PushSequencer.h

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/*  Copyright (C) 2003-2021 Free Electron Organization
    Any use of this software requires a license.  If a valid license
    was not distributed with this file, visit freeelectron.org. */

/** @file */

#ifndef __signal_PushSequencer_h__
#define __signal_PushSequencer_h__

#define FE_SEQUENCER_ROLLOVER_WINDOW (U32)(1 << 31)


namespace fe
{
namespace ext
{

/** @brief Mechanism to fire scheduled signals

    @ingroup signal

    Entries for the sequencer are represented by pulse records which have
    these four attributes:

    - time --
        The time at which to fire the signal.

    - interval --
        Interval in which to repeat the signal.

    - count --
        Number of times to repeatedly fire the signal.  Setting this to
        zero will repeat an unlimited number of times.  A non-zero count
        is decremented every time the signal is fired, and when decremented
        form 1 to 0 the signal is removed from the sequencer.
        A negative count will halt repeating without removing the signal,
        which is a way to pause repeating.

    - periodic --
        The mode to repeat signals.
        - 0 -- the repeat signal is set to the sequencer handle time plus the
            interval.
            This means that the true interval between firings in likely longer
            than the interval setting, but such signals will never
            'fall behind'.
        - 1 --  The time for a repeat signal is set to the previous time plus
            the interval.  Note that this could lead to the system getting
            swamped by periodic signals.  However, if the computation load
            varies a lot, this setting could allow repeats to 'catch up'.
        - 2 -- The time for a repeat signal is set to the previous time plus
            the interval unless such time has already passed in which case the
            time is set to the sequencer handle time.  This is like setting 1
            that will
            not fall behind.
        - 3 -- the repeat signal is set to the current time (after the immediate
            handling of the signal is processed) plus the interval.  This
            is a sort of 'forced yield for a time' mode.

    @copydoc PushSequencer_info
    */
class FE_DL_EXPORT PushSequencer :
    virtual public SequencerI,
    virtual public HandlerI
{
    public:
        PushSequencer(void);
virtual ~PushSequencer(void);
        // AS SequencerI
virtual U32     getCurrentTime( void);
virtual void    setTime(        U32 counter);
virtual Record  add(            sp<Layout> spLayout,
                                U32 startTime,
                                U32 interval);
virtual Record  lookup(         sp<Layout> spLayout,
                                U32 interval);
virtual bool    remove(         Record pulse);

        // AS HandlerI
virtual void    handle(         Record &signal);
virtual void    handleBind(     sp<SignalerI> spSignalerI,
                                sp<Layout> spLayout);

    private:

    class t_pulse : public Counted
    {
        public:
            Record              m_record;
            AsSequenceSignal    m_asSeqSignal;
            int time(void)
            {
                return m_asSeqSignal.time(m_record);
            }
            int interval(void)
            {
                return m_asSeqSignal.interval(m_record);
            }
    };

        void    insert(         sp<t_pulse> &a_pulse);

    private:
        U32                     m_timeOffset;
        SignalerI               *m_pSignaler;
        std::list<sp<t_pulse> > m_pulseList;
        SystemTicker            m_ticker;
};

} /* namespace ext */
} /* namespace fe */

#endif /* __signal_PushSequencer_h__ */