A TProcessID identifies a ROOT job in a unique way in time and space.

The TProcessID title consists of a TUUID object which provides a globally unique identifier (for more see TUUID.h).

A TProcessID is automatically created by the TROOT constructor. When a TFile contains referenced objects (see TRef), the TProcessID object is written to the file. If a file has been written in multiple sessions (same machine or not), a TProcessID is written for each session. These objects are used by the class TRef to uniquely identified any TObject pointed by a TRef.

When a referenced object is read from a file (its bit kIsReferenced is set), this object is entered into the objects table of the corresponding TProcessID. Each TFile has a list of TProcessIDs (see TFile::fProcessIDs) also accessible via TProcessID::fgPIDs (for all files). When this object is deleted, it is removed from the table via the cleanup mechanism invoked by the TObject destructor.

Each TProcessID has a table (TObjArray *fObjects) that keeps track of all referenced objects. If a referenced object has a fUniqueID set, a pointer to this unique object may be found via fObjects->At(fUniqueID). In the same way, when a TRef::GetObject is called, GetObject uses its own fUniqueID to find the pointer to the referenced object. See TProcessID::GetObjectWithID and PutObjectWithID.

When a referenced object is deleted, its slot in fObjects is set to null.

See also TProcessUUID: a specialized TProcessID to manage the single list of TUUIDs.

Definition at line 74 of file TProcessID.h.

Public Member Functions
	TProcessID ()
	Default constructor.

virtual	~TProcessID ()
	Destructor.

void	CheckInit ()
	Initialize fObjects.

virtual void	Clear (Option_t *option="")
	delete the TObjArray pointing to referenced objects this function is called by TFile::Close("R")

Int_t	DecrementCount ()
	The reference fCount is used to delete the TProcessID in the TFile destructor when fCount = 0.

Int_t	GetCount () const

TObjArray *	GetObjects () const

TObject *	GetObjectWithID (UInt_t uid)
	returns the TObject with unique identifier uid in the table of objects

Int_t	IncrementCount ()
	Increase the reference count to this object.

void	PutObjectWithID (TObject *obj, UInt_t uid=0)
	stores the object at the uid th slot in the table of objects The object uniqued is set as well as its kMustCleanup bit

virtual void	RecursiveRemove (TObject *obj)
	called by the object destructor remove reference to obj from the current table if it is referenced

Public Member Functions inherited from TNamed
	TNamed ()

	TNamed (const char name, const char title)

	TNamed (const TNamed &named)
	TNamed copy ctor.

	TNamed (const TString &name, const TString &title)

virtual	~TNamed ()
	TNamed destructor.

virtual TObject *	Clone (const char *newname="") const
	Make a clone of an object using the Streamer facility.

virtual Int_t	Compare (const TObject *obj) const
	Compare two TNamed objects.

virtual void	Copy (TObject &named) const
	Copy this to obj.

virtual void	FillBuffer (char *&buffer)
	Encode TNamed into output buffer.

virtual const char *	GetName () const
	Returns name of object.

virtual const char *	GetTitle () const
	Returns title of object.

virtual ULong_t	Hash () const
	Return hash value for this object.

virtual Bool_t	IsSortable () const

virtual void	ls (Option_t *option="") const
	List TNamed name and title.

TNamed &	operator= (const TNamed &rhs)
	TNamed assignment operator.

virtual void	Print (Option_t *option="") const
	Print TNamed name and title.

virtual void	SetName (const char *name)
	Set the name of the TNamed.

virtual void	SetNameTitle (const char name, const char title)
	Set all the TNamed parameters (name and title).

virtual void	SetTitle (const char *title="")
	Set the title of the TNamed.

virtual Int_t	Sizeof () const
	Return size of the TNamed part of the TObject.

Public Member Functions inherited from TObject
	TObject ()
	TObject constructor.

	TObject (const TObject &object)
	TObject copy ctor.

virtual	~TObject ()
	TObject destructor.

void	AbstractMethod (const char *method) const
	Use this method to implement an "abstract" method that you don't want to leave purely abstract.

virtual void	AppendPad (Option_t *option="")
	Append graphics object to current pad.

virtual void	Browse (TBrowser *b)
	Browse object. May be overridden for another default action.

