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 Most Recently Used replacement policy.
|
34 * The victim is chosen using the timestamp. The block that was accessed the
|
34 * The victim is chosen using the timestamp. The entry that was accessed the |
35 * last is the one chosen to be replaced. 36 */ 37 38#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_MRU_RP_HH__ 39#define __MEM_CACHE_REPLACEMENT_POLICIES_MRU_RP_HH__ 40 41#include "mem/cache/replacement_policies/base.hh" 42#include "params/MRURP.hh" 43 44class MRURP : public BaseReplacementPolicy 45{
|
46 protected: 47 /** MRU-specific implementation of replacement data. */ 48 struct MRUReplData : ReplacementData 49 { 50 /** Tick on which the entry was last touched. */ 51 Tick lastTouchTick; 52 53 /** 54 * Default constructor. Invalidate data. 55 */ 56 MRUReplData() : lastTouchTick(0) {} 57 }; 58 |
59 public: 60 /** Convenience typedef. */ 61 typedef MRURPParams Params; 62 63 /** 64 * Construct and initiliaze this replacement policy. 65 */ 66 MRURP(const Params *p); 67 68 /** 69 * Destructor. 70 */ 71 ~MRURP() {} 72 73 /**
|
61 * Touch a block to update its last touch tick.
|
74 * Invalidate replacement data to set it as the next probable victim. 75 * Sets its last touch tick as the starting tick. |
76 *
|
63 * @param blk Cache block to be touched.
|
77 * @param replacement_data Replacement data to be invalidated. |
78 */
|
65 void touch(CacheBlk *blk) override;
|
79 void invalidate(const std::shared_ptr<ReplacementData>& replacement_data) 80 const override; |
81 82 /**
|
68 * Reset replacement data for a block. Used when a block is inserted.
|
83 * Touch an entry to update its replacement data. |
84 * Sets its last touch tick as the current tick. 85 *
|
71 * @param blk Cache block to be reset.
|
86 * @param replacement_data Replacement data to be touched. |
87 */
|
73 void reset(CacheBlk *blk) override;
|
88 void touch(const std::shared_ptr<ReplacementData>& replacement_data) const 89 override; |
90 91 /**
|
92 * Reset replacement data. Used when an entry is inserted. 93 * Sets its last touch tick as the current tick. 94 * 95 * @param replacement_data Replacement data to be reset. 96 */ 97 void reset(const std::shared_ptr<ReplacementData>& replacement_data) const 98 override; 99 100 /** |
101 * Find replacement victim using access timestamps.
|
102 * |
103 * @param cands Replacement candidates, selected by indexing policy.
|
78 * @return Cache block to be replaced.
|
104 * @return Replacement entry to be replaced. |
105 */
|
80 CacheBlk* getVictim(const ReplacementCandidates& candidates) override;
|
106 ReplaceableEntry* getVictim(const ReplacementCandidates& candidates) const 107 override; 108 109 /** 110 * Instantiate a replacement data entry. 111 * 112 * @return A shared pointer to the new replacement data. 113 */ 114 std::shared_ptr<ReplacementData> instantiateEntry() override; |
115}; 116 117#endif // __MEM_CACHE_REPLACEMENT_POLICIES_MRU_RP_HH__
|