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/*
* Copyright (c) 2012, 2015, 2017 ARM Limited
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*
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*
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#include "sim/drain.hh"
#include <algorithm>
#include "base/logging.hh"
#include "base/named.hh"
#include "base/trace.hh"
#include "debug/Drain.hh"
#include "sim/sim_exit.hh"
namespace gem5
{
DrainManager DrainManager::_instance;
DrainManager::DrainManager()
: _count(0),
_state(DrainState::Running)
{
}
DrainManager::~DrainManager()
{
}
bool
DrainManager::tryDrain()
{
panic_if(_state == DrainState::Drained,
"Trying to drain a drained system\n");
panic_if(_count != 0,
"Drain counter must be zero at the start of a drain cycle\n");
DPRINTF(Drain, "Trying to drain %u objects.\n", drainableCount());
_state = DrainState::Draining;
for (auto *obj : _allDrainable) {
DrainState status = obj->dmDrain();
if (debug::Drain && status != DrainState::Drained) {
Named *temp = dynamic_cast<Named*>(obj);
if (temp)
DPRINTF(Drain, "Failed to drain %s\n", temp->name());
}
_count += status == DrainState::Drained ? 0 : 1;
}
if (_count == 0) {
DPRINTF(Drain, "Drain done.\n");
_state = DrainState::Drained;
return true;
} else {
DPRINTF(Drain, "Need another drain cycle. %u/%u objects not ready.\n",
_count, drainableCount());
return false;
}
}
void
DrainManager::resume()
{
panic_if(_state == DrainState::Running,
"Trying to resume a system that is already running\n");
warn_if(_state == DrainState::Draining,
"Resuming a system that isn't fully drained, this is untested and "
"likely to break\n");
panic_if(_state == DrainState::Resuming,
"Resuming a system that is already trying to resume. This should "
"never happen.\n");
panic_if(_count != 0,
"Resume called in the middle of a drain cycle. %u objects "
"left to drain.\n", _count);
// At this point in time the DrainManager and all objects will be
// in the the Drained state. New objects (i.e., objects created
// while resuming) will inherit the Resuming state from the
// DrainManager, which means we have to resume objects until all
// objects are in the Running state.
_state = DrainState::Resuming;
do {
DPRINTF(Drain, "Resuming %u objects.\n", drainableCount());
for (auto *obj : _allDrainable) {
if (obj->drainState() != DrainState::Running) {
assert(obj->drainState() == DrainState::Drained ||
obj->drainState() == DrainState::Resuming);
obj->dmDrainResume();
}
}
} while (!allInState(DrainState::Running));
_state = DrainState::Running;
}
void
DrainManager::preCheckpointRestore()
{
panic_if(_state != DrainState::Running,
"preCheckpointRestore() called on a system that isn't in the "
"Running state.\n");
DPRINTF(Drain, "Applying pre-restore fixes to %u objects.\n",
drainableCount());
_state = DrainState::Drained;
for (auto *obj : _allDrainable)
obj->_drainState = DrainState::Drained;
}
void
DrainManager::signalDrainDone()
{
assert(_count > 0);
if (--_count == 0) {
DPRINTF(Drain, "All %u objects drained..\n", drainableCount());
exitSimLoop("Finished drain", 0);
}
}
void
DrainManager::registerDrainable(Drainable *obj)
{
std::lock_guard<std::mutex> lock(globalLock);
assert(std::find(_allDrainable.begin(), _allDrainable.end(), obj) ==
_allDrainable.end());
_allDrainable.push_back(obj);
}
void
DrainManager::unregisterDrainable(Drainable *obj)
{
std::lock_guard<std::mutex> lock(globalLock);
auto o = std::find(_allDrainable.begin(), _allDrainable.end(), obj);
assert(o != _allDrainable.end());
_allDrainable.erase(o);
}
bool
DrainManager::allInState(DrainState state) const
{
for (const auto *obj : _allDrainable) {
if (obj->drainState() != state)
return false;
}
return true;
}
size_t
DrainManager::drainableCount() const
{
std::lock_guard<std::mutex> lock(globalLock);
return _allDrainable.size();
}
Drainable::Drainable()
: _drainManager(DrainManager::instance()),
_drainState(_drainManager.state())
{
_drainManager.registerDrainable(this);
}
Drainable::~Drainable()
{
_drainManager.unregisterDrainable(this);
}
DrainState
Drainable::dmDrain()
{
_drainState = DrainState::Draining;
_drainState = drain();
assert(_drainState == DrainState::Draining ||
_drainState == DrainState::Drained);
return _drainState;
}
void
Drainable::dmDrainResume()
{
panic_if(_drainState != DrainState::Drained &&
_drainState != DrainState::Resuming,
"Trying to resume an object that hasn't been drained\n");
_drainState = DrainState::Running;
drainResume();
}
} // namespace gem5