Method replace

output/java_guava/1.4.17/AtomicLongMap.java:436–443

If (key, expectedOldValue) is currently in the map, this method replaces expectedOldValue with newValue and returns true; otherwise, this method returns false. If expectedOldValue is zero, this method will succeed if (key, zero) is currently in the map, or

(K key, long expectedOldValue, long newValue)

   */

  boolean replace(K key, long expectedOldValue, long newValue) {
    if (expectedOldValue == 0L) {
      return putIfAbsent(key, newValue) == 0L;
    } else {
      AtomicLong atomic = map.get(key);
      return (atomic == null) ? false : atomic.compareAndSet(expectedOldValue, newValue);
    }
  }

  /**
   * If {@code (key, value)} is currently in the map, this method removes it and returns true;