jenkinsci / stapler

I was browsing the thread dump of a controller slow to start up and was surprised to see a mention of JDK 1.2 and a library I had not heard of.

Thread stack

"Handling GET /…/user/admin/contextMenu from … : Jetty (winstone)-…" … elapsed=3.93s … runnable  […]
   java.lang.Thread.State: RUNNABLE
	at java.util.zip.ZipFile$Source.getEntryPos(java.base@11.0.16.1/ZipFile.java:1649)
	at java.util.zip.ZipFile.getEntry(java.base@11.0.16.1/ZipFile.java:350)
	- locked <0x00000000ec194810> (a java.util.jar.JarFile)
	at java.util.zip.ZipFile$1.getEntry(java.base@11.0.16.1/ZipFile.java:1143)
	at java.util.jar.JarFile.getEntry0(java.base@11.0.16.1/JarFile.java:586)
	at java.util.jar.JarFile.getEntry(java.base@11.0.16.1/JarFile.java:516)
	at java.util.jar.JarFile.getJarEntry(java.base@11.0.16.1/JarFile.java:478)
	at jdk.internal.loader.URLClassPath$JarLoader.getResource(java.base@11.0.16.1/URLClassPath.java:943)
	at jdk.internal.loader.URLClassPath$JarLoader.findResource(java.base@11.0.16.1/URLClassPath.java:926)
	at jdk.internal.loader.URLClassPath.findResource(java.base@11.0.16.1/URLClassPath.java:292)
	at java.net.URLClassLoader$2.run(java.base@11.0.16.1/URLClassLoader.java:660)
	at java.net.URLClassLoader$2.run(java.base@11.0.16.1/URLClassLoader.java:658)
	at java.security.AccessController.doPrivileged(java.base@11.0.16.1/Native Method)
	at java.net.URLClassLoader.findResource(java.base@11.0.16.1/URLClassLoader.java:657)
	at org.eclipse.jetty.webapp.WebAppClassLoader.getResource(WebAppClassLoader.java:408)
	at org.apache.commons.discovery.jdk.JDK12Hooks.getResources(JDK12Hooks.java:134)
	at org.apache.commons.discovery.resource.DiscoverResources$1.getNextResources(DiscoverResources.java:124)
	at org.apache.commons.discovery.resource.DiscoverResources$1.getNextResource(DiscoverResources.java:98)
	at org.apache.commons.discovery.resource.DiscoverResources$1.hasNext(DiscoverResources.java:84)
	at org.apache.commons.discovery.resource.names.DiscoverNamesInFile$1.getNextClassNames(DiscoverNamesInFile.java:226)
	at org.apache.commons.discovery.resource.names.DiscoverNamesInFile$1.getNextClassName(DiscoverNamesInFile.java:209)
	at org.apache.commons.discovery.resource.names.DiscoverNamesInFile$1.hasNext(DiscoverNamesInFile.java:196)
	at org.kohsuke.stapler.Facet.discoverExtensions(Facet.java:93)
	at org.kohsuke.stapler.jelly.JellyTagFileLoader.discover(JellyTagFileLoader.java:50)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.<init>(CustomTagLibrary.java:73)
	at org.kohsuke.stapler.jelly.JellyClassLoaderTearOff.lambda$getTagLibrary$0(JellyClassLoaderTearOff.java:76)
	at org.kohsuke.stapler.jelly.JellyClassLoaderTearOff$$Lambda$241/0x00000008402fe040.apply(Unknown Source)
	at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(java.base@11.0.16.1/ConcurrentHashMap.java:1705)
	- locked <0x00000000e8400ae8> (a java.util.concurrent.ConcurrentHashMap$ReservationNode)
	at org.kohsuke.stapler.jelly.JellyClassLoaderTearOff.getTagLibrary(JellyClassLoaderTearOff.java:65)
	at org.kohsuke.stapler.jelly.CustomJellyContext.getTagLibrary(CustomJellyContext.java:112)
	at org.apache.commons.jelly.JellyContext.getTagLibrary(JellyContext.java:457)
	at org.kohsuke.stapler.jelly.CustomJellyContext.getTagLibrary(CustomJellyContext.java:108)
	at org.apache.commons.jelly.parser.XMLParser.createTag(XMLParser.java:1066)
	at org.apache.commons.jelly.parser.XMLParser.startElement(XMLParser.java:686)
	at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(java.xml@11.0.16.1/AbstractSAXParser.java:510)
