Refactor code.

Author: chkr1011

Source/MQTTnet/Client/MqttClient.cs

@@ -91,9 +91,7 @@ public event Func<InspectMqttPacketEventArgs, Task> InspectPackage
  add => _inspectPacketEvent.AddHandler(value);
  remove => _inspectPacketEvent.RemoveHandler(value);
  }
-
- [Obsolete(
- "This property will be removed in the future. Checking for a working connection should be done via calling _PinAsync_. Also other successful traffic can be used to indicate connection status.")]
+ 
  public bool IsConnected => (MqttClientConnectionStatus)_connectionStatus == MqttClientConnectionStatus.Connected;
 
  public MqttClientOptions Options { get; private set; }

Source/MQTTnet/Internal/AsyncLock.cs

@@ -10,8 +10,8 @@ namespace MQTTnet.Internal
 {
  public sealed class AsyncLock : IDisposable
  {
- readonly object _syncRoot = new object();
  readonly Task<IDisposable> _releaser;
+ readonly object _syncRoot = new object();
 
  SemaphoreSlim _semaphore = new SemaphoreSlim(1, 1);
 
@@ -20,6 +20,15 @@ public AsyncLock()
  _releaser = Task.FromResult((IDisposable)new Releaser(this));
  }
 
+ public void Dispose()
+ {
+ lock (_syncRoot)
+ {
+ _semaphore?.Dispose();
+ _semaphore = null;
+ }
+ }
+
  public Task<IDisposable> WaitAsync(CancellationToken cancellationToken)
  {
  Task task;
@@ -45,22 +54,10 @@ public Task<IDisposable> WaitAsync(CancellationToken cancellationToken)
  }
 
  // Wait for the _WaitAsync_ method and return the releaser afterwards.
- return task.ContinueWith(
- (_, state) => (IDisposable)state, 
- _releaser.Result, 
- cancellationToken, TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Default);
- }
-
- public void Dispose()
- {
- lock (_syncRoot)
- {
- _semaphore?.Dispose();
- _semaphore = null;
- }
+ return task.ContinueWith((_, state) => (IDisposable)state, _releaser.Result, cancellationToken, TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Default);
  }
 
- internal void Release()
+ void Release()
  {
  lock (_syncRoot)
  {
@@ -83,4 +80,4 @@ public void Dispose()
  }
  }
  }
-}
+}

Source/MQTTnet/Server/Internal/MqttClientSessionsManager.cs

@@ -23,6 +23,8 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
  {
  readonly Dictionary<string, MqttClient> _clients = new Dictionary<string, MqttClient>(4096);
 
+ readonly AsyncLock _createConnectionSyncRoot = new AsyncLock();
+
  readonly MqttServerEventContainer _eventContainer;
  readonly MqttNetSourceLogger _logger;
  readonly MqttServerOptions _options;
@@ -38,8 +40,6 @@ public sealed class MqttClientSessionsManager : ISubscriptionChangedNotification
  readonly object _sessionsManagementLock = new object();
  readonly HashSet<MqttSession> _subscriberSessions = new HashSet<MqttSession>();
 
- readonly SemaphoreSlim _createConnectionSyncRoot = new SemaphoreSlim(1, 1);
- 
  public MqttClientSessionsManager(
  MqttServerOptions options,
  MqttRetainedMessagesManager retainedMessagesManager,
@@ -77,7 +77,7 @@ public async Task CloseAllConnectionsAsync()
  public async Task DeleteSessionAsync(string clientId)
  {
  _logger.Verbose("Deleting session for client '{0}'.", clientId);
- 
+
  MqttClient connection;
 
  lock (_clients)
@@ -441,6 +441,11 @@ public Task UnsubscribeAsync(string clientId, ICollection<string> topicFilters)
  return GetClientSession(clientId).SubscriptionsManager.Unsubscribe(fakeUnsubscribePacket, CancellationToken.None);
  }
 
+ MqttClient CreateClient(MqttConnectPacket connectPacket, IMqttChannelAdapter channelAdapter, MqttSession session)
+ {
+ return new MqttClient(connectPacket, channelAdapter, session, _options, _eventContainer, this, _rootLogger);
+ }
+
  async Task<MqttClient> CreateClientConnection(
  MqttConnectPacket connectPacket,
  MqttConnAckPacket connAckPacket,
@@ -473,9 +478,8 @@ async Task<MqttClient> CreateClientConnection(
 
  sessionShouldPersist = !connectPacket.CleanSession;
  }
- 
- await _createConnectionSyncRoot.WaitAsync(CancellationToken.None).ConfigureAwait(false);
- try
+
+ using (await _createConnectionSyncRoot.WaitAsync(CancellationToken.None).ConfigureAwait(false))
  {
  MqttSession session;
  lock (_sessionsManagementLock)
@@ -528,24 +532,19 @@ async Task<MqttClient> CreateClientConnection(
 
  if (_eventContainer.ClientConnectedEvent.HasHandlers)
  {
- var eventArgs = new ClientDisconnectedEventArgs(existingClient.Id, MqttClientDisconnectType.Takeover, existingClient.Endpoint, existingClient.Session.Items);
+ var eventArgs = new ClientDisconnectedEventArgs(
+ existingClient.Id,
+ MqttClientDisconnectType.Takeover,
+ existingClient.Endpoint,
+ existingClient.Session.Items);
  await _eventContainer.ClientDisconnectedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
  }
  }
  }
- finally
- {
- _createConnectionSyncRoot.Release();
- }
 
  return client;
  }
 
- MqttClient CreateClient(MqttConnectPacket connectPacket, IMqttChannelAdapter channelAdapter, MqttSession session)
- {
- return new MqttClient(connectPacket, channelAdapter, session, _options, _eventContainer, this, _rootLogger);
- }
-
  MqttSession CreateSession(string clientId, IDictionary sessionItems, bool isPersistent)
  {
  _logger.Verbose("Created new session for client '{0}'.", clientId);