TimerTable.cc revision 7455 
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/eventqueue/RubyEventQueue.hh"
31#include "mem/ruby/system/TimerTable.hh"
32
33TimerTable::TimerTable()
34{
35    m_consumer_ptr  = NULL;
36    m_next_valid = false;
37    m_next_address = Address(0);
38    m_next_time = 0;
39}
40
41bool
42TimerTable::isReady() const
43{
44    if (m_map.empty())
45        return false;
46
47    if (!m_next_valid) {
48        updateNext();
49    }
50    assert(m_next_valid);
51    return (g_eventQueue_ptr->getTime() >= m_next_time);
52}
53
54const Address&
55TimerTable::readyAddress() const
56{
57    assert(isReady());
58
59    if (!m_next_valid) {
60        updateNext();
61    }
62    assert(m_next_valid);
63    return m_next_address;
64}
65
66void
67TimerTable::set(const Address& address, Time relative_latency)
68{
69    assert(address == line_address(address));
70    assert(relative_latency > 0);
71    assert(!m_map.count(address));
72    Time ready_time = g_eventQueue_ptr->getTime() + relative_latency;
73    m_map[address] = ready_time;
74    assert(m_consumer_ptr != NULL);
75    g_eventQueue_ptr->scheduleEventAbsolute(m_consumer_ptr, ready_time);
76    m_next_valid = false;
77
78    // Don't always recalculate the next ready address
79    if (ready_time <= m_next_time) {
80        m_next_valid = false;
81    }
82}
83
84void
85TimerTable::unset(const Address& address)
86{
87    assert(address == line_address(address));
88    assert(m_map.count(address));
89    m_map.erase(address);
90
91    // Don't always recalculate the next ready address
92    if (address == m_next_address) {
93        m_next_valid = false;
94    }
95}
96
97void
98TimerTable::print(std::ostream& out) const
99{
100}
101
102void
103TimerTable::updateNext() const
104{
105    if (m_map.empty()) {
106        assert(!m_next_valid);
107        return;
108    }
109
110    AddressMap::const_iterator i = m_map.begin();
111    AddressMap::const_iterator end = m_map.end();
112
113    m_next_address = i->first;
114    m_next_time = i->second;
115    ++i;
116
117    for (; i != end; ++i) {
118        if (i->second < m_next_time) {
119            m_next_address = i->first;
120            m_next_time = i->second;
121        }
122    }
123
124    m_next_valid = true;
125}
126