lru_rp.hh revision 12600
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/** 32 * @file 33 * Declaration of a Least Recently Used replacement policy. 34 * The victim is chosen using the timestamp. The timestamp may be true or 35 * pseudo, depending on the quantity of bits allocated for that. 36 */ 37 38#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_LRU_RP_HH__ 39#define __MEM_CACHE_REPLACEMENT_POLICIES_LRU_RP_HH__ 40 41#include "mem/cache/replacement_policies/base.hh" 42#include "params/LRURP.hh" 43 44class LRURP : public BaseReplacementPolicy 45{ 46 public: 47 /** Convenience typedef. */ 48 typedef LRURPParams Params; 49 50 /** 51 * Construct and initiliaze this replacement policy. 52 */ 53 LRURP(const Params *p); 54 55 /** 56 * Destructor. 57 */ 58 ~LRURP() {} 59 60 /** 61 * Touch a block to update its last touch tick. 62 * 63 * @param blk Cache block to be touched. 64 */ 65 void touch(CacheBlk *blk); 66 67 /** 68 * Reset replacement data for a block. Used when a block is inserted. 69 * Sets its last touch tick as the current tick. 70 * 71 * @param blk Cache block to be reset. 72 */ 73 void reset(CacheBlk *blk); 74 75 /** 76 * Find replacement victim using LRU timestamps. 77 * 78 * @param candidates Replacement candidates, selected by indexing policy. 79 * @return Cache block to be replaced. 80 */ 81 CacheBlk* getVictim(const ReplacementCandidates& candidates) override; 82}; 83 84#endif // __MEM_CACHE_REPLACEMENT_POLICIES_LRU_RP_HH__ 85