drain.cc revision 11417 
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#include "sim/sim_object.hh"
47
48DrainManager DrainManager::_instance;
49
50DrainManager::DrainManager()
51    : _count(0),
52      _state(DrainState::Running)
53{
54}
55
56DrainManager::~DrainManager()
57{
58}
59
60bool
61DrainManager::tryDrain()
62{
63    panic_if(_state == DrainState::Drained,
64             "Trying to drain a drained system\n");
65
66    panic_if(_count != 0,
67             "Drain counter must be zero at the start of a drain cycle\n");
68
69    DPRINTF(Drain, "Trying to drain %u objects.\n", drainableCount());
70    _state = DrainState::Draining;
71    for (auto *obj : _allDrainable) {
72        DrainState status = obj->dmDrain();
73        if (DTRACE(Drain) && status != DrainState::Drained) {
74            SimObject *temp = dynamic_cast<SimObject*>(obj);
75            if (temp)
76                DPRINTF(Drain, "Failed to drain %s\n", temp->name());
77        }
78        _count += status == DrainState::Drained ? 0 : 1;
79    }
80
81    if (_count == 0) {
82        DPRINTF(Drain, "Drain done.\n");
83        _state = DrainState::Drained;
84        return true;
85    } else {
86        DPRINTF(Drain, "Need another drain cycle. %u/%u objects not ready.\n",
87                _count, drainableCount());
88        return false;
89    }
90}
91
92void
93DrainManager::resume()
94{
95    panic_if(_state == DrainState::Running,
96             "Trying to resume a system that is already running\n");
97
98    warn_if(_state == DrainState::Draining,
99            "Resuming a system that isn't fully drained, this is untested and "
100            "likely to break\n");
101
102    panic_if(_count != 0,
103             "Resume called in the middle of a drain cycle. %u objects "
104             "left to drain.\n", _count);
105
106    DPRINTF(Drain, "Resuming %u objects.\n", drainableCount());
107    _state = DrainState::Running;
108    for (auto *obj : _allDrainable)
109        obj->dmDrainResume();
110}
111
112void
113DrainManager::preCheckpointRestore()
114{
115    panic_if(_state != DrainState::Running,
116             "preCheckpointRestore() called on a system that isn't in the "
117             "Running state.\n");
118
119    DPRINTF(Drain, "Applying pre-restore fixes to %u objects.\n",
120            drainableCount());
121    _state = DrainState::Drained;
122    for (auto *obj : _allDrainable)
123        obj->_drainState = DrainState::Drained;
124}
125
126void
127DrainManager::signalDrainDone()
128{
129    if (--_count == 0) {
130        DPRINTF(Drain, "All %u objects drained..\n", drainableCount());
131        exitSimLoop("Finished drain", 0);
132    }
133}
134
135
136void
137DrainManager::registerDrainable(Drainable *obj)
138{
139    std::lock_guard<std::mutex> lock(globalLock);
140    _allDrainable.insert(obj);
141}
142
143void
144DrainManager::unregisterDrainable(Drainable *obj)
145{
146    std::lock_guard<std::mutex> lock(globalLock);
147    _allDrainable.erase(obj);
148}
149
150size_t
151DrainManager::drainableCount() const
152{
153    std::lock_guard<std::mutex> lock(globalLock);
154    return _allDrainable.size();
155}
156
157
158
159Drainable::Drainable()
160    : _drainManager(DrainManager::instance()),
161      _drainState(_drainManager.state())
162{
163    _drainManager.registerDrainable(this);
164}
165
166Drainable::~Drainable()
167{
168    _drainManager.unregisterDrainable(this);
169}
170
171DrainState
172Drainable::dmDrain()
173{
174    _drainState = DrainState::Draining;
175    _drainState = drain();
176    assert(_drainState == DrainState::Draining ||
177           _drainState == DrainState::Drained);
178
179    return _drainState;
180}
181
182void
183Drainable::dmDrainResume()
184{
185    panic_if(_drainState != DrainState::Drained,
186             "Trying to resume an object that hasn't been drained\n");
187
188    _drainState = DrainState::Running;
189    drainResume();
190}
191