Specialization for accessing a copy-on-write disk image layer. More...

#include <disk_image.hh>

Inheritance diagram for CowDiskImage:

Classes
struct	Sector

Public Types
typedef CowDiskImageParams	Params

Public Types inherited from DiskImage
typedef DiskImageParams	Params

Public Types inherited from SimObject
typedef SimObjectParams	Params

Public Member Functions
	CowDiskImage (const Params *p)

	~CowDiskImage ()

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

void	initSectorTable (int hash_size)

bool	open (const std::string &file)

void	save () const

void	save (const std::string &file) const

void	writeback ()

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

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

std::streampos	size () const override

std::streampos	read (uint8_t *data, std::streampos offset) const override

std::streampos	write (const uint8_t *data, std::streampos offset) override

Public Member Functions inherited from DiskImage
	DiskImage (const Params *p)

virtual	~DiskImage ()

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...

Static Public Attributes
static const uint32_t	VersionMajor = 1

static const uint32_t	VersionMinor = 0

Static Public Attributes inherited from Serializable
static int	ckptCount = 0

static int	ckptMaxCount = 0

static int	ckptPrevCount = -1

Protected Types
typedef std::unordered_map < uint64_t, Sector * >	SectorTable

Protected Attributes
std::string	filename

DiskImage *	child

SectorTable *	table

Protected Attributes inherited from DiskImage
bool	initialized

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...

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...

Detailed Description

Specialization for accessing a copy-on-write disk image layer.

A copy-on-write(COW) layer must be stacked on top of another disk image layer this layer can be another CowDiskImage, or a RawDiskImage.

This object is designed to provide a mechanism for persistant changes to a main disk image, or to provide a place for temporary changes to the image to take place that later may be thrown away.

Definition at line 106 of file disk_image.hh.

Member Typedef Documentation

typedef CowDiskImageParams CowDiskImage::Params

Definition at line 124 of file disk_image.hh.

typedef std::unordered_map<uint64_t, Sector *> CowDiskImage::SectorTable

protected

Definition at line 116 of file disk_image.hh.

Constructor & Destructor Documentation

CowDiskImage::CowDiskImage ( const Params * p )

Definition at line 183 of file disk_image.cc.

References fatal, filename, initSectorTable(), open(), and registerExitCallback().

CowDiskImage::~CowDiskImage ( )

Definition at line 200 of file disk_image.cc.

References ArmISA::i, and table.

Member Function Documentation

void CowDiskImage::initSectorTable ( int hash_size )

Definition at line 297 of file disk_image.cc.

References DiskImage::initialized, and table.

Referenced by CowDiskImage().

void CowDiskImage::notifyFork ( )

overridevirtual

Notify a child process of a fork.

When calling fork in gem5, we need to ensure that resources shared between the parent and the child are consistent. This method is intended to be overloaded to handle that. For example, an object could use this method to re-open input files to get a separate file description with a private file offset.

This method is only called in the child of the fork. The call takes place in a drained system.

Reimplemented from Drainable.

Definition at line 212 of file disk_image.cc.

References filename, inform, and SimObject::params().

bool CowDiskImage::open ( const std::string & file )

Definition at line 251 of file disk_image.cc.

References ArmISA::i, DiskImage::initialized, ArmISA::offset, panic, SafeRead(), SafeReadSwap(), table, VersionMajor, and VersionMinor.

Referenced by CowDiskImage(), and unserialize().