arunpandianp commented on code in PR #38767: URL: https://github.com/apache/beam/pull/38767#discussion_r3362464648
########## runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/util/KeyGroupWorkQueue.java: ########## @@ -0,0 +1,463 @@ +/* + * 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.beam.runners.dataflow.worker.util; + +import static org.apache.beam.sdk.util.Preconditions.checkArgumentNotNull; +import static org.apache.beam.sdk.util.Preconditions.checkStateNotNull; + +import java.util.AbstractQueue; +import java.util.Collection; +import java.util.HashMap; +import java.util.Iterator; +import java.util.Map; +import java.util.Objects; +import java.util.concurrent.BlockingQueue; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.locks.Condition; +import java.util.concurrent.locks.ReentrantLock; +import javax.annotation.concurrent.GuardedBy; +import org.apache.beam.runners.dataflow.worker.streaming.Work; +import org.apache.beam.runners.dataflow.worker.util.BoundedQueueExecutor.QueuedWork; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList; +import org.checkerframework.checker.nullness.qual.Nullable; +import org.jspecify.annotations.NonNull; + +/** + * A custom, thread-safe doubly-linked BlockingQueue. In addition to global FIFO ordering, the queue + * supports polling work by computation + key group in FIFO order + */ +class KeyGroupWorkQueue extends AbstractQueue<Runnable> implements BlockingQueue<Runnable> { + + static class Node { + final @Nullable Runnable task; + final @Nullable String computationId; + final Work.@Nullable KeyGroup keyGroup; + // cached keyGroupList if the Node is part of one. + @Nullable KeyGroupWorkList keyGroupList; + + // prevNode, nextNode are used for the global order across all queued Runnables + @Nullable Node prevNode; + @Nullable Node nextNode; + + // prevKeyGroupNode and nextKeyGroupNode are used for the keyGroup level lists linking + // QueuedWork with same keyGroup + @Nullable Node prevKeyGroupNode; + @Nullable Node nextKeyGroupNode; + + Node(@Nullable Runnable task) { + this.task = task; + if (task instanceof QueuedWork) { + this.computationId = ((QueuedWork) task).getWork().getComputationId(); + this.keyGroup = ((QueuedWork) task).getWork().getKeyGroup(); + } else { + this.computationId = null; + this.keyGroup = null; + } + } + } + + /** Double linked list implementing key group level queue */ + private static class KeyGroupWorkList { + final Node head = new Node(null); + final Node tail = new Node(null); + + KeyGroupWorkList() { + head.nextKeyGroupNode = tail; + tail.prevKeyGroupNode = head; + } + + boolean isEmpty() { + return head.nextKeyGroupNode == tail; + } + + void append(Node node) { + @Nullable Node last = tail.prevKeyGroupNode; + if (last == null) { + throw new NullPointerException("tail.prevComp is null"); + } + node.prevKeyGroupNode = last; + node.nextKeyGroupNode = tail; + last.nextKeyGroupNode = node; + tail.prevKeyGroupNode = node; + } + + void remove(Node node) { + @Nullable Node prev = node.prevKeyGroupNode; + @Nullable Node next = node.nextKeyGroupNode; + if (prev != null && next != null) { + prev.nextKeyGroupNode = next; + next.prevKeyGroupNode = prev; + node.prevKeyGroupNode = null; + node.nextKeyGroupNode = null; + } + } + } + + private final ReentrantLock lock; + private final Condition notEmpty; + + // Sentinels for the global list + @GuardedBy("lock") + private final Node globalHead = new Node(null); + + @GuardedBy("lock") + private final Node globalTail = new Node(null); + + @GuardedBy("lock") + private final Map<QueueKey, KeyGroupWorkList> keyGroupQueueMap = new HashMap<>(); + + @GuardedBy("lock") + private int size = 0; + + public KeyGroupWorkQueue(boolean fair) { + this.lock = new ReentrantLock(fair); + this.notEmpty = lock.newCondition(); + globalHead.nextNode = globalTail; + globalTail.prevNode = globalHead; + } + + @GuardedBy("lock") + private void unlinkNode(Node node) { + // An existing node should always have previous and next since we have sentinels + // 1. Unlink from global list + Node prevG = checkArgumentNotNull(node.prevNode); + Node nextG = checkArgumentNotNull(node.nextNode); + prevG.nextNode = nextG; + nextG.prevNode = prevG; + node.prevNode = null; + node.nextNode = null; + + // 2. Unlink from key group list + KeyGroupWorkList list = node.keyGroupList; + if (list != null) { + list.remove(node); + if (list.isEmpty()) { + String compId = checkStateNotNull(node.computationId); + Work.KeyGroup keyGroup = checkStateNotNull(node.keyGroup); + QueueKey key = new QueueKey(compId, keyGroup); + keyGroupQueueMap.remove(key); + } + node.keyGroupList = null; + } + --size; + } + + @GuardedBy("lock") + private @Nullable Node removeFirstGlobal() { + @Nullable Node first = globalHead.nextNode; + if (first == null || first == globalTail) { + return null; + } + unlinkNode(first); + return first; + } + + /** + * Remove and Return QueuedWork for the computationId, keyGroup in the FIFO order Returns null, if + * there are no matches. + */ + public @Nullable QueuedWork pollWork(String computationId, Work.KeyGroup keyGroup) { + Preconditions.checkArgument(computationId != null && keyGroup != null); + if (keyGroup.equals(Work.KeyGroup.DEFAULT)) { Review Comment: done. I kept the equals check to avoid having to suppress https://errorprone.info/bugpattern/ReferenceEquality -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
