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37 * Authors: Andrew Bardsley
43 * Base classes for ClockedObjects which have evaluate functions to
44 * look like clock ticking operations. TickedObject attaches gem5's event
45 * queue to Ticked to apply actual scheduling.
48 #ifndef __SIM_TICKED_OBJECT_HH__
49 #define __SIM_TICKED_OBJECT_HH__
51 #include "params/TickedObject.hh"
52 #include "sim/clocked_object.hh"
54 /** Ticked attaches gem5's event queue/scheduler to evaluate
55 * calls and provides a start/stop interface to ticking.
57 * Ticked is not a ClockedObject but can be attached to one by
58 * inheritance and by calling regStats, serialize/unserialize */
59 class Ticked : public Serializable
62 /** An event to call process periodically */
63 class ClockEvent : public Event
68 ClockEvent(Ticked &owner_, Priority priority) :
73 /** Evaluate and reschedule */
79 owner.countCycles(Cycles(1));
82 owner.object.schedule(this,
83 owner.object.clockEdge(Cycles(1)));
88 friend class ClockEvent;
90 /** ClockedObject who is responsible for this Ticked's actions/stats */
91 ClockedObject &object;
93 /** The single instance of ClockEvent used */
96 /** Have I been started? and am not stopped */
99 /** Time of last stop event to calculate run time */
103 /** Locally allocated stats */
104 Stats::Scalar *numCyclesLocal;
107 /** Total number of cycles either ticked or spend stopped */
108 Stats::Scalar &numCycles;
110 /** Number of cycles ticked */
111 Stats::Scalar tickCycles;
113 /** Number of cycles stopped */
114 Stats::Formula idleCycles;
117 Ticked(ClockedObject &object_,
118 Stats::Scalar *imported_num_cycles = NULL,
119 Event::Priority priority = Event::CPU_Tick_Pri);
121 virtual ~Ticked() { }
123 /** Register {num,ticks}Cycles if necessary. If numCycles is
124 * imported, be sure to register it *before* calling this regStats */
132 if (!event.scheduled())
133 object.schedule(event, object.clockEdge(Cycles(1)));
135 numCycles += cyclesSinceLastStopped();
136 countCycles(cyclesSinceLastStopped());
140 /** How long have we been stopped for? */
142 cyclesSinceLastStopped() const
144 return object.curCycle() - lastStopped;
147 /** Reset stopped time to current time */
151 lastStopped = object.curCycle();
154 /** Cancel the next tick event and issue no more */
159 if (event.scheduled())
160 object.deschedule(event);
166 /** Checkpoint lastStopped */
167 void serialize(CheckpointOut &cp) const override;
168 void unserialize(CheckpointIn &cp) override;
170 /** Action to call on the clock tick */
171 virtual void evaluate() = 0;
174 * Callback to handle cycle statistics and probes.
176 * This callback is called at the beginning of a new cycle active
177 * cycle and when restarting the ticked object. The delta
178 * parameter indicates the number of cycles elapsed since the
179 * previous call is normally '1' unless the object has been
180 * stopped and restarted.
182 * @param delta Number of cycles since the previous call.
184 virtual void countCycles(Cycles delta) {}
187 /** TickedObject attaches Ticked to ClockedObject and can be used as
188 * a base class where ticked operation */
189 class TickedObject : public ClockedObject, public Ticked
192 TickedObject(TickedObjectParams *params,
193 Event::Priority priority = Event::CPU_Tick_Pri);
195 /** Disambiguate to make these functions overload correctly */
196 using ClockedObject::regStats;
197 using ClockedObject::serialize;
198 using ClockedObject::unserialize;
200 /** Pass on regStats, serialize etc. onto Ticked */
201 void regStats() override;
202 void serialize(CheckpointOut &cp) const override;
203 void unserialize(CheckpointIn &cp) override;
206 #endif /* __SIM_TICKED_OBJECT_HH__ */