ULong_t	CheckedHash ()
	Check and record whether this class has a consistent Hash/RecursiveRemove setup (*) and then return the regular Hash value for this object.

virtual const char *	ClassName () const
	Returns name of class to which the object belongs.

virtual void	Delete (Option_t *option="")
	Delete this object.

virtual Int_t	DistancetoPrimitive (Int_t px, Int_t py)
	Computes distance from point (px,py) to the object.

virtual void	Draw (Option_t *option="")
	Default Draw method for all objects.

virtual void	DrawClass () const
	Draw class inheritance tree of the class to which this object belongs.

virtual TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current selected pad for instance with: `gROOT->SetSelectedPad(gPad)`.

virtual void	Dump () const
	Dump contents of object on stdout.

virtual void	Error (const char method, const char msgfmt,...) const
	Issue error message.

virtual void	Execute (const char method, const char params, Int_t *error=0)
	Execute method on this object with the given parameter string, e.g.

virtual void	Execute (TMethod method, TObjArray params, Int_t *error=0)
	Execute method on this object with parameters stored in the TObjArray.

virtual void	ExecuteEvent (Int_t event, Int_t px, Int_t py)
	Execute action corresponding to an event at (px,py).

virtual void	Fatal (const char method, const char msgfmt,...) const
	Issue fatal error message.

virtual TObject *	FindObject (const char *name) const
	Must be redefined in derived classes.

virtual TObject *	FindObject (const TObject *obj) const
	Must be redefined in derived classes.

virtual Option_t *	GetDrawOption () const
	Get option used by the graphics system to draw this object.

virtual const char *	GetIconName () const
	Returns mime type name of object.

virtual char *	GetObjectInfo (Int_t px, Int_t py) const
	Returns string containing info about the object at position (px,py).

virtual Option_t *	GetOption () const

virtual UInt_t	GetUniqueID () const
	Return the unique object id.

virtual Bool_t	HandleTimer (TTimer *timer)
	Execute action in response of a timer timing out.

Bool_t	HasInconsistentHash () const
	Return true is the type of this object is known to have an inconsistent setup for Hash and RecursiveRemove (i.e.

virtual void	Info (const char method, const char msgfmt,...) const
	Issue info message.

virtual Bool_t	InheritsFrom (const char *classname) const
	Returns kTRUE if object inherits from class "classname".

virtual Bool_t	InheritsFrom (const TClass *cl) const
	Returns kTRUE if object inherits from TClass cl.

virtual void	Inspect () const
	Dump contents of this object in a graphics canvas.

void	InvertBit (UInt_t f)

virtual Bool_t	IsEqual (const TObject *obj) const
	Default equal comparison (objects are equal if they have the same address in memory).

virtual Bool_t	IsFolder () const
	Returns kTRUE in case object contains browsable objects (like containers or lists of other objects).

R__ALWAYS_INLINE Bool_t	IsOnHeap () const

R__ALWAYS_INLINE Bool_t	IsZombie () const

void	MayNotUse (const char *method) const
	Use this method to signal that a method (defined in a base class) may not be called in a derived class (in principle against good design since a child class should not provide less functionality than its parent, however, sometimes it is necessary).

virtual Bool_t	Notify ()
	This method must be overridden to handle object notification.

void	Obsolete (const char method, const char asOfVers, const char *removedFromVers) const
	Use this method to declare a method obsolete.

void	operator delete (void *ptr)
	Operator delete.

void	operator delete[] (void *ptr)
	Operator delete [].

void *	operator new (size_t sz)

void *	operator new (size_t sz, void *vp)

void *	operator new[] (size_t sz)

void *	operator new[] (size_t sz, void *vp)

TObject &	operator= (const TObject &rhs)
	TObject assignment operator.

virtual void	Paint (Option_t *option="")
	This method must be overridden if a class wants to paint itself.

virtual void	Pop ()
	Pop on object drawn in a pad to the top of the display list.

virtual Int_t	Read (const char *name)
	Read contents of object with specified name from the current directory.

