CopyOnWriteRegistry possibly not correctly disposed

[dozm]

at: Autofac/src/Autofac/Core/Registration/CopyOnWriteRegistry.cs line:59
_readRegistry?.Dispose();
Whether it should be:
_writeRegistry?.Dispose();

this code will not throw an exception,Since you did not call _componentRegistry.Dispose() in LifetimeScope.Dispose()

[tillig]

This gets a little complicated, but I think you might be right.

Some research/notes:

The only place we create CopyOnWriteRegistry is during LifetimeScope.BeginLifetimeScope like here. The point of the CopyOnWriteRegistry is to isolate new registrations that get made in lifetime scope configuration actions from a parent component registry.

The CopyOnWriteRegistry gets the parent component registry as a constructor parameter (the "read registry") and then creates a "scope restricted registry" when writes (new registrations) are made.

While the parent lifetime scope (or container) is responsible for disposing of the root component registry, the creation of these disposable scope restricted registries doesn't actually appear to get handled - the _writeRegistry?.Dispose() as noted in the original issue isn't called.

That said, it doesn't look like anything actually ever does dispose of these CopyOnWriteRegistry instances. The registry isn't added to the new lifetime scope's Disposer so I'm not sure where that happens, if at all. I haven't hooked a debugger up to it to verify.

What it looks to me needs to happen:

• The CopyOnWriteRegistry needs to be added to the Disposer of the child lifetime scope so new registrations will be actively disposed.
• The _writeRegistry should be disposed, not the parent _readRegistry.
• A little doc should be added to LifetimeScope.CreateScopeRestrictedRegistry to indicate how this all works.

@alexmg Does this sound right to you?

[alexmg]

This fix is included in 4.6.1 which has been pushed to NuGet.