TimerTable.cc revision 7055 
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.size() == 0) {
45        return false;
46    }
47
48    if (!m_next_valid) {
49        updateNext();
50    }
51    assert(m_next_valid);
52    return (g_eventQueue_ptr->getTime() >= m_next_time);
53}
54
55const Address&
56TimerTable::readyAddress() const
57{
58    assert(isReady());
59
60    if (!m_next_valid) {
61        updateNext();
62    }
63    assert(m_next_valid);
64    return m_next_address;
65}
66
67void
68TimerTable::set(const Address& address, Time relative_latency)
69{
70    assert(address == line_address(address));
71    assert(relative_latency > 0);
72    assert(m_map.exist(address) == false);
73    Time ready_time = g_eventQueue_ptr->getTime() + relative_latency;
74    m_map.add(address, ready_time);
75    assert(m_consumer_ptr != NULL);
76    g_eventQueue_ptr->scheduleEventAbsolute(m_consumer_ptr, ready_time);
77    m_next_valid = false;
78
79    // Don't always recalculate the next ready address
80    if (ready_time <= m_next_time) {
81        m_next_valid = false;
82    }
83}
84
85void
86TimerTable::unset(const Address& address)
87{
88    assert(address == line_address(address));
89    assert(m_map.exist(address) == true);
90    m_map.remove(address);
91
92    // Don't always recalculate the next ready address
93    if (address == m_next_address) {
94        m_next_valid = false;
95    }
96}
97
98void
99TimerTable::print(std::ostream& out) const
100{
101}
102
103void
104TimerTable::updateNext() const
105{
106    if (m_map.size() == 0) {
107        assert(m_next_valid == false);
108        return;
109    }
110
111    Vector<Address> addresses = m_map.keys();
112    m_next_address = addresses[0];
113    m_next_time = m_map.lookup(m_next_address);
114
115    // Search for the minimum time
116    int size = addresses.size();
117    for (int i=1; i<size; i++) {
118        Address maybe_next_address = addresses[i];
119        Time maybe_next_time = m_map.lookup(maybe_next_address);
120        if (maybe_next_time < m_next_time) {
121            m_next_time = maybe_next_time;
122            m_next_address= maybe_next_address;
123        }
124    }
125    m_next_valid = true;
126}
127