Implements a Persistent FastCheckpointer, i.e. implements an interface to save checkpoints to disk. More...

#include <PersistentFastCheckpointer.hpp>

Inheritance diagram for sparta::serialization::checkpoint::PersistentFastCheckpointer:

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Collaboration diagram for sparta::serialization::checkpoint::PersistentFastCheckpointer:

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Classes
class	FileReadAdapter
	file storage adpater for ArchData More...

class	FileWriteAdapter
	file storage adpater for ArchData More...

Construction & Initialization
	PersistentFastCheckpointer (TreeNode &root, sparta::Scheduler *sched=nullptr)
	PersistentFastCheckpointer Constructor.

virtual	~PersistentFastCheckpointer ()
	Destructor.

FastCheckpointer::chkpt_id_t	save (std::ostream &outf)

FastCheckpointer::chkpt_id_t	save (std::string filename)

FastCheckpointer::chkpt_id_t	save ()

void	restore (std::istream &in)

void	restore (const std::string &filename)

Additional Inherited Members
Public Types inherited from sparta::serialization::checkpoint::FastCheckpointer
typedef DeltaCheckpoint< storage::VectorStorage >	checkpoint_type

Public Types inherited from sparta::serialization::checkpoint::Checkpointer
typedef Checkpoint::tick_t	tick_t
	tick_t Tick type to which checkpoints will refer

typedef Checkpoint::chkpt_id_t	chkpt_id_t
	tick_t Tick type to which checkpoints will refer

Public Member Functions inherited from sparta::serialization::checkpoint::FastCheckpointer
	FastCheckpointer (TreeNode &root, Scheduler *sched=nullptr)
	FastCheckpointer Constructor.

	~FastCheckpointer ()
	Destructor.

uint32_t	getSnapshotThreshold () const noexcept
	Returns the next-shapshot threshold.

void	setSnapshotThreshold (uint32_t thresh) noexcept
	Sets the snapshot threshold.

void	deleteCheckpoint (chkpt_id_t id) override
	Deletes a checkpoint by ID.

void	loadCheckpoint (chkpt_id_t id) override
	Loads state from a specific checkpoint by ID.

bool	checkpointExists (chkpt_id_t id)
	Queries a specific checkpoint by ID.

std::vector< chkpt_id_t >	getCheckpointsAt (tick_t t) const override
	Gets all checkpoints taken at tick t on any timeline.

std::vector< chkpt_id_t >	getCheckpoints () const override
	Gets all checkpoint IDs available on any timeline sorted by tick (or equivalently checkpoint ID).

uint32_t	getNumCheckpoints () const noexcept override
	Gets the current number of checkpoints having valid IDs.

uint32_t	getNumSnapshots () const noexcept
	Gets the current number of snapshots with valid IDs.

uint32_t	getNumDeltas () const noexcept
	Gets the current number of delta checkpoints with valid IDs.

uint32_t	getNumDeadCheckpoints () const noexcept
	Gets the curent number of checkpoints (delta or snapshot) withOUT valid IDs.

std::deque< chkpt_id_t >	getCheckpointChain (chkpt_id_t id) const override
	Debugging utility which gets a deque of checkpoints representing a chain starting at the checkpoint head and ending at the checkpoint specified by id. Ths results can contain checkpoint_type::UNIDENTIFIED_CHECKPOINT to represent temporary deleted checkpoints in the chain.

checkpoint_type *	findLatestCheckpointAtOrBefore (tick_t tick, chkpt_id_t from) override
	Finds the latest checkpoint at or before the given tick starting at the from checkpoint and working backward. If no checkpoints before or at tick are found, returns nullptr.

checkpoint_type *	findInternalCheckpoint (chkpt_id_t id)
	Gets a checkpoint through findCheckpoint interface casted to the type of Checkpoint subclass used by this class.

std::string	stringize () const override
	Returns a string describing this object.

void	traceValue (std::ostream &o, chkpt_id_t id, const ArchData *container, uint32_t offset, uint32_t size) override
	Forwards debug/trace info onto checkpoint by ID.

Public Member Functions inherited from sparta::serialization::checkpoint::Checkpointer
	Checkpointer (TreeNode &root, sparta::Scheduler *sched=nullptr)
	Checkpointer Constructor.

virtual	~Checkpointer ()
	Destructor.

const TreeNode &	getRoot () const noexcept
	Returns the root associated with this checkpointer.

TreeNode &	getRoot () noexcept
	Non-const variant of getRoot.

const Scheduler *	getScheduler () const noexcept
	Returns the sheduler associated with this checkpointer.

uint64_t	getTotalMemoryUse () const noexcept
	Computes and returns the memory usage by this checkpointer at this moment including any framework overhead.

uint64_t	getContentMemoryUse () const noexcept
	Computes and returns the memory usage by this checkpointer at this moment purely for the checkpoint state being held.

uint64_t	getTotalCheckpointsCreated () const noexcept
	Returns the total number of checkpoints which have been created by this checkpointer. This is unrelated to the current number of checkpoints in existance. Includes the head checkpoint if created.

void	createHead ()
	Creates a head without taking an identified checkpoint. Cannot already have a head.

chkpt_id_t	createCheckpoint (bool force_snapshot=false)
	Creates a checkpoint at the given scheduler's current tick with a new checkpoint ID some point after the current checkpoint (see getCurrentID). If the current checkpoint already has other next checkpoints, the new checkpoint will be an alternate branch of the current checkpoint. This snapshot may be stored as a full snapshot if the checkpointer requires it, or if the snapshot threshold is exceeded, or if the force_snapshot argument is true Current tick will be read from scheduler (if not null) and must be >= the head checkpoint's tick. The current tick must also be >= the current checkpoints tick (See getCurrenTick).

void	forgetCurrent ()
	Forgets the current checkpoint and current checkpoint (resetting to the head checkpoint) so that checkpoints can be taken at a different time without assuming simulation state continutiy with this checkpointers. This is ONLY to be used by a simulator IFF another checkpointer restores state at another cycle or the simulator resets but this checkpointer's tree is still expected to exist.

