#include <mem_checker.hh>

Inheritance diagram for gem5::MemChecker:

Classes
class	ByteTracker
	The ByteTracker keeps track of transactions for the same byte – all outstanding reads, the completed reads (and what they observed) and write clusters (see WriteCluster). More...

class	Transaction
	The Transaction class captures the lifetimes of read and write operations, and the values they consumed or produced respectively. More...

class	WriteCluster
	The WriteCluster class captures sets of writes where all writes are overlapping with at least one other write. More...

Public Types
typedef uint64_t	Serial
	The Serial type is used to be able to uniquely identify a transaction as it passes through the system.

typedef std::list< Transaction >	TransactionList

typedef std::list< WriteCluster >	WriteClusterList

Public Types inherited from gem5::SimObject
typedef SimObjectParams	Params

Public Member Functions
	MemChecker (const MemCheckerParams &p)

virtual	~MemChecker ()

Serial	startRead (Tick start, Addr addr, size_t size)
	Starts a read transaction.

Serial	startWrite (Tick start, Addr addr, size_t size, const uint8_t *data)
	Starts a write transaction.

bool	completeRead (Serial serial, Tick complete, Addr addr, size_t size, uint8_t *data)
	Completes a previously started read transaction.

void	completeWrite (Serial serial, Tick complete, Addr addr, size_t size)
	Completes a previously started write transaction.

void	abortWrite (Serial serial, Addr addr, size_t size)
	Aborts a previously started write transaction.

void	reset ()
	Resets the entire checker.

void	reset (Addr addr, size_t size)
	Resets an address-range.

const std::string &	getErrorMessage () const
	In completeRead, if an error is encountered, this does not print nor cause an error, but instead should be handled by the caller.

Public Member Functions inherited from gem5::SimObject
const Params &	params () const

	SimObject (const Params &p)

virtual	~SimObject ()

virtual void	init ()
	init() is called after all C++ SimObjects have been created and all ports are connected.

virtual void	loadState (CheckpointIn &cp)
	loadState() is called on each SimObject when restoring from a checkpoint.

virtual void	initState ()
	initState() is called on each SimObject when not restoring from a checkpoint.

virtual void	regProbePoints ()
	Register probe points for this object.

virtual void	regProbeListeners ()
	Register probe listeners for this object.

ProbeManager *	getProbeManager ()
	Get the probe manager for this object.

virtual Port &	getPort (const std::string &if_name, PortID idx=InvalidPortID)
	Get a port with a given name and index.

virtual void	startup ()
	startup() is the final initialization call before simulation.

DrainState	drain () override
	Provide a default implementation of the drain interface for objects that don't need draining.

virtual void	memWriteback ()
	Write back dirty buffers to memory using functional writes.

virtual void	memInvalidate ()
	Invalidate the contents of memory buffers.

void	serialize (CheckpointOut &cp) const override
	Serialize an object.

void	unserialize (CheckpointIn &cp) override
	Unserialize an object.

Public Member Functions inherited from gem5::EventManager
EventQueue *	eventQueue () const

void	schedule (Event &event, Tick when)

void	deschedule (Event &event)

void	reschedule (Event &event, Tick when, bool always=false)

void	schedule (Event *event, Tick when)

void	deschedule (Event *event)

void	reschedule (Event *event, Tick when, bool always=false)

void	wakeupEventQueue (Tick when=(Tick) -1)
	This function is not needed by the usual gem5 event loop but may be necessary in derived EventQueues which host gem5 on other schedulers.

void	setCurTick (Tick newVal)

	EventManager (EventManager &em)
	Event manger manages events in the event queue.

	EventManager (EventManager *em)

	EventManager (EventQueue *eq)

Public Member Functions inherited from gem5::Serializable
	Serializable ()

virtual	~Serializable ()

void	serializeSection (CheckpointOut &cp, const char *name) const
	Serialize an object into a new section.

void	serializeSection (CheckpointOut &cp, const std::string &name) const

void	unserializeSection (CheckpointIn &cp, const char *name)
	Unserialize an a child object.

void	unserializeSection (CheckpointIn &cp, const std::string &name)

Public Member Functions inherited from gem5::Drainable
DrainState	drainState () const
	Return the current drain state of an object.

virtual void	notifyFork ()
	Notify a child process of a fork.

