/*
 * Copyright 2009, Axel Dörfler, axeld@pinc-software.de.
 * Copyright 2002, Marcus Overhagen. All Rights Reserved.
 * Distributed under the terms of the MIT License.
 */
#ifndef _SHARED_BUFFER_LIST_H_
#define _SHARED_BUFFER_LIST_H_


#include <Buffer.h>


namespace BPrivate {


class SharedBufferList
{
public:
        static  area_id                                         Create(SharedBufferList** _list);
        static  SharedBufferList*                       Get();
        static  void                                            Invalidate();

                        void                                            Put();
                        void                                            DeleteGroupAndPut(
                                                                                        sem_id groupReclaimSem);

                        status_t                                        Lock();
                        status_t                                        Unlock();

                        status_t                                        AddBuffer(sem_id groupReclaimSem,
                                                                                        const buffer_clone_info& info,
                                                                                        BBuffer** buffer);
                        status_t                                        RemoveBuffer(BBuffer* buffer);

                        // Call AddBuffer and CheckID locked
                        status_t                                        AddBuffer(sem_id groupReclaimSem,
                                                                                        BBuffer* buffer);
                        status_t                                        CheckID(sem_id groupSem,
                                                                                        media_buffer_id id) const;

                        status_t                                        RequestBuffer(sem_id groupReclaimSem,
                                                                                        int32 buffersInGroup, size_t size,
                                                                                        media_buffer_id wantID,
                                                                                        BBuffer** _buffer,
                                                                                        bigtime_t timeout);

                        status_t                                        RecycleBuffer(BBuffer* buffer);

                        status_t                                        GetBufferList(sem_id groupReclaimSem,
                                                                                        int32 bufferCount,
                                                                                        BBuffer** buffers);
private:
        struct _shared_buffer_info {
                media_buffer_id                 id;
                BBuffer*                                buffer;
                bool                                    reclaimed;
                // The reclaim_sem belonging to the BBufferGroup of this BBuffer
                // is also used as a unique identifier of the group
                sem_id                                  reclaim_sem;
        };

        // 16 bytes per buffer, 8 pages in total (one entry less for the list)
        enum { kMaxBuffers = 2047 };

                        status_t                                        _Init();
                        void                                            _RequestBufferInOtherGroups(
                                                                                        sem_id groupReclaimSem,
                                                                                        media_buffer_id id);

private:
                        sem_id                                          fSemaphore;
                        int32                                           fAtom;

                        _shared_buffer_info                     fInfos[kMaxBuffers];
                        int32                                           fCount;
};


}       // namespace BPrivate


#endif  // _SHARED_BUFFER_LIST_H_