| package org.eclipse.aether.synccontext; |
| |
| /* |
| * 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 java.util.Collection; |
| import java.util.concurrent.locks.Lock; |
| import java.util.concurrent.locks.ReentrantReadWriteLock; |
| |
| import javax.annotation.Priority; |
| import javax.inject.Named; |
| import javax.inject.Singleton; |
| |
| import org.eclipse.aether.RepositorySystemSession; |
| import org.eclipse.aether.SyncContext; |
| import org.eclipse.aether.artifact.Artifact; |
| import org.eclipse.aether.impl.SyncContextFactory; |
| import org.eclipse.aether.metadata.Metadata; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * A singleton factory to create synchronization contexts using a global lock based on |
| * {@link ReentrantReadWriteLock}. Explicit artifacts and metadata passed are ignored. |
| * <p> |
| * <strong>Note: This component is still considered to be experimental, use with caution!</strong> |
| */ |
| @Named |
| @Priority( Integer.MAX_VALUE ) |
| @Singleton |
| public class GlobalSyncContextFactory |
| implements SyncContextFactory |
| { |
| private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); |
| |
| public SyncContext newInstance( RepositorySystemSession session, boolean shared ) |
| { |
| return new GlobalSyncContext( shared ? lock.readLock() : lock.writeLock(), shared ); |
| } |
| |
| static class GlobalSyncContext |
| implements SyncContext |
| { |
| private static final Logger LOGGER = LoggerFactory.getLogger( GlobalSyncContext.class ); |
| |
| private final Lock lock; |
| private final boolean shared; |
| private int lockHoldCount; |
| |
| private GlobalSyncContext( Lock lock, boolean shared ) |
| { |
| this.lock = lock; |
| this.shared = shared; |
| } |
| |
| public void acquire( Collection<? extends Artifact> artifact, Collection<? extends Metadata> metadata ) |
| { |
| LOGGER.trace( "Acquiring global {} lock (currently held: {})", |
| shared ? "read" : "write", lockHoldCount ); |
| lock.lock(); |
| lockHoldCount++; |
| } |
| |
| public void close() |
| { |
| while ( lockHoldCount > 0 ) |
| { |
| LOGGER.trace( "Releasing global {} lock (currently held: {})", |
| shared ? "read" : "write", lockHoldCount ); |
| lock.unlock(); |
| lockHoldCount--; |
| } |
| } |
| |
| } |
| |
| } |