exception - ConcurrentModificationException in spite of using Iterator -

i using following class:

public class ticker implements runnable {  private linkedlist<timeable> timeables = new linkedlist<>();  @override public void run() {      listiterator<timeable> = timeables.listiterator();     while (it.hasnext()) {         it.next().tick();     } }  public void add(timeable timeable) {     timeables.add(timeable); }  public void remove(timeable timeable) {     timeables.remove(timeable); } 

}

i thought iterators prevent concurrentmodificationexception throws 1 @ "it.next().tick();".

how can solve this?

the java collection classes fail-fast, linkedlist throw concurrentmodificationexception if structure modified 1 thread while thread in process of iterating on elements.

for multithreaded code should use thread safe collection such copyonwritearraylist (which provides fail safe iterator of collection @ point in time) or concurrentlinkeddeque (if need access first or last element).