diff options
Diffstat (limited to 'src/actors/scala/actors/threadpool/Queue.java')
| -rw-r--r-- | src/actors/scala/actors/threadpool/Queue.java | 191 |
1 files changed, 0 insertions, 191 deletions
diff --git a/src/actors/scala/actors/threadpool/Queue.java b/src/actors/scala/actors/threadpool/Queue.java deleted file mode 100644 index f952e9d94c..0000000000 --- a/src/actors/scala/actors/threadpool/Queue.java +++ /dev/null @@ -1,191 +0,0 @@ -/* - * Written by Doug Lea with assistance from members of JCP JSR-166 - * Expert Group and released to the public domain, as explained at - * http://creativecommons.org/licenses/publicdomain - */ - -package scala.actors.threadpool; - -import java.util.Collection; - -/** - * A collection designed for holding elements prior to processing. - * Besides basic {@link java.util.Collection Collection} operations, - * queues provide additional insertion, extraction, and inspection - * operations. Each of these methods exists in two forms: one throws - * an exception if the operation fails, the other returns a special - * value (either <tt>null</tt> or <tt>false</tt>, depending on the - * operation). The latter form of the insert operation is designed - * specifically for use with capacity-restricted <tt>Queue</tt> - * implementations; in most implementations, insert operations cannot - * fail. - * - * <p> - * <table BORDER CELLPADDING=3 CELLSPACING=1> - * <tr> - * <td></td> - * <td ALIGN=CENTER><em>Throws exception</em></td> - * <td ALIGN=CENTER><em>Returns special value</em></td> - * </tr> - * <tr> - * <td><b>Insert</b></td> - * <td>{@link #add add(e)}</td> - * <td>{@link #offer offer(e)}</td> - * </tr> - * <tr> - * <td><b>Remove</b></td> - * <td>{@link #remove remove()}</td> - * <td>{@link #poll poll()}</td> - * </tr> - * <tr> - * <td><b>Examine</b></td> - * <td>{@link #element element()}</td> - * <td>{@link #peek peek()}</td> - * </tr> - * </table> - * - * <p>Queues typically, but do not necessarily, order elements in a - * FIFO (first-in-first-out) manner. Among the exceptions are - * priority queues, which order elements according to a supplied - * comparator, or the elements' natural ordering, and LIFO queues (or - * stacks) which order the elements LIFO (last-in-first-out). - * Whatever the ordering used, the <em>head</em> of the queue is that - * element which would be removed by a call to {@link #remove() } or - * {@link #poll()}. In a FIFO queue, all new elements are inserted at - * the <em> tail</em> of the queue. Other kinds of queues may use - * different placement rules. Every <tt>Queue</tt> implementation - * must specify its ordering properties. - * - * <p>The {@link #offer offer} method inserts an element if possible, - * otherwise returning <tt>false</tt>. This differs from the {@link - * java.util.Collection#add Collection.add} method, which can fail to - * add an element only by throwing an unchecked exception. The - * <tt>offer</tt> method is designed for use when failure is a normal, - * rather than exceptional occurrence, for example, in fixed-capacity - * (or "bounded") queues. - * - * <p>The {@link #remove()} and {@link #poll()} methods remove and - * return the head of the queue. - * Exactly which element is removed from the queue is a - * function of the queue's ordering policy, which differs from - * implementation to implementation. The <tt>remove()</tt> and - * <tt>poll()</tt> methods differ only in their behavior when the - * queue is empty: the <tt>remove()</tt> method throws an exception, - * while the <tt>poll()</tt> method returns <tt>null</tt>. - * - * <p>The {@link #element()} and {@link #peek()} methods return, but do - * not remove, the head of the queue. - * - * <p>The <tt>Queue</tt> interface does not define the <i>blocking queue - * methods</i>, which are common in concurrent programming. These methods, - * which wait for elements to appear or for space to become available, are - * defined in the {@link edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue} interface, which - * extends this interface. - * - * <p><tt>Queue</tt> implementations generally do not allow insertion - * of <tt>null</tt> elements, although some implementations, such as - * {@link LinkedList}, do not prohibit insertion of <tt>null</tt>. - * Even in the implementations that permit it, <tt>null</tt> should - * not be inserted into a <tt>Queue</tt>, as <tt>null</tt> is also - * used as a special return value by the <tt>poll</tt> method to - * indicate that the queue contains no elements. - * - * <p><tt>Queue</tt> implementations generally do not define - * element-based versions of methods <tt>equals</tt> and - * <tt>hashCode</tt> but instead inherit the identity based versions - * from class <tt>Object</tt>, because element-based equality is not - * always well-defined for queues with the same elements but different - * ordering properties. - * - * - * <p>This interface is a member of the - * <a href="{@docRoot}/../technotes/guides/collections/index.html"> - * Java Collections Framework</a>. - * - * @see java.util.Collection - * @see LinkedList - * @see PriorityQueue - * @see edu.emory.mathcs.backport.java.util.concurrent.LinkedBlockingQueue - * @see edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue - * @see edu.emory.mathcs.backport.java.util.concurrent.ArrayBlockingQueue - * @see edu.emory.mathcs.backport.java.util.concurrent.LinkedBlockingQueue - * @see edu.emory.mathcs.backport.java.util.concurrent.PriorityBlockingQueue - * @since 1.5 - * @author Doug Lea - */ -public interface Queue extends Collection { - /** - * Inserts the specified element into this queue if it is possible to do so - * immediately without violating capacity restrictions, returning - * <tt>true</tt> upon success and throwing an <tt>IllegalStateException</tt> - * if no space is currently available. - * - * @param e the element to add - * @return <tt>true</tt> (as specified by {@link Collection#add}) - * @throws IllegalStateException if the element cannot be added at this - * time due to capacity restrictions - * @throws ClassCastException if the class of the specified element - * prevents it from being added to this queue - * @throws NullPointerException if the specified element is null and - * this queue not permit null elements - * @throws IllegalArgumentException if some property of this element - * prevents it from being added to this queue - */ - boolean add(Object e); - - /** - * Inserts the specified element into this queue if it is possible to do - * so immediately without violating capacity restrictions. - * When using a capacity-restricted queue, this method is generally - * preferable to {@link #add}, which can fail to insert an element only - * by throwing an exception. - * - * @param e the element to add - * @return <tt>true</tt> if the element was added to this queue, else - * <tt>false</tt> - * @throws ClassCastException if the class of the specified element - * prevents it from being added to this queue - * @throws NullPointerException if the specified element is null and - * this queue does not permit null elements - * @throws IllegalArgumentException if some property of this element - * prevents it from being added to this queue - */ - boolean offer(Object e); - - /** - * Retrieves and removes the head of this queue. This method differs - * from {@link #poll poll} only in that it throws an exception if this - * queue is empty. - * is empty. - * - * @return the head of this queue - * @throws NoSuchElementException if this queue is empty - */ - Object remove(); - - /** - * Retrieves and removes the head of this queue, - * or returns <tt>null</tt> if this queue is empty. - * - * @return the head of this queue, or <tt>null</tt> if this queue is empty - */ - Object poll(); - - /** - * Retrieves, but does not remove, the head of this queue. This method - * differs from {@link #peek peek} only in that it throws an exception - * if this queue is empty. - * - * @return the head of this queue - * @throws NoSuchElementException if this queue is empty - */ - Object element(); - - /** - * Retrieves, but does not remove, the head of this queue, - * or returns <tt>null</tt> if this queue is empty. - * - * @return the head of this queue, or <tt>null</tt> if this queue is empty - */ - Object peek(); -} |