drain.cc revision 10998:cd22d66592bf 
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 "base/misc.hh"
43#include "base/trace.hh"
44#include "debug/Drain.hh"
45#include "sim/sim_exit.hh"
46
47DrainManager DrainManager::_instance;
48
49DrainManager::DrainManager()
50    : _count(0),
51      _state(DrainState::Running)
52{
53}
54
55DrainManager::~DrainManager()
56{
57}
58
59bool
60DrainManager::tryDrain()
61{
62    panic_if(_state == DrainState::Drained,
63             "Trying to drain a drained system\n");
64
65    panic_if(_count != 0,
66             "Drain counter must be zero at the start of a drain cycle\n");
67
68    DPRINTF(Drain, "Trying to drain %u objects.\n", drainableCount());
69    _state = DrainState::Draining;
70    for (auto *obj : _allDrainable)
71        _count += obj->dmDrain() == DrainState::Drained ? 0 : 1;
72
73    if (_count == 0) {
74        DPRINTF(Drain, "Drain done.\n");
75        _state = DrainState::Drained;
76        return true;
77    } else {
78        DPRINTF(Drain, "Need another drain cycle. %u/%u objects not ready.\n",
79                _count, drainableCount());
80        return false;
81    }
82}
83
84void
85DrainManager::resume()
86{
87    panic_if(_state == DrainState::Running,
88             "Trying to resume a system that is already running\n");
89
90    warn_if(_state == DrainState::Draining,
91            "Resuming a system that isn't fully drained, this is untested and "
92            "likely to break\n");
93
94    panic_if(_count != 0,
95             "Resume called in the middle of a drain cycle. %u objects "
96             "left to drain.\n", _count);
97
98    DPRINTF(Drain, "Resuming %u objects.\n", drainableCount());
99    _state = DrainState::Running;
100    for (auto *obj : _allDrainable)
101        obj->dmDrainResume();
102}
103
104void
105DrainManager::preCheckpointRestore()
106{
107    panic_if(_state != DrainState::Running,
108             "preCheckpointRestore() called on a system that isn't in the "
109             "Running state.\n");
110
111    DPRINTF(Drain, "Applying pre-restore fixes to %u objects.\n",
112            drainableCount());
113    _state = DrainState::Drained;
114    for (auto *obj : _allDrainable)
115        obj->_drainState = DrainState::Drained;
116}
117
118void
119DrainManager::signalDrainDone()
120{
121    if (--_count == 0) {
122        DPRINTF(Drain, "All %u objects drained..\n", drainableCount());
123        exitSimLoop("Finished drain", 0);
124    }
125}
126
127
128void
129DrainManager::registerDrainable(Drainable *obj)
130{
131    std::lock_guard<std::mutex> lock(globalLock);
132    _allDrainable.insert(obj);
133}
134
135void
136DrainManager::unregisterDrainable(Drainable *obj)
137{
138    std::lock_guard<std::mutex> lock(globalLock);
139    _allDrainable.erase(obj);
140}
141
142size_t
143DrainManager::drainableCount() const
144{
145    std::lock_guard<std::mutex> lock(globalLock);
146    return _allDrainable.size();
147}
148
149
150
151Drainable::Drainable()
152    : _drainManager(DrainManager::instance()),
153      _drainState(_drainManager.state())
154{
155    _drainManager.registerDrainable(this);
156}
157
158Drainable::~Drainable()
159{
160    _drainManager.unregisterDrainable(this);
161}
162
163DrainState
164Drainable::dmDrain()
165{
166    _drainState = DrainState::Draining;
167    _drainState = drain();
168    assert(_drainState == DrainState::Draining ||
169           _drainState == DrainState::Drained);
170
171    return _drainState;
172}
173
174void
175Drainable::dmDrainResume()
176{
177    panic_if(_drainState != DrainState::Drained,
178             "Trying to resume an object that hasn't been drained\n");
179
180    _drainState = DrainState::Running;
181    drainResume();
182}
183