Inconsistent scheduling with custom scheduler thread #16
Description
I'm trying to have a somewhat accurate yet flexible scheduler (it seems like I'd need to replace the scheduler every time I update it), so I came up with some test code like this:
lazy_static! {
static ref SCHEDULER: Mutex<Scheduler> = Mutex::new(Scheduler::new());
}
fn init_scheduler() {
let mut sched = SCHEDULER.try_lock().expect("Mutex was locked after initialization");
sched.every(5.seconds()).run(|| info!("Hello World"));
}
fn main() {
pretty_env_logger::init_timed();
init_scheduler();
info!("Scheduler started");
loop {
let mut nanos = 1_100_000_000 - (Local::now().nanosecond() as u64);
thread::sleep(Duration::from_nanos(nanos));
match SCHEDULER.try_lock() {
Ok(mut sched) => sched.run_pending(),
Err(err) => warn!("Unable to run scheduler: {}", err)
};
}
}I explicitly decided to align the scheduler calls to every second because even with just calling a logger, I got varying time intervals when just sleeping a second instead. However, this code made it absolutely worse as I now get 4, 5 and 6 second intervals randomly instead of a clean 5 second interval that I expected.
Since your scheduler seems to align everything to the next minute/hour/day, I'm supprised by this behaviour. Now, one second offset is not very bad, but I was hoping that for a schedule every 10 minutes and one every half our, I'd get away with calling the scheduler every 10 minutes, but having the interval fluctuate to 20 minutes is not acceptable.