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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 "sim/clocked_object.hh"
53 class TickedObjectParams;
55 /** Ticked attaches gem5's event queue/scheduler to evaluate
56 * calls and provides a start/stop interface to ticking.
58 * Ticked is not a ClockedObject but can be attached to one by
59 * inheritance and by calling regStats, serialize/unserialize */
60 class Ticked : public Serializable
63 /** An event to call process periodically */
64 class ClockEvent : public Event
69 ClockEvent(Ticked &owner_, Priority priority) :
74 /** Evaluate and reschedule */
80 owner.countCycles(Cycles(1));
83 owner.object.schedule(this,
84 owner.object.clockEdge(Cycles(1)));
89 friend class ClockEvent;
91 /** ClockedObject who is responsible for this Ticked's actions/stats */
92 ClockedObject &object;
94 /** The single instance of ClockEvent used */
97 /** Have I been started? and am not stopped */
100 /** Time of last stop event to calculate run time */
104 /** Locally allocated stats */
105 Stats::Scalar *numCyclesLocal;
108 /** Total number of cycles either ticked or spend stopped */
109 Stats::Scalar &numCycles;
111 /** Number of cycles ticked */
112 Stats::Scalar tickCycles;
114 /** Number of cycles stopped */
115 Stats::Formula idleCycles;
118 Ticked(ClockedObject &object_,
119 Stats::Scalar *imported_num_cycles = NULL,
120 Event::Priority priority = Event::CPU_Tick_Pri);
122 virtual ~Ticked() { }
124 /** Register {num,ticks}Cycles if necessary. If numCycles is
125 * imported, be sure to register it *before* calling this regStats */
133 if (!event.scheduled())
134 object.schedule(event, object.clockEdge(Cycles(1)));
136 numCycles += cyclesSinceLastStopped();
137 countCycles(cyclesSinceLastStopped());
141 /** How long have we been stopped for? */
143 cyclesSinceLastStopped() const
145 return object.curCycle() - lastStopped;
148 /** Reset stopped time to current time */
152 lastStopped = object.curCycle();
155 /** Cancel the next tick event and issue no more */
160 if (event.scheduled())
161 object.deschedule(event);
167 /** Checkpoint lastStopped */
168 void serialize(CheckpointOut &cp) const override;
169 void unserialize(CheckpointIn &cp) override;
171 /** Action to call on the clock tick */
172 virtual void evaluate() = 0;
175 * Callback to handle cycle statistics and probes.
177 * This callback is called at the beginning of a new cycle active
178 * cycle and when restarting the ticked object. The delta
179 * parameter indicates the number of cycles elapsed since the
180 * previous call is normally '1' unless the object has been
181 * stopped and restarted.
183 * @param delta Number of cycles since the previous call.
185 virtual void countCycles(Cycles delta) {}
188 /** TickedObject attaches Ticked to ClockedObject and can be used as
189 * a base class where ticked operation */
190 class TickedObject : public ClockedObject, public Ticked
193 TickedObject(TickedObjectParams *params,
194 Event::Priority priority = Event::CPU_Tick_Pri);
196 /** Disambiguate to make these functions overload correctly */
197 using ClockedObject::regStats;
198 using ClockedObject::serialize;
199 using ClockedObject::unserialize;
201 /** Pass on regStats, serialize etc. onto Ticked */
202 void regStats() override;
203 void serialize(CheckpointOut &cp) const override;
204 void unserialize(CheckpointIn &cp) override;
207 #endif /* __SIM_TICKED_OBJECT_HH__ */