in spring-taskqueue/src/main/java/org/apache/archiva/components/taskqueue/execution/ThreadedTaskQueueExecutor.java [267:289]
        public synchronized boolean cancelTask( Task task )
        {
            if ( !task.equals( currentTask ) )
            {
                logger.debug( "Not cancelling task - it is not running" );
                return false;
            }
            if ( command != SHUTDOWN )
            {
                logger.debug( "Signalling executor thread to cancel task" );
                command = CANCEL_TASK;
                interrupt( );
            }
            else
            {
                logger.debug( "Executor thread already stopping; task will be cancelled automatically" );
            }
            return true;
        }