+ "plugin(s) that have goals not marked as thread-safe to support parallel execution.",
                        "While this /may/ work fine, please look for plugin updates and/or "
                                + "request plugins be made thread-safe.",
                        "If reporting an issue, report it against the plugin in question, not against Apache Maven.")) {

        }
    }

    static class OwnerReentrantLock extends ReentrantLock {
        @Override
        public Thread getOwner() {
            return super.getOwner();
        }
    }

    static class OwnerReentrantReadWriteLock extends ReentrantReadWriteLock {
        @Override
        public Thread getOwner() {
            return super.getOwner();
        }
    }

    private static void warn(String msg) {

    private List<File> filesToDelete = new ArrayList<>();

    private final String baseFilename;

    private final String fileSuffix;

    private StackTraceElement callerInfo;

    private Thread cleanupWarning;

    private boolean warnAboutCleanup = false;

    public TestFileManager(String baseFilename, String fileSuffix) {
        this.baseFilename = baseFilename;
        this.fileSuffix = fileSuffix;

        // lookups that occur in contextualize calls in line with the right realm.
        ClassRealm oldLookupRealm = container.setLookupRealm(pluginRealm);

        ClassLoader oldClassLoader = Thread.currentThread().getContextClassLoader();
        Thread.currentThread().setContextClassLoader(pluginRealm);

        try {
            if (mojoDescriptor.isV4Api()) {

 * abused as a cache (i.e. for storing values that can be re-calculated) to avoid memory exhaustion.
 * <p>
 * <strong>Note:</strong> Actual implementations must be thread-safe.
 *
 * @see Session#getData()
 * @since 4.0.0
 */
@Experimental
@ThreadSafe
@Provider
public interface SessionData {

    /**
     * Associates the specified session data with the given key.

            }
        };
        injector.bindInstance(Injector.class, injector);
        bind(Injector.class).toInstance(injector);
        ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
        if (classLoader == null) {
            classLoader = getClass().getClassLoader();
        }
        try {
            for (Iterator<URL> it = classLoader

    private final Executor executor;

    public DefaultArtifactResolver() {
        int threads = Integer.getInteger("maven.artifact.threads", 5);
        if (threads <= 1) {
            executor = Runnable::run;
        } else {
            executor = new ThreadPoolExecutor(
                    threads, threads, 3, TimeUnit.SECONDS, new LinkedBlockingQueue<>(), new DaemonThreadCreator());
        }
    }

        defaultLegacySupport.setSession(m1);

        MyRunnable myRunnable = new MyRunnable();
        Thread thread = new Thread(myRunnable);
        thread.start();

        MavenSession m2 = new MavenSession(null, null, mavenExecutionRequest, null);
        defaultLegacySupport.setSession(m2);
        latch.countDown();
        thread.join();
        assertNull(myRunnable.getSession());
    }

    class MyRunnable implements Runnable {

 */
public class SystemProperties {
    /**
     * Thread-safe System.properties copy implementation.
     */
    public static void addSystemProperties(Properties props) {
        props.putAll(getSystemProperties());
    }

    /**
     * Returns a copy of {@link System#getProperties()} in a thread-safe manner.
     *
     * @return {@link System#getProperties()} obtained in a thread-safe manner.
     */

        msgs.add("* as @threadSafe to support parallel building.                  *");
        msgs.add("* While this /may/ work fine, please look for plugin updates    *");
        msgs.add("* and/or request plugins be made thread-safe.                   *");
        msgs.add("* If reporting an issue, report it against the plugin in        *");
        msgs.add("* question, not against maven-core                              *");