/*
 * Copyright 2018-2022, Andrew Lindesay <apl@lindesay.co.nz>.
 * All rights reserved. Distributed under the terms of the MIT License.
 */
#ifndef ABSTRACT_PROCESS_NODE_H
#define ABSTRACT_PROCESS_NODE_H


#include <AutoLocker.h>
#include <Locker.h>
#include <ObjectList.h>
#include <OS.h>
#include <String.h>


class AbstractProcess;
class ProcessListener;


/*! This class is designed to be used by the ProcessCoordinator class.  The
    purpose of the class is to hold a process and also any dependent processes
    of this one.  This effectively creates a dependency tree of processes.
*/

class AbstractProcessNode {
public:
                                                                AbstractProcessNode(AbstractProcess* process);
        virtual                                         ~AbstractProcessNode();

                        AbstractProcess*        Process() const;
        virtual status_t                        Start() = 0;
        virtual status_t                        RequestStop() = 0;
        virtual bool                            IsRunning();

                        void                            AddPredecessor(AbstractProcessNode* node);
                        int32                           CountPredecessors() const;
                        AbstractProcessNode*
                                                                PredecessorAt(int32 index) const;
                        bool                            AllPredecessorsComplete() const;

                        int32                           CountSuccessors() const;
                        AbstractProcessNode*
                                                                SuccessorAt(int32 index) const;

        virtual void                            SetListener(ProcessListener* listener);

                        BString                         LogReport();

protected:
                        status_t                        _SpinUntilProcessState(
                                                                        uint32 desiredStatesMask,
                                                                        int32 timeoutSeconds);

protected:
                        BLocker                         fLock;
                        ProcessListener*        fListener;

private:
                        void                            _AddSuccessor(AbstractProcessNode* node);

                        AbstractProcess*        fProcess;
                        BObjectList<AbstractProcessNode>
                                                                fPredecessorNodes;
                        BObjectList<AbstractProcessNode>
                                                                fSuccessorNodes;
};


#endif // ABSTRACT_PROCESS_NODE_H