Add overridable DefaultOptionsProvider.AfterDisconnectAsync() callback

docs/ReleaseNotes.md

@@ -8,7 +8,7 @@ Current package versions:
 
 ## Unreleased
 
-- (none)
+- Add overrideable `AfterDisconnectAsync()` callback on `DefaultOptionsProvider` ([#2952 by philon-msft](https://github.com/StackExchange/StackExchange.Redis/pull/2952))
 
 ## 2.9.17
 

src/StackExchange.Redis/Configuration/DefaultOptionsProvider.cs

@@ -307,6 +307,12 @@ protected virtual string GetDefaultClientName() =>
         /// <param name="log">The logger for the connection, to emit to the connection output log.</param>
         public virtual Task AfterConnectAsync(ConnectionMultiplexer multiplexer, Action<string> log) => Task.CompletedTask;
 
+        /// <summary>
+        /// The action to perform, if any, immediately after a connection is closed.
+        /// </summary>
+        /// <param name="multiplexer">The multiplexer that just disconnected.</param>
+        public virtual Task AfterDisconnectAsync(ConnectionMultiplexer multiplexer) => Task.CompletedTask;
+
         /// <summary>
         /// Gets the default SSL "enabled or not" based on a set of endpoints.
         /// Note: this setting then applies for *all* endpoints.

src/StackExchange.Redis/ConfigurationOptions.cs

@@ -210,6 +210,8 @@ public DefaultOptionsProvider Defaults
 
         internal Func<ConnectionMultiplexer, Action<string>, Task> AfterConnectAsync => Defaults.AfterConnectAsync;
 
+        internal Func<ConnectionMultiplexer, Task> AfterDisconnectAsync => Defaults.AfterDisconnectAsync;
+
         /// <summary>
         /// Gets or sets whether connect/configuration timeouts should be explicitly notified via a TimeoutException.
         /// </summary>
@@ -305,8 +307,8 @@ public bool HighIntegrity
         /// <summary>
         /// Supply a user certificate from a PEM file pair and enable TLS.
         /// </summary>
-        /// <param name="userCertificatePath">The path for the the user certificate (commonly a .crt file).</param>
-        /// <param name="userKeyPath">The path for the the user key (commonly a .key file).</param>
+        /// <param name="userCertificatePath">The path for the user certificate (commonly a .crt file).</param>
+        /// <param name="userKeyPath">The path for the user key (commonly a .key file).</param>
         public void SetUserPemCertificate(string userCertificatePath, string? userKeyPath = null)
         {
             CertificateSelectionCallback = CreatePemUserCertificateCallback(userCertificatePath, userKeyPath);
@@ -317,7 +319,7 @@ public void SetUserPemCertificate(string userCertificatePath, string? userKeyPat
         /// <summary>
         /// Supply a user certificate from a PFX file and optional password and enable TLS.
         /// </summary>
-        /// <param name="userCertificatePath">The path for the the user certificate (commonly a .pfx file).</param>
+        /// <param name="userCertificatePath">The path for the user certificate (commonly a .pfx file).</param>
         /// <param name="password">The password for the certificate file.</param>
         public void SetUserPfxCertificate(string userCertificatePath, string? password = null)
         {
@@ -383,7 +385,7 @@ private static bool CheckTrustedIssuer(X509Certificate2 certificateToValidate, X
             chain.ChainPolicy.VerificationFlags = X509VerificationFlags.AllowUnknownCertificateAuthority;
             chain.ChainPolicy.VerificationTime = chainToValidate?.ChainPolicy?.VerificationTime ?? DateTime.Now;
             chain.ChainPolicy.UrlRetrievalTimeout = new TimeSpan(0, 0, 0);
-            // Ensure entended key usage checks are run and that we're observing a server TLS certificate
+            // Ensure intended key usage checks are run and that we're observing a server TLS certificate
             chain.ChainPolicy.ApplicationPolicy.Add(_serverAuthOid);
 
             chain.ChainPolicy.ExtraStore.Add(authority);

src/StackExchange.Redis/ConnectionMultiplexer.cs

@@ -2294,9 +2294,11 @@ public void Close(bool allowCommandsToComplete = true)
                 var quits = QuitAllServers();
                 WaitAllIgnoreErrors(quits);
             }
+
             DisposeAndClearServers();
             OnCloseReaderWriter();
             OnClosing(true);
+            RawConfig.AfterDisconnectAsync?.Invoke(this).Wait(SyncConnectTimeout(true));
             Interlocked.Increment(ref _connectionCloseCount);
         }
 
