/**@class java.util.concurrent.ConcurrentLinkedDeque implements java.util.Deque implements java.io.Serializable @extends java.util.AbstractCollection An unbounded concurrent {@linkplain Deque deque} based on linked nodes. Concurrent insertion, removal, and access operations execute safely across multiple threads. A {@code ConcurrentLinkedDeque} is an appropriate choice when many threads will share access to a common collection. Like most other concurrent collection implementations, this class does not permit the use of {@code null} elements. <p>Iterators and spliterators are <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>. <p>Beware that, unlike in most collections, the {@code size} method is <em>NOT</em> a constant-time operation. Because of the asynchronous nature of these deques, determining the current number of elements requires a traversal of the elements, and so may report inaccurate results if this collection is modified during traversal. Additionally, the bulk operations {@code addAll}, {@code removeAll}, {@code retainAll}, {@code containsAll}, {@code equals}, and {@code toArray} are <em>not</em> guaranteed to be performed atomically. For example, an iterator operating concurrently with an {@code addAll} operation might view only some of the added elements. <p>This class and its iterator implement all of the <em>optional</em> methods of the {@link Deque} and {@link Iterator} interfaces. <p>Memory consistency effects: As with other concurrent collections, actions in a thread prior to placing an object into a {@code ConcurrentLinkedDeque} <a href="package-summary.html#MemoryVisibility"><i>happen-before</i></a> actions subsequent to the access or removal of that element from the {@code ConcurrentLinkedDeque} in another thread. @since 1.7 @author Doug Lea @author Martin Buchholz @param <E> the type of elements held in this deque */ var ConcurrentLinkedDeque = { /**Inserts the specified element at the front of this deque. As the deque is unbounded, this method will never throw {@link IllegalStateException}. @throws NullPointerException if the specified element is null */ addFirst : function( ) {}, /**Inserts the specified element at the end of this deque. As the deque is unbounded, this method will never throw {@link IllegalStateException}. <p>This method is equivalent to {@link #add}. @throws NullPointerException if the specified element is null */ addLast : function( ) {}, /**Inserts the specified element at the front of this deque. As the deque is unbounded, this method will never return {@code false}. @return {Boolean} {@code true} (as specified by {@link Deque#offerFirst}) @throws NullPointerException if the specified element is null */ offerFirst : function( ) {}, /**Inserts the specified element at the end of this deque. As the deque is unbounded, this method will never return {@code false}. <p>This method is equivalent to {@link #add}. @return {Boolean} {@code true} (as specified by {@link Deque#offerLast}) @throws NullPointerException if the specified element is null */ offerLast : function( ) {}, /** */ peekFirst : function( ) {}, /** */ peekLast : function( ) {}, /** @throws NoSuchElementException {@inheritDoc} */ getFirst : function( ) {}, /** @throws NoSuchElementException {@inheritDoc} */ getLast : function( ) {}, /** */ pollFirst : function( ) {}, /** */ pollLast : function( ) {}, /** @throws NoSuchElementException {@inheritDoc} */ removeFirst : function( ) {}, /** @throws NoSuchElementException {@inheritDoc} */ removeLast : function( ) {}, /**Inserts the specified element at the tail of this deque. As the deque is unbounded, this method will never return {@code false}. @return {Boolean} {@code true} (as specified by {@link Queue#offer}) @throws NullPointerException if the specified element is null */ offer : function( ) {}, /**Inserts the specified element at the tail of this deque. As the deque is unbounded, this method will never throw {@link IllegalStateException} or return {@code false}. @return {Boolean} {@code true} (as specified by {@link Collection#add}) @throws NullPointerException if the specified element is null */ add : function( ) {}, /** */ poll : function( ) {}, /** */ peek : function( ) {}, /** @throws NoSuchElementException {@inheritDoc} */ remove : function( ) {}, /** @throws NoSuchElementException {@inheritDoc} */ pop : function( ) {}, /** @throws NoSuchElementException {@inheritDoc} */ element : function( ) {}, /** @throws NullPointerException {@inheritDoc} */ push : function( ) {}, /**Removes the first occurrence of the specified element from this deque. If the deque does not contain the element, it is unchanged. More formally, removes the first element {@code e} such that {@code o.equals(e)} (if such an element exists). Returns {@code true} if this deque contained the specified element (or equivalently, if this deque changed as a result of the call). @param {Object {Object}} o element to be removed from this deque, if present @return {Boolean} {@code true} if the deque contained the specified element @throws NullPointerException if the specified element is null */ removeFirstOccurrence : function( ) {}, /**Removes the last occurrence of the specified element from this deque. If the deque does not contain the element, it is unchanged. More formally, removes the last element {@code e} such that {@code o.equals(e)} (if such an element exists). Returns {@code true} if this deque contained the specified element (or equivalently, if this deque changed as a result of the call). @param {Object {Object}} o element to be removed from this deque, if present @return {Boolean} {@code true} if the deque contained the specified element @throws NullPointerException if the specified element is null */ removeLastOccurrence : function( ) {}, /**Returns {@code true} if this deque contains the specified element. More