TimerTable.cc revision 6467 
1
2/*
3 * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30/*
31 * $Id$
32 */
33
34#include "mem/ruby/common/Global.hh"
35#include "mem/ruby/system/TimerTable.hh"
36#include "mem/ruby/eventqueue/RubyEventQueue.hh"
37
38TimerTable::TimerTable()
39{
40  m_consumer_ptr  = NULL;
41  m_next_valid = false;
42  m_next_address = Address(0);
43  m_next_time = 0;
44}
45
46
47bool TimerTable::isReady() const
48{
49  if (m_map.size() == 0) {
50    return false;
51  }
52
53  if (!m_next_valid) {
54    updateNext();
55  }
56  assert(m_next_valid);
57  return (g_eventQueue_ptr->getTime() >= m_next_time);
58}
59
60const Address& TimerTable::readyAddress() const
61{
62  assert(isReady());
63
64  if (!m_next_valid) {
65    updateNext();
66  }
67  assert(m_next_valid);
68  return m_next_address;
69}
70
71void TimerTable::set(const Address& address, Time relative_latency)
72{
73  assert(address == line_address(address));
74  assert(relative_latency > 0);
75  assert(m_map.exist(address) == false);
76  Time ready_time = g_eventQueue_ptr->getTime() + relative_latency;
77  m_map.add(address, ready_time);
78  assert(m_consumer_ptr != NULL);
79  g_eventQueue_ptr->scheduleEventAbsolute(m_consumer_ptr, 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 TimerTable::unset(const Address& address)
89{
90  assert(address == line_address(address));
91  assert(m_map.exist(address) == true);
92  m_map.remove(address);
93
94  // Don't always recalculate the next ready address
95  if (address == m_next_address) {
96    m_next_valid = false;
97  }
98}
99
100void TimerTable::print(ostream& out) const
101{
102}
103
104
105void TimerTable::updateNext() const
106{
107  if (m_map.size() == 0) {
108    assert(m_next_valid == false);
109    return;
110  }
111
112  Vector<Address> addresses = m_map.keys();
113  m_next_address = addresses[0];
114  m_next_time = m_map.lookup(m_next_address);
115
116  // Search for the minimum time
117  int size = addresses.size();
118  for (int i=1; i<size; i++) {
119    Address maybe_next_address = addresses[i];
120    Time maybe_next_time = m_map.lookup(maybe_next_address);
121    if (maybe_next_time < m_next_time) {
122      m_next_time = maybe_next_time;
123      m_next_address= maybe_next_address;
124    }
125  }
126  m_next_valid = true;
127}
128