Throw when using a disposed looper pool

Author: mayuki

src/LogicLooper/LogicLooperPool.cs

@@ -9,10 +9,17 @@ public sealed partial class LogicLooperPool : ILogicLooperPool, IDisposable
 {
     private readonly PooledLogicLooper[] _loopers;
     private readonly ILogicLooperPoolBalancer _balancer;
-    private readonly CancellationTokenSource _shutdownTokenSource = new();
+    private bool _isDisposed;
 
     /// <inheritdoc />
-    public IReadOnlyList<ILogicLooper> Loopers => _loopers;
+    public IReadOnlyList<ILogicLooper> Loopers
+    {
+        get
+        {
+            ThrowIfDisposed();
+            return _loopers;
+        }
+    }
 
     /// <summary>
     /// Initialize the looper pool with specified configurations.
@@ -101,15 +108,25 @@ public Task RegisterActionAsync<TState>(LogicLooperAsyncActionWithStateDelegate<
     /// <inheritdoc />
     public async Task ShutdownAsync(TimeSpan shutdownDelay)
     {
+        ThrowIfDisposed();
         await Task.WhenAll(_loopers.Select(x => x.WrappedLooper.ShutdownAsync(shutdownDelay)));
     }
 
     /// <inheritdoc />
     public ILogicLooper GetLooper()
-        => _balancer.GetPooledLooper(_loopers);
+    {
+        ThrowIfDisposed();
+        return _balancer.GetPooledLooper(_loopers);
+    }
 
     public void Dispose()
     {
+        if (_isDisposed)
+        {
+            return;
+        }
+        _isDisposed = true;
+
         foreach (var looper in _loopers)
         {
             try
@@ -120,7 +137,14 @@ public void Dispose()
             {
             }
         }
-        _shutdownTokenSource.Cancel();
+    }
+
+    private void ThrowIfDisposed()
+    {
+        if (_isDisposed)
+        {
+            throw new ObjectDisposedException(nameof(LogicLooperPool));
+        }
     }
 
     private class PooledLogicLooper : ILogicLooper

test/LogicLooper.Test/LogicLooperPoolTest.cs

@@ -141,6 +141,34 @@ public async Task PooledLogicLooper_ShutdownAsyncFromLooperPool()
         Assert.True(looperFactory.CreatedLoopers[3].IsShutdownRequested);
     }
 
+    [Fact]
+    public async Task OperationsAfterDispose_ThrowObjectDisposedException()
+    {
+        var looperFactory = new FakeLogicLooperPoolLooperFactory();
+        var pool = new LogicLooperPool(60, 4, RoundRobinLogicLooperPoolBalancer.Instance, looperFactory);
+
+        pool.Dispose();
+
+        LogicLooperActionDelegate action = (in LogicLooperActionContext _) => false;
+        LogicLooperActionWithStateDelegate<int> actionWithState = (in LogicLooperActionContext _, int _) => false;
+        LogicLooperAsyncActionDelegate asyncAction = _ => ValueTask.FromResult(false);
+        LogicLooperAsyncActionWithStateDelegate<int> asyncActionWithState = (_, _) => ValueTask.FromResult(false);
+
+        Assert.Throws<ObjectDisposedException>(() => { _ = pool.RegisterActionAsync(action); });
+        Assert.Throws<ObjectDisposedException>(() => { _ = pool.RegisterActionAsync(action, LooperActionOptions.Default); });
+        Assert.Throws<ObjectDisposedException>(() => { _ = pool.RegisterActionAsync(actionWithState, 0); });
+        Assert.Throws<ObjectDisposedException>(() => { _ = pool.RegisterActionAsync(actionWithState, 0, LooperActionOptions.Default); });
+        Assert.Throws<ObjectDisposedException>(() => { _ = pool.RegisterActionAsync(asyncAction); });
+        Assert.Throws<ObjectDisposedException>(() => { _ = pool.RegisterActionAsync(asyncAction, LooperActionOptions.Default); });
+        Assert.Throws<ObjectDisposedException>(() => { _ = pool.RegisterActionAsync(asyncActionWithState, 0); });
+        Assert.Throws<ObjectDisposedException>(() => { _ = pool.RegisterActionAsync(asyncActionWithState, 0, LooperActionOptions.Default); });
+        Assert.Throws<ObjectDisposedException>(() => pool.GetLooper());
+        Assert.Throws<ObjectDisposedException>(() => _ = pool.Loopers);
+        await Assert.ThrowsAsync<ObjectDisposedException>(() => pool.ShutdownAsync(TimeSpan.Zero));
+
+        pool.Dispose();
+    }
+
     class FakeSequentialLogicLooperPoolBalancer : ILogicLooperPoolBalancer
     {
         private int _count;