assertFalse(lockA.tryLock());

    thread.releaseLockAndFinish();
    assertTrue(lockA.tryLock());
  }

  public void testReentrantWriteLock_tryLock() throws Exception {
    LockingThread thread = new LockingThread(writeLockA);
    thread.start();

    thread.waitUntilHoldingLock();
    assertFalse(writeLockA.tryLock());
    assertFalse(readLockA.tryLock());

    thread.releaseLockAndFinish();

    assertFalse(lockA.tryLock());

    thread.releaseLockAndFinish();
    assertTrue(lockA.tryLock());
  }

  public void testReentrantWriteLock_tryLock() throws Exception {
    LockingThread thread = new LockingThread(writeLockA);
    thread.start();

    thread.waitUntilHoldingLock();
    assertFalse(writeLockA.tryLock());
    assertFalse(readLockA.tryLock());

    thread.releaseLockAndFinish();

        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  /**
   * Invokes {@code lock.}{@link Lock#tryLock(long, TimeUnit) tryLock(timeout, unit)}
   * uninterruptibly.
   *
   * @since NEXT (but since 30.0 in the JRE flavor)
   */
  @J2ktIncompatible
  @GwtIncompatible // concurrency
  @SuppressWarnings("Java7ApiChecker")

        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  /**
   * Invokes {@code lock.}{@link Lock#tryLock(long, TimeUnit) tryLock(timeout, unit)}
   * uninterruptibly.
   *
   * @since 30.0 (but only since 33.4.0 in the Android flavor)
   */
  @J2ktIncompatible
  @GwtIncompatible // concurrency

    }

    // reference queues, for garbage collection cleanup

    /** Cleanup collected entries when the lock is available. */
    void tryDrainReferenceQueues() {
      if (tryLock()) {
        try {
          maybeDrainReferenceQueues();
        } finally {
          unlock();
        }
      }
    }

    @GuardedBy("this")

      }
    }

    // reference queues, for garbage collection cleanup

    /** Cleanup collected entries when the lock is available. */
    void tryDrainReferenceQueues() {
      if (tryLock()) {
        try {
          drainReferenceQueues();
        } finally {
          unlock();
        }
      }
    }

    /**

    }

    // reference queues, for garbage collection cleanup

    /** Cleanup collected entries when the lock is available. */
    void tryDrainReferenceQueues() {
      if (tryLock()) {
        try {
          maybeDrainReferenceQueues();
        } finally {
          unlock();
        }
      }
    }

    @GuardedBy("this")