ticked_object.hh revision 10905
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 "params/TickedObject.hh" 52#include "sim/clocked_object.hh" 53 54/** Ticked attaches gem5's event queue/scheduler to evaluate 55 * calls and provides a start/stop interface to ticking. 56 * 57 * Ticked is not a ClockedObject but can be attached to one by 58 * inheritance and by calling regStats, serialize/unserialize */ 59class Ticked : public Serializable 60{ 61 protected: 62 /** An event to call process periodically */ 63 class ClockEvent : public Event 64 { 65 public: 66 Ticked &owner; 67 68 ClockEvent(Ticked &owner_, Priority priority) : 69 Event(priority), 70 owner(owner_) 71 { } 72 73 /** Evaluate and reschedule */ 74 void 75 process() 76 { 77 ++owner.tickCycles; 78 ++owner.numCycles; 79 owner.countCycles(Cycles(1)); 80 owner.evaluate(); 81 if (owner.running) { 82 owner.object.schedule(this, 83 owner.object.clockEdge(Cycles(1))); 84 } 85 } 86 }; 87 88 friend class ClockEvent; 89 90 /** ClockedObject who is responsible for this Ticked's actions/stats */ 91 ClockedObject &object; 92 93 /** The single instance of ClockEvent used */ 94 ClockEvent event; 95 96 /** Have I been started? and am not stopped */ 97 bool running; 98 99 /** Time of last stop event to calculate run time */ 100 Cycles lastStopped; 101 102 private: 103 /** Locally allocated stats */ 104 Stats::Scalar *numCyclesLocal; 105 106 protected: 107 /** Total number of cycles either ticked or spend stopped */ 108 Stats::Scalar &numCycles; 109 110 /** Number of cycles ticked */ 111 Stats::Scalar tickCycles; 112 113 /** Number of cycles stopped */ 114 Stats::Formula idleCycles; 115 116 public: 117 Ticked(ClockedObject &object_, 118 Stats::Scalar *imported_num_cycles = NULL, 119 Event::Priority priority = Event::CPU_Tick_Pri); 120 121 virtual ~Ticked() { } 122 123 /** Register {num,ticks}Cycles if necessary. If numCycles is 124 * imported, be sure to register it *before* calling this regStats */ 125 void regStats(); 126 127 /** Start ticking */ 128 void 129 start() 130 { 131 if (!running) { 132 if (!event.scheduled()) 133 object.schedule(event, object.clockEdge(Cycles(1))); 134 running = true; 135 numCycles += cyclesSinceLastStopped(); 136 countCycles(cyclesSinceLastStopped()); 137 } 138 } 139 140 /** How long have we been stopped for? */ 141 Cycles 142 cyclesSinceLastStopped() const 143 { 144 return object.curCycle() - lastStopped; 145 } 146 147 /** Reset stopped time to current time */ 148 void 149 resetLastStopped() 150 { 151 lastStopped = object.curCycle(); 152 } 153 154 /** Cancel the next tick event and issue no more */ 155 void 156 stop() 157 { 158 if (running) { 159 if (event.scheduled()) 160 object.deschedule(event); 161 running = false; 162 resetLastStopped(); 163 } 164 } 165 166 /** Checkpoint lastStopped */ 167 void serialize(CheckpointOut &cp) const M5_ATTR_OVERRIDE; 168 void unserialize(CheckpointIn &cp) M5_ATTR_OVERRIDE; 169 170 /** Action to call on the clock tick */ 171 virtual void evaluate() = 0; 172 173 /** 174 * Callback to handle cycle statistics and probes. 175 * 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. 181 * 182 * @param delta Number of cycles since the previous call. 183 */ 184 virtual void countCycles(Cycles delta) {} 185}; 186 187/** TickedObject attaches Ticked to ClockedObject and can be used as 188 * a base class where ticked operation */ 189class TickedObject : public ClockedObject, public Ticked 190{ 191 public: 192 TickedObject(TickedObjectParams *params, 193 Event::Priority priority = Event::CPU_Tick_Pri); 194 195 /** Disambiguate to make these functions overload correctly */ 196 using ClockedObject::regStats; 197 using ClockedObject::serialize; 198 using ClockedObject::unserialize; 199 200 /** Pass on regStats, serialize etc. onto Ticked */ 201 void regStats(); 202 void serialize(CheckpointOut &cp) const M5_ATTR_OVERRIDE; 203 void unserialize(CheckpointIn &cp) M5_ATTR_OVERRIDE; 204}; 205 206#endif /* __SIM_TICKED_OBJECT_HH__ */ 207