@@ -2306,7 +2308,11 @@ public void Close(bool allowCommandsToComplete = true)
         /// <param name="allowCommandsToComplete">Whether to allow all in-queue commands to complete first.</param>
         public async Task CloseAsync(bool allowCommandsToComplete = true)
         {
+            if (_isDisposed) return;
+
+            OnClosing(false);
             _isDisposed = true;
+            _profilingSessionProvider = null;
             using (var tmp = pulse)
             {
                 pulse = null;
@@ -2319,6 +2325,10 @@ public async Task CloseAsync(bool allowCommandsToComplete = true)
             }
 
             DisposeAndClearServers();
+            OnCloseReaderWriter();
+            OnClosing(true);
+            await RawConfig.AfterDisconnectAsync(this).ForAwait();
+            Interlocked.Increment(ref _connectionCloseCount);
         }
 
         private void DisposeAndClearServers()

src/StackExchange.Redis/PublicAPI/PublicAPI.Shipped.txt

@@ -1848,6 +1848,7 @@ static StackExchange.Redis.StreamPosition.Beginning.get -> StackExchange.Redis.R
 static StackExchange.Redis.StreamPosition.NewMessages.get -> StackExchange.Redis.RedisValue
 virtual StackExchange.Redis.Configuration.DefaultOptionsProvider.AbortOnConnectFail.get -> bool
 virtual StackExchange.Redis.Configuration.DefaultOptionsProvider.AfterConnectAsync(StackExchange.Redis.ConnectionMultiplexer! multiplexer, System.Action<string!>! log) -> System.Threading.Tasks.Task!
+virtual StackExchange.Redis.Configuration.DefaultOptionsProvider.AfterDisconnectAsync(StackExchange.Redis.ConnectionMultiplexer! multiplexer) -> System.Threading.Tasks.Task!
 virtual StackExchange.Redis.Configuration.DefaultOptionsProvider.AllowAdmin.get -> bool
 virtual StackExchange.Redis.Configuration.DefaultOptionsProvider.BacklogPolicy.get -> StackExchange.Redis.BacklogPolicy!
 virtual StackExchange.Redis.Configuration.DefaultOptionsProvider.CheckCertificateRevocation.get -> bool

tests/StackExchange.Redis.Tests/DefaultOptionsTests.cs

@@ -151,6 +151,31 @@ public async Task AfterConnectAsyncHandler()
         Assert.Equal(1, provider.Calls);
     }
 
+    public class TestAfterDisconnectOptionsProvider : DefaultOptionsProvider
+    {
+        public int Calls;
+
+        public override Task AfterDisconnectAsync(ConnectionMultiplexer muxer)
+        {
+            Interlocked.Increment(ref Calls);
+            return Task.CompletedTask;
+        }
+    }
+
+    [Fact]
+    public async Task AfterDisconnectAsyncHandler()
+    {
+        var options = ConfigurationOptions.Parse(GetConfiguration());
+        var provider = new TestAfterDisconnectOptionsProvider();
+        options.Defaults = provider;
+
+        await using var conn = await ConnectionMultiplexer.ConnectAsync(options, Writer);
+        await conn.CloseAsync();
+
+        Assert.False(conn.IsConnected);
+        Assert.Equal(1, provider.Calls);
+    }
+
     public class TestClientNameOptionsProvider : DefaultOptionsProvider
     {
         protected override string GetDefaultClientName() => "Hey there";