// release the lock in the reverse order of the acquisition
            if (acquiredProjectLock != null) {
                acquiredProjectLock.unlock();
            }
            if (acquiredAggregatorLock != null) {
                acquiredAggregatorLock.unlock();
            }
            mojos.remove(Thread.currentThread());
        }

        private OwnerReentrantLock getProjectLock(MavenSession session) {

     *
     * @param  id identifier of the remote repository to create
     * @param  url location of the remote repository
     * @return remote repository that can be used to download or upload artifacts
     *
     * @see org.apache.maven.api.services.RepositoryFactory#createRemote(String, String)
     */
    @Nonnull
    RemoteRepository createRemoteRepository(@Nonnull String id, @Nonnull String url);

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Immutable;
import org.apache.maven.api.annotations.Nonnull;

/**
 * A remote repository that can be used to download or upload artifacts.
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface RemoteRepository extends Repository {

    @Nonnull
    String getUrl();

    @Nonnull
    String getProtocol();

                    return;
                }
                List<Path> toLoad = new ArrayList<>();
                Path root = defaultModelBuilder.getModelProcessor().locateExistingPom(rootDirectory);
                toLoad.add(root);
                while (!toLoad.isEmpty()) {
                    Path pom = toLoad.remove(0);
                    try {
                        ModelBuilderRequest gaBuildingRequest =

     * @throws IOException if any
     * @throws XmlPullParserException if any
     */
    Settings buildSettings() throws IOException, XmlPullParserException;

    /**
     * @param useCachedSettings if true, doesn't reload the user settings
     * @return a <code>Settings</code> object from the user settings file.
     * @throws IOException if any
     * @throws XmlPullParserException if any
     */

                lock = channel.lock();

                if (touchfile.canRead()) {
                    getLogger().debug("Reading resolution-state from: " + touchfile);
                    props.load(Channels.newInputStream(channel));
                }

                props.setProperty(key, Long.toString(System.currentTimeMillis()));

                if (error != null) {

        for (ComponentDescriptor<?> descriptor : pluginDescriptor.getComponents()) {
            assertNotNull(descriptor.getRealm());
            assertNotNull(descriptor.getImplementationClass());
        }

        // reload plugin realm from cache
        session = createMavenSession(getProject("project-contributing-system-scope-plugin-dep"));
        project = session.getCurrentProject();

            if (desc == null) {
                synchronized (key) {
                    desc = descriptors.get(key);
                    if (desc == null) {
                        desc = supplier.load();
                        descriptors.putIfAbsent(key, clone(desc));
                    }
                }
            }
            return clone(desc);

    /**
     * A cache key.
     */
    interface Key {
        // marker interface for cache keys
    }

    @FunctionalInterface
    interface PluginDescriptorSupplier {
        PluginDescriptor load()
                throws PluginResolutionException, PluginDescriptorParsingException, InvalidPluginDescriptorException;
    }

    Key createKey(Plugin plugin, List<RemoteRepository> repositories, RepositorySystemSession session);

        File pom0 = new File(localRepo, "p0/pom.xml");
        File pom0Basedir = pom0.getParentFile();
        File pom1 = new File(pom0Basedir, "p1/pom.xml");

        // load the child project, which inherits from p0...
        MavenProject project0 = getProjectWithDependencies(pom0);
        MavenProject project1 = getProjectWithDependencies(pom1);