lfu_rp.hh (12628:458d655f2abb) lfu_rp.hh (12684:44ebd2bc020f)
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;

--- 18 unchanged lines hidden (view full) ---

27 *
28 * Authors: Daniel Carvalho
29 */
30
31/**
32 * @file
33 * Declaration of a Least Frequently Used replacement policy.
34 * The victim is chosen using the reference frequency. The least referenced
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;

--- 18 unchanged lines hidden (view full) ---

27 *
28 * Authors: Daniel Carvalho
29 */
30
31/**
32 * @file
33 * Declaration of a Least Frequently Used replacement policy.
34 * The victim is chosen using the reference frequency. The least referenced
35 * block is always chosen to be evicted, regardless of the amount of times
35 * entry is always chosen to be evicted, regardless of the amount of times
36 * it has been touched, or how long has passed since its last touch.
37 */
38
39#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_LFU_RP_HH__
40#define __MEM_CACHE_REPLACEMENT_POLICIES_LFU_RP_HH__
41
42#include "mem/cache/replacement_policies/base.hh"
43#include "params/LFURP.hh"
44
45class LFURP : public BaseReplacementPolicy
46{
36 * it has been touched, or how long has passed since its last touch.
37 */
38
39#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_LFU_RP_HH__
40#define __MEM_CACHE_REPLACEMENT_POLICIES_LFU_RP_HH__
41
42#include "mem/cache/replacement_policies/base.hh"
43#include "params/LFURP.hh"
44
45class LFURP : public BaseReplacementPolicy
46{
47 protected:
48 /** LFU-specific implementation of replacement data. */
49 struct LFUReplData : ReplacementData
50 {
51 /** Number of references to this entry since it was reset. */
52 unsigned refCount;
53
54 /**
55 * Default constructor. Invalidate data.
56 */
57 LFUReplData() : refCount(0) {}
58 };
59
47 public:
48 /** Convenience typedef. */
49 typedef LFURPParams Params;
50
51 /**
52 * Construct and initiliaze this replacement policy.
53 */
54 LFURP(const Params *p);
55
56 /**
57 * Destructor.
58 */
59 ~LFURP() {}
60
61 /**
60 public:
61 /** Convenience typedef. */
62 typedef LFURPParams Params;
63
64 /**
65 * Construct and initiliaze this replacement policy.
66 */
67 LFURP(const Params *p);
68
69 /**
70 * Destructor.
71 */
72 ~LFURP() {}
73
74 /**
75 * Invalidate replacement data to set it as the next probable victim.
76 * Clear the number of references.
77 *
78 * @param replacement_data Replacement data to be invalidated.
79 */
80 void invalidate(const std::shared_ptr<ReplacementData>& replacement_data)
81 const override;
82
83 /**
84 * Touch an entry to update its replacement data.
85 * Increase number of references.
86 *
87 * @param replacement_data Replacement data to be touched.
88 */
89 void touch(const std::shared_ptr<ReplacementData>& replacement_data) const
90 override;
91
92 /**
93 * Reset replacement data. Used when an entry is inserted.
94 * Reset number of references.
95 *
96 * @param replacement_data Replacement data to be reset.
97 */
98 void reset(const std::shared_ptr<ReplacementData>& replacement_data) const
99 override;
100
101 /**
62 * Find replacement victim using reference frequency.
63 *
64 * @param cands Replacement candidates, selected by indexing policy.
102 * Find replacement victim using reference frequency.
103 *
104 * @param cands Replacement candidates, selected by indexing policy.
65 * @return Cache block to be replaced.
105 * @return Replacement entry to be replaced.
66 */
106 */
67 CacheBlk* getVictim(const ReplacementCandidates& candidates) override;
107 ReplaceableEntry* getVictim(const ReplacementCandidates& candidates) const
108 override;
109
110 /**
111 * Instantiate a replacement data entry.
112 *
113 * @return A shared pointer to the new replacement data.
114 */
115 std::shared_ptr<ReplacementData> instantiateEntry() override;
68};
69
70#endif // __MEM_CACHE_REPLACEMENT_POLICIES_LFU_RP_HH__
116};
117
118#endif // __MEM_CACHE_REPLACEMENT_POLICIES_LFU_RP_HH__