fifo_rp.cc revision 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;
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/fifo_rp.hh"
32
33#include <memory>
34
35FIFORP::FIFORP(const Params *p)
36    : BaseReplacementPolicy(p)
37{
38}
39
40void
41FIFORP::invalidate(const std::shared_ptr<ReplacementData>& replacement_data)
42const
43{
44    // Reset insertion tick
45    std::static_pointer_cast<FIFOReplData>(
46        replacement_data)->tickInserted = Tick(0);
47}
48
49void
50FIFORP::touch(const std::shared_ptr<ReplacementData>& replacement_data) const
51{
52    // A touch does not modify the insertion tick
53}
54
55void
56FIFORP::reset(const std::shared_ptr<ReplacementData>& replacement_data) const
57{
58    // Set insertion tick
59    std::static_pointer_cast<FIFOReplData>(
60        replacement_data)->tickInserted = curTick();
61}
62
63ReplaceableEntry*
64FIFORP::getVictim(const ReplacementCandidates& candidates) const
65{
66    // There must be at least one replacement candidate
67    assert(candidates.size() > 0);
68
69    // Visit all candidates to find victim
70    ReplaceableEntry* victim = candidates[0];
71    for (const auto& candidate : candidates) {
72        // Update victim entry if necessary
73        if (std::static_pointer_cast<FIFOReplData>(
74                    candidate->replacementData)->tickInserted <
75                std::static_pointer_cast<FIFOReplData>(
76                    victim->replacementData)->tickInserted) {
77            victim = candidate;
78        }
79    }
80
81    return victim;
82}
83
84std::shared_ptr<ReplacementData>
85FIFORP::instantiateEntry()
86{
87    return std::shared_ptr<ReplacementData>(new FIFOReplData());
88}
89
90FIFORP*
91FIFORPParams::create()
92{
93    return new FIFORP(this);
94}
95