当使用 ArrayList 的 Stack 或 Queue 实现比在 Java 中实现的 LinkedList 提供更好、更快的性能时，是否有任何情况？

Question

In this Question I read the following:

If you're doing comparatively few operations, ie less than 1000 or so enqueue/dequeues in total, then an array would be faster because it is contiguous in memory.

My question is: How caching an ArrayList works in Java? Are there cases, when an ArrayList implemented Queue or Stack perform better then a LinkedList implemented in Java?

Answer 1

hen an ArrayList implemented Queue or Stack perform better then a LinkedList implemented in Java?

When the queue is almost always empty or with 1 element, ArrayList is faster and creates less garbage (ie none)

If you have a fast consumer, it will almost always consumer what ever the producer produces as it produces it. This means there is typically 0 or 1 elements in the queue. Under these conditions ArrayList is faster as it doesn't create any objects or produce garbage.

BTW ArrayDeque is a better choice because this performs well even if there is more than 1 element.

How caching an ArrayList works in Java?

There is nothing special about the way the CPU caches accesses to an ArrayList.