Blog Scheduler approach 2

approach3-queue-producer-thread.java

@Override
void run()
{
    while(true)
    {
        newJob = getNewJobFromCrontabFile() // blocking call
        jobQueue.push(newJob)
        if(newJob == jobQueue.peek())
        {
            // The new job is the one that will be scheduled next.
            // So wakeup consumer thread so that it does not oversleep.
            jobQueueConsumerThread.interrupt()
        }
    }
}