c>false</c> to release only unmanaged resources.</param>
-        protected virtual void Dispose(bool disposing)
-        {
-            if (_disposed)
-            {
-                return;
-            }
-
-            if (disposing)
-            {
-                _idleTimer?.Dispose();
-            }
-
-            _idleTimer = null;
-
-            _deviceManager.DeviceOptionsUpdated -= OnDeviceManagerDeviceOptionsUpdated;
-
-            _disposed = true;
-        }
-
         private void CheckDisposed()
         {
             if (_disposed)
@@ -1331,32 +1302,6 @@ namespace Emby.Server.Implementations.Session
         }
 
         /// <summary>
-        /// Sends the server shutdown notification.
-        /// </summary>
-        /// <param name="cancellationToken">The cancellation token.</param>
-        /// <returns>Task.</returns>
-        public Task SendServerShutdownNotification(CancellationToken cancellationToken)
-        {
-            CheckDisposed();
-
-            return SendMessageToSessions(Sessions, SessionMessageType.ServerShuttingDown, string.Empty, cancellationToken);
-        }
-
-        /// <summary>
-        /// Sends the server restart notification.
-        /// </summary>
-        /// <param name="cancellationToken">The cancellation token.</param>
-        /// <returns>Task.</returns>
-        public Task SendServerRestartNotification(CancellationToken cancellationToken)
-        {
-            CheckDisposed();
-
-            _logger.LogDebug("Beginning SendServerRestartNotification");
-
-            return SendMessageToSessions(Sessions, SessionMessageType.ServerRestarting, string.Empty, cancellationToken);
-        }
-
-        /// <summary>
         /// Adds the additional user.
         /// </summary>
         /// <param name="sessionId">The session identifier.</param>
@@ -1833,5 +1778,51 @@ namespace Emby.Server.Implementations.Session
 
             return SendMessageToSessions(sessions, name, data, cancellationToken);
         }
+
+        /// <inheritdoc />
+        public async ValueTask DisposeAsync()
+        {
+            if (_disposed)
+            {
+                return;
+            }
+
+            foreach (var session in _activeConnections.Values)
+            {
+                await session.DisposeAsync().ConfigureAwait(false);
+            }
+
+            if (_idleTimer is not null)
+            {
+                await _idleTimer.DisposeAsync().ConfigureAwait(false);
+                _idleTimer = null;
+            }
+
+            await _shutdownCallback.DisposeAsync().ConfigureAwait(false);
+
+            _deviceManager.DeviceOptionsUpdated -= OnDeviceManagerDeviceOptionsUpdated;
+            _disposed = true;
+        }
+
+        private async void OnApplicationStopping()
+        {
+            _logger.LogInformation("Sending shutdown notifications");
+            try
+            {
+                var messageType = _appHost.ShouldRestart ? SessionMessageType.ServerRestarting : SessionMessageType.ServerShuttingDown;
+
+                await SendMessageToSessions(Sessions, messageType, string.Empty, CancellationToken.None).ConfigureAwait(false);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Error sending server shutdown notifications");
+            }
+
+            // Close open websockets to allow Kestrel to shut down cleanly
+            foreach (var session in _activeConnections.Values)
+            {
+                await session.DisposeAsync().ConfigureAwait(false);
+            }
+        }
     }
 }