konstantinb commented on code in PR #8426: URL: https://github.com/apache/hadoop/pull/8426#discussion_r3455213468
########## hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/impl/LazySharedThreadPoolHolder.java: ########## @@ -0,0 +1,112 @@ +/* + * 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.hadoop.fs.s3a.impl; + +import java.util.Optional; +import java.util.concurrent.ScheduledExecutorService; +import java.util.concurrent.ScheduledThreadPoolExecutor; +import java.util.concurrent.TimeUnit; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.hadoop.classification.InterfaceAudience; +import org.apache.hadoop.classification.InterfaceStability; +import org.apache.hadoop.conf.Configuration; + +import static org.apache.hadoop.fs.s3a.Constants.AWS_CLIENT_SHARED_THREADPOOL_KEEPALIVE_DEFAULT; +import static org.apache.hadoop.fs.s3a.Constants.AWS_CLIENT_SHARED_THREADPOOL_SIZE_DEFAULT; +import static org.apache.hadoop.util.Preconditions.checkArgument; + +/** + * Holder for a lazily initialized shared ScheduledExecutorService. + */ [email protected] [email protected] +public class LazySharedThreadPoolHolder { + + private static final Logger LOG = + LoggerFactory.getLogger(LazySharedThreadPoolHolder.class); + + private final String enabledKey; + private final String sizeKey; + private final String keepAliveKey; + private final String namePrefix; + + private volatile Optional<ScheduledExecutorService> executor; + + /** + * Create a holder for a lazy shared thread pool. + * @param enabledKey config key to enable the shared pool + * @param sizeKey config key for pool size + * @param keepAliveKey config key for thread keep-alive in seconds + * @param namePrefix thread name prefix for debugging + */ + public LazySharedThreadPoolHolder(String enabledKey, String sizeKey, + String keepAliveKey, String namePrefix) { + this.enabledKey = enabledKey; + this.sizeKey = sizeKey; + this.keepAliveKey = keepAliveKey; + this.namePrefix = namePrefix; + } + + /** + * Get the shared executor, creating it on first call if enabled. + * @param conf configuration + * @return the executor, or null if not enabled + */ + public synchronized ScheduledExecutorService get(Configuration conf) { + if (executor == null) { + if (conf.getBoolean(enabledKey, false)) { + int poolSize = conf.getInt(sizeKey, AWS_CLIENT_SHARED_THREADPOOL_SIZE_DEFAULT); + int keepAlive = conf.getInt(keepAliveKey, AWS_CLIENT_SHARED_THREADPOOL_KEEPALIVE_DEFAULT); + checkArgument(poolSize > 0, + "Value of %s must be positive, got: %s", sizeKey, poolSize); Review Comment: > S3AUtils.intOption() can combine range checks with retrieval My apologies, I totally missed this comment originally. Done — get() now uses S3AUtils.intOption(conf, key, default, 1) for size and keepalive, folding the range check into retrieval and dropping the checkArgument calls; updated the unit test's expected message to match. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