Checkpoint *	findCheckpoint (chkpt_id_t id) noexcept
	Finds a checkpoint by its ID.

virtual bool	hasCheckpoint (chkpt_id_t id) const noexcept
	Tests whether this checkpoint manager has a checkpoint with the given id.

const Checkpoint *	getHead () const noexcept
	Returns the head checkpoint which is equivalent to the earliest checkpoint taken.

chkpt_id_t	getHeadID () const noexcept
	Returns the checkpoint ID of the head checkpoint (if it exists) which is equivalent to the earliest checkpoint taken.

chkpt_id_t	getCurrentID () const
	Returns the current checkpoint ID. This is mainly a debugging utility as the current ID changes when adding, deleting, and loading checkpoints based on whether the checkpoints take were deltas or snapshots. A correct integration of the checkpointer by a simulator should not depend on this method for behavior decisions.

tick_t	getCurrentTick () const
	Gets the tick number of the current checkpoint (see getCurrentID). This is the tick number of the latest checkpoint either saved or written through this checkpointer. The next checkpoint taken will be on the same chain as a checkpoint taken at this tick.

void	dumpList (std::ostream &o) const
	Dumps this checkpointer's flat list of checkpoints to an ostream with a newline following each checkpoint.

void	dumpData (std::ostream &o) const
	Dumps this checkpointer's data to an ostream with a newline following each checkpoint.

void	dumpAnnotatedData (std::ostream &o) const
	Dumps this checkpointer's data to an ostream with annotations between each ArchData and a newline following each checkpoint description and each checkpoint data dump.

void	dumpTree (std::ostream &o) const
	Dumps this checkpointer's tree to an ostream with a line for each branch. Printout timescale is not relevant. Multi-line printouts for deep branches will be difficult to read.

void	dumpBranch (std::ostream &o, const Checkpoint *chkpt, uint32_t indent, uint32_t pos, std::deque< uint32_t > &continues) const
	Recursively dumps one branch (and sub-branches) to an ostream with a line for each branch.

Protected Member Functions inherited from sparta::serialization::checkpoint::FastCheckpointer
void	cleanupChain_ (checkpoint_type *d)
	Delete given checkpoint and all contiguous previous checkpoints which can be deleted (See checkpoint_type::canDelete). This is the only place where checkpoint objects are actually freed (aside from destruction) and it ensures that they will not disrupt the checkpoint delta chains. All other deletion is simply flagging and re-identifying checkpoints.

bool	recursForwardFindAlive_ (checkpoint_type *d) const
	Look forward to see if any future checkpoints depend on d.

checkpoint_type *	findCheckpoint_ (chkpt_id_t id) noexcept override
	Attempts to find a checkpoint within this checkpointer by ID.

const checkpoint_type *	findCheckpoint_ (chkpt_id_t id) const noexcept override
	const variant of findCheckpoint_

void	dumpCheckpointNode_ (const Checkpoint *chkpt, std::ostream &o) const override
	Implements Checkpointer::dumpCheckpointNode_.

Protected Member Functions inherited from sparta::serialization::checkpoint::Checkpointer
const std::vector< ArchData * > &	getArchDatas () const
	Returns ArchDatas enumerated by this Checkpointer for iteration when saving or loading checkpoint data.

Checkpoint *	getHead_ () noexcept
	Non-const variant of getHead_.

const Checkpoint *	getHead_ () const noexcept
	Gets the head checkpoint. Returns nullptr if none created yet.

void	setHead_ (Checkpoint *head)
	Sets the head checkpointer pointer to head for the first time.

Checkpoint *	getCurrent_ () const noexcept
	Gets the current checkpointer pointer. Returns nullptr if there is no current checkpoint object.

void	setCurrent_ (Checkpoint *current)
	Sets the current checkpoint pointer.

Protected Attributes inherited from sparta::serialization::checkpoint::Checkpointer
std::map< chkpt_id_t, std::unique_ptr< Checkpoint > >	chkpts_
	All checkpoints sorted by ascending tick number (or equivalently ascending checkpoint ID since both are monotonically increasing)

Scheduler *const	sched_
	Scheduler whose tick count will be set and read. Cannnot be updated after first checkpoint without bad side effects. Keeping this const for simplicity.

Detailed Description

Implements a Persistent FastCheckpointer, i.e. implements an interface to save checkpoints to disk.

Used in conjunction with the fast checkpointer (which saves checkpoints to memory), this class enables user the save the checkpoints to disk for loading later.

Definition at line 27 of file PersistentFastCheckpointer.hpp.

Constructor & Destructor Documentation

◆ PersistentFastCheckpointer()

sparta::serialization::checkpoint::PersistentFastCheckpointer::PersistentFastCheckpointer	(	TreeNode &	root,
		sparta::Scheduler *	sched = `nullptr`
	)

inline

PersistentFastCheckpointer Constructor.

Parameters

root	TreeNode at which checkpoints will be taken. This cannot be changed later. This does not necessarily need to be a RootTreeNode. Before the first checkpoint is taken, this node must be finalized (see sparta::TreeNode::isFinalized). At this point, the node does not need to be finalized
sched	Scheduler whose current cycle will be read when taking checkpoints and restored when restoring checkpoints. See sparta::serialization::Checkpoint::Checkpoint for details

Definition at line 149 of file PersistentFastCheckpointer.hpp.