/*
 * Copyright 2009-2010, Ingo Weinhold, ingo_weinhold@gmx.de.
 * Distributed under the terms of the MIT License.
 */
#ifndef IO_SCHEDULER_ROSTER_H
#define IO_SCHEDULER_ROSTER_H


#include <Notifications.h>

#include "IOScheduler.h"


// I/O scheduler notifications
#define IO_SCHEDULER_MONITOR                    '_io_'
#define IO_SCHEDULER_ADDED                              0x01
#define IO_SCHEDULER_REMOVED                    0x02
#define IO_SCHEDULER_REQUEST_SCHEDULED  0x04
#define IO_SCHEDULER_REQUEST_FINISHED   0x08
#define IO_SCHEDULER_OPERATION_STARTED  0x10
#define IO_SCHEDULER_OPERATION_FINISHED 0x20



typedef DoublyLinkedList<IOScheduler> IOSchedulerList;


class IOSchedulerRoster final {
public:
        static  void                            Init();
        static  IOSchedulerRoster*      Default()       { return &sDefaultInstance; }

                        bool                            Lock()  { return mutex_lock(&fLock) == B_OK; }
                        void                            Unlock()        { mutex_unlock(&fLock); }

                        const IOSchedulerList& SchedulerList() const
                                                                        { return fSchedulers; }
                                                                        // caller must keep the roster locked,
                                                                        // while accessing the list

                        void                            AddScheduler(IOScheduler* scheduler);
                        void                            RemoveScheduler(IOScheduler* scheduler);

                        void                            Notify(uint32 eventCode,
                                                                        const IOScheduler* scheduler,
                                                                        IORequest* request = NULL,
                                                                        IOOperation* operation = NULL);

                        int32                           NextID();

                        void                            Dump() const;

private:
                                                                IOSchedulerRoster();
                                                                ~IOSchedulerRoster();

private:
                        mutex                           fLock;
                        int32                           fNextID;
                        IOSchedulerList         fSchedulers;
                        DefaultNotificationService fNotificationService;
                        char                            fEventBuffer[256];

        static  IOSchedulerRoster       sDefaultInstance;
};


#endif  // IO_SCHEDULER_ROSTER_H