JobScheduler::new() - CantInit Error

[ev94]

Hi,

Thx for the great work.
We just update to 0.7.2. The call to JobScheduler::new() in the code below fails with a CantInit error.
Are we missing something?

Thx for your help
Emmanuel

tokio::spawn(async move {
	info!("spawning cron job");
	let sched = JobScheduler::new().expect("failed to create job scheduler");
	let _ = sched.add(
		Job::new_async(
			move |_uuid, _l| {
    			Box::pin(async move {
   					info!("job started);
				})
			},
		).expect("failed to create async job"),
	);
	if let Err(e) = sched.start() {
   		error!("failed to start scheduler: {:?}", e);
	}
});

[mvniekerk]

Hi @ev94
Thanks for the bug report. Did this code compile at all? You're missing the cron text for the Job::new_async(, ) code.

[ev94]

Hi @mvniekerk,
Thanks for your reply.
Sorry my code sample was incorrect. The cron text is in it.

tokio::spawn(async move {
	info!("spawning cron job");
	let sched = JobScheduler::new().expect("failed to create job scheduler");
	let _ = sched.add(
		Job::new_async(
		       app_config.load_data_cron.as_str(),
			move |_uuid, _l| {
    			Box::pin(async move {
   					info!("job started);
				})
			},
		).expect("failed to create async job"),
	);
	if let Err(e) = sched.start() {
   		error!("failed to start scheduler: {:?}", e);
	}
});

[mvniekerk]

Hi @ev94
I could replicate the problem.
For some reason it seems like init-ing the scheduler inside a tokio::spawn causes a block on the async-sync code.

[mvniekerk]

I've reached out to the Rust Reddit community on this. I don't know how to resolve this issue apart from marking all the functions as async fn's and then breaking the API of this library.

[mvniekerk]

https://www.reddit.com/r/rust/comments/vvn5fp/tokio_async_sync_bridging_causes_block/ FYI

[ev94]

Hi @mvniekerk
Thanks for your feedback. So a possible solution is to init the scheduler outside of the tokio::spawn and then to move it to the spawn and start it?

let sched = JobScheduler::new().expect("failed to create job scheduler");
let _ = sched.add(
               Job::new_async(
		app_config.load_data_cron.as_str(),
			move |_uuid, _l| {
    			Box::pin(async move {
   			   info!("job started);
			})
		},
	).expect("failed to create async job"),
);
tokio::spawn(async move {
	info!("starting  cron jobs");

	if let Err(e) = sched.start() {
   		error!("failed to start scheduler: {:?}", e);
	}
});

[mvniekerk]

Hi @ev94
Please check 0.8.0. I've made an example that covers your use case. Note that the API did change accordingly