PersistentTable.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/gems_common/util.hh"
30#include "mem/ruby/system/PersistentTable.hh"
31
32using namespace std;
33
34// randomize so that handoffs are not locality-aware
35#if 0
36int persistent_randomize[] = {0, 4, 8, 12, 1, 5, 9, 13, 2, 6,
37                              10, 14, 3, 7, 11, 15};
38int persistent_randomize[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
39                              10, 11, 12, 13, 14, 15};
40#endif
41
42PersistentTable::PersistentTable()
43{
44    m_map_ptr = new Map<Address, PersistentTableEntry>;
45}
46
47PersistentTable::~PersistentTable()
48{
49    delete m_map_ptr;
50    m_map_ptr = NULL;
51}
52
53void
54PersistentTable::persistentRequestLock(const Address& address,
55                                       MachineID locker,
56                                       AccessType type)
57{
58#if 0
59    if (locker == m_chip_ptr->getID())
60        cout << "Chip " << m_chip_ptr->getID() << ": " << llocker
61             << " requesting lock for " << address << endl;
62
63    MachineID locker = (MachineID) persistent_randomize[llocker];
64#endif
65
66    assert(address == line_address(address));
67    if (!m_map_ptr->exist(address)) {
68        // Allocate if not present
69        PersistentTableEntry entry;
70        entry.m_starving.add(locker);
71        if (type == AccessType_Write) {
72            entry.m_request_to_write.add(locker);
73        }
74        m_map_ptr->add(address, entry);
75    } else {
76        PersistentTableEntry& entry = m_map_ptr->lookup(address);
77
78        //
79        // Make sure we're not already in the locked set
80        //
81        assert(!(entry.m_starving.isElement(locker)));
82
83        entry.m_starving.add(locker);
84        if (type == AccessType_Write) {
85            entry.m_request_to_write.add(locker);
86        }
87        assert(entry.m_marked.isSubset(entry.m_starving));
88    }
89}
90
91void
92PersistentTable::persistentRequestUnlock(const Address& address,
93                                         MachineID unlocker)
94{
95#if 0
96    if (unlocker == m_chip_ptr->getID())
97        cout << "Chip " << m_chip_ptr->getID() << ": " << uunlocker
98             << " requesting unlock for " << address << endl;
99
100    MachineID unlocker = (MachineID) persistent_randomize[uunlocker];
101#endif
102
103    assert(address == line_address(address));
104    assert(m_map_ptr->exist(address));
105    PersistentTableEntry& entry = m_map_ptr->lookup(address);
106
107    //
108    // Make sure we're in the locked set
109    //
110    assert(entry.m_starving.isElement(unlocker));
111    assert(entry.m_marked.isSubset(entry.m_starving));
112    entry.m_starving.remove(unlocker);
113    entry.m_marked.remove(unlocker);
114    entry.m_request_to_write.remove(unlocker);
115    assert(entry.m_marked.isSubset(entry.m_starving));
116
117    // Deallocate if empty
118    if (entry.m_starving.isEmpty()) {
119        assert(entry.m_marked.isEmpty());
120        m_map_ptr->erase(address);
121    }
122}
123
124bool
125PersistentTable::okToIssueStarving(const Address& address,
126                                   MachineID machId) const
127{
128    assert(address == line_address(address));
129    if (!m_map_ptr->exist(address)) {
130        // No entry present
131        return true;
132    } else if (m_map_ptr->lookup(address).m_starving.isElement(machId)) {
133        // We can't issue another lockdown until are previous unlock
134        // has occurred
135        return false;
136    } else {
137        return m_map_ptr->lookup(address).m_marked.isEmpty();
138    }
139}
140
141MachineID
142PersistentTable::findSmallest(const Address& address) const
143{
144    assert(address == line_address(address));
145    assert(m_map_ptr->exist(address));
146    const PersistentTableEntry& entry = m_map_ptr->lookup(address);
147    return entry.m_starving.smallestElement();
148}
149
150AccessType
151PersistentTable::typeOfSmallest(const Address& address) const
152{
153    assert(address == line_address(address));
154    assert(m_map_ptr->exist(address));
155    const PersistentTableEntry& entry = m_map_ptr->lookup(address);
156    if (entry.m_request_to_write.
157        isElement(entry.m_starving.smallestElement())) {
158        return AccessType_Write;
159    } else {
160        return AccessType_Read;
161    }
162}
163
164void
165PersistentTable::markEntries(const Address& address)
166{
167    assert(address == line_address(address));
168    if (m_map_ptr->exist(address)) {
169        PersistentTableEntry& entry = m_map_ptr->lookup(address);
170
171        // None should be marked
172        assert(entry.m_marked.isEmpty());
173
174        // Mark all the nodes currently in the table
175        entry.m_marked = entry.m_starving;
176    }
177}
178
179bool
180PersistentTable::isLocked(const Address& address) const
181{
182    assert(address == line_address(address));
183
184    // If an entry is present, it must be locked
185    return m_map_ptr->exist(address);
186}
187
188int
189PersistentTable::countStarvingForAddress(const Address& address) const
190{
191    if (m_map_ptr->exist(address)) {
192        PersistentTableEntry& entry = m_map_ptr->lookup(address);
193        return (entry.m_starving.count());
194    } else {
195        return 0;
196    }
197}
198
199int
200PersistentTable::countReadStarvingForAddress(const Address& address) const
201{
202    if (m_map_ptr->exist(address)) {
203        PersistentTableEntry& entry = m_map_ptr->lookup(address);
204        return (entry.m_starving.count() - entry.m_request_to_write.count());
205    } else {
206        return 0;
207    }
208}
209
210void
211PersistentTable::print(ostream& out) const
212{
213}
214
215