private void schedule()

in server/src/main/java/org/apache/cassandra/sidecar/tasks/PeriodicTaskExecutor.java [81:129]
39 lines of code
10 McCabe index (conditional complexity)

    private void schedule(PeriodicTaskKey key, long priorExecDurationMillis, long delayMillis, long execCount)
    {
        long actualDelayMillis = delayMillis - priorExecDurationMillis;
        AtomicBoolean runNow = new AtomicBoolean(actualDelayMillis <= 0);
        timerIds.compute(key, (k, tid) -> {
            // The periodic task has been scheduled already. Exit early and avoid scheduling the duplication
            if (tid != null && execCount == 0)
            {
                LOGGER.debug("Task is already scheduled. task='{}'", key);
                runNow.set(false);
                return tid;
            }

            // Cleanup the unscheduled task from map
            if (tid != null && tid == UNSCHEDULED_STATE_TIMER_ID) // at this step, execCount != 0
            {
                LOGGER.debug("Task is now unscheduled. task='{}' execCount={}", key, execCount);
                runNow.set(false);
                return null; // remove the entry from the map, since it is unscheduled
            }

            if (tid == null && execCount != 0)
            {
                LOGGER.info("The executor is closed or the task is already unscheduled. " +
                            "Avoid scheduling more runs." +
                            "tid=null task='{}' execCount={}", key, execCount);
                runNow.set(false);
                return null;
            }

            LOGGER.debug("Scheduling task {}. task='{}' execCount={}",
                         runNow.get() ? "immediately" : "in " + actualDelayMillis + " milliseconds",
                         key, execCount);

            // If run immediately, do not execute within the compute block.
            // Return the placeholder timer ID, and execute after exiting the compute block.
            if (runNow.get())
            {
                return RUN_NOW_TIMER_ID; // use the placeholder ID, since this run is not scheduled as a timer
            }
            // Schedule and update the timer id
            return internalPool.setTimer(delayMillis, timerId -> executeAndScheduleNext(key, execCount));
        });

        if (runNow.get())
        {
            executeAndScheduleNext(key, execCount);
        }
    }