lru_rp.cc revision 12684
1/** 2 * Copyright (c) 2018 Inria 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Daniel Carvalho 29 */ 30 31#include "mem/cache/replacement_policies/lru_rp.hh" 32 33#include <memory> 34 35LRURP::LRURP(const Params *p) 36 : BaseReplacementPolicy(p) 37{ 38} 39 40void 41LRURP::invalidate(const std::shared_ptr<ReplacementData>& replacement_data) 42const 43{ 44 // Reset last touch timestamp 45 std::static_pointer_cast<LRUReplData>( 46 replacement_data)->lastTouchTick = Tick(0); 47} 48 49void 50LRURP::touch(const std::shared_ptr<ReplacementData>& replacement_data) const 51{ 52 // Update last touch timestamp 53 std::static_pointer_cast<LRUReplData>( 54 replacement_data)->lastTouchTick = curTick(); 55} 56 57void 58LRURP::reset(const std::shared_ptr<ReplacementData>& replacement_data) const 59{ 60 // Set last touch timestamp 61 std::static_pointer_cast<LRUReplData>( 62 replacement_data)->lastTouchTick = curTick(); 63} 64 65ReplaceableEntry* 66LRURP::getVictim(const ReplacementCandidates& candidates) const 67{ 68 // There must be at least one replacement candidate 69 assert(candidates.size() > 0); 70 71 // Visit all candidates to find victim 72 ReplaceableEntry* victim = candidates[0]; 73 for (const auto& candidate : candidates) { 74 // Update victim entry if necessary 75 if (std::static_pointer_cast<LRUReplData>( 76 candidate->replacementData)->lastTouchTick < 77 std::static_pointer_cast<LRUReplData>( 78 victim->replacementData)->lastTouchTick) { 79 victim = candidate; 80 } 81 } 82 83 return victim; 84} 85 86std::shared_ptr<ReplacementData> 87LRURP::instantiateEntry() 88{ 89 return std::shared_ptr<ReplacementData>(new LRUReplData()); 90} 91 92LRURP* 93LRURPParams::create() 94{ 95 return new LRURP(this); 96} 97