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https://issues.apache.org/jira/browse/STORM-1253?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15144224#comment-15144224
]
ASF GitHub Bot commented on STORM-1253:
---------------------------------------
Github user abhishekagarwal87 commented on a diff in the pull request:
https://github.com/apache/storm/pull/1098#discussion_r52712733
--- Diff: storm-core/src/jvm/org/apache/storm/StormTimer.java ---
@@ -0,0 +1,231 @@
+/**
+ * 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;
+ }
+
+ @Override
+ public String toString() {
+ return this.id + " " + this.endTimeMs + " " + this.afn;
+ }
+ }
+
+ 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();
+ }
+ });
+
+ private AtomicBoolean active = new AtomicBoolean(false);
+
+ private TimerFunc onKill;
+
+ private Random random = new Random();
+
+ private Semaphore cancelNotifier = new Semaphore(0);
+
+ 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);
+ }
+ }
+
+ public static StormTimerTask mkTimer(String name, TimerFunc onKill) {
+ if (onKill == null) {
+ throw new RuntimeException("onKill func is null!");
+ }
+ StormTimerTask task = new StormTimerTask();
+ if (name == null) {
+ task.setName("timer");
+ } else {
+ task.setName(name);
+ }
+ task.setOnKillFunc(onKill);
+ task.setActive(true);
+
+ task.setDaemon(true);
+ task.setPriority(Thread.MAX_PRIORITY);
+ task.start();
+ return task;
+ }
+ public static void schedule(StormTimerTask task, int delaySecs,
TimerFunc afn, boolean checkActive, int jitterMs) {
+ if (task == null) {
+ throw new RuntimeException("task is null!");
+ }
+ if (afn == null) {
+ throw new RuntimeException("function to schedule is null!");
+ }
+ String id = Utils.uuid();
+ long endTimeMs = Time.currentTimeMillis() +
Time.secsToMillisLong(delaySecs);
+ if (jitterMs > 0) {
+ endTimeMs = task.random.nextInt(jitterMs) + endTimeMs;
+ }
+ synchronized (task.lock) {
+ task.add(new QueueEntry(endTimeMs, afn, id));
+ }
+ }
+ public static void schedule(StormTimerTask task, int delaySecs,
TimerFunc afn) {
+ schedule(task, delaySecs, afn, true, 0);
+ }
+
+ public static void scheduleRecurring(final StormTimerTask task, int
delaySecs, final int recurSecs, final TimerFunc afn) {
+ schedule(task, delaySecs, new TimerFunc() {
+ @Override
+ public void run(Object o) {
+ afn.run(null);
+ // This avoids a race condition with cancel-timer.
+ schedule(task, recurSecs, this, false, 0);
+ }
+ });
+ }
+
+ public static void scheduleRecurringWithJitter(final StormTimerTask
task, int delaySecs, final int recurSecs, final int jitterMs, final TimerFunc
afn) {
--- End diff --
same comment regarding the method parameters ordering.
> 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
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