void	ResetBit (UInt_t f)

virtual void	SaveAs (const char filename="", Option_t option="") const
	Save this object in the file specified by filename.

virtual void	SavePrimitive (std::ostream &out, Option_t *option="")
	Save a primitive as a C++ statement(s) on output stream "out".

void	SetBit (UInt_t f)

void	SetBit (UInt_t f, Bool_t set)
	Set or unset the user status bits as specified in f.

virtual void	SetDrawOption (Option_t *option="")
	Set drawing option for object.

virtual void	SetUniqueID (UInt_t uid)
	Set the unique object id.

virtual void	SysError (const char method, const char msgfmt,...) const
	Issue system error message.

R__ALWAYS_INLINE Bool_t	TestBit (UInt_t f) const

Int_t	TestBits (UInt_t f) const

virtual void	UseCurrentStyle ()
	Set current style settings in this object This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked.

virtual void	Warning (const char method, const char msgfmt,...) const
	Issue warning message.

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0)
	Write this object to the current directory.

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const
	Write this object to the current directory.

Static Public Member Functions
static TProcessID *	AddProcessID ()
	Static function to add a new TProcessID to the list of PIDs.

static UInt_t	AssignID (TObject *obj)
	static function returning the ID assigned to obj If the object is not yet referenced, its kIsReferenced bit is set and its fUniqueID set to the current number of referenced objects so far.

static void	Cleanup ()
	static function (called by TROOT destructor) to delete all TProcessIDs

static UInt_t	GetNProcessIDs ()
	Return the (static) number of process IDs.

static UInt_t	GetObjectCount ()
	Return the current referenced object count fgNumber is incremented every time a new object is referenced.

static TProcessID *	GetPID ()
	static: returns pointer to current TProcessID

static TObjArray *	GetPIDs ()
	static: returns array of TProcessIDs

static TProcessID *	GetProcessID (UShort_t pid)
	static function returning a pointer to TProcessID number pid in fgPIDs

static TProcessID *	GetProcessWithUID (const TObject *obj)
	static function returning a pointer to TProcessID with its pid encoded in the highest byte of obj->GetUniqueID()

static TProcessID *	GetProcessWithUID (UInt_t uid, const void *obj)
	static function returning a pointer to TProcessID with its pid encoded in the highest byte of uid

static TProcessID *	GetSessionProcessID ()
	static function returning the pointer to the session TProcessID

static Bool_t	IsValid (TProcessID *pid)
	static function. return kTRUE if pid is a valid TProcessID

static void	SetObjectCount (UInt_t number)
	static function to set the current referenced object count fgNumber is incremented every time a new object is referenced

Static Public Member Functions inherited from TObject
static Long_t	GetDtorOnly ()
	Return destructor only flag.

static Bool_t	GetObjectStat ()
	Get status of object stat flag.

static void	SetDtorOnly (void *obj)
	Set destructor only flag.

static void	SetObjectStat (Bool_t stat)
	Turn on/off tracking of objects in the TObjectTable.

Protected Attributes
std::atomic_int	fCount

std::atomic_flag	fLock
	Array pointing to the referenced objects.

ROOT::Internal::TAtomicPointer< TObjArray * >	fObjects
	Reference count to this object (from TFile)

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

Static Protected Attributes
static std::atomic_uint	fgNumber

static TExMap *	fgObjPIDs = nullptr

static TProcessID *	fgPID = nullptr
	Spin lock for initialization of fObjects.

static TObjArray *	fgPIDs = nullptr

Private Member Functions
	TProcessID (const TProcessID &ref)

TProcessID &	operator= (const TProcessID &ref)

Additional Inherited Members
Public Types inherited from TObject
enum	{ kIsOnHeap = 0x01000000 , kNotDeleted = 0x02000000 , kZombie = 0x04000000 , kInconsistent = 0x08000000 , kBitMask = 0x00ffffff }

enum	{ kSingleKey = BIT(0) , kOverwrite = BIT(1) , kWriteDelete = BIT(2) }

enum	EDeprecatedStatusBits { kObjInCanvas = BIT(3) }

enum	EStatusBits { kCanDelete = BIT(0) , kMustCleanup = BIT(3) , kIsReferenced = BIT(4) , kHasUUID = BIT(5) , kCannotPick = BIT(6) , kNoContextMenu = BIT(8) , kInvalidObject = BIT(13) }

