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Posted to issues@eventmesh.apache.org by "pandaapo (via GitHub)" <gi...@apache.org> on 2023/10/23 08:14:09 UTC
Re: [PR] [ISSUE #4402] Refactor the retry module with HashedWheelTimer. (eventmesh)
pandaapo commented on code in PR #4505:
URL: https://github.com/apache/eventmesh/pull/4505#discussion_r1368287781
##########
eventmesh-runtime/src/main/java/org/apache/eventmesh/runtime/core/timer/HashedWheelTimer.java:
##########
@@ -0,0 +1,802 @@
+/*
+ * 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.eventmesh.runtime.core.timer;
+
+import static org.apache.eventmesh.common.Constants.OS_NAME_KEY;
+import static org.apache.eventmesh.common.Constants.OS_WIN_PREFIX;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Queue;
+import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * A {@link Timer} optimized for approximated I/O timeout scheduling.
+ *
+ * <h3>Tick Duration</h3>
+ * <p>
+ * As described with 'approximated', this timer does not execute the scheduled
+ * {@link TimerTask} on time. {@link HashedWheelTimer}, on every tick, will
+ * check if there are any {@link TimerTask}s behind the schedule and execute
+ * them.
+ * <p>
+ * You can increase or decrease the accuracy of the execution timing by
+ * specifying smaller or larger tick duration in the constructor. In most
+ * network applications, I/O timeout does not need to be accurate. Therefore,
+ * the default tick duration is 100 milliseconds, and you will not need to try
+ * different configurations in most cases.
+ *
+ * <h3>Ticks per Wheel (Wheel Size)</h3>
+ * <p>
+ * {@link HashedWheelTimer} maintains a data structure called 'wheel'.
+ * To put simply, a wheel is a hash table of {@link TimerTask}s whose hash
+ * function is 'deadline of the task'. The default number of ticks per wheel
+ * (i.e. the size of the wheel) is 512. You could specify a larger value
+ * if you are going to schedule a lot of timeouts.
+ *
+ * <h3>Do not create many instances.</h3>
+ * <p>
+ * {@link HashedWheelTimer} creates a new thread whenever it is instantiated and
+ * started. Therefore, you should make sure to create only one instance and
+ * share it across your application. One of the common mistakes, that makes
+ * your application unresponsive, is to create a new instance for every connection.
+ *
+ * <h3>Implementation Details</h3>
+ * <p>
+ * {@link HashedWheelTimer} is based on
+ * <a href="http://cseweb.ucsd.edu/users/varghese/">George Varghese</a> and
+ * Tony Lauck's paper,
+ * <a href="http://cseweb.ucsd.edu/users/varghese/PAPERS/twheel.ps.Z">'Hashed
+ * and Hierarchical Timing Wheels: data structures to efficiently implement a
+ * timer facility'</a>. More comprehensive slides are located
+ * <a href="http://www.cse.wustl.edu/~cdgill/courses/cs6874/TimingWheels.ppt">here</a>.
+ */
+public class HashedWheelTimer implements Timer {
Review Comment:
Why not just use netty's `HashedWheelTimer` and write an almost identical class repeatedly?
---
为什么不直接使用netty的`HashedWheelTimer`，而重复写一个几乎相同的类?
##########
eventmesh-runtime/src/main/java/org/apache/eventmesh/runtime/core/timer/HashedWheelTimer.java:
##########
@@ -0,0 +1,802 @@
+/*
+ * 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.eventmesh.runtime.core.timer;
+
+import static org.apache.eventmesh.common.Constants.OS_NAME_KEY;
+import static org.apache.eventmesh.common.Constants.OS_WIN_PREFIX;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Queue;
+import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
+import java.util.concurrent.atomic.AtomicLong;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * A {@link Timer} optimized for approximated I/O timeout scheduling.
+ *
+ * <h3>Tick Duration</h3>
+ * <p>
+ * As described with 'approximated', this timer does not execute the scheduled
+ * {@link TimerTask} on time. {@link HashedWheelTimer}, on every tick, will
+ * check if there are any {@link TimerTask}s behind the schedule and execute
+ * them.
+ * <p>
+ * You can increase or decrease the accuracy of the execution timing by
+ * specifying smaller or larger tick duration in the constructor. In most
+ * network applications, I/O timeout does not need to be accurate. Therefore,
+ * the default tick duration is 100 milliseconds, and you will not need to try
+ * different configurations in most cases.
+ *
+ * <h3>Ticks per Wheel (Wheel Size)</h3>
+ * <p>
+ * {@link HashedWheelTimer} maintains a data structure called 'wheel'.
+ * To put simply, a wheel is a hash table of {@link TimerTask}s whose hash
+ * function is 'deadline of the task'. The default number of ticks per wheel
+ * (i.e. the size of the wheel) is 512. You could specify a larger value
+ * if you are going to schedule a lot of timeouts.
+ *
+ * <h3>Do not create many instances.</h3>
+ * <p>
+ * {@link HashedWheelTimer} creates a new thread whenever it is instantiated and
+ * started. Therefore, you should make sure to create only one instance and
+ * share it across your application. One of the common mistakes, that makes
+ * your application unresponsive, is to create a new instance for every connection.
+ *
+ * <h3>Implementation Details</h3>
+ * <p>
+ * {@link HashedWheelTimer} is based on
+ * <a href="http://cseweb.ucsd.edu/users/varghese/">George Varghese</a> and
+ * Tony Lauck's paper,
+ * <a href="http://cseweb.ucsd.edu/users/varghese/PAPERS/twheel.ps.Z">'Hashed
+ * and Hierarchical Timing Wheels: data structures to efficiently implement a
+ * timer facility'</a>. More comprehensive slides are located
+ * <a href="http://www.cse.wustl.edu/~cdgill/courses/cs6874/TimingWheels.ppt">here</a>.
+ */
+public class HashedWheelTimer implements Timer {
Review Comment:
Why not just use netty's `HashedWheelTimer` and write an almost identical class repeatedly?
---
为什么不直接使用netty的`HashedWheelTimer`，而重复写一个几乎相同的类?
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