Clean up job manager activation

src/Tgstation.Server.Host/Components/IInstanceCoreProvider.cs

@@ -3,7 +3,7 @@
 	/// <summary>
 	/// Provider for <see cref="IInstanceCore"/>s.
 	/// </summary>
-	interface IInstanceCoreProvider
+	public interface IInstanceCoreProvider
 	{
 		/// <summary>
 		/// Get the <see cref="IInstanceCore"/> for a given <paramref name="instance"/> if it's online.

src/Tgstation.Server.Host/Components/InstanceManager.cs

@@ -431,7 +431,7 @@ namespace Tgstation.Server.Host.Components
 
 				await Task.WhenAll(instanceOnliningTasks);
 
-				jobManager.Activate();
+				jobManager.Activate(this);
 
 				logger.LogInformation("Server ready!");
 				readyTcs.SetResult();

src/Tgstation.Server.Host/Core/Application.cs

@@ -355,7 +355,6 @@ namespace Tgstation.Server.Host.Core
 
 			services.AddSingleton<InstanceManager>();
 			services.AddSingleton<IBridgeDispatcher>(x => x.GetRequiredService<InstanceManager>());
-			services.AddSingleton(x => new Lazy<IInstanceCoreProvider>(() => x.GetRequiredService<InstanceManager>()));
 			services.AddSingleton<IInstanceManager>(x => x.GetRequiredService<InstanceManager>());
 		}
 

src/Tgstation.Server.Host/Jobs/IJobManager.cs

@@ -3,6 +3,7 @@ using System.Threading.Tasks;
 
 using Microsoft.Extensions.Hosting;
 using Tgstation.Server.Api.Models.Response;
+using Tgstation.Server.Host.Components;
 using Tgstation.Server.Host.Models;
 
 namespace Tgstation.Server.Host.Jobs
@@ -50,6 +51,7 @@ namespace Tgstation.Server.Host.Jobs
 		/// <summary>
 		/// Activate the <see cref="IJobManager"/>.
 		/// </summary>
-		void Activate();
+		/// <param name="instanceCoreProvider">The <see cref="IInstanceCoreProvider"/> for the <see cref="IJobManager"/>.</param>
+		void Activate(IInstanceCoreProvider instanceCoreProvider);
 	}
 }

src/Tgstation.Server.Host/Jobs/JobManager.cs

@@ -33,20 +33,15 @@ namespace Tgstation.Server.Host.Jobs
 		/// </summary>
 		readonly ILogger<JobManager> logger;
 
-		/// <summary>
-		/// The <see cref="IInstanceCoreProvider"/> for the <see cref="JobManager"/>.
-		/// </summary>
-		readonly Lazy<IInstanceCoreProvider> instanceCoreProvider;
-
 		/// <summary>
 		/// <see cref="Dictionary{TKey, TValue}"/> of <see cref="Job"/> <see cref="Api.Models.EntityId.Id"/>s to running <see cref="JobHandler"/>s.
 		/// </summary>
 		readonly Dictionary<long, JobHandler> jobs;
 
 		/// <summary>
-		/// <see cref="TaskCompletionSource"/> to delay starting jobs until the server is ready.
+		/// <see cref="TaskCompletionSource{TResult}"/> to delay starting jobs until the server is ready.
 		/// </summary>
-		readonly TaskCompletionSource activationTcs;
+		readonly TaskCompletionSource<IInstanceCoreProvider> activationTcs;
 
 		/// <summary>
 		/// <see langword="lock"/> <see cref="object"/> for various operations.
@@ -62,21 +57,18 @@ namespace Tgstation.Server.Host.Jobs
 		/// Initializes a new instance of the <see cref="JobManager"/> class.
 		/// </summary>
 		/// <param name="databaseContextFactory">The value of <see cref="databaseContextFactory"/>.</param>
-		/// <param name="instanceCoreProvider">The value of <see cref="instanceCoreProvider"/>.</param>
 		/// <param name="loggerFactory">The value of <see cref="loggerFactory"/>.</param>
 		/// <param name="logger">The value of <see cref="logger"/>.</param>
 		public JobManager(
 			IDatabaseContextFactory databaseContextFactory,
-			Lazy<IInstanceCoreProvider> instanceCoreProvider,
 			ILoggerFactory loggerFactory,
 			ILogger<JobManager> logger)
 		{
 			this.databaseContextFactory = databaseContextFactory ?? throw new ArgumentNullException(nameof(databaseContextFactory));
-			this.instanceCoreProvider = instanceCoreProvider ?? throw new ArgumentNullException(nameof(instanceCoreProvider));
 			this.loggerFactory = loggerFactory ?? throw new ArgumentNullException(nameof(loggerFactory));
 			this.logger = logger ?? throw new ArgumentNullException(nameof(logger));
 			jobs = new Dictionary<long, JobHandler>();
-			activationTcs = new TaskCompletionSource();
+			activationTcs = new TaskCompletionSource<IInstanceCoreProvider>();
 			synchronizationLock = new object();
 			addCancelLock = new object();
 		}
@@ -265,10 +257,13 @@ namespace Tgstation.Server.Host.Jobs
 		}
 
 		/// <inheritdoc />
-		public void Activate()
+		public void Activate(IInstanceCoreProvider instanceCoreProvider)
 		{
+			if (instanceCoreProvider == null)
+				throw new ArgumentNullException(nameof(instanceCoreProvider));
+
 			logger.LogTrace("Activating job manager...");
-			activationTcs.SetResult();
+			activationTcs.SetResult(instanceCoreProvider);
 		}
 
 		/// <summary>
@@ -322,11 +317,11 @@ namespace Tgstation.Server.Host.Jobs
 								}
 						}
 
-						await activationTcs.Task.WithToken(cancellationToken);
+						var instanceCoreProvider = await activationTcs.Task.WithToken(cancellationToken);
 
 						logger.LogTrace("Starting job...");
 						await operation(
-							instanceCoreProvider.Value.GetInstance(oldJob.Instance),
+							instanceCoreProvider.GetInstance(oldJob.Instance),
 							databaseContextFactory,
 							job,
 							new JobProgressReporter(