Public Member Functions inherited from gem5::statistics::Group
	Group (Group parent, const char name=nullptr)
	Construct a new statistics group.

virtual	~Group ()

virtual void	regStats ()
	Callback to set stat parameters.

virtual void	resetStats ()
	Callback to reset stats.

virtual void	preDumpStats ()
	Callback before stats are dumped.

void	addStat (statistics::Info *info)
	Register a stat with this group.

const std::map< std::string, Group * > &	getStatGroups () const
	Get all child groups associated with this object.

const std::vector< Info * > &	getStats () const
	Get all stats associated with this object.

void	addStatGroup (const char name, Group block)
	Add a stat block as a child of this block.

const Info *	resolveStat (std::string name) const
	Resolve a stat by its name within this group.

void	mergeStatGroup (Group *block)
	Merge the contents (stats & children) of a block to this block.

	Group ()=delete

	Group (const Group &)=delete

Group &	operator= (const Group &)=delete

Public Member Functions inherited from gem5::Named
	Named (const std::string &name_)

virtual	~Named ()=default

virtual std::string	name () const

Static Public Attributes
static const Serial	SERIAL_INITIAL = 0
	Initial serial.

static const Tick	TICK_INITIAL = 0
	The initial tick the system starts with.

static const Tick	TICK_FUTURE = MaxTick
	The maximum value that curTick() could ever return.

static const uint8_t	DATA_INITIAL = 0x00
	Initial data value.

Private Member Functions
ByteTracker *	getByteTracker (Addr addr)
	Returns the instance of ByteTracker for the requested location.

Private Attributes
std::string	errorMessage
	Detailed error message of the last violation in completeRead.

Serial	nextSerial
	Next distinct serial to be assigned to the next transaction to be started.

std::unordered_map< Addr, ByteTracker >	byte_trackers
	Maintain a map of address --> byte-tracker.

Additional Inherited Members
Static Public Member Functions inherited from gem5::SimObject
static void	serializeAll (const std::string &cpt_dir)
	Create a checkpoint by serializing all SimObjects in the system.

static SimObject *	find (const char *name)
	Find the SimObject with the given name and return a pointer to it.

static void	setSimObjectResolver (SimObjectResolver *resolver)
	There is a single object name resolver, and it is only set when simulation is restoring from checkpoints.

static SimObjectResolver *	getSimObjectResolver ()
	There is a single object name resolver, and it is only set when simulation is restoring from checkpoints.

Static Public Member Functions inherited from gem5::Serializable
static const std::string &	currentSection ()
	Gets the fully-qualified name of the active section.

static void	generateCheckpointOut (const std::string &cpt_dir, std::ofstream &outstream)
	Generate a checkpoint file so that the serialization can be routed to it.

Protected Member Functions inherited from gem5::Drainable
	Drainable ()

virtual	~Drainable ()

virtual void	drainResume ()
	Resume execution after a successful drain.

void	signalDrainDone () const
	Signal that an object is drained.

Protected Attributes inherited from gem5::SimObject
const SimObjectParams &	_params
	Cached copy of the object parameters.

Protected Attributes inherited from gem5::EventManager
EventQueue *	eventq
	A pointer to this object's event queue.

Detailed Description

MemChecker.

Verifies that reads observe the values from permissible writes. As memory operations have a start and completion time, we consider them as transactions which have a start and end time. Because of this, the lifetimes of transactions of memory operations may be overlapping – we assume that if there is overlap between writes, they could be reordered by the memory subsystem, and a read could any of these. For more detail, see comments of inExpectedData().

For simplicity, the permissible values a read can observe are only dependent on the particular location, and we do not consider the effect of multi-byte reads or writes. This precludes us from discovering single-copy atomicity violations.

Definition at line 74 of file mem_checker.hh.

Member Typedef Documentation

◆ Serial

typedef uint64_t gem5::MemChecker::Serial

The Serial type is used to be able to uniquely identify a transaction as it passes through the system.

It's value is independent of any other system counters.

Definition at line 82 of file mem_checker.hh.

◆ TransactionList

typedef std::list<Transaction> gem5::MemChecker::TransactionList

Definition at line 197 of file mem_checker.hh.

◆ WriteClusterList

typedef std::list<WriteCluster> gem5::MemChecker::WriteClusterList

Definition at line 198 of file mem_checker.hh.

Constructor & Destructor Documentation

◆ MemChecker()

gem5::MemChecker::MemChecker ( const MemCheckerParams & p )

inline

Definition at line 377 of file mem_checker.hh.

