ticked_object.hh revision 11800:54436a1784dc
1/* 2 * Copyright (c) 2013-2014 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions are 16 * met: redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer; 18 * redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution; 21 * neither the name of the copyright holders nor the names of its 22 * contributors may be used to endorse or promote products derived from 23 * this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 * 37 * Authors: Andrew Bardsley 38 */ 39 40/** 41 * @file 42 * 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. 46 */ 47 48#ifndef __SIM_TICKED_OBJECT_HH__ 49#define __SIM_TICKED_OBJECT_HH__ 50 51#include "sim/clocked_object.hh" 52 53class TickedObjectParams; 54 55/** Ticked attaches gem5's event queue/scheduler to evaluate 56 * calls and provides a start/stop interface to ticking. 57 * 58 * Ticked is not a ClockedObject but can be attached to one by 59 * inheritance and by calling regStats, serialize/unserialize */ 60class Ticked : public Serializable 61{ 62 protected: 63 /** An event to call process periodically */ 64 class ClockEvent : public Event 65 { 66 public: 67 Ticked &owner; 68 69 ClockEvent(Ticked &owner_, Priority priority) : 70 Event(priority), 71 owner(owner_) 72 { } 73 74 /** Evaluate and reschedule */ 75 void 76 process() 77 { 78 ++owner.tickCycles; 79 ++owner.numCycles; 80 owner.countCycles(Cycles(1)); 81 owner.evaluate(); 82 if (owner.running) { 83 owner.object.schedule(this, 84 owner.object.clockEdge(Cycles(1))); 85 } 86 } 87 }; 88 89 friend class ClockEvent; 90 91 /** ClockedObject who is responsible for this Ticked's actions/stats */ 92 ClockedObject &object; 93 94 /** The single instance of ClockEvent used */ 95 ClockEvent event; 96 97 /** Have I been started? and am not stopped */ 98 bool running; 99 100 /** Time of last stop event to calculate run time */ 101 Cycles lastStopped; 102 103 private: 104 /** Locally allocated stats */ 105 Stats::Scalar *numCyclesLocal; 106 107 protected: 108 /** Total number of cycles either ticked or spend stopped */ 109 Stats::Scalar &numCycles; 110 111 /** Number of cycles ticked */ 112 Stats::Scalar tickCycles; 113 114 /** Number of cycles stopped */ 115 Stats::Formula idleCycles; 116 117 public: 118 Ticked(ClockedObject &object_, 119 Stats::Scalar *imported_num_cycles = NULL, 120 Event::Priority priority = Event::CPU_Tick_Pri); 121 122 virtual ~Ticked() { } 123 124 /** Register {num,ticks}Cycles if necessary. If numCycles is 125 * imported, be sure to register it *before* calling this regStats */ 126 void regStats(); 127 128 /** Start ticking */ 129 void 130 start() 131 { 132 if (!running) { 133 if (!event.scheduled()) 134 object.schedule(event, object.clockEdge(Cycles(1))); 135 running = true; 136 numCycles += cyclesSinceLastStopped(); 137 countCycles(cyclesSinceLastStopped()); 138 } 139 } 140 141 /** How long have we been stopped for? */ 142 Cycles 143 cyclesSinceLastStopped() const 144 { 145 return object.curCycle() - lastStopped; 146 } 147 148 /** Reset stopped time to current time */ 149 void 150 resetLastStopped() 151 { 152 lastStopped = object.curCycle(); 153 } 154 155 /** Cancel the next tick event and issue no more */ 156 void 157 stop() 158 { 159 if (running) { 160 if (event.scheduled()) 161 object.deschedule(event); 162 running = false; 163 resetLastStopped(); 164 } 165 } 166 167 /** Checkpoint lastStopped */ 168 void serialize(CheckpointOut &cp) const override; 169 void unserialize(CheckpointIn &cp) override; 170 171 /** Action to call on the clock tick */ 172 virtual void evaluate() = 0; 173 174 /** 175 * Callback to handle cycle statistics and probes. 176 * 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. 182 * 183 * @param delta Number of cycles since the previous call. 184 */ 185 virtual void countCycles(Cycles delta) {} 186}; 187 188/** TickedObject attaches Ticked to ClockedObject and can be used as 189 * a base class where ticked operation */ 190class TickedObject : public ClockedObject, public Ticked 191{ 192 public: 193 TickedObject(TickedObjectParams *params, 194 Event::Priority priority = Event::CPU_Tick_Pri); 195 196 /** Disambiguate to make these functions overload correctly */ 197 using ClockedObject::regStats; 198 using ClockedObject::serialize; 199 using ClockedObject::unserialize; 200 201 /** Pass on regStats, serialize etc. onto Ticked */ 202 void regStats() override; 203 void serialize(CheckpointOut &cp) const override; 204 void unserialize(CheckpointIn &cp) override; 205}; 206 207#endif /* __SIM_TICKED_OBJECT_HH__ */ 208