package com.atlassian.sal.core.executor;
   
   import com.atlassian.sal.api.executor.ThreadLocalContextManager;
   
   import static com.google.common.base.Preconditions.checkNotNull;
   
   /**
    * A delegating runnable that copies the thread local state into the executing thread.
    *
   * @since 2.0
   */
  class ThreadLocalDelegateRunnable<C> implements Runnable {
      private final C context;
      private final Runnable delegate;
      private final ThreadLocalContextManager<C> manager;
      private final ClassLoader contextClassLoader;
  
      /**
       * @param manager  The manager to get the context from
       * @param delegate The runnable to delegate to
       */
      ThreadLocalDelegateRunnable(ThreadLocalContextManager<C> manager, Runnable delegate) {
          this.delegate = checkNotNull(delegate);
          this.manager = checkNotNull(manager);
          this.context = manager.getThreadLocalContext();
          this.contextClassLoader = Thread.currentThread().getContextClassLoader();
      }
  
      public void run() {
          ClassLoader oldContextClassLoader = Thread.currentThread().getContextClassLoader();
          try {
              Thread.currentThread().setContextClassLoader(contextClassLoader);
              manager.setThreadLocalContext(context);
              delegate.run();
          } finally {
              Thread.currentThread().setContextClassLoader(oldContextClassLoader);
              manager.clearThreadLocalContext();
          }
      }
  }