HostedMultiService

HostedMultiService.cs

    public static class HostedServicesExtensions {
        private class HostedMultiService<THostedService> : IHostedService where THostedService : class, IHostedService {
            readonly THostedService[] _hostedServices;

            public HostedMultiService(IEnumerable<THostedService> hostedServices) {
                _hostedServices = hostedServices.ToArray();
                if (_hostedServices.Any(s => s == null))
                    throw new ArgumentNullException(nameof(hostedServices));
            }

            public Task StartAsync(CancellationToken cancellationToken) =>
                Task.WhenAll(_hostedServices.Select(s => s.StartAsync(cancellationToken)));

            public Task StopAsync(CancellationToken cancellationToken) =>
                Task.WhenAll(_hostedServices.Select(s => s.StopAsync(cancellationToken)));
        }

        public static IServiceCollection AddHostedMultiService<THostedService>(this IServiceCollection services, Func<IServiceProvider, IEnumerable<THostedService>> factory)
            where THostedService : class, IHostedService => services.AddHostedService(provider => new HostedMultiService<THostedService>(factory(provider)));
    }