c# - 多个 Worker 在 .NET Core 中并行运行

Question

我在 .NET Core 中创建了一个 Worker Service 项目，目的是让 3 名独立 worker 参与。所有这 3 个 worker 应该并行运行并且独立于其他 worker。这个辅助服务作为一个整体将作为 Windows 服务运行。

在主 Program.cs 中，我注册了 3 个 worker ，如下所示:

public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .UseWindowsService()
                .ConfigureServices((hostContext, services) =>
                {
                    IConfiguration configuration = hostContext.Configuration;
                    services.AddHostedService<WorkerA>();
                    services.AddHostedService<WorkerB>();
                    services.AddHostedService<WorkerC>();
                });
    }

每个 worker 代码如下，做他们预定的工作:

protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
     while (!stoppingToken.IsCancellationRequested)
     {
          WorkerA_DoWork();
          await Task.Delay(6000, stoppingToken);
     }
}

问题陈述:当我执行项目时，我遇到了一些问题，例如，当 WorkerA() 没有任何进程要运行时，WorkerB()(或)WorkerC() 没有开始他们的工作。我认为它基本上是在等待 WorkerA() 做一些事情，然后 WorkerB() 或 WorkerC() 才能开始工作。

请告知他们如何独立工作，即:每个 worker 不应该等待其他 worker ，应该独立运行。

Answer 1

When I execute the project, I am facing few issues like, when WorkerA() doesn't have any process to run, WorkerB() (or) WorkerC() do not start their work. I think it is basically waiting for WorkerA() to do something before WorkerB() or WorkerC() can start doing their work.

.NET Core 允许任意数量的托管服务；然而，它开始连续执行它们。所以这段代码的问题:

protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
  while (!stoppingToken.IsCancellationRequested)
  {
    WorkerA_DoWork();
    await Task.Delay(6000, stoppingToken);
  }
}

是 WorkerA_DoWork 是同步的。即，它正在同步等待工作。

解决方案可以是以下两种情况之一。要么使“获取下一个工作项”方法异步:

protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
  while (!stoppingToken.IsCancellationRequested)
  {
    await WorkerA_DoWorkAsync();
    await Task.Delay(6000, stoppingToken);
  }
}

或者将整个 ExecuteAsync 包装在 Task.Run 中:

protected override Task ExecuteAsync(CancellationToken stoppingToken) => Task.Run(async () =>
{
  while (!stoppingToken.IsCancellationRequested)
  {
    WorkerA_DoWork();
    await Task.Delay(6000, stoppingToken);
  }
});