throw new CrawlerSystemException("Process terminated.", e);
        } finally {
            if (mt != null) {
                mt.setFinished(true);
                try {
                    mt.interrupt();
                } catch (final Exception e) {}
            }
            if (currentProcess != null) {
                try {
                    currentProcess.destroy();

                    cleanupExecutor.shutdownNow();
                }
            } catch (InterruptedException e) {
                cleanupExecutor.shutdownNow();
                Thread.currentThread().interrupt();
            }
        }

        // Clean up expired weak references
        cleanupExpiredReferences();

        // Release all leases
        releaseAll();

        // Clear file cache

            } catch (InterruptedException ex) {
              interrupted = true; // note interruption and retry
            }
          }
          if (e == null) {
            break; // we already waited enough, and there are no more elements in sight
          }
          buffer.add(e);
          added++;
        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }

 *   <li>Tasks may be of type {@code AsyncCallable}.
 *   <li>Running tasks <i>cannot</i> be interrupted. (Note that {@code newSequentialExecutor} does
 *       not return {@code Future} objects, so it doesn't support interruption directly, either.
 *       However, utilities that <i>use</i> that executor have the ability to interrupt tasks
 *       running on it. This class, by contrast, does not expose an {@code Executor} API.)
 * </ul>
 *

            if (!channelExecutor.awaitTermination(5, TimeUnit.SECONDS)) {
                channelExecutor.shutdownNow();
            }
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }

    // Private helper methods

    private int getMaxChannelsFromConfig(Configuration config) {
        // In a real implementation, this would read from configuration

        if (t != null && Thread.currentThread() != t) {
            this.thread = null;
            try {
                log.debug("Interrupting transport thread");
                t.interrupt();
                log.debug("Joining transport thread");
                t.join(timeout);
                log.debug("Joined transport thread");
            } catch (final InterruptedException e) {

     * Stops background processing and waits for threads to complete.
     */
    @PreDestroy
    public void destroy() {
        generating = false;
        thumbnailQueueThread.interrupt();
        try {
            thumbnailQueueThread.join(10000);
        } catch (final InterruptedException e) {
            logger.warn("Thumbnail thread timed out.", e);
        }

    AtomicBoolean terminated = new AtomicBoolean();
    // we need to keep this in a flag because t.isInterrupted() returns false after t.join()
    AtomicBoolean interrupted = new AtomicBoolean();
    // we need to use another thread because it will be interrupted and thus using
    // the current one, owned by JUnit, would make the test fail
    Thread thread =
        new Thread(
            new Runnable() {

                            completedOps.incrementAndGet();
                        }
                    } catch (InterruptedException e) {
                        Thread.currentThread().interrupt();
                    } finally {
                        endLatch.countDown();
                    }
                });
            }

            startLatch.countDown(); // Start all threads

    this.futures = checkNotNull(futures);
    this.allMustSucceed = allMustSucceed;
    this.collectsValues = collectsValues;
  }

  @Override
  @SuppressWarnings("Interruption") // We are propagating an interrupt from a caller.
  protected final void afterDone() {
    super.afterDone();

    @RetainedLocalRef ImmutableCollection<? extends Future<?>> localFutures = futures;