Legacy Code

TTask is a legacy interface: there will be no bug fixes nor new developments. Therefore it is not recommended to use it in new long-term production code. But, depending on the context, using TTask might still be a valid solution.

TTask is a base class that can be used to build a complex tree of Tasks. Each TTask derived class may contain other TTasks that can be executed recursively, such that a complex program can be dynamically built and executed by invoking the services of the top level Task or one of its subtasks.

Use the TTask::Add function to add a subtask to an existing TTask. To execute a TTask, one calls the ExecuteTask function. ExecuteTask will call recursively:

the TTask::Exec function of the derived class
TTask::ExecuteTasks to execute for each task the list of its subtasks.

If the top level task (see example below) is added to the list of Root browsable objects, the tree of tasks can be visualized by the Root browser. The browser can be used to start a task, set break points at the beginning of a task or when the task has completed. At a breakpoint, data structures generated by the execution up this point may be inspected asynchronously and then the execution can be resumed by selecting the "Continue" function of a task.

A Task may be active or inactive (controlled by TTask::SetActive). When a task is not active, its sub tasks are not executed.

A TTask tree may be made persistent, saving the status of all the tasks.

The Root browser's picture below has been generated by executing the following script:

{
   TTask *aliroot  = new TTask("aliroot","ALICE reconstruction main task");
   TTask *geominit = new TTask("geomInit","Initialize ALICE geometry");
   TTask *matinit  = new TTask("matInit","Initialize ALICE materials");
   TTask *physinit = new TTask("physInit","Initialize Physics processes");
   TTask *tracker  = new TTask("tracker","Track reconstruction manager");
   TTask *tpcrec   = new TTask("tpcrec","TPC reconstruction");
   TTask *itsrec   = new TTask("itsrec","ITS reconstruction");
   TTask *muonrec  = new TTask("muonRec","Muon Reconstruction");
   TTask *phosrec  = new TTask("phosRec","Phos Reconstruction");
   TTask *richrec  = new TTask("richRec","Rich Reconstruction");
   TTask *trdrec   = new TTask("trdRec","TRD Reconstruction");
   TTask *globrec  = new TTask("globRec","Global Track Reconstruction");
   TTask *pstats   = new TTask("printStats","Print Run Statistics");
   TTask *run      = new TTask("run","Process one run");
   TTask *event    = new TTask("event","Process one event");
   aliroot->Add(geominit);
   aliroot->Add(matinit);
   aliroot->Add(physinit);
   aliroot->Add(run);
   run->Add(event);
   event->Add(tracker);
   event->Add(muonrec);
   event->Add(phosrec);
   event->Add(richrec);
   event->Add(trdrec);
   event->Add(globrec);
   tracker->Add(tpcrec);
   tracker->Add(itsrec);
   run->Add(pstats);
 
   gROOT->GetListOfBrowsables()->Add(aliroot,"aliroot");
   new TBrowser;
}

Definition at line 35 of file TTask.h.

Public Member Functions
	TTask ()
	Default constructor invoked when reading a TTask object from a file.

	TTask (const char name, const char title)
	Standard constructor.

	TTask (const TTask &task)
	Copy constructor.

virtual	~TTask ()
	Delete a task and its subtasks.

virtual void	Abort ()
	Abort current tree of tasks.

virtual void	Add (TTask *task)
	Add TTask to this.

void	Browse (TBrowser *b) override
	Browse the list of tasks.

virtual void	CleanTasks ()
	Reset tasks state: breakpoints and execute flags also invokes the Clear function of each task to clear all data structures created by a previous execution of a task.

void	Clear (Option_t *option="") override
	Recursively call the Clear function of this task and its subtasks.

virtual void	Continue ()
	Resume execution at the current break point.

virtual void	Exec (Option_t *option)
	Dummy Execute.

virtual void	ExecuteTask (Option_t *option="0")
	Execute main task and its subtasks.

virtual void	ExecuteTasks (Option_t *option)
	Execute all the subtasks of a task.

Int_t	GetBreakin () const

Int_t	GetBreakout () const

TList *	GetListOfTasks () const

TClass *	IsA () const override

Bool_t	IsActive () const

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

void	ls (Option_t option="") const override
	List the tree of tasks.

