timeandspaceio/cronscheduler

An alternative to ScheduledThreadPoolExecutor proof against the clock drift problem

cronscheduler's Issues

scheduleAtFixedRateSkippingToLatest increases the cpu resouces to 95% on 1 hour time shift.

Below code :

private CronScheduler getCronSchedulerExecutor() {
        final ThreadFactory threadFactory = new ThreadFactoryBuilder()
                .setNameFormat("merged-config-%d")
                .setDaemon(true)
                .build();
        Duration syncPeriod = Duration.ofMillis(30_000L);
        CronSchedulerBuilder cronSchedulerBuilder = CronScheduler.newBuilder(syncPeriod);
        cronSchedulerBuilder.setThreadFactory(threadFactory);
        cronSchedulerBuilder.setThreadName("merged-config-refresher");
        return cronSchedulerBuilder.build();
    }

cronScheduler.scheduleAtFixedRateSkippingToLatest(1000, 1800, TimeUnit.MILLISECONDS, runTimeMillis -> {
            runJob(); // some execution
        });

I change the time to 1 hour past and it suddenly spikes the cpu after 30 secs (maybe because my syncPeriod is set to 30secs).
May I know where I am doing wrong ?

~Thanks

Add implementation to support cron expressions.

Should provide a parser and docs for using standard cron expressions.

Having some issues, wanted to make sure my code is correct.

Trying to schedule a task to turn on at midnight on Thursday local time (and repeat weekly):

    LocalDateTime now = LocalDateTime.now();
    Duration syncPeriod = Duration.ofMinutes(1);

    LocalDateTime thursdayAtMidnight = now.with(TemporalAdjusters.next(DayOfWeek.THURSDAY));
    long timeBetweenServerStartAndThursday = ChronoUnit.DAYS.between(now, thursdayAtMidnight);
    CronScheduler turnOnCron = CronScheduler.create(syncPeriod);
    turnOnCron.scheduleAtFixedRateSkippingToLatest(timeBetweenServerStartAndThursday, 7, TimeUnit.DAYS, runTimeMillis -> {
        //Do action
    });

Am I doing something wrong?