rework concurrencyfilter

MareSynchronosServer/MareSynchronosServer/Hubs/ConcurrencyFilter.cs

@@ -2,12 +2,13 @@
 using MareSynchronosShared.Services;
 using MareSynchronosShared.Utils.Configuration;
 using Microsoft.AspNetCore.SignalR;
+using System.Threading.RateLimiting;
 
 namespace MareSynchronosServer.Hubs;
 
 public sealed class ConcurrencyFilter : IHubFilter, IDisposable
 {
-    private SemaphoreSlim _limiter;
+    private ConcurrencyLimiter _limiter;
     private int _setLimit = 0;
     private readonly IConfigurationService<ServerConfiguration> _config;
     private readonly CancellationTokenSource _cts = new();
@@ -19,14 +20,19 @@ public sealed class ConcurrencyFilter : IHubFilter, IDisposable
         _config = config;
         _config.ConfigChangedEvent += OnConfigChange;
 
-        RecreateSemaphore();
+        RecreateLimiter();
 
         _ = Task.Run(async () =>
         {
             var token = _cts.Token;
             while (!token.IsCancellationRequested)
             {
-                mareMetrics.SetGaugeTo(MetricsAPI.GaugeHubConcurrency, _limiter?.CurrentCount ?? 0);
+                var stats = _limiter?.GetStatistics();
+                if (stats != null)
+                {
+                    mareMetrics.SetGaugeTo(MetricsAPI.GaugeHubConcurrency, stats.CurrentAvailablePermits);
+                    mareMetrics.SetGaugeTo(MetricsAPI.GaugeHubQueuedConcurrency, stats.CurrentQueuedCount);
+                }
                 await Task.Delay(TimeSpan.FromSeconds(1)).ConfigureAwait(false);
             }
         });
@@ -34,18 +40,26 @@ public sealed class ConcurrencyFilter : IHubFilter, IDisposable
 
     private void OnConfigChange(object sender, EventArgs e)
     {
-        RecreateSemaphore();
+        RecreateLimiter();
     }
 
-    private void RecreateSemaphore()
+    private void RecreateLimiter()
     {
         var newLimit = _config.GetValueOrDefault(nameof(ServerConfiguration.HubExecutionConcurrencyFilter), 50);
-        if (newLimit != _setLimit)
+
+        if (newLimit == _setLimit && _limiter is not null)
         {
+            return;
+        }
+
         _setLimit = newLimit;
         _limiter?.Dispose();
-            _limiter = new(initialCount: _setLimit, maxCount: _setLimit);
-        }
+        _limiter = new(new ConcurrencyLimiterOptions()
+        {
+            PermitLimit = newLimit,
+            QueueProcessingOrder = QueueProcessingOrder.OldestFirst,
+            QueueLimit = newLimit * 100,
+        });
     }
 
     public async ValueTask<object> InvokeMethodAsync(
@@ -56,15 +70,25 @@ public sealed class ConcurrencyFilter : IHubFilter, IDisposable
             return await next(invocationContext).ConfigureAwait(false);
         }
 
-        await _limiter.WaitAsync(invocationContext.Context.ConnectionAborted).ConfigureAwait(false);
-
+        var ct = invocationContext.Context.ConnectionAborted;
+        RateLimitLease lease;
         try
         {
-            return await next(invocationContext).ConfigureAwait(false);
+            lease = await _limiter.AcquireAsync(1, ct).ConfigureAwait(false);
         }
-        finally
+        catch (OperationCanceledException) when (ct.IsCancellationRequested)
         {
-            _limiter.Release();
+            throw;
+        }
+
+        if (!lease.IsAcquired)
+        {
+            throw new HubException("Concurrency limit exceeded. Try again later.");
+        }
+
+        using (lease)
+        {
+            return await next(invocationContext).ConfigureAwait(false);
         }
     }
 
@@ -77,6 +101,8 @@ public sealed class ConcurrencyFilter : IHubFilter, IDisposable
 
         _disposed = true;
         _cts.Cancel();
+        _limiter?.Dispose();
         _config.ConfigChangedEvent -= OnConfigChange;
+        _cts.Dispose();
     }
 }

MareSynchronosServer/MareSynchronosServer/Hubs/SignalRLimitFilter.cs

@@ -48,7 +48,7 @@ public class SignalRLimitFilter : IHubFilter
     }
 
     // Optional method
-    public async Task OnConnectedAsync(HubLifetimeContext context, Func<HubLifetimeContext, Task> next)
+    /* public async Task OnConnectedAsync(HubLifetimeContext context, Func<HubLifetimeContext, Task> next)
     {
         await ConnectionLimiterSemaphore.WaitAsync().ConfigureAwait(false);
         try
@@ -108,5 +108,5 @@ public class SignalRLimitFilter : IHubFilter
         {
             DisconnectLimiterSemaphore.Release();
         }
-    }
+    } */
 }

MareSynchronosServer/MareSynchronosServer/Startup.cs

@@ -122,7 +122,7 @@ public class Startup
             hubOptions.MaximumParallelInvocationsPerClient = 10;
             hubOptions.StreamBufferCapacity = 200;
 
-            hubOptions.AddFilter<SignalRLimitFilter>();
+            //hubOptions.AddFilter<SignalRLimitFilter>();
             hubOptions.AddFilter<ConcurrencyFilter>();
         }).AddMessagePackProtocol(opt =>
         {

MareSynchronosServer/MareSynchronosShared/Metrics/MetricsAPI.cs

@@ -49,4 +49,5 @@ public class MetricsAPI
     public const string GaugeGposeLobbies = "mare_gpose_lobbies";
     public const string GaugeGposeLobbyUsers = "mare_gpose_lobby_users";
     public const string GaugeHubConcurrency = "mare_free_concurrent_hub_calls";
+    public const string GaugeHubQueuedConcurrency = "mare_free_concurrent_queued_hub_calls";
 }