Implement dipose pattern in NpgsqlDataSourceManager

Author: marcusber

src/EFCore.PG/Storage/Internal/NpgsqlDataSourceManager.cs

@@ -164,13 +164,17 @@ enumDefinition.StoreTypeSchema is null
     ///     any release. You should only use it directly in your code with extreme caution and knowing that
     ///     doing so can result in application failures when updating to a new Entity Framework Core release.
     /// </summary>
-    public void Dispose()
+    /// <param name="disposing"><see langword="true"/> when disposed from Dispose(), false when called from DisposeAsync().</param>
+    protected void Dispose(bool disposing)
     {
-        if (Interlocked.CompareExchange(ref _isDisposed, 1, 0) == 0)
+        if (disposing)
         {
-            foreach (var dataSource in _dataSources.Values)
+            if (Interlocked.CompareExchange(ref _isDisposed, 1, 0) == 0)
             {
-                dataSource.Dispose();
+                foreach (var dataSource in _dataSources.Values)
+                {
+                    dataSource.Dispose();
+                }
             }
         }
     }
@@ -181,7 +185,19 @@ public void Dispose()
     ///     any release. You should only use it directly in your code with extreme caution and knowing that
     ///     doing so can result in application failures when updating to a new Entity Framework Core release.
     /// </summary>
-    public async ValueTask DisposeAsync()
+    public void Dispose()
+    {
+        Dispose(disposing: true);
+        GC.SuppressFinalize(this);
+    }
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    protected async ValueTask DisposeAsyncCore()
     {
         if (Interlocked.CompareExchange(ref _isDisposed, 1, 0) == 0)
         {
@@ -191,4 +207,17 @@ public async ValueTask DisposeAsync()
             }
         }
     }
+
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public async ValueTask DisposeAsync()
+    {
+        await DisposeAsyncCore().ConfigureAwait(false);
+        Dispose(disposing: false);
+        GC.SuppressFinalize(this);
+    }
 }