Implement IDisposable on ConnectionPool.

This allows all background work to be cancelled when a pool is no longer needed; the primary use case is cleanly shutting down a connection pool represented by a MySqlDataSource.

Author: bgrainger

src/MySqlConnector/Core/ConnectionPool.cs

@@ -8,9 +8,7 @@
 
 namespace MySqlConnector.Core;
 
-#pragma warning disable CA1001 // Types that own disposable fields should be disposable
-internal sealed class ConnectionPool
-#pragma warning restore CA1001 // Types that own disposable fields should be disposable
+internal sealed class ConnectionPool : IDisposable
 {
 	public int Id { get; }
 
@@ -223,6 +221,30 @@ public async Task ReapAsync(IOBehavior ioBehavior, CancellationToken cancellatio
 		return procedureCache;
 	}
 
+	public void Dispose()
+	{
+		Log.Debug("Pool{0} disposing connection pool", m_logArguments);
+#if NET6_0_OR_GREATER
+		m_dnsCheckTimer?.Dispose();
+		m_dnsCheckTimer = null;
+		m_reaperTimer?.Dispose();
+		m_reaperTimer = null;
+#else
+		if (m_dnsCheckTimer is not null)
+		{
+			using var dnsCheckWaitHandle = new ManualResetEvent(false);
+			m_dnsCheckTimer.Dispose(dnsCheckWaitHandle);
+			dnsCheckWaitHandle.WaitOne();
+		}
+		if (m_reaperTimer is not null)
+		{
+			using var reaperWaitHandle = new ManualResetEvent(false);
+			m_reaperTimer.Dispose(reaperWaitHandle);
+			reaperWaitHandle.WaitOne();
+		}
+#endif
+	}
+
 	/// <summary>
 	/// Examines all the <see cref="ServerSession"/> objects in <see cref="m_leasedSessions"/> to determine if any
 	/// have an owning <see cref="MySqlConnection"/> that has been garbage-collected. If so, assumes that the connection

src/MySqlConnector/MySqlDataSource.cs

@@ -91,7 +91,10 @@ protected override void Dispose(bool disposing)
 	private async ValueTask DisposeAsync(IOBehavior ioBehavior)
 	{
 		if (Pool is not null)
+		{
 			await Pool.ClearAsync(ioBehavior, default).ConfigureAwait(false);
+			Pool.Dispose();
+		}
 		m_isDisposed = true;
 	}