improve to disable re-start after disposing and properly throw ObjectDisposedException

Author: smdn

src/Smdn.Net.MuninNode/Smdn.Net.MuninNode/NodeBase.cs

@@ -44,10 +44,18 @@ public abstract class NodeBase : IDisposable, IAsyncDisposable {
 
   private Socket? server;
 
-  public EndPoint LocalEndPoint => server?.LocalEndPoint ?? throw new InvalidOperationException("not yet bound or already disposed");
+  public EndPoint LocalEndPoint {
+    get {
+      ThrowIfDisposed();
+
+      return server?.LocalEndPoint ?? throw new InvalidOperationException("not yet bound or already disposed");
+    }
+  }
 
   private readonly ArrayBufferWriter<byte> responseBuffer = new(initialCapacity: 1024); // TODO: define best initial capacity
 
+  private bool disposed;
+
   protected NodeBase(
     IAccessRule? accessRule,
     ILogger? logger
@@ -94,6 +102,8 @@ ValueTask DisposeAsyncCore()
     server?.Dispose();
     server = null;
 
+    disposed = true;
+
 #if !SYSTEM_NET_SOCKETS_SOCKET_DISCONNECTASYNC_REUSESOCKET_CANCELLATIONTOKEN
     return default;
 #endif
@@ -115,6 +125,14 @@ protected virtual void Dispose(bool disposing)
     server?.Close();
     server?.Dispose();
     server = null!;
+
+    disposed = true;
+  }
+
+  protected void ThrowIfDisposed()
+  {
+    if (disposed)
+      throw new ObjectDisposedException(GetType().FullName);
   }
 
   protected void ThrowIfPluginProviderIsNull()
@@ -127,6 +145,8 @@ protected void ThrowIfPluginProviderIsNull()
 
   public void Start()
   {
+    ThrowIfDisposed();
+
     if (server is not null)
       throw new InvalidOperationException("already started");
 
@@ -153,6 +173,8 @@ public async ValueTask AcceptAsync(
     CancellationToken cancellationToken
   )
   {
+    ThrowIfDisposed();
+
     Logger?.LogInformation("starting to accept");
 
     try {
@@ -186,6 +208,8 @@ public async ValueTask AcceptSingleSessionAsync(
     CancellationToken cancellationToken = default
   )
   {
+    ThrowIfDisposed();
+
     if (server is null)
       throw new InvalidOperationException("not started or already closed");
 

tests/Smdn.Net.MuninNode/Smdn.Net.MuninNode/NodeBase.cs

@@ -140,6 +140,38 @@ Func<NodeBase, TcpClient, StreamWriter, StreamReader, CancellationToken, Task> a
     }
   }
 
+  [Test]
+  public async Task Dispose()
+  {
+    await using var node = CreateNode();
+
+    Assert.That(node.Dispose, Throws.Nothing, "Dispose() #1");
+
+    Assert.That(() => _ = node.LocalEndPoint, Throws.TypeOf<ObjectDisposedException>());
+    Assert.That(node.Start, Throws.TypeOf<ObjectDisposedException>());
+    Assert.That(async () => await node.AcceptAsync(false, default), Throws.TypeOf<ObjectDisposedException>());
+    Assert.That(async () => await node.AcceptSingleSessionAsync(default), Throws.TypeOf<ObjectDisposedException>());
+
+    Assert.That(node.Dispose, Throws.Nothing, "Dispose() #2");
+    Assert.That(node.DisposeAsync, Throws.Nothing, "DisposeAsync() after Dispose()");
+  }
+
+  [Test]
+  public async Task DisposeAsync()
+  {
+    await using var node = CreateNode();
+
+    Assert.That(node.DisposeAsync, Throws.Nothing, "DisposeAsync() #1");
+
+    Assert.That(() => _ = node.LocalEndPoint, Throws.TypeOf<ObjectDisposedException>());
+    Assert.That(node.Start, Throws.TypeOf<ObjectDisposedException>());
+    Assert.That(async () => await node.AcceptAsync(false, default), Throws.TypeOf<ObjectDisposedException>());
+    Assert.That(async () => await node.AcceptSingleSessionAsync(default), Throws.TypeOf<ObjectDisposedException>());
+
+    Assert.That(node.DisposeAsync, Throws.Nothing, "DisposeAsync() #2");
+    Assert.That(node.Dispose, Throws.Nothing, "Dispose() after DisposeAsync()");
+  }
+
   [Test]
   public async Task Start()
   {