233     /**

   234      *  Previous versions of ResourceBundle exhibited the following caching behavior.

   235      *  Assume the class Bug4168625Resource_en exists. Bug4168625Resource_en_US does

   236      *  not.  Two threads, ThreadA and ThreadB both try to get the same bundle.

   237      *  <P>

   238      *  <pre>

   239      *  ThreadA.getBundle("Bug4168625Resource", new Locale("en", "US"));

   240      *      A-->try to load Bug4168625Resource_en_US

   241      *  ThreadB.getBundle("Bug4168625Resource", new Locale("en", "US"));

   242      *      B-->try to load Bug4168625Resource_en_US

   243      *      B-->load Bug4168625Resource_en (#1)

   244      *      A-->load Bug4168625Resource_en (#2)

   245      *      A-->cache Bug4168625Resource_en (#2) as Bug4168625Resource_en

   246      *      A-->cache Bug4168625Resource_en (#2) as Bug4168625Resource_en_US

   247      *      A-->return Bug4168625Resource_en (#2)

   248      *      B-->cache Bug4168625Resource_en (#1) as Bug4168625Resource_en

   249      *      B-->cache Bug4168625Resource_en (#1) as Bug4168625Resource_en_US

   250      *      B-->return Bug4168625Resource_en (#1)

   251      *  </pre>

   252      *  <P>

   253      *  Both threads try and fail to load Bug4168625Resource_en_US.  Both

   254      *  threads load Bug4168625Resource_en.  Both threads get their own copy

   255      *  of the Bug4168625Resource_en resource.

   256      *

   257      *  The desired behavior is as follows:

   258      *  <P>

   259      *  <pre>

   260      *  ThreadA.getBundle("Bug4168625Resource", new Locale("en", "US"));

   261      *      A-->try to load Bug4168625Resource_en_US

   262      *  ThreadB.getBundle("Bug4168625Resource", new Locale("en", "US"));

   263      *      B-->try to load Bug4168625Resource_en_US

   264      *      B-->load Bug4168625Resource_en

   265      *      A-->load Bug4168625Resource_en (block in ResourceBundle.getBundle)

   266      *      B-->cache Bug4168625Resource_en as Bug4168625Resource_en

   267      *      B-->cache Bug4168625Resource_en as Bug4168625Resource_en_US

   268      *      A-->return Bug4168625Resource_en

   269      *      B-->return Bug4168625Resource_en

   270      *  </pre>

   271      *  <P>

   272      *  Note that both threads return the same bundle object.

   273      */

   274     public void testConcurrentLoading1() throws Exception {

   275         final Loader loader = new Loader( new String[] { "Bug4168625Class" }, new String[] { "Bug4168625Resource3_en_US", "Bug4168625Resource3_en_CA" });

   276         final Class c = loader.loadClass("Bug4168625Class");

   277         final Bug4168625Getter test = (Bug4168625Getter)c.newInstance();

   278 

   279             //both threads want the same resource

   280         ConcurrentLoadingThread thread1 = new ConcurrentLoadingThread(loader, test, new Locale("en", "US"));

   281         ConcurrentLoadingThread thread2 = new ConcurrentLoadingThread(loader, test, new Locale("en", "US"));

   282 

   283         thread1.start();            //start thread 1

   284         loader.waitForNotify(1);    //wait for thread1 to do getBundle & block in loader

   285         thread2.start();            //start second thread

   286         loader.waitForNotify(2, 1000);  //wait until thread2 blocks somewhere in getBundle

   287         thread1.ping();             //continue both threads

   288         thread2.ping();

   289 

   290         thread1.join();             //wait unitl both threads complete

   291         thread2.join();

   292 

   293             //Now, examine the class loads that were done.

   294         loader.logClasses("Classes loaded after completion of both threads:");

   295 

   296         boolean dups = false;

   297         for (int i = loader.loadedClasses.size() - 1; i >= 0 ; i--) {

   298             final Object item = loader.loadedClasses.elementAt(i);

   299             loader.loadedClasses.removeElementAt(i);

   300             if (loader.loadedClasses.contains(item)) {

   301                 logln("Resource loaded more than once: "+item);

   302                 dups = true;

   303             }

   304         }

   305         if (dups) {

   306             errln("ResourceBundle loaded some classes multiple times");

   307         }

   308     }

   309