◆ ~MemChecker()

virtual gem5::MemChecker::~MemChecker ( )

inlinevirtual

Definition at line 382 of file mem_checker.hh.

Member Function Documentation

◆ abortWrite()

void gem5::MemChecker::abortWrite	(	MemChecker::Serial	serial,
		Addr	addr,
		size_t	size )

inline

Aborts a previously started write transaction.

Parameters

serial	A serial of a write that was previously started and matches the address of the previously started write.
addr	Address for write.
size	The size of the data written.

Definition at line 560 of file mem_checker.hh.

References gem5::MemChecker::ByteTracker::abortWrite(), gem5::X86ISA::addr, DPRINTF, getByteTracker(), and gem5::ArmISA::i.

Referenced by gem5::MemCheckerMonitor::recvTimingResp().

◆ completeRead()

bool gem5::MemChecker::completeRead	(	MemChecker::Serial	serial,
		Tick	complete,
		Addr	addr,
		size_t	size,
		uint8_t *	data )

Completes a previously started read transaction.

Parameters

serial	A serial of a read that was previously started and matches the address of the previously started read.
complete	Tick we received the response from the memory subsystem.
addr	Address for read.
size	Size of data received.
data	Pointer to size bytes, containing data received.

Returns: True if the data we received is in the expected set, false otherwise.

Definition at line 302 of file mem_checker.cc.

References gem5::X86ISA::addr, gem5::MemChecker::ByteTracker::completeRead(), gem5::csprintf(), data, DPRINTF, errorMessage, getByteTracker(), gem5::ArmISA::i, and gem5::MemChecker::ByteTracker::lastExpectedData().

Referenced by gem5::MemCheckerMonitor::recvTimingResp().

◆ completeWrite()

void gem5::MemChecker::completeWrite	(	MemChecker::Serial	serial,
		Tick	complete,
		Addr	addr,
		size_t	size )

inline

Completes a previously started write transaction.

Parameters

serial	A serial of a write that was previously started and matches the address of the previously started write.
complete	Tick we received acknowledgment of completion from the memory subsystem.
addr	Address for write.
size	The size of the data written.

Definition at line 547 of file mem_checker.hh.

References gem5::X86ISA::addr, gem5::MemChecker::ByteTracker::completeWrite(), DPRINTF, getByteTracker(), and gem5::ArmISA::i.

Referenced by gem5::MemCheckerMonitor::recvTimingResp().

◆ getByteTracker()

ByteTracker * gem5::MemChecker::getByteTracker ( Addr addr )

inlineprivate

Returns the instance of ByteTracker for the requested location.

Definition at line 482 of file mem_checker.hh.

References gem5::X86ISA::addr, and byte_trackers.

Referenced by abortWrite(), completeRead(), completeWrite(), startRead(), and startWrite().

◆ getErrorMessage()

const std::string & gem5::MemChecker::getErrorMessage ( ) const

inline

In completeRead, if an error is encountered, this does not print nor cause an error, but instead should be handled by the caller.

However, to record information about the cause of an error, completeRead creates an errorMessage. This function returns the last error that was detected in completeRead.

Returns: Reference to string of error message.

Definition at line 476 of file mem_checker.hh.

References errorMessage.

Referenced by gem5::MemCheckerMonitor::recvTimingResp().

◆ reset() [1/2]

void gem5::MemChecker::reset ( )

inline

Resets the entire checker.

Note that if there are transactions in-flight, this will cause a warning to be issued if these are completed after the reset. This does not reset nextSerial to avoid such a race condition: where a transaction started before a reset with serial S, then reset() was called, followed by a start of a transaction with the same serial S and then receive a completion of the transaction before the reset with serial S.

Definition at line 454 of file mem_checker.hh.

References byte_trackers.

Referenced by gem5::MemCheckerMonitor::recvFunctional(), and gem5::MemCheckerMonitor::recvFunctionalSnoop().

◆ reset() [2/2]

void gem5::MemChecker::reset	(	Addr	addr,
		size_t	size )

Resets an address-range.

This may be useful in case other unmonitored parts of the system caused modification to this memory, but we cannot track their written values.

Parameters

addr	Address base.
size	Size of range to be invalidated.

Definition at line 347 of file mem_checker.cc.

References gem5::X86ISA::addr, byte_trackers, and gem5::ArmISA::i.

◆ startRead()

MemChecker::Serial gem5::MemChecker::startRead	(	Tick	start,
		Addr	addr,
		size_t	size )

inline

Starts a read transaction.

