/*
 * Copyright 2001-2014 Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 */
#ifndef _MESSAGE_QUEUE_H
#define _MESSAGE_QUEUE_H


#include <Locker.h>
#include <Message.h>
        // For convenience


class BMessageQueue {
public:
                                                                BMessageQueue();
        virtual                                         ~BMessageQueue();

                        void                            AddMessage(BMessage* message);
                        void                            RemoveMessage(BMessage* message);

                        int32                           CountMessages() const;
                        bool                            IsEmpty() const;

                        BMessage*                       FindMessage(int32 index) const;
                        BMessage*                       FindMessage(uint32 what, int32 index = 0) const;

                        bool                            Lock();
                        void                            Unlock();
                        bool                            IsLocked() const;

                        BMessage*                       NextMessage();
                        bool                            IsNextMessage(const BMessage* message) const;

private:
                        // Reserved space in the vtable for future changes to BMessageQueue
        virtual void                            _ReservedMessageQueue1();
        virtual void                            _ReservedMessageQueue2();
        virtual void                            _ReservedMessageQueue3();

                                                                BMessageQueue(const BMessageQueue &);
                        BMessageQueue&          operator=(const BMessageQueue &);

                        bool                            IsLocked();
                                // this needs to be exported for R5 compatibility and should
                                // be dropped as soon as possible

private:
                        BMessage*                       fHead;
                        BMessage*                       fTail;
                        int32                           fMessageCount;
        mutable BLocker                         fLock;

                        uint32                          _reserved[3];
};


#endif  // _MESSAGE_QUEUE_H