#include <mem_checker.hh>

Inheritance diagram for 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. More...

typedef std::list< Transaction >	TransactionList

typedef std::list< WriteCluster >	WriteClusterList

Public Types inherited from 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. More...

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

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

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

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

void	reset ()
	Resets the entire checker. More...

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

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. More...

Public Member Functions inherited from SimObject
const Params *	params () const

	SimObject (const Params *_params)

virtual	~SimObject ()

virtual const std::string	name () const

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

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

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

virtual void	regStats ()
	Register statistics for this object. More...

virtual void	resetStats ()
	Reset statistics associated with this object. More...

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

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

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

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

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

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

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

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

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

Public Member Functions inherited from EventManager
	EventManager (EventManager &em)

	EventManager (EventManager *em)

	EventManager (EventQueue *eq)

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)

void	setCurTick (Tick newVal)

Public Member Functions inherited from Serializable
	Serializable ()

virtual	~Serializable ()

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

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

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

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

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

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

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

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

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

static const uint8_t	DATA_INITIAL = 0x00
	Initial data value. More...

Static Public Attributes inherited from Serializable
static int	ckptCount = 0

static int	ckptMaxCount = 0

static int	ckptPrevCount = -1

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

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

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

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

Additional Inherited Members
Static Public Member Functions inherited from SimObject
static void	serializeAll (CheckpointOut &cp)
	Serialize all SimObjects in the system. More...

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

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

static void	serializeAll (const std::string &cpt_dir)

static void	unserializeGlobals (CheckpointIn &cp)

Protected Member Functions inherited from Drainable
	Drainable ()

virtual	~Drainable ()

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

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

Protected Attributes inherited from SimObject
const SimObjectParams *	_params
	Cached copy of the object parameters. More...

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

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 72 of file mem_checker.hh.

Member Typedef Documentation

typedef uint64_t 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 80 of file mem_checker.hh.

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

Definition at line 195 of file mem_checker.hh.

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

Definition at line 196 of file mem_checker.hh.

Constructor & Destructor Documentation

MemChecker::MemChecker ( const MemCheckerParams * p )

inline

Definition at line 375 of file mem_checker.hh.

virtual MemChecker::~MemChecker ( )

inlinevirtual

Definition at line 380 of file mem_checker.hh.

Member Function Documentation

void 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 558 of file mem_checker.hh.

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

Referenced by MemCheckerMonitor::recvTimingResp().

bool 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 298 of file mem_checker.cc.

References MemChecker::ByteTracker::completeRead(), csprintf(), DPRINTF, errorMessage, getByteTracker(), ArmISA::i, ArmISA::j, MemChecker::ByteTracker::lastExpectedData(), and X86ISA::size().

Referenced by MemCheckerMonitor::recvTimingResp().

void 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 545 of file mem_checker.hh.

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

Referenced by MemCheckerMonitor::recvTimingResp().

ByteTracker* MemChecker::getByteTracker ( Addr addr )

inlineprivate

Returns the instance of ByteTracker for the requested location.

Definition at line 480 of file mem_checker.hh.

References byte_trackers.

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

const std::string& 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 474 of file mem_checker.hh.

References errorMessage.

Referenced by MemCheckerMonitor::recvTimingResp().

void 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 452 of file mem_checker.hh.

References byte_trackers.

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

void 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 343 of file mem_checker.cc.

References byte_trackers, ArmISA::i, and X86ISA::size().

MemChecker::Serial 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 517 of file mem_checker.hh.

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

Referenced by MemCheckerMonitor::recvTimingReq().

MemChecker::Serial 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 531 of file mem_checker.hh.

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

Referenced by MemCheckerMonitor::recvTimingReq().

Member Data Documentation

std::unordered_map<Addr, ByteTracker> 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 513 of file mem_checker.hh.

Referenced by getByteTracker(), and reset().

const uint8_t MemChecker::DATA_INITIAL = 0x00

static

Initial data value.

No requirements.

Definition at line 99 of file mem_checker.hh.

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

std::string MemChecker::errorMessage

private

Detailed error message of the last violation in completeRead.