cstamas commented on code in PR #213: URL: https://github.com/apache/maven-resolver/pull/213#discussion_r1015227078
########## maven-resolver-impl/src/main/java/org/eclipse/aether/internal/impl/concurrency/DefaultResolverExecutorService.java: ########## @@ -0,0 +1,92 @@ +package org.eclipse.aether.internal.impl.concurrency; + +/* + * 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. + */ + +import javax.inject.Named; +import javax.inject.Singleton; + +import java.util.concurrent.ExecutorService; +import java.util.concurrent.LinkedBlockingQueue; +import java.util.concurrent.ThreadPoolExecutor; +import java.util.concurrent.TimeUnit; + +import org.eclipse.aether.RepositorySystemSession; +import org.eclipse.aether.spi.concurrency.ResolverExecutor; +import org.eclipse.aether.spi.concurrency.ResolverExecutorService; +import org.eclipse.aether.util.concurrency.WorkerThreadFactory; + +import static java.util.Objects.requireNonNull; + +/** + * Default implementation of {@link ResolverExecutor}. + * <p> + * This implementation uses {@link RepositorySystemSession#getData()} to store created {@link ExecutorService} + * instances. It creates instances that may be eventually garbage collected, so no explicit shutdown happens on + * them. When {@code maxThreads} parameter is 1 (accepted values are greater than zero), this implementation assumes + * caller wants "direct execution" (on caller thread) and creates {@link ResolverExecutor} instances accordingly. + */ +@Singleton +@Named +public final class DefaultResolverExecutorService implements ResolverExecutorService +{ + @Override + public ResolverExecutor getResolverExecutor( RepositorySystemSession session, + Class<?> service, + int maxThreads ) + { + requireNonNull( session ); + requireNonNull( service ); + if ( maxThreads < 1 ) + { + throw new IllegalArgumentException( "threads must be greater than zero" ); + } + + final ExecutorService executorService; + if ( maxThreads == 1 ) // direct + { + executorService = null; + } + else // shared && pooled + { + String key = DefaultResolverExecutorService.class.getName() + "." + service.getSimpleName(); + executorService = (ExecutorService) session.getData() + .computeIfAbsent( key, () -> createExecutorService( service, maxThreads ) ); + } + return new DefaultResolverExecutor( executorService ); + } + + /** + * Creates am {@link ExecutorService} that allows its core threads to die off in case of inactivity, and allows + * for proper garbage collection. This is important detail, as these instances are kept within session data, and + * currently there is no way to shut down them. + */ + private ExecutorService createExecutorService( Class<?> service, int maxThreads ) + { + ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor( + maxThreads, + maxThreads, + 3L, TimeUnit.SECONDS, + new LinkedBlockingQueue<>(), + new WorkerThreadFactory( getClass().getSimpleName() + "-" + service.getSimpleName() + "-" ) Review Comment: Fixed -- 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: issues-unsubscr...@maven.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
