drain.cc revision 11859:76c36516e0ae 
1/*
2 * Copyright (c) 2012, 2015 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Andreas Sandberg
38 */
39
40#include "sim/drain.hh"
41
42#include <algorithm>
43
44#include "base/misc.hh"
45#include "base/trace.hh"
46#include "debug/Drain.hh"
47#include "sim/sim_exit.hh"
48#include "sim/sim_object.hh"
49
50DrainManager DrainManager::_instance;
51
52DrainManager::DrainManager()
53    : _count(0),
54      _state(DrainState::Running)
55{
56}
57
58DrainManager::~DrainManager()
59{
60}
61
62bool
63DrainManager::tryDrain()
64{
65    panic_if(_state == DrainState::Drained,
66             "Trying to drain a drained system\n");
67
68    panic_if(_count != 0,
69             "Drain counter must be zero at the start of a drain cycle\n");
70
71    DPRINTF(Drain, "Trying to drain %u objects.\n", drainableCount());
72    _state = DrainState::Draining;
73    for (auto *obj : _allDrainable) {
74        DrainState status = obj->dmDrain();
75        if (DTRACE(Drain) && status != DrainState::Drained) {
76            SimObject *temp = dynamic_cast<SimObject*>(obj);
77            if (temp)
78                DPRINTF(Drain, "Failed to drain %s\n", temp->name());
79        }
80        _count += status == DrainState::Drained ? 0 : 1;
81    }
82
83    if (_count == 0) {
84        DPRINTF(Drain, "Drain done.\n");
85        _state = DrainState::Drained;
86        return true;
87    } else {
88        DPRINTF(Drain, "Need another drain cycle. %u/%u objects not ready.\n",
89                _count, drainableCount());
90        return false;
91    }
92}
93
94void
95DrainManager::resume()
96{
97    panic_if(_state == DrainState::Running,
98             "Trying to resume a system that is already running\n");
99
100    warn_if(_state == DrainState::Draining,
101            "Resuming a system that isn't fully drained, this is untested and "
102            "likely to break\n");
103
104    panic_if(_count != 0,
105             "Resume called in the middle of a drain cycle. %u objects "
106             "left to drain.\n", _count);
107
108    DPRINTF(Drain, "Resuming %u objects.\n", drainableCount());
109    _state = DrainState::Running;
110    for (auto *obj : _allDrainable)
111        obj->dmDrainResume();
112}
113
114void
115DrainManager::preCheckpointRestore()
116{
117    panic_if(_state != DrainState::Running,
118             "preCheckpointRestore() called on a system that isn't in the "
119             "Running state.\n");
120
121    DPRINTF(Drain, "Applying pre-restore fixes to %u objects.\n",
122            drainableCount());
123    _state = DrainState::Drained;
124    for (auto *obj : _allDrainable)
125        obj->_drainState = DrainState::Drained;
126}
127
128void
129DrainManager::signalDrainDone()
130{
131    assert(_count > 0);
132    if (--_count == 0) {
133        DPRINTF(Drain, "All %u objects drained..\n", drainableCount());
134        exitSimLoop("Finished drain", 0);
135    }
136}
137
138
139void
140DrainManager::registerDrainable(Drainable *obj)
141{
142    std::lock_guard<std::mutex> lock(globalLock);
143    assert(std::find(_allDrainable.begin(), _allDrainable.end(), obj) ==
144           _allDrainable.end());
145    _allDrainable.push_back(obj);
146}
147
148void
149DrainManager::unregisterDrainable(Drainable *obj)
150{
151    std::lock_guard<std::mutex> lock(globalLock);
152    auto o = std::find(_allDrainable.begin(), _allDrainable.end(), obj);
153    assert(o != _allDrainable.end());
154    _allDrainable.erase(o);
155}
156
157size_t
158DrainManager::drainableCount() const
159{
160    std::lock_guard<std::mutex> lock(globalLock);
161    return _allDrainable.size();
162}
163
164
165
166Drainable::Drainable()
167    : _drainManager(DrainManager::instance()),
168      _drainState(_drainManager.state())
169{
170    _drainManager.registerDrainable(this);
171}
172
173Drainable::~Drainable()
174{
175    _drainManager.unregisterDrainable(this);
176}
177
178DrainState
179Drainable::dmDrain()
180{
181    _drainState = DrainState::Draining;
182    _drainState = drain();
183    assert(_drainState == DrainState::Draining ||
184           _drainState == DrainState::Drained);
185
186    return _drainState;
187}
188
189void
190Drainable::dmDrainResume()
191{
192    panic_if(_drainState != DrainState::Drained,
193             "Trying to resume an object that hasn't been drained\n");
194
195    _drainState = DrainState::Running;
196    drainResume();
197}
198