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/*
* Copyright (c) 2017 simplity.org
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package org.simplity.job;
import java.util.Calendar;
import org.simplity.kernel.Tracer;
/**
* our own scheduler that schedules job based on time-of-day rather than
* intervals
*
* @author simplity.org
*
*/
public class TimeOfDayScheduler implements Runnable {
private static final int MAX_MINUTES = 24 * 60;
/*
* design: polls on each of the job. next poll is the least of the values
* returned. Not tracking NEVER returned by poll, and we continue to poll
*
* polling is very short, and hence most of the time this thread would
* sleep. wakeUp() designed to facilitate any change in the polling needs.
* interrupt (without wake-up) in honored as a request to shut down
*/
/**
* jobs to be scheduled
*/
private ScheduledJob[] pollers;
/**
* track a wake-up call
*/
private boolean wakeupRequested;
/**
* thread in which scheduler is running, or rather sleeping :-(
*/
private Thread thread;
/**
* interrupt the infinite-loop.
*
* @param justWakeup
* true to request to wake-up. Typically when scheduler has been
* modified. false is to stop the agony of infinite work
*/
public void interrupt(boolean justWakeup) {
this.wakeupRequested = justWakeup;
this.thread.interrupt();
}
/**
*
* @param jobs
*/
public TimeOfDayScheduler(ScheduledJob[] jobs) {
this.pollers = jobs;
}
/*
* (non-Javadoc)
*
* @see java.lang.Runnable#run()
*/
@Override
public void run() {
this.thread = Thread.currentThread();
Tracer.trace("TimeOfDay scheduler started.");
while (true) {
int nextDue = MAX_MINUTES;
Calendar cal = Calendar.getInstance();
int minutes = cal.get(Calendar.HOUR_OF_DAY) * 60 + cal.get(Calendar.MINUTE);
for (ScheduledJob job : this.pollers) {
int n = job.poll(minutes);
Tracer.trace("Job " + job.scheduledJob.name + " can wait for " + n + " minutes");
if (n > 0 && n < nextDue) {
nextDue = n;
}
}
try {
Tracer.trace("TimeOfDay scheduler taking a nap for " + nextDue + " minutes.");
Thread.sleep(nextDue * 60000);
} catch (InterruptedException e) {
if (this.wakeupRequested) {
this.wakeupRequested = false;
} else {
Tracer.trace("TimeOfDayScheduler interrupted");
return;
}
}
}
}
}