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28 * Authors: Daniel Carvalho
33 * Declaration of a Least Recently Used replacement policy.
34 * The victim is chosen using the last touch timestamp.
37 #ifndef __MEM_CACHE_REPLACEMENT_POLICIES_LRU_RP_HH__
38 #define __MEM_CACHE_REPLACEMENT_POLICIES_LRU_RP_HH__
40 #include "mem/cache/replacement_policies/base.hh"
44 class LRURP : public BaseReplacementPolicy
47 /** LRU-specific implementation of replacement data. */
48 struct LRUReplData : ReplacementData
50 /** Tick on which the entry was last touched. */
54 * Default constructor. Invalidate data.
56 LRUReplData() : lastTouchTick(0) {}
60 /** Convenience typedef. */
61 typedef LRURPParams Params;
64 * Construct and initiliaze this replacement policy.
66 LRURP(const Params *p);
74 * Invalidate replacement data to set it as the next probable victim.
75 * Sets its last touch tick as the starting tick.
77 * @param replacement_data Replacement data to be invalidated.
79 void invalidate(const std::shared_ptr<ReplacementData>& replacement_data)
83 * Touch an entry to update its replacement data.
84 * Sets its last touch tick as the current tick.
86 * @param replacement_data Replacement data to be touched.
88 void touch(const std::shared_ptr<ReplacementData>& replacement_data) const
92 * Reset replacement data. Used when an entry is inserted.
93 * Sets its last touch tick as the current tick.
95 * @param replacement_data Replacement data to be reset.
97 void reset(const std::shared_ptr<ReplacementData>& replacement_data) const
101 * Find replacement victim using LRU timestamps.
103 * @param candidates Replacement candidates, selected by indexing policy.
104 * @return Replacement entry to be replaced.
106 ReplaceableEntry* getVictim(const ReplacementCandidates& candidates) const
110 * Instantiate a replacement data entry.
112 * @return A shared pointer to the new replacement data.
114 std::shared_ptr<ReplacementData> instantiateEntry() override;
117 #endif // __MEM_CACHE_REPLACEMENT_POLICIES_LRU_RP_HH__