171     private final ReentrantLock lock = new ReentrantLock();

   171     private final ReentrantLock lock = new ReentrantLock();

   172 

   172 

   173     /**

   173     /**

   174      * Condition for blocking when empty.

   174      * Condition for blocking when empty.

   175      */

   175      */

   176     private final Condition notEmpty = lock.newCondition();

   177     private final Condition notEmpty = lock.newCondition();

   177 

   178 

   178     /**

   179     /**

   179      * Spinlock for allocation, acquired via CAS.

   180      * Spinlock for allocation, acquired via CAS.

   180      */

   181      */