Tapestry - Render body in parallel

Page.tml

<t:parallel>
   <t:someComponent />
</t:parallel>

Parallel.java

package com.foo.bar.components;

public class Parallel {
   @Inject ComponentResources componentResources;
   @Inject TypeCoercer typeCoercer;
   @Inject PerThreadManager perThreadManager;
   @Inject ParallelManager parallelManager;
   @Inject Logger logger;
   
   public boolean setupRender(MarkupWriter markupWriter) {
      Block bodyBlock = componentResources.getBody();
      final RenderCommand bodyCommand = typeCoercer.coerce(bodyBlock, RenderCommand.class);
      final Element newDiv = markupWriter.element("div");
      markupWriter.end();
      final Thread parentThread = Thread.currentThread();
      
      Runnable task = new Runnable {
         public void run() {
            try {
               parallelManager.setParentThread(parentThread);
               MarkupWriterImpl parallelWriter = new MarkupWriterImpl();
               RenderQueueImpl parallelQueue = new RenderQueueImpl(logger);
               bodyCommand.render(parallelWriter, parallelQueue);
               
               Element rootElement = parallelWriter.getDocument().getRootElement();
               for (Node node : rootElement.getChildren()) {
                  // hopefully this doesn't cause a concurrent modification exception
                  node.moveToBottom(newDiv);
               }
            } finally {
               parallelManager.taskFinished(task);
               perThreadManager.cleanupThread();
            }
         }
      };
      
      parallelManager.submitTask(task);

      // return false to exit the normal render flow
      return false;
   }
}

ParallelManager.java

/**
 * The implementation of this class will be @Scope(ScopeConstants.PER_THREAD)
 */
public interface ParallelManager {
   // Submit a task to the thread pool and maintain a mechanism to wait for in waitForTasks()
   Future<?> submitTask(Runnable task);
   
   // this will allow waitForTasks() to finish when all tasks (for the current request) complete
   void taskFinished(Runnable task);
   
   // Since this service is PER_THREAD scoped, set a member variable
   void setParentThread(Thread parentThread);
   
   // A custom PerThreadManager could check this boolean
   boolean isChildThread();
   
   // A custom PerThreadManager could delegate to the parent Thread's PerThreadValues somehow
   Thread getParentThread();
   
   // The request thread will need to wait for all child tasks to complete before writing to the response
   void waitForTasks();
}