formally, returns {@code true} if and only if this deque contains at least one element {@code e} such that {@code o.equals(e)}. @param {Object {Object}} o element whose presence in this deque is to be tested @return {Boolean} {@code true} if this deque contains the specified element */ contains : function( ) {}, /**Returns {@code true} if this collection contains no elements. @return {Boolean} {@code true} if this collection contains no elements */ isEmpty : function( ) {}, /**Returns the number of elements in this deque. If this deque contains more than {@code Integer.MAX_VALUE} elements, it returns {@code Integer.MAX_VALUE}. <p>Beware that, unlike in most collections, this method is <em>NOT</em> a constant-time operation. Because of the asynchronous nature of these deques, determining the current number of elements requires traversing them all to count them. Additionally, it is possible for the size to change during execution of this method, in which case the returned result will be inaccurate. Thus, this method is typically not very useful in concurrent applications. @return {Number} the number of elements in this deque */ size : function( ) {}, /**Removes the first occurrence of the specified element from this deque. If the deque does not contain the element, it is unchanged. More formally, removes the first element {@code e} such that {@code o.equals(e)} (if such an element exists). Returns {@code true} if this deque contained the specified element (or equivalently, if this deque changed as a result of the call). <p>This method is equivalent to {@link #removeFirstOccurrence}(Object). @param {Object {Object}} o element to be removed from this deque, if present @return {Boolean} {@code true} if the deque contained the specified element @throws NullPointerException if the specified element is null */ remove : function( ) {}, /**Appends all of the elements in the specified collection to the end of this deque, in the order that they are returned by the specified collection's iterator. Attempts to {@code addAll} of a deque to itself result in {@code IllegalArgumentException}. @param {Object {java.util.Collection}} c the elements to be inserted into this deque @return {Boolean} {@code true} if this deque changed as a result of the call @throws NullPointerException if the specified collection or any of its elements are null @throws IllegalArgumentException if the collection is this deque */ addAll : function( ) {}, /**Removes all of the elements from this deque. */ clear : function( ) {}, /** */ toString : function( ) {}, /**Returns an array containing all of the elements in this deque, in proper sequence (from first to last element). <p>The returned array will be "safe" in that no references to it are maintained by this deque. (In other words, this method must allocate a new array). The caller is thus free to modify the returned array. <p>This method acts as bridge between array-based and collection-based APIs. @return {Object {java.lang.Object}} an array containing all of the elements in this deque */ toArray : function( ) {}, /**Returns an array containing all of the elements in this deque, in proper sequence (from first to last element); the runtime type of the returned array is that of the specified array. If the deque fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this deque. <p>If this deque fits in the specified array with room to spare (i.e., the array has more elements than this deque), the element in the array immediately following the end of the deque is set to {@code null}. <p>Like the {@link #toArray}() method, this method acts as bridge between array-based and collection-based APIs. Further, this method allows precise control over the runtime type of the output array, and may, under certain circumstances, be used to save allocation costs. <p>Suppose {@code x} is a deque known to contain only strings. The following code can be used to dump the deque into a newly allocated array of {@code String}: <pre> {@code String[] y = x.toArray(new String[0]);}</pre> Note that {@code toArray(new Object[0])} is identical in function to {@code toArray()}. @param {Object {java.lang.Object[]}} a the array into which the elements of the deque are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose @return {Object {java.lang.Object}} an array containing all of the elements in this deque @throws ArrayStoreException if the runtime type of the specified array is not a supertype of the runtime type of every element in this deque @throws NullPointerException if the specified array is null */ toArray : function( ) {}, /**Returns an iterator over the elements in this deque in proper sequence. The elements will be returned in order from first (head) to last (tail). <p>The returned iterator is <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>. @return {Object {java.util.Iterator}} an iterator over the elements in this deque in proper sequence */ iterator : function( ) {}, /**Returns an iterator over the elements in this deque in reverse sequential order. The elements will be returned in order from last (tail) to first (head). <p>The returned iterator is <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>. @return {Object {java.util.Iterator}} an iterator over the elements in this deque in reverse order */ descendingIterator : function( ) {}, /**Returns a {@link Spliterator} over the elements in this deque. <p>The returned spliterator is <a href="package-summary.html#Weakly"><i>weakly consistent</i></a>. <p>The {@code Spliterator} reports {@link Spliterator#CONCURRENT}, {@link Spliterator#ORDERED}, and {@link Spliterator#NONNULL}. @implNote The {@code Spliterator} implements {@code trySplit} to permit limited parallelism. @return {Object {java.util.Spliterator}} a {@code Spliterator} over the elements in this deque @since 1.8 */ spliterator : function( ) {}, };