Fix startround deadlock (#11498)

Content.Server/GameTicking/GameTicker.RoundFlow.cs

@@ -19,11 +19,14 @@ using Robust.Shared.Random;
 using Robust.Shared.Utility;
 using System.Linq;
 using System.Threading.Tasks;
+using Robust.Shared.Asynchronous;
 
 namespace Content.Server.GameTicking
 {
     public sealed partial class GameTicker
     {
+        [Dependency] private readonly ITaskManager _taskManager = default!;
+
         private static readonly Counter RoundNumberMetric = Metrics.CreateCounter(
             "ss14_round_number",
             "Round number.");
@@ -152,16 +155,18 @@ namespace Content.Server.GameTicking
 
             var playerIds = _playerGameStatuses.Keys.Select(player => player.UserId).ToArray();
             var serverName = _configurationManager.GetCVar(CCVars.AdminLogsServerName);
+
             // TODO FIXME AAAAAAAAAAAAAAAAAAAH THIS IS BROKEN
             // Task.Run as a terrible dirty workaround to avoid synchronization context deadlock from .Result here.
             // This whole setup logic should be made asynchronous so we can properly wait on the DB AAAAAAAAAAAAAH
-#pragma warning disable RA0004
-            RoundId = Task.Run(async () =>
+            var task = Task.Run(async () =>
             {
                 var server = await _db.AddOrGetServer(serverName);
                 return await _db.AddNewRound(server, playerIds);
-            }).Result;
-#pragma warning restore RA0004
+            });
+
+            _taskManager.BlockWaitOnTask(task);
+            RoundId = task.GetAwaiter().GetResult();
 
             var startingEvent = new RoundStartingEvent(RoundId);
             RaiseLocalEvent(startingEvent);