if (oldValue == 0L) {
          // don't compareAndSet a zero
          if (map.replace(key, atomic, new AtomicLong(delta))) {
            return delta;
          }
          // atomic replaced
          continue outer;
        }

        long newValue = oldValue + delta;
        if (atomic.compareAndSet(oldValue, newValue)) {
          return newValue;
        }

      assertBitEquals(x, at.doubleValue());
    }
  }

  /** compareAndSet treats +0.0 and -0.0 as distinct values */
  public void testDistinctZeros() {
    AtomicDouble at = new AtomicDouble(+0.0);
    assertFalse(at.compareAndSet(-0.0, 7.0));
    assertFalse(at.weakCompareAndSet(-0.0, 7.0));
    assertBitEquals(+0.0, at.get());
    assertTrue(at.compareAndSet(+0.0, -0.0));
    assertBitEquals(-0.0, at.get());

      for (double x : VALUES) {
        assertBitEquals(prev, aa.get(i));
        assertFalse(aa.compareAndSet(i, unused, x));
        assertBitEquals(prev, aa.get(i));
        assertTrue(aa.compareAndSet(i, prev, x));
        assertBitEquals(x, aa.get(i));
        prev = x;
      }
    }
  }

  /** compareAndSet in one thread enables another waiting for value to succeed */

   * @return {@code true} if successful. False return indicates that the actual value was not
   *     bitwise equal to the expected value.
   */
  public final boolean compareAndSet(double expect, double update) {
    return value.compareAndSet(doubleToRawLongBits(expect), doubleToRawLongBits(update));
  }

  /**
   * Atomically sets the value to the given updated value if the current value is <a

      for (double x : VALUES) {
        assertBitEquals(prev, aa.get(i));
        assertFalse(aa.compareAndSet(i, unused, x));
        assertBitEquals(prev, aa.get(i));
        assertTrue(aa.compareAndSet(i, prev, x));
        assertBitEquals(x, aa.get(i));
        prev = x;
      }
    }
  }

  /** compareAndSet in one thread enables another waiting for value to succeed */

   * @param update the new value
   * @return true if successful. False return indicates that the actual value was not equal to the
   *     expected value.
   */
  public final boolean compareAndSet(int i, double expect, double update) {
    return longs.compareAndSet(i, doubleToRawLongBits(expect), doubleToRawLongBits(update));
  }

  /**
   * Atomically sets the element at position {@code i} to the given updated value if the current

     * interrupt, yet it will still run, since interruptTask will leave the runner value null,
     * allowing the CAS below to succeed.
     */
    Thread currentThread = Thread.currentThread();
    if (!compareAndSet(null, currentThread)) {
      return; // someone else has run or is running.
    }

    boolean run = !isDone();
    T result = null;
    Throwable error = null;
    try {
      if (run) {

      assertBitEquals(x, at.doubleValue());
    }
  }

  /** compareAndSet treats +0.0 and -0.0 as distinct values */
  public void testDistinctZeros() {
    AtomicDouble at = new AtomicDouble(+0.0);
    assertFalse(at.compareAndSet(-0.0, 7.0));
    assertFalse(at.weakCompareAndSet(-0.0, 7.0));
    assertBitEquals(+0.0, at.get());
    assertTrue(at.compareAndSet(+0.0, -0.0));
    assertBitEquals(-0.0, at.get());

    if (computed == null) {
      computed = compute()
    }

    // If we successfully add the computed element, we're done.
    val newTags = tags.plus(type, computed)
    if (compareAndSet(tags, newTags)) return computed

    // We lost the race. Possibly to other code that was putting a *different* key. Try again!
  }

        AbstractFutureState<?> future, @Nullable Waiter expect, @Nullable Waiter update) {
      return waitersUpdater.compareAndSet(future, expect, update);
    }

    @Override
    boolean casListeners(
        AbstractFutureState<?> future, @Nullable Listener expect, Listener update) {
      return listenersUpdater.compareAndSet(future, expect, update);
    }

    @Override