PersistentTable.cc revision 6791 
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#include "PersistentTable.hh"
31#include "NetDest.h"
32#include "Map.h"
33#include "Address.h"
34#include "AbstractChip.h"
35#include "util.h"
36
37// randomize so that handoffs are not locality-aware
38// int persistent_randomize[] = {0, 4, 8, 12, 1, 5, 9, 13, 2, 6, 10, 14, 3, 7, 11, 15};
39// int persistent_randomize[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
40
41
42class PersistentTableEntry {
43public:
44  NetDest m_starving;
45  NetDest m_marked;
46  NetDest m_request_to_write;
47};
48
49PersistentTable::PersistentTable(AbstractChip* chip_ptr, int version)
50{
51  m_chip_ptr = chip_ptr;
52  m_map_ptr = new Map<Address, PersistentTableEntry>;
53  m_version = version;
54}
55
56PersistentTable::~PersistentTable()
57{
58  delete m_map_ptr;
59  m_map_ptr = NULL;
60  m_chip_ptr = NULL;
61}
62
63void PersistentTable::persistentRequestLock(const Address& address, MachineID locker, AccessType type)
64{
65
66  // if (locker == m_chip_ptr->getID()  )
67  // cout << "Chip " << m_chip_ptr->getID() << ": " << llocker << " requesting lock for " << address << endl;
68
69  // MachineID locker = (MachineID) persistent_randomize[llocker];
70
71  assert(address == line_address(address));
72  if (!m_map_ptr->exist(address)) {
73    // Allocate if not present
74    PersistentTableEntry entry;
75    entry.m_starving.add(locker);
76    if (type == AccessType_Write) {
77      entry.m_request_to_write.add(locker);
78    }
79    m_map_ptr->add(address, entry);
80  } else {
81    PersistentTableEntry& entry = m_map_ptr->lookup(address);
82    assert(!(entry.m_starving.isElement(locker))); // Make sure we're not already in the locked set
83
84    entry.m_starving.add(locker);
85    if (type == AccessType_Write) {
86      entry.m_request_to_write.add(locker);
87    }
88    assert(entry.m_marked.isSubset(entry.m_starving));
89  }
90}
91
92void PersistentTable::persistentRequestUnlock(const Address& address, MachineID unlocker)
93{
94  // if (unlocker == m_chip_ptr->getID() )
95  // cout << "Chip " << m_chip_ptr->getID() << ": " << uunlocker << " requesting unlock for " << address << endl;
96
97  // MachineID unlocker = (MachineID) persistent_randomize[uunlocker];
98
99  assert(address == line_address(address));
100  assert(m_map_ptr->exist(address));
101  PersistentTableEntry& entry = m_map_ptr->lookup(address);
102  assert(entry.m_starving.isElement(unlocker)); // Make sure we're in the locked set
103  assert(entry.m_marked.isSubset(entry.m_starving));
104  entry.m_starving.remove(unlocker);
105  entry.m_marked.remove(unlocker);
106  entry.m_request_to_write.remove(unlocker);
107  assert(entry.m_marked.isSubset(entry.m_starving));
108
109  // Deallocate if empty
110  if (entry.m_starving.isEmpty()) {
111    assert(entry.m_marked.isEmpty());
112    m_map_ptr->erase(address);
113  }
114}
115
116bool PersistentTable::okToIssueStarving(const Address& address) const
117{
118  assert(address == line_address(address));
119  if (!m_map_ptr->exist(address)) {
120    return true; // No entry present
121  } else if (m_map_ptr->lookup(address).m_starving.isElement( (MachineID) {MachineType_L1Cache, m_version})) {
122    return false; // We can't issue another lockdown until are previous unlock has occurred
123  } else {
124    return (m_map_ptr->lookup(address).m_marked.isEmpty());
125  }
126}
127
128MachineID PersistentTable::findSmallest(const Address& address) const
129{
130  assert(address == line_address(address));
131  assert(m_map_ptr->exist(address));
132  const PersistentTableEntry& entry = m_map_ptr->lookup(address);
133  // cout << "Node " <<  m_chip_ptr->getID() << " returning " << persistent_randomize[entry.m_starving.smallestElement()] << " for findSmallest(" << address << ")" << endl;
134  // return (MachineID) persistent_randomize[entry.m_starving.smallestElement()];
135  return (MachineID) { MachineType_L1Cache, entry.m_starving.smallestElement() };
136}
137
138AccessType PersistentTable::typeOfSmallest(const Address& address) const
139{
140  assert(address == line_address(address));
141  assert(m_map_ptr->exist(address));
142  const PersistentTableEntry& entry = m_map_ptr->lookup(address);
143  if (entry.m_request_to_write.isElement((MachineID) {MachineType_L1Cache, entry.m_starving.smallestElement()})) {
144    return AccessType_Write;
145  } else {
146    return AccessType_Read;
147  }
148}
149
150void PersistentTable::markEntries(const Address& address)
151{
152  assert(address == line_address(address));
153  if (m_map_ptr->exist(address)) {
154    PersistentTableEntry& entry = m_map_ptr->lookup(address);
155    assert(entry.m_marked.isEmpty());  // None should be marked
156    entry.m_marked = entry.m_starving; // Mark all the nodes currently in the table
157  }
158}
159
160bool PersistentTable::isLocked(const Address& address) const
161{
162  assert(address == line_address(address));
163  // If an entry is present, it must be locked
164  return (m_map_ptr->exist(address));
165}
166
167int PersistentTable::countStarvingForAddress(const Address& address) const
168{
169  if (m_map_ptr->exist(address)) {
170    PersistentTableEntry& entry = m_map_ptr->lookup(address);
171    return (entry.m_starving.count());
172  }
173  else {
174    return 0;
175  }
176}
177
178int PersistentTable::countReadStarvingForAddress(const Address& address) const
179{
180  int count = 0;
181  if (m_map_ptr->exist(address)) {
182    PersistentTableEntry& entry = m_map_ptr->lookup(address);
183    return (entry.m_starving.count() - entry.m_request_to_write.count());
184  }
185  else {
186    return 0;
187  }
188}
189
190
191