#fixed code
                                Module(final ConcreteModuleSpec spec, final ModuleLoader moduleLoader, final Object myKey) {
        this.moduleLoader = moduleLoader;
        this.myKey = myKey;

        // Initialize state from the spec.
        identifier = spec.getModuleIdentifier();
        mainClassName = spec.getMainClass();
        fallbackLoader = spec.getFallbackLoader();
        //noinspection ThisEscapedInObjectConstruction
        final ModuleClassLoader.Configuration configuration = new ModuleClassLoader.Configuration(this, spec.getAssertionSetting(), spec.getResourceLoaders(), spec.getClassFileTransformer());
        final ModuleClassLoaderFactory factory = spec.getModuleClassLoaderFactory();
        ModuleClassLoader moduleClassLoader = null;
        if (factory != null) moduleClassLoader = factory.create(configuration);
        if (moduleClassLoader == null) moduleClassLoader = new ModuleClassLoader(configuration);
        this.moduleClassLoader = moduleClassLoader;
    }
#vulnerable code 
                                void linkIfNecessary() throws ModuleLoadException {
        Linkage linkage = this.linkage;
        if (linkage.getState().compareTo(LINKING) >= 0) {
            return;
        }
        synchronized (this) {
            linkage = this.linkage;
            if (linkage.getState().compareTo(LINKING) >= 0) {
                return;
            }
            this.linkage = linkage = new Linkage(linkage.getSourceList(), LINKING);
        }
        link(linkage);
    } 
                            #location 13 
                            #vulnerability type THREAD_SAFETY_VIOLATION