Protected Types inherited from TObject
enum	{ kOnlyPrepStep = BIT(3) }

Protected Member Functions inherited from TObject
virtual void	DoError (int level, const char location, const char fmt, va_list va) const
	Interface to ErrorHandler (protected).

void	MakeZombie ()

#include <TProcessID.h>

Inheritance diagram for TProcessID:

[legend]

Constructor & Destructor Documentation

◆ TProcessID() [1/2]

TProcessID::TProcessID ( const TProcessID & ref )

private

◆ TProcessID() [2/2]

TProcessID::TProcessID ( )

Default constructor.

Definition at line 77 of file TProcessID.cxx.

◆ ~TProcessID()

TProcessID::~TProcessID ( )

virtual

Destructor.

Definition at line 95 of file TProcessID.cxx.

Member Function Documentation

◆ AddProcessID()

TProcessID * TProcessID::AddProcessID ( )

static

Static function to add a new TProcessID to the list of PIDs.

Definition at line 116 of file TProcessID.cxx.

◆ AssignID()

UInt_t TProcessID::AssignID ( TObject * obj )

static

static function returning the ID assigned to obj If the object is not yet referenced, its kIsReferenced bit is set and its fUniqueID set to the current number of referenced objects so far.

Definition at line 155 of file TProcessID.cxx.

◆ CheckInit()

void TProcessID::CheckInit ( )

Initialize fObjects.

Definition at line 192 of file TProcessID.cxx.

◆ Cleanup()

void TProcessID::Cleanup ( )

static

static function (called by TROOT destructor) to delete all TProcessIDs

Definition at line 204 of file TProcessID.cxx.

◆ Clear()

void TProcessID::Clear ( Option_t * option = "" )

virtual

delete the TObjArray pointing to referenced objects this function is called by TFile::Close("R")

Reimplemented from TNamed.

Definition at line 218 of file TProcessID.cxx.

◆ DecrementCount()

Int_t TProcessID::DecrementCount ( )

The reference fCount is used to delete the TProcessID in the TFile destructor when fCount = 0.

Definition at line 238 of file TProcessID.cxx.

◆ GetCount()

Int_t TProcessID::GetCount ( ) const

inline

Definition at line 98 of file TProcessID.h.

◆ GetNProcessIDs()

UInt_t TProcessID::GetNProcessIDs ( )

static

Return the (static) number of process IDs.

Definition at line 256 of file TProcessID.cxx.

◆ GetObjectCount()

UInt_t TProcessID::GetObjectCount ( )

static

Return the current referenced object count fgNumber is incremented every time a new object is referenced.

Definition at line 324 of file TProcessID.cxx.

◆ GetObjects()

TObjArray * TProcessID::GetObjects ( ) const

inline

Definition at line 99 of file TProcessID.h.

◆ GetObjectWithID()

TObject * TProcessID::GetObjectWithID ( UInt_t uid )

returns the TObject with unique identifier uid in the table of objects

Definition at line 332 of file TProcessID.cxx.

◆ GetPID()

TProcessID * TProcessID::GetPID ( )

static

static: returns pointer to current TProcessID

Definition at line 343 of file TProcessID.cxx.

◆ GetPIDs()

TObjArray * TProcessID::GetPIDs ( )

static

static: returns array of TProcessIDs

Definition at line 351 of file TProcessID.cxx.

◆ GetProcessID()

TProcessID * TProcessID::GetProcessID ( UShort_t pid )

static

static function returning a pointer to TProcessID number pid in fgPIDs

Definition at line 248 of file TProcessID.cxx.

◆ GetProcessWithUID() [1/2]

TProcessID * TProcessID::GetProcessWithUID ( const TObject * obj )

static

static function returning a pointer to TProcessID with its pid encoded in the highest byte of obj->GetUniqueID()

Definition at line 297 of file TProcessID.cxx.

