Is the internal implementation of the library supplying me with a cancellation token source, or do I need to create my own?
I'm reading the documentation and it seems like I would need to create my own source in the caller method, then pass the token to the service.
Is the internal implementation of the library supplying me with a cancellation token source, or do I need to create my own?
No, you will not be getting CancellationTokenSource, only CancelationToken's for StartAsync/StopAsync methods (to support graceful shutdown/interruption, some docs).
If need to cancel call to some service additionally you will need to create your own CancellationTokenSource via CancellationTokenSource.CreateLinkedTokenSource. Something along these lines:
class MyHostedService : IHostedService
{
public Task StartAsync(CancellationToken cancellationToken)
{
var cts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
cts.CancelAfter(1000); // for example
_ = someService.DoAsync(cts.Token);
return Task.CompletedTask;
}
public Task StopAsync(CancellationToken cancellationToken)
{
var cts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
cts.CancelAfter(1000); // for example
await anotherService.DoAsync(cts.Token);
}
}
If you don't have custom cancellation logic then using passed cancellationToken is enough.
Also consider using BackgroundService base class, it encapsulates some of usual hosted service boilerplate code.
If you are using the AddHostedService<T> extension method to add the service, then it will be supplied with a stopping token that will be cancelled if/when the host is gracefully terminated.
If for some reason you are calling the service through some other manual approach (i.e. testing), then you would want to provide it a cancellation token.
