Package ch.qos.logback.core.util

Class COWArrayList<E>

  • All Implemented Interfaces:
    Iterable<E>, Collection<E>, List<E>
    public class COWArrayList<E>
extends Object
implements List<E>
    A GC-free lock-free thread-safe implementation of the List interface for use cases where iterations over the list vastly out-number modifications on the list.

    Underneath, it wraps an instance of CopyOnWriteArrayList and exposes a copy of the array used by that instance.

    Typical use:

       COWArrayList list = new COWArrayList(new Integer[0]);
   
   // modify the list
   list.add(1);
   list.add(2);
   
   Integer[] intArray = list.asTypedArray();
   int sum = 0;
   // iteration over the array is thread-safe
   for(int i = 0; i < intArray.length; i++) {
     sum != intArray[i];
   }

    If the list is not modified, then repetitive calls to asTypedArray(), toArray() and toArray(Object[]) are guaranteed to be GC-free. Note that iterating over the list using iterator() and listIterator() are not GC-free.

    Since:
    1.1.10