	at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(java.xml@11.0.16.1/AbstractXMLDocumentParser.java:183)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(java.xml@11.0.16.1/XMLNSDocumentScannerImpl.java:351)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(java.xml@11.0.16.1/XMLDocumentFragmentScannerImpl.java:2710)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(java.xml@11.0.16.1/XMLDocumentScannerImpl.java:605)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(java.xml@11.0.16.1/XMLNSDocumentScannerImpl.java:112)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(java.xml@11.0.16.1/XMLDocumentFragmentScannerImpl.java:534)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(java.xml@11.0.16.1/XML11Configuration.java:888)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(java.xml@11.0.16.1/XML11Configuration.java:824)
	at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(java.xml@11.0.16.1/XMLParser.java:141)
	at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(java.xml@11.0.16.1/AbstractSAXParser.java:1141)
	at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(java.xml@11.0.16.1/SAXParserImpl.java:647)
	at org.apache.commons.jelly.parser.XMLParser.parse(XMLParser.java:368)
	at org.apache.commons.jelly.JellyContext.compileScript(JellyContext.java:531)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.loadJellyScript(CustomTagLibrary.java:152)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.load(CustomTagLibrary.java:132)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.load(CustomTagLibrary.java:121)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.createTagScript(CustomTagLibrary.java:78)
	at org.apache.commons.jelly.parser.XMLParser.createTag(XMLParser.java:1091)
	at org.apache.commons.jelly.parser.XMLParser.startElement(XMLParser.java:686)
	at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(java.xml@11.0.16.1/AbstractSAXParser.java:510)
	at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(java.xml@11.0.16.1/AbstractXMLDocumentParser.java:183)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(java.xml@11.0.16.1/XMLNSDocumentScannerImpl.java:351)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(java.xml@11.0.16.1/XMLDocumentFragmentScannerImpl.java:2710)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(java.xml@11.0.16.1/XMLDocumentScannerImpl.java:605)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(java.xml@11.0.16.1/XMLNSDocumentScannerImpl.java:112)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(java.xml@11.0.16.1/XMLDocumentFragmentScannerImpl.java:534)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(java.xml@11.0.16.1/XML11Configuration.java:888)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(java.xml@11.0.16.1/XML11Configuration.java:824)
	at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(java.xml@11.0.16.1/XMLParser.java:141)
	at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(java.xml@11.0.16.1/AbstractSAXParser.java:1141)
	at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(java.xml@11.0.16.1/SAXParserImpl.java:647)
	at org.apache.commons.jelly.parser.XMLParser.parse(XMLParser.java:368)
	at org.apache.commons.jelly.JellyContext.compileScript(JellyContext.java:531)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.loadJellyScript(CustomTagLibrary.java:152)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.load(CustomTagLibrary.java:132)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.load(CustomTagLibrary.java:121)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.createTagScript(CustomTagLibrary.java:78)
	at org.apache.commons.jelly.parser.XMLParser.createTag(XMLParser.java:1091)
	at org.apache.commons.jelly.parser.XMLParser.startElement(XMLParser.java:686)
