Oracle Coherence for C++ API
Release 3.6.0.0
E15728-01

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# coherence/util/Queue.hpp

    00001 /*
    00002 * Queue.hpp
    00003 *
    00004 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
    00005 *
    00006 * Oracle is a registered trademarks of Oracle Corporation and/or its
    00007 * affiliates.
    00008 *
    00009 * This software is the confidential and proprietary information of Oracle
    00010 * Corporation. You shall not disclose such confidential and proprietary
    00011 * information and shall use it only in accordance with the terms of the
    00012 * license agreement you entered into with Oracle.
    00013 *
    00014 * This notice may not be removed or altered.
    00015 */
    00016 #ifndef COH_QUEUE_HPP
    00017 #define COH_QUEUE_HPP
    00018
    00019 #include "coherence/lang.ns"
    00020
    00021 #include "coherence/util/Iterator.hpp"
    00022
    00023 COH_OPEN_NAMESPACE2(coherence,util)
    00024
    00025
    00026 /**
    00027 * The Queue provides a means to efficiently (and in a thread-safe manner)
    00028 * queue received messages and messages to be sent.
    00029 *
    00030 * @author nsa 2008.01.18
    00031 */
    00032 class COH_EXPORT Queue
    00033     : public interface_spec<Queue>
    00034     {
    00035     // ----- Queue interface ------------------------------------------------
    00036
    00037     public:
    00038         /**
    00039         * Appends the specified element to the end of this queue. Queues may
    00040         * place limitations on what types of elements may be added and should
    00041         * clearly specify in their documentation any restrictions.
    00042         *
    00043         * @param oh  element to be appended to this Queue
    00044         *
    00045         * @return true if the collection changed as a result of this call
    00046         *
    00047         * @throw ClassCastException if the class of the specified element
    00048         *        prevents it from being added to this Queue
    00049         */
    00050         virtual bool add(Object::Holder oh) = 0;
    00051
    00052         /**
    00053         * Insert the specified element to the front of this queue. Queues may
    00054         * place limitations on what types of elements may be added and should
    00055         * clearly specify in their documentation any restrictions.
    00056         *
    00057         * @param oh  element ot be prepended to this Queue
    00058         *
    00059         * @return true if the collection changed as a result of this call
    00060         *
    00061         * @throw ClassCastException if the class of the specified element
    00062         *        prevents it from being added to this Queue
    00063         */
    00064         virtual bool addHead(Object::Holder oh) = 0;
    00065
    00066         /**
    00067         * Flush the queue.
    00068         */
    00069         virtual void flush() = 0;
    00070
    00071         /**
    00072         * Determine whether the Queue is empty or not.
    00073         *
    00074         * @return true if the Queue is empty; false if not
    00075         */
    00076         virtual bool isEmpty() const = 0;
    00077
    00078         /**
    00079         * Returns the first element from the front of this Queue.
    00080         *
    00081         * There is no blocking equivalent of this method as it would require
    00082         * notification to wake up from an empty Queue, and this would mean
    00083         * that the "add" and "addHead" methods would need to perform
    00084         * notifyAll over notify which has performance implications.
    00085         *
    00086         * @return the first element in the front of this Queue or null if
    00087         *         the Queue is empty
    00088         */
    00089         virtual Object::Holder peekNoWait() = 0;
    00090
    00091         /**
    00092         * Waits for and removes the first element from the front of this
    00093         * Queue.
    00094         *
    00095         * If the Queue is empty, this method will block until an element is
    00096         * in the Queue. The unblocking equivalent of this method is
    00097         * "removeNoWait".
    00098         *
    00099         * @return the first element in the front of this Queue
    00100         */
    00101         virtual Object::Holder remove() = 0;
    00102
    00103         /**
    00104         * Removes and returns the first element from the front of this Queue.
    00105         *
    00106         * The blocking equivalent of this method is "remove".
    00107         *
    00108         * @return the first element in the front of this Queue or NULL if
    00109         *         the Queue is empty
    00110         */
    00111         virtual Object::Holder removeNoWait() = 0;
    00112
    00113         /**
    00114         * Determine the number of elements in this Queue. The size of the
    00115         * Queue may change after the size is returned from this method.
    00116         *
    00117         * @return the number of elements in this Queue
    00118         */
    00119         virtual size32_t size() const = 0;
    00120     };
    00121
    00122 COH_CLOSE_NAMESPACE2
    00123
    00124 #endif // COH_QUEUE_HPP

Copyright © 2000, 2010, Oracle and/or its affiliates. All rights reserved.