.NET CORE 3.1.1--HostingAbstractionsHostExtensions 类源码

// Assembly location: C:Program FilesdotnetsharedMicrosoft.AspNetCore.App3.1.1Microsoft.Extensions.Hosting.Abstractions.dll

using Microsoft.Extensions.DependencyInjection;
using System;
using System.Threading;
using System.Threading.Tasks;

namespace Microsoft.Extensions.Hosting
{
  public static class HostingAbstractionsHostExtensions
  {
    public static void Start(this IHost host)
    {
      host.StartAsync(new CancellationToken()).GetAwaiter().GetResult();
    }

    public static Task StopAsync(this IHost host, TimeSpan timeout)
    {
      return host.StopAsync(new CancellationTokenSource(timeout).Token);
    }

    public static void WaitForShutdown(this IHost host)
    {
      host.WaitForShutdownAsync(new CancellationToken()).GetAwaiter().GetResult();
    }

    public static void Run(this IHost host)
    {
      host.RunAsync(new CancellationToken()).GetAwaiter().GetResult();
    }

    public static async Task RunAsync(this IHost host, CancellationToken token = default (CancellationToken))
    {
      try
      {
        await host.StartAsync(token);
        await host.WaitForShutdownAsync(token);
      }
      finally
      {
        if (host is IAsyncDisposable asyncDisposable)
          await asyncDisposable.DisposeAsync();
        else
          host.Dispose();
      }
    }

    public static async Task WaitForShutdownAsync(this IHost host, CancellationToken token = default (CancellationToken))
    {
      IHostApplicationLifetime service = host.Services.GetService<IHostApplicationLifetime>();
      token.Register((Action<object>) (state => ((IHostApplicationLifetime) state).StopApplication()), (object) service);
      TaskCompletionSource<object> completionSource = new TaskCompletionSource<object>(TaskCreationOptions.RunContinuationsAsynchronously);
      service.ApplicationStopping.Register((Action<object>) (obj => ((TaskCompletionSource<object>) obj).TrySetResult((object) null)), (object) completionSource);
      object task = await completionSource.Task;
      await host.StopAsync(new CancellationToken());
    }
  }
}