1552 mqttnetservermqttclientsessionsmanager subscribersessions is not proper removed on special case (#1562)

Author: chkr1011

.github/workflows/ReleaseNotes.md

@@ -1 +1,2 @@
+* [Core] Fixed several dead locks by implementing a new async signal (#1552)
 * [Server] Fixed duplicated invocation of the event _ClientAcknowledgedPublishPacketAsync_ for QoS level 2 (#1550)

Source/MQTTnet.Tests/Internal/AsyncSignal_Tests.cs

@@ -0,0 +1,114 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Diagnostics;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using MQTTnet.Internal;
+
+namespace MQTTnet.Tests.Internal
+{
+ [TestClass]
+ public sealed class AsyncSignal_Tests
+ {
+ [TestMethod]
+ [ExpectedException(typeof(TaskCanceledException))]
+ public async Task Cancel_If_No_Signal()
+ {
+ var asyncSignal = new AsyncSignal();
+
+ using (var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(2)))
+ {
+ await asyncSignal.WaitAsync(timeout.Token);
+
+ Assert.Fail("There is no signal. So we must fail here!");
+ }
+ }
+
+ [TestMethod]
+ [ExpectedException(typeof(ObjectDisposedException))]
+ public async Task Dispose_Properly()
+ {
+ var asyncSignal = new AsyncSignal();
+
+ // The timeout will not be reached but another task will kill the async signal.
+ using (var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(999)))
+ {
+ _ = Task.Run(
+ async () =>
+ {
+ await Task.Delay(2000, CancellationToken.None);
+ asyncSignal.Dispose();
+ },
+ CancellationToken.None);
+
+ await asyncSignal.WaitAsync(timeout.Token);
+
+ Assert.Fail("There is no signal. So we must fail here!");
+ }
+ }
+
+ [TestMethod]
+ public async Task Loop_Signal()
+ {
+ var asyncSignal = new AsyncSignal();
+
+ for (var i = 0; i < 10; i++)
+ {
+ asyncSignal.Set();
+ 
+ // WaitAsync should return directly because the signal is available.
+ await asyncSignal.WaitAsync();
+ }
+ }
+
+ [TestMethod]
+ public async Task Signal()
+ {
+ var asyncSignal = new AsyncSignal();
+
+ // The timeout will not be reached but another task will kill the async signal.
+ using (var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(3)))
+ {
+ var stopwatch = Stopwatch.StartNew();
+
+ _ = Task.Run(
+ async () =>
+ {
+ await Task.Delay(1000, CancellationToken.None);
+ asyncSignal.Set();
+ },
+ CancellationToken.None);
+
+ await asyncSignal.WaitAsync(timeout.Token);
+
+ stopwatch.Stop();
+
+ Assert.IsTrue(stopwatch.ElapsedMilliseconds > 900);
+ }
+ }
+ 
+ [TestMethod]
+ [ExpectedException(typeof(InvalidOperationException))]
+ public async Task Fail_For_Two_Waiters()
+ {
+ var asyncSignal = new AsyncSignal();
+
+ // This thread will wait properly because it is the first waiter.
+ _ = Task.Run(
+ async () =>
+ {
+ await asyncSignal.WaitAsync();
+ },
+ CancellationToken.None);
+
+ await Task.Delay(1000);
+ 
+ // Now the current thread must fail because there is already a waiter.
+ await asyncSignal.WaitAsync();
+ }
+ }
+}

Source/MQTTnet.Tests/Internal/MqttPacketBus_Tests.cs

@@ -15,7 +15,7 @@ namespace MQTTnet.Tests.Internal
  public sealed class MqttPacketBus_Tests
  {
  [TestMethod]
- [ExpectedException(typeof(OperationCanceledException))]
+ [ExpectedException(typeof(TaskCanceledException))]
  public async Task Wait_With_Empty_Bus()
  {
  var bus = new MqttPacketBus();

Source/MQTTnet.Tests/Server/Load_Tests.cs

@@ -55,7 +55,7 @@ await client.PublishAsync(message)
  });
  }
 
- SpinWait.SpinUntil(() => receivedMessages == 100000, TimeSpan.FromSeconds(60));
+ SpinWait.SpinUntil(() => receivedMessages == 100000, TimeSpan.FromSeconds(90));
 
  Assert.AreEqual(100000, receivedMessages);
  }