src/sim/drain.cc

   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
  47 DrainManager DrainManager::_instance;
  48
  49 DrainManager::DrainManager()
  50     : _count(0),
  51       _state(DrainState::Running)
  52 {
  53 }
  54
  55 DrainManager::~DrainManager()
  56 {
  57 }
  58
  59 bool
  60 DrainManager::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
  84 void
  85 DrainManager::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
 104 void
 105 DrainManager::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
 118 void
 119 DrainManager::signalDrainDone()
 120 {
 121     if (--_count == 0) {
 122         DPRINTF(Drain, "All %u objects drained..\n", drainableCount());
 123         exitSimLoop("Finished drain", 0);
 124     }
 125 }
 126
 127
 128 void
 129 DrainManager::registerDrainable(Drainable *obj)
 130 {
 131     std::lock_guard<std::mutex> lock(globalLock);
 132     _allDrainable.insert(obj);
 133 }
 134
 135 void
 136 DrainManager::unregisterDrainable(Drainable *obj)
 137 {
 138     std::lock_guard<std::mutex> lock(globalLock);
 139     _allDrainable.erase(obj);
 140 }
 141
 142 size_t
 143 DrainManager::drainableCount() const
 144 {
 145     std::lock_guard<std::mutex> lock(globalLock);
 146     return _allDrainable.size();
 147 }
 148
 149
 150
 151 Drainable::Drainable()
 152     : _drainManager(DrainManager::instance()),
 153       _drainState(DrainState::Running)
 154 {
 155     _drainManager.registerDrainable(this);
 156 }
 157
 158 Drainable::~Drainable()
 159 {
 160     _drainManager.unregisterDrainable(this);
 161 }
 162
 163 DrainState
 164 Drainable::dmDrain()
 165 {
 166     _drainState = DrainState::Draining;
 167     _drainState = drain();
 168     assert(_drainState == DrainState::Draining ||
 169            _drainState == DrainState::Drained);
 170
 171     return _drainState;
 172 }
 173
 174 void
 175 Drainable::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 }