◆ GetProcessWithUID() [2/2]

TProcessID * TProcessID::GetProcessWithUID	(	UInt_t	uid,
		const void *	obj
	)

static

static function returning a pointer to TProcessID with its pid encoded in the highest byte of uid

Definition at line 265 of file TProcessID.cxx.

◆ GetSessionProcessID()

TProcessID * TProcessID::GetSessionProcessID ( )

static

static function returning the pointer to the session TProcessID

Definition at line 305 of file TProcessID.cxx.

◆ IncrementCount()

Int_t TProcessID::IncrementCount ( )

Increase the reference count to this object.

Definition at line 313 of file TProcessID.cxx.

◆ IsValid()

Bool_t TProcessID::IsValid ( TProcessID * pid )

static

static function. return kTRUE if pid is a valid TProcessID

Definition at line 360 of file TProcessID.cxx.

◆ operator=()

TProcessID & TProcessID::operator= ( const TProcessID & ref )

private

◆ PutObjectWithID()

void TProcessID::PutObjectWithID	(	TObject *	obj,
		UInt_t	uid = `0`
	)

stores the object at the uid th slot in the table of objects The object uniqued is set as well as its kMustCleanup bit

Definition at line 383 of file TProcessID.cxx.

◆ RecursiveRemove()

void TProcessID::RecursiveRemove ( TObject * obj )

virtual

called by the object destructor remove reference to obj from the current table if it is referenced

Reimplemented from TObject.

Definition at line 412 of file TProcessID.cxx.

◆ SetObjectCount()

void TProcessID::SetObjectCount ( UInt_t number )

static

static function to set the current referenced object count fgNumber is incremented every time a new object is referenced

Definition at line 436 of file TProcessID.cxx.

Member Data Documentation

◆ fCount

std::atomic_int TProcessID::fCount

protected

Definition at line 81 of file TProcessID.h.

◆ fgNumber

std::atomic_uint TProcessID::fgNumber

staticprotected

Definition at line 89 of file TProcessID.h.

◆ fgObjPIDs

TExMap * TProcessID::fgObjPIDs = nullptr

staticprotected

Definition at line 87 of file TProcessID.h.

◆ fgPID

TProcessID * TProcessID::fgPID = nullptr

staticprotected

Spin lock for initialization of fObjects.

Definition at line 85 of file TProcessID.h.

◆ fgPIDs

TObjArray * TProcessID::fgPIDs = nullptr

staticprotected

Definition at line 86 of file TProcessID.h.

◆ fLock

std::atomic_flag TProcessID::fLock

protected

Array pointing to the referenced objects.

Definition at line 83 of file TProcessID.h.

◆ fObjects

ROOT::Internal::TAtomicPointer<TObjArray*> TProcessID::fObjects

protected

Reference count to this object (from TFile)

Definition at line 82 of file TProcessID.h.

core/base/inc/TProcessID.h

core/base/src/TProcessID.cxx

Public Member Functions

Static Public Member Functions

Protected Attributes

Static Protected Attributes

Private Member Functions

Additional Inherited Members

Constructor & Destructor Documentation

◆ TProcessID() [1/2]

◆ TProcessID() [2/2]

◆ ~TProcessID()

Member Function Documentation

◆ AddProcessID()

◆ AssignID()

◆ CheckInit()

◆ Cleanup()

◆ Clear()

◆ DecrementCount()

◆ GetCount()

◆ GetNProcessIDs()

◆ GetObjectCount()

◆ GetObjects()

◆ GetObjectWithID()

◆ GetPID()

◆ GetPIDs()

◆ GetProcessID()

◆ GetProcessWithUID() [1/2]

◆ GetProcessWithUID() [2/2]

◆ GetSessionProcessID()

◆ IncrementCount()

◆ IsValid()

◆ operator=()

◆ PutObjectWithID()

◆ RecursiveRemove()

◆ SetObjectCount()

Member Data Documentation

◆ fCount

◆ fgNumber

◆ fgObjPIDs

◆ fgPID

◆ fgPIDs

◆ fLock

◆ fObjects