How can my ILoggerProvider get a DisposeAsync() or any kind of shutdown message

[DavidThielen]

Blazor server

I have just written an ILoggerProvider and the one thing it is missing is a way to shut down when the app closes.

This is not a biggie as everything is written to the log repository. But I dislike leaving things like file handles open when closing an application.

So, is there a way to be notified that the app is closing? And as a logger, be the last to be notified in case any other parts are logging while closing down?

thanks - dave

[david-acker]

Could you implement IAsyncDisposable on your custom ILoggerProvider, and then handle any shutdown/clean up logic in the DisposeAsync method implemented by that?

Since ILoggerProvider also implements IDisposable, here's some guidance on implementing both the dispose and async dispose patterns.

[DavidThielen]

I have those written. They're never called. I'm guessing the logging system never closes down its providers.

[david-acker]

Hmm, the custom ILoggerProvider is registered with the DI container, correct? Are there any other logging-related libraries being used?

[DavidThielen]

I'm using 4 of the standard loggers. The way mine are added is as follows:

	public static class LoggingBuilderExtensions
	{
		public static ILoggingBuilder AddFileLogger(this ILoggingBuilder builder)
		{
			builder.AddConfiguration();

			builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<ILoggerProvider,
				FileLoggerProvider>());
			builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IConfigureOptions<FileLoggerOptions>,
				FileLoggerOptionsSetup>());
			builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IOptionsChangeTokenSource<FileLoggerOptions>,
				LoggerProviderOptionsChangeTokenSource<FileLoggerOptions, FileLoggerProvider>>());
			return builder;
		}

		public static ILoggingBuilder AddAzureBlobLogger(this ILoggingBuilder builder)
		{
			builder.AddConfiguration();

			builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<ILoggerProvider,
				BlobLoggerProvider>());

			builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IConfigureOptions<BlobLoggerOptions>,
				BlobLoggerOptionsSetup>());
			builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IOptionsChangeTokenSource<BlobLoggerOptions>,
				LoggerProviderOptionsChangeTokenSource<BlobLoggerOptions, BlobLoggerProvider>>());

			return builder;
		}
	}

So they're singletons. Are singleton services disposed when the system shuts down? Or are they left alone? (I could probably make a good argument for either approach.)

thanks - dave

[david-acker]

In this situation, the DI container should automatically handle disposing of the ILoggerProvider, since its handles creating the instance on its own. To my knowledge, the only time when the container won't handle disposal is when create an instance of a service on your own and then register it (e.g. builder.Services.AddSingleton(new ExampleService())). Disposal of services

It might be worth asking this question in the discussions for the dotnet/runtime repo to see if they have any insight on this issue since that's actually where ILoggerProvider and ILoggingBuilder are defined.

[DavidThielen]

Thank you - I just did.