TimerTable.cc revision 10301:44839e8febbd 
1/*
2 * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
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
29#include "mem/ruby/common/Global.hh"
30#include "mem/ruby/structures/TimerTable.hh"
31#include "mem/ruby/system/System.hh"
32
33TimerTable::TimerTable()
34    : m_next_time(0)
35{
36    m_consumer_ptr  = NULL;
37    m_clockobj_ptr = NULL;
38
39    m_next_valid = false;
40    m_next_address = Address(0);
41}
42
43bool
44TimerTable::isReady() const
45{
46    if (m_map.empty())
47        return false;
48
49    if (!m_next_valid) {
50        updateNext();
51    }
52    assert(m_next_valid);
53    return (m_clockobj_ptr->curCycle() >= m_next_time);
54}
55
56const Address&
57TimerTable::readyAddress() const
58{
59    assert(isReady());
60
61    if (!m_next_valid) {
62        updateNext();
63    }
64    assert(m_next_valid);
65    return m_next_address;
66}
67
68void
69TimerTable::set(const Address& address, Cycles relative_latency)
70{
71    assert(address == line_address(address));
72    assert(relative_latency > 0);
73    assert(!m_map.count(address));
74
75    Cycles ready_time = m_clockobj_ptr->curCycle() + relative_latency;
76    m_map[address] = ready_time;
77    assert(m_consumer_ptr != NULL);
78    m_consumer_ptr->
79        scheduleEventAbsolute(m_clockobj_ptr->clockPeriod() * ready_time);
80    m_next_valid = false;
81
82    // Don't always recalculate the next ready address
83    if (ready_time <= m_next_time) {
84        m_next_valid = false;
85    }
86}
87
88void
89TimerTable::unset(const Address& address)
90{
91    assert(address == line_address(address));
92    assert(m_map.count(address));
93    m_map.erase(address);
94
95    // Don't always recalculate the next ready address
96    if (address == m_next_address) {
97        m_next_valid = false;
98    }
99}
100
101void
102TimerTable::print(std::ostream& out) const
103{
104}
105
106void
107TimerTable::updateNext() const
108{
109    if (m_map.empty()) {
110        assert(!m_next_valid);
111        return;
112    }
113
114    AddressMap::const_iterator i = m_map.begin();
115    AddressMap::const_iterator end = m_map.end();
116
117    m_next_address = i->first;
118    m_next_time = i->second;
119    ++i;
120
121    for (; i != end; ++i) {
122        if (i->second < m_next_time) {
123            m_next_address = i->first;
124            m_next_time = i->second;
125        }
126    }
127
128    m_next_valid = true;
129}
130