[jira] [Created] (XALANJ-2589) ObjectFactory is reloading classes over-and-over causing performance issues with XPATH.

["brian yoder (JIRA)" <ji...@apache.org>]

brian yoder created XALANJ-2589:
-----------------------------------

             Summary: ObjectFactory is reloading classes over-and-over causing performance issues with XPATH.
                 Key: XALANJ-2589
                 URL: https://issues.apache.org/jira/browse/XALANJ-2589
             Project: XalanJ2
          Issue Type: Bug
      Security Level: No security risk; visible to anyone (Ordinary problems in Xalan projects.  Anybody can view the issue.)
    Affects Versions: 2.7.2
         Environment: Glassfish 3.1 with JDK 1.6 u37
            Reporter: brian yoder
            Assignee: Steven J. Hathaway


I have done some performance benchmarking on XPath, and found that the ObjectFactory kept calling findProviderClass, which has code that is calling the following:

providerClass = cl.loadClass(className);

This is VERY inefficient, and is causing a severe bottleneck.  If i comment this code out, and instead use the following I see a significant performance improvement.

Class providerClass = Class.forName(className);

I am running on Glassfish 3.1 - and the bottlneck is really bad because my JAR files were on SAN, so this code is running very slow.

// Here is the code which I commented out, and rely ONLY on the Class.forName method.  Not sure why the other stuff is needed, maybe only to support older JVM's?

    /**
     * Find a Class using the specified ClassLoader
     */ 
    static Class findProviderClass(String className, ClassLoader cl,
                                           boolean doFallback)
        throws ClassNotFoundException, ConfigurationError
    {   
        //throw security exception if the calling thread is not allowed to access the
        //class. Restrict the access to the package classes as specified in java.security policy.
        SecurityManager security = System.getSecurityManager();
        try{
                if (security != null){
                    final int lastDot = className.lastIndexOf('.');
                    String packageName = className;
                    if (lastDot != -1) packageName = className.substring(0, lastDot);
                    security.checkPackageAccess(packageName);
                 }   
        }catch(SecurityException e){
            throw e;
        }
               
        Class providerClass = Class.forName(className);
        /*
        if (cl == null) {
            // XXX Use the bootstrap ClassLoader.  There is no way to
            // load a class using the bootstrap ClassLoader that works
            // in both JDK 1.1 and Java 2.  However, this should still
            // work b/c the following should be true:
            //
            // (cl == null) iff current ClassLoader == null
            //
            // Thus Class.forName(String) will use the current
            // ClassLoader which will be the bootstrap ClassLoader.
            providerClass = Class.forName(className);
        } else {
            try {
                providerClass = cl.loadClass(className);
            } catch (ClassNotFoundException x) {
                if (doFallback) {
                    // Fall back to current classloader
                    ClassLoader current = ObjectFactory.class.getClassLoader();
                    if (current == null) {
                        providerClass = Class.forName(className);
                    } else if (cl != current) {
                        cl = current;
                        providerClass = cl.loadClass(className);
                    } else {
                        throw x;
                    }
                } else {
                    throw x;
                }
            }
        }
		*/
        return providerClass;
    }



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