	at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(java.xml@11.0.16.1/AbstractSAXParser.java:510)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(java.xml@11.0.16.1/XMLNSDocumentScannerImpl.java:374)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(java.xml@11.0.16.1/XMLDocumentFragmentScannerImpl.java:2710)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(java.xml@11.0.16.1/XMLDocumentScannerImpl.java:605)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(java.xml@11.0.16.1/XMLNSDocumentScannerImpl.java:112)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(java.xml@11.0.16.1/XMLDocumentFragmentScannerImpl.java:534)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(java.xml@11.0.16.1/XML11Configuration.java:888)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(java.xml@11.0.16.1/XML11Configuration.java:824)
	at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(java.xml@11.0.16.1/XMLParser.java:141)
	at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(java.xml@11.0.16.1/AbstractSAXParser.java:1141)
	at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(java.xml@11.0.16.1/SAXParserImpl.java:647)
	at org.apache.commons.jelly.parser.XMLParser.parse(XMLParser.java:368)
	at org.apache.commons.jelly.JellyContext.compileScript(JellyContext.java:531)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.loadJellyScript(CustomTagLibrary.java:152)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.load(CustomTagLibrary.java:132)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.load(CustomTagLibrary.java:121)
	at org.kohsuke.stapler.jelly.CustomTagLibrary.createTagScript(CustomTagLibrary.java:78)
	at org.apache.commons.jelly.parser.XMLParser.createTag(XMLParser.java:1091)
	at org.apache.commons.jelly.parser.XMLParser.startElement(XMLParser.java:686)
	at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(java.xml@11.0.16.1/AbstractSAXParser.java:510)
	at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(java.xml@11.0.16.1/AbstractXMLDocumentParser.java:183)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(java.xml@11.0.16.1/XMLNSDocumentScannerImpl.java:351)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(java.xml@11.0.16.1/XMLDocumentFragmentScannerImpl.java:2710)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(java.xml@11.0.16.1/XMLDocumentScannerImpl.java:605)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(java.xml@11.0.16.1/XMLNSDocumentScannerImpl.java:112)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(java.xml@11.0.16.1/XMLDocumentFragmentScannerImpl.java:534)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(java.xml@11.0.16.1/XML11Configuration.java:888)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(java.xml@11.0.16.1/XML11Configuration.java:824)
	at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(java.xml@11.0.16.1/XMLParser.java:141)
	at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(java.xml@11.0.16.1/AbstractSAXParser.java:1141)
	at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(java.xml@11.0.16.1/SAXParserImpl.java:647)
	at org.apache.commons.jelly.parser.XMLParser.parse(XMLParser.java:368)
	at org.apache.commons.jelly.JellyContext.compileScript(JellyContext.java:531)
	at org.kohsuke.stapler.jelly.JellyClassTearOff.parseScript(JellyClassTearOff.java:57)
	at org.kohsuke.stapler.jelly.JellyClassTearOff.parseScript(JellyClassTearOff.java:47)
	at org.kohsuke.stapler.AbstractTearOff.resolveScript(AbstractTearOff.java:166)
	at org.kohsuke.stapler.jelly.JellyClassTearOff.resolveScript(JellyClassTearOff.java:95)
	at org.kohsuke.stapler.jelly.JellyClassTearOff.resolveScript(JellyClassTearOff.java:47)
	at org.kohsuke.stapler.AbstractTearOff.loadScript(AbstractTearOff.java:197)
	at org.kohsuke.stapler.CachingScriptLoader.findScript(CachingScriptLoader.java:61)
	at jenkins.model.ModelObjectWithContextMenu$ContextMenu.from(ModelObjectWithContextMenu.java:242)
	at jenkins.model.ModelObjectWithContextMenu$ContextMenu.from(ModelObjectWithContextMenu.java:237)
	at hudson.model.User.doContextMenu(User.java:1037)

