This class coordinates draining of a System. More...

#include <drain.hh>

Public Member Functions
bool	tryDrain ()
	Try to drain the system. More...

void	resume ()
	Resume normal simulation in a Drained system. More...

void	preCheckpointRestore ()
	Run state fixups before a checkpoint restore operation. More...

bool	isDrained () const
	Check if the system is drained. More...

DrainState	state () const
	Get the simulators global drain state. More...

void	signalDrainDone ()
	Notify the DrainManager that a Drainable object has finished draining. More...

void	registerDrainable (Drainable *obj)

void	unregisterDrainable (Drainable *obj)

Static Public Member Functions
static DrainManager &	instance ()
	Get the singleton DrainManager instance. More...

Private Member Functions
	DrainManager ()

	DrainManager (DrainManager &)=delete

	~DrainManager ()

bool	allInState (DrainState state) const
	Helper function to check if all Drainable objects are in a specific state. More...

size_t	drainableCount () const
	Thread-safe helper function to get the number of Drainable objects in a system. More...

Private Attributes
std::mutex	globalLock
	Lock protecting the set of drainable objects. More...

std::vector< Drainable * >	_allDrainable
	Set of all drainable objects. More...

std::atomic_uint	_count
	Number of objects still draining. More...

DrainState	_state
	Global simulator drain state. More...

Static Private Attributes
static DrainManager	_instance
	Singleton instance of the drain manager. More...

Detailed Description

This class coordinates draining of a System.

When draining the simulator, we need to make sure that all Drainable objects within the system have ended up in the drained state before declaring the operation to be successful. This class keeps track of how many objects are still in the process of draining. Once it determines that all objects have drained their state, it exits the simulation loop.

Note: A System might not be completely drained even though the DrainManager has caused the simulation loop to exit. Draining needs to be restarted until all Drainable objects declare that they don't need further simulation to be completely drained. See Drainable for more information.

Definition at line 94 of file drain.hh.

Constructor & Destructor Documentation

DrainManager::DrainManager ( )

private

Definition at line 52 of file drain.cc.

References Running.

DrainManager::DrainManager ( DrainManager & )

privatedelete

DrainManager::~DrainManager ( )

private

Definition at line 58 of file drain.cc.

Member Function Documentation

bool DrainManager::allInState ( DrainState state ) const

private

Helper function to check if all Drainable objects are in a specific state.

Definition at line 177 of file drain.cc.

References _allDrainable, and state().

Referenced by resume().

size_t DrainManager::drainableCount ( ) const

private

Thread-safe helper function to get the number of Drainable objects in a system.

Definition at line 188 of file drain.cc.

References _allDrainable, globalLock, and X86ISA::lock.

Referenced by preCheckpointRestore(), resume(), signalDrainDone(), and tryDrain().

static DrainManager& DrainManager::instance ( )

inlinestatic

Get the singleton DrainManager instance.

Definition at line 103 of file drain.hh.

References _instance.

Referenced by CxxConfigManager::drain(), CxxConfigManager::drainResume(), and init_drain().

bool DrainManager::isDrained ( ) const

inline

Check if the system is drained.

Definition at line 140 of file drain.hh.

References _state, and Drained.

Referenced by init_drain().

void DrainManager::preCheckpointRestore ( )

Run state fixups before a checkpoint restore operation.

The drain state of an object isn't stored in a checkpoint since the whole system is always going to be in the Drained state when the checkpoint is created. When the checkpoint is restored at a later stage, recreated objects will be in the Running state since the state isn't stored in checkpoints. This method performs state fixups on all Drainable objects and the DrainManager itself.

Definition at line 134 of file drain.cc.

References _allDrainable, _state, DPRINTF, drainableCount(), Drained, panic_if(), and Running.

Referenced by init_drain().

void DrainManager::registerDrainable ( Drainable * obj )

Definition at line 159 of file drain.cc.

References _allDrainable, globalLock, and X86ISA::lock.

Referenced by Drainable::Drainable().

void DrainManager::resume ( )

Resume normal simulation in a Drained system.

Definition at line 95 of file drain.cc.

References _allDrainable, _count, _state, allInState(), DPRINTF, drainableCount(), Drained, Draining, panic_if(), Resuming, Running, and warn_if.

Referenced by CxxConfigManager::drainResume(), and init_drain().

void DrainManager::signalDrainDone ( )

Notify the DrainManager that a Drainable object has finished draining.

Definition at line 148 of file drain.cc.

References _count, DPRINTF, drainableCount(), and exitSimLoop().

Referenced by init_drain(), and Drainable::signalDrainDone().

DrainState DrainManager::state ( ) const

inline

Get the simulators global drain state.

Definition at line 143 of file drain.hh.

References _state.

Referenced by allInState(), and init_drain().

bool DrainManager::tryDrain ( )

Try to drain the system.

Try to drain the system and return true if all objects are in a the Drained state at which point the whole simulator is in a consistent state and ready for checkpointing or CPU handover. The simulation script must continue simulating until the simulation loop returns "Finished drain", at which point this method should be called again. This cycle should continue until this method returns true.