Parameters

start	Tick this read was sent to the memory subsystem.
addr	Address for read.
size	Size of data expected.

Returns: Serial representing the unique identifier for this transaction.

Definition at line 519 of file mem_checker.hh.

References gem5::X86ISA::addr, DPRINTF, getByteTracker(), gem5::ArmISA::i, nextSerial, and gem5::MemChecker::ByteTracker::startRead().

Referenced by gem5::MemCheckerMonitor::recvTimingReq().

◆ startWrite()

MemChecker::Serial gem5::MemChecker::startWrite	(	Tick	start,
		Addr	addr,
		size_t	size,
		const uint8_t *	data )

inline

Starts a write transaction.

Parameters

start	Tick when this write was sent to the memory subsystem.
addr	Address for write.
size	Size of data to be written.
data	Pointer to size bytes, containing data to be written.

Returns: Serial representing the unique identifier for this transaction.

Definition at line 533 of file mem_checker.hh.

References gem5::X86ISA::addr, data, DPRINTF, getByteTracker(), gem5::ArmISA::i, nextSerial, and gem5::MemChecker::ByteTracker::startWrite().

Referenced by gem5::MemCheckerMonitor::recvTimingReq().

Member Data Documentation

◆ byte_trackers

std::unordered_map<Addr, ByteTracker> gem5::MemChecker::byte_trackers

private

Maintain a map of address --> byte-tracker.

Per-byte entries are initialized as needed.

The required space for this obviously grows with the number of distinct addresses used for a particular workload. The used size is independent on the number of nodes in the system, those may affect the size of per-byte tracking information.

Access via getByteTracker()!

Definition at line 515 of file mem_checker.hh.

Referenced by getByteTracker(), reset(), and reset().

◆ DATA_INITIAL

const uint8_t gem5::MemChecker::DATA_INITIAL = 0x00

static

Initial data value.

No requirements.

Definition at line 101 of file mem_checker.hh.

Referenced by gem5::MemChecker::ByteTracker::ByteTracker().

◆ errorMessage

std::string gem5::MemChecker::errorMessage

private

Detailed error message of the last violation in completeRead.

Definition at line 496 of file mem_checker.hh.

Referenced by completeRead(), and getErrorMessage().

◆ nextSerial

Serial gem5::MemChecker::nextSerial

private

Next distinct serial to be assigned to the next transaction to be started.

Definition at line 502 of file mem_checker.hh.

Referenced by startRead(), and startWrite().

◆ SERIAL_INITIAL

const Serial gem5::MemChecker::SERIAL_INITIAL = 0

static

Initial serial.

Definition at line 84 of file mem_checker.hh.

Referenced by gem5::MemChecker::ByteTracker::ByteTracker().

◆ TICK_FUTURE

const Tick gem5::MemChecker::TICK_FUTURE = MaxTick

static

The maximum value that curTick() could ever return.

Definition at line 96 of file mem_checker.hh.

Referenced by gem5::MemChecker::WriteCluster::completeWrite(), gem5::MemChecker::WriteCluster::isComplete(), gem5::MemChecker::ByteTracker::startRead(), and gem5::MemChecker::WriteCluster::startWrite().

◆ TICK_INITIAL

const Tick gem5::MemChecker::TICK_INITIAL = 0

static

The initial tick the system starts with.

Must not be larger than the minimum value that curTick() could return at any time in the system's execution.

Definition at line 91 of file mem_checker.hh.

Referenced by gem5::MemChecker::ByteTracker::ByteTracker(), and gem5::MemChecker::ByteTracker::inExpectedData().

The documentation for this class was generated from the following files:

mem/mem_checker.hh
mem/mem_checker.cc

Classes

Public Types

Public Member Functions

Static Public Attributes

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ Serial

◆ TransactionList

◆ WriteClusterList

Constructor & Destructor Documentation

◆ MemChecker()

◆ ~MemChecker()

Member Function Documentation

◆ abortWrite()

◆ completeRead()

◆ completeWrite()

◆ getByteTracker()

◆ getErrorMessage()

◆ reset() [1/2]

◆ reset() [2/2]

◆ startRead()

◆ startWrite()

Member Data Documentation

◆ byte_trackers

◆ DATA_INITIAL

◆ errorMessage

◆ nextSerial

◆ SERIAL_INITIAL

◆ TICK_FUTURE

◆ TICK_INITIAL