Method compress

future-java/src/main/java/io/trane/future/Promise.java:327–338

()

  }

  @SuppressWarnings("unchecked")
  private final Promise<T> compress() {
    while (true) {
      final Object curr = state;
      if (curr instanceof Promise && !(curr instanceof Continuation)) { // Linked
        final Promise<T> target = ((Promise<T>) curr).compress();
        if (curr == target || cas(curr, target))
          return target;
      } else
        return this;
    }
  }

  /**
   * Completes this promise with value.