org.eclipse.aether.SyncContext Maven / Gradle / Ivy
/*
* 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.eclipse.aether;
import java.io.Closeable;
import java.util.Collection;
import org.eclipse.aether.artifact.Artifact;
import org.eclipse.aether.metadata.Metadata;
/**
* A synchronization context used to coordinate concurrent access to artifacts or metadatas. The typical usage of a
* synchronization context looks like this:
*
*
* SyncContext syncContext = repositorySystem.newSyncContext( ... );
* try {
* syncContext.acquire( artifacts, metadatas );
* // work with the artifacts and metadatas
* } finally {
* syncContext.close();
* }
*
*
* Within one thread, synchronization contexts may be nested which can naturally happen in a hierarchy of method calls.
* The nested synchronization contexts may also acquire overlapping sets of artifacts/metadatas as long as the following
* conditions are met. If the outer-most context holding a particular resource is exclusive, that resource can be
* reacquired in any nested context. If however the outer-most context is shared, the resource may only be reacquired by
* nested contexts if these are also shared.
*
* A synchronization context is meant to be utilized by only one thread and as such is not thread-safe.
*
* Note that the level of actual synchronization is subject to the implementation and might range from OS-wide to none.
*
* @see RepositorySystem#newSyncContext(RepositorySystemSession, boolean)
*/
public interface SyncContext extends Closeable {
/**
* Acquires synchronized access to the specified artifacts and metadatas. The invocation will potentially block
* until all requested resources can be acquired by the calling thread. Acquiring resources that are already
* acquired by this synchronization context has no effect. Please also see the class-level documentation for
* information regarding reentrancy. The method may be invoked multiple times on a synchronization context until all
* desired resources have been acquired.
*
* @param artifacts The artifacts to acquire, may be {@code null} or empty if none.
* @param metadatas The metadatas to acquire, may be {@code null} or empty if none.
*/
void acquire(Collection artifacts, Collection metadatas);
/**
* Releases all previously acquired artifacts/metadatas. If no resources have been acquired before or if this
* synchronization context has already been closed, this method does nothing.
*/
void close();
}