It looks like

stapler/core/src/main/java/org/kohsuke/stapler/Facet.java

Lines 77 to 112 in 2a13b90

    
               /** 
        
                * Discovers all the facets in the classloader. 
        
                */ 
        
               public static List<Facet> discover(ClassLoader cl) { 
        
                   return discoverExtensions(Facet.class, cl); 
        
               } 
        
               public static <T> List<T> discoverExtensions(Class<T> type, ClassLoader... cls) { 
        
                   List<T> r = new ArrayList<>(); 
        
                   Set<String> classNames = new HashSet<>(); 
        
                   for (ClassLoader cl : cls) { 
        
                       ClassLoaders classLoaders = new ClassLoaders(); 
        
                       classLoaders.put(cl); 
        
                       DiscoverServiceNames dc = new DiscoverServiceNames(classLoaders); 
        
                       ResourceNameIterator itr = dc.findResourceNames(type.getName()); 
        
                       while(itr.hasNext()) { 
        
                           String name = itr.nextResourceName(); 
        
                           if (!classNames.add(name))  continue;   // avoid duplication 
        
                           Class<? extends T> c; 
        
                           try { 
        
                               c = cl.loadClass(name).asSubclass(type); 
        
                           } catch (ClassNotFoundException e) { 
        
                               LOGGER.log(Level.WARNING, "Failed to load "+name,e); 
        
                               continue; 
        
                           } 
        
                           try { 
        
                               r.add(c.newInstance()); 
        
                           } catch (InstantiationException | IllegalAccessException e) { 
        
                               LOGGER.log(Level.WARNING, "Failed to instantiate "+c,e); 
        
                           } 
        
                       } 
        
                   } 
        
                   return r; 
        
               }

could be replaced with a couple of lines using the standard ServiceLoader. (The only implementations are JellyFacet and GroovyFacet.)

Actually removing the library dep will be a bit trickier. Jenkins core implicitly uses it via Stapler https://github.com/jenkinsci/jenkins/blob/6d179998e18adfbaa4e443c7e837135bf36c53d7/core/src/main/java/hudson/cli/CLICommand.java#L564-L582 though it looks like this duplicates what is also done via SezPoz https://github.com/jenkinsci/jenkins/blob/6d179998e18adfbaa4e443c7e837135bf36c53d7/core/src/main/java/hudson/cli/CLICommand.java#L516-L528 and see https://github.com/jenkinsci/jenkins/blob/632033d6ada7c04bbc77ae710dc0a4635fdf9baa/core/src/main/java/hudson/cli/declarative/OptionHandlerExtension.java#L38 as well. Jelly also uses the lib for reasons I do not yet follow: https://github.com/jenkinsci/jelly/blob/114461d92a3c38d2b2e8f3b500a757a59b4035b0/src/java/org/apache/commons/jelly/impl/DefaultTagLibraryResolver.java#L67-L113

	/**
	* Discovers all the facets in the classloader.
	*/
	public static List<Facet> discover(ClassLoader cl) {
	return discoverExtensions(Facet.class, cl);
	}

	public static <T> List<T> discoverExtensions(Class<T> type, ClassLoader... cls) {
	List<T> r = new ArrayList<>();
	Set<String> classNames = new HashSet<>();

	for (ClassLoader cl : cls) {
	ClassLoaders classLoaders = new ClassLoaders();
	classLoaders.put(cl);
	DiscoverServiceNames dc = new DiscoverServiceNames(classLoaders);
	ResourceNameIterator itr = dc.findResourceNames(type.getName());
	while(itr.hasNext()) {
	String name = itr.nextResourceName();
	if (!classNames.add(name)) continue; // avoid duplication

	Class<? extends T> c;
	try {
	c = cl.loadClass(name).asSubclass(type);
	} catch (ClassNotFoundException e) {
	LOGGER.log(Level.WARNING, "Failed to load "+name,e);
	continue;
	}
	try {
	r.add(c.newInstance());
	} catch (InstantiationException \| IllegalAccessException e) {
	LOGGER.log(Level.WARNING, "Failed to instantiate "+c,e);
	}
	}
	}
	return r;
	}

Remove use of `commons-discovery`