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ASF GitHub Bot commented on STORM-1253: --------------------------------------- Github user revans2 commented on a diff in the pull request: https://github.com/apache/storm/pull/1098#discussion_r52782172 --- Diff: storm-core/src/jvm/org/apache/storm/StormTimer.java --- @@ -0,0 +1,274 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.storm; + +import org.apache.storm.utils.Time; +import org.apache.storm.utils.Utils; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.Comparator; +import java.util.Random; +import java.util.concurrent.PriorityBlockingQueue; +import java.util.concurrent.Semaphore; +import java.util.concurrent.atomic.AtomicBoolean; + +/** + * The timer defined in this file is very similar to java.util.Timer, except + * it integrates with Storm's time simulation capabilities. This lets us test + * code that does asynchronous work on the timer thread + */ + +public class StormTimer { + private static final Logger LOG = LoggerFactory.getLogger(StormTimer.class); + + public interface TimerFunc { + public void run(Object o); + } + + public static class QueueEntry { + public final Long endTimeMs; + public final TimerFunc afn; + public final String id; + + public QueueEntry(Long endTimeMs, TimerFunc afn, String id) { + this.endTimeMs = endTimeMs; + this.afn = afn; + this.id = id; + } + } + + public static class StormTimerTask extends Thread { + + private PriorityBlockingQueue<QueueEntry> queue = new PriorityBlockingQueue<QueueEntry>(10, new Comparator() { + @Override + public int compare(Object o1, Object o2) { + return ((QueueEntry)o1).endTimeMs.intValue() - ((QueueEntry)o2).endTimeMs.intValue(); + } + }); + + // boolean to indicate whether timer is active + private AtomicBoolean active = new AtomicBoolean(false); + + // function to call when timer is killed + private TimerFunc onKill; + + //random number generator + private Random random = new Random(); + + // synchronization for cancelling the timer + private Semaphore cancelNotifier = new Semaphore(0); + + //used for synchronization + private Object lock = new Object(); + + @Override + public void run() { + while (this.active.get()) { + QueueEntry queueEntry = null; + try { + synchronized (this.lock) { + queueEntry = this.queue.peek(); + } + if ((queueEntry != null) && (Time.currentTimeMillis() >= queueEntry.endTimeMs)) { + // It is imperative to not run the function + // inside the timer lock. Otherwise, it is + // possible to deadlock if the fn deals with + // other locks, like the submit lock. + synchronized (this.lock) { + this.queue.poll(); + } + queueEntry.afn.run(null); + } else if (queueEntry != null) { + // If any events are scheduled, sleep until + // event generation. If any recurring events + // are scheduled then we will always go + // through this branch, sleeping only the + // exact necessary amount of time. We give + // an upper bound, e.g. 1000 millis, to the + // sleeping time, to limit the response time + // for detecting any new event within 1 secs. + Time.sleep(Math.min(1000, (queueEntry.endTimeMs - Time.currentTimeMillis()))); + } else { + // Otherwise poll to see if any new event + // was scheduled. This is, in essence, the + // response time for detecting any new event + // schedulings when there are no scheduled + // events. + Time.sleep(1000); + } + } catch (Throwable t) { + if (!(Utils.exceptionCauseIsInstanceOf(InterruptedException.class, t))) { + this.onKill.run(t); + this.setActive(false); + throw new RuntimeException(t); + } + } + } + this.cancelNotifier.release(); + } + + public void setOnKillFunc(TimerFunc onKill) { + this.onKill = onKill; + } + + public void setActive(boolean flag) { + this.active.set(flag); + } + + public boolean isActive() { + return this.active.get(); + } + + public void add(QueueEntry queueEntry) { + this.queue.add(queueEntry); + } + } + + /** + * Makes a Timer in the form of a StormTimerTask Object + * @param name name of the timer + * @param onKill function to call when timer is killed unexpectedly + * @return StormTimerTask object that was initialized + */ + public static StormTimerTask mkTimer(String name, TimerFunc onKill) { --- End diff -- Why not make this a Constructor, and hide StormTimerTask as an implementation detail? > port backtype.storm.timer to java > ---------------------------------- > > Key: STORM-1253 > URL: https://issues.apache.org/jira/browse/STORM-1253 > Project: Apache Storm > Issue Type: New Feature > Components: storm-core > Reporter: Robert Joseph Evans > Assignee: Boyang Jerry Peng > Labels: java-migration, jstorm-merger > > Timer like class that uses simulated time -- This message was sent by Atlassian JIRA (v6.3.4#6332)