TTask &	operator= (const TTask &tt)
	Assignment operator.

void	SetActive (Bool_t active=kTRUE)

void	SetBreakin (Int_t breakin=1)

void	SetBreakout (Int_t breakout=1)

void	Streamer (TBuffer &) override
	Stream an object of class TObject.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

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.

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

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

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

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

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

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

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

Bool_t	IsSortable () const override

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

void	Print (Option_t *option="") const override
	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.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

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.

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 with: `gROOT->SetSelectedPad(c1)`.

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=nullptr)
	Execute method on this object with the given parameter string, e.g.

virtual void	Execute (TMethod method, TObjArray params, Int_t *error=nullptr)
	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)

Bool_t	IsDestructed () const
	IsDestructed.

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

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 (the base implementation is no-op).

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.

virtual void	RecursiveRemove (TObject *obj)
	Recursively remove this object from a list.

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.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

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=nullptr, Int_t option=0, Int_t bufsize=0)
	Write this object to the current directory.

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

Static Public Member Functions
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

Static Public Member Functions inherited from TNamed
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

Static Public Member Functions inherited from TObject
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

static Longptr_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
Bool_t	fActive

Int_t	fBreakin

Int_t	fBreakout

Bool_t	fHasExecuted

TString	fOption

TList *	fTasks

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

Static Protected Attributes
static TTask *	fgBeginTask = nullptr

static TTask *	fgBreakPoint = nullptr

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

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

enum	EDeprecatedStatusBits { kObjInCanvas = (1ULL << ( 3 )) }

enum	EStatusBits { kCanDelete = (1ULL << ( 0 )) , kMustCleanup = (1ULL << ( 3 )) , kIsReferenced = (1ULL << ( 4 )) , kHasUUID = (1ULL << ( 5 )) , kCannotPick = (1ULL << ( 6 )) , kNoContextMenu = (1ULL << ( 8 )) , kInvalidObject = (1ULL << ( 13 )) }

Protected Types inherited from TObject
enum	{ kOnlyPrepStep = (1ULL << ( 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 <TTask.h>

Inheritance diagram for TTask:

[legend]

Constructor & Destructor Documentation

◆ TTask() [1/3]

TTask::TTask ( )

Default constructor invoked when reading a TTask object from a file.

Definition at line 98 of file TTask.cxx.

◆ TTask() [2/3]

TTask::TTask	(	const char *	name,
		const char *	title
	)

Standard constructor.

Definition at line 110 of file TTask.cxx.

◆ ~TTask()

TTask::~TTask ( )

virtual

Delete a task and its subtasks.

Definition at line 168 of file TTask.cxx.

◆ TTask() [3/3]

TTask::TTask ( const TTask & task )

Copy constructor.

Definition at line 150 of file TTask.cxx.

Member Function Documentation

◆ Abort()

void TTask::Abort ( )

virtual

Abort current tree of tasks.

After this call, the tree of tasks is ready to be executed again. The application must take care of cleaning data structures created by previous executions.

Definition at line 192 of file TTask.cxx.

◆ Add()

void TTask::Add ( TTask * task )

virtual

Add TTask to this.

Definition at line 176 of file TTask.cxx.

◆ Browse()

void TTask::Browse ( TBrowser * b )

overridevirtual

Browse the list of tasks.

It is recommended to add the top level task to the list of ROOT browsables by:

gROOT->GetListOfBrowsables()->Add(myTopLevelTask)

Reimplemented from TObject.

Definition at line 211 of file TTask.cxx.

◆ Class()

static TClass * TTask::Class ( )

static

Returns: TClass describing this class

◆ Class_Name()

static const char * TTask::Class_Name ( )

static

Returns: Name of this class

◆ Class_Version()

static constexpr Version_t TTask::Class_Version ( )

inlinestaticconstexpr

Returns: Version of this class

Definition at line 76 of file TTask.h.

◆ CleanTasks()

void TTask::CleanTasks ( )

virtual

Reset tasks state: breakpoints and execute flags also invokes the Clear function of each task to clear all data structures created by a previous execution of a task.

Definition at line 222 of file TTask.cxx.

◆ Clear()

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

overridevirtual

Recursively call the Clear function of this task and its subtasks.

The Clear function must be implemented for each derived class to clear all data structures created by a previous execution of a task. This function is automatically called by the CleanTasks function.

Reimplemented from TNamed.

Definition at line 240 of file TTask.cxx.

◆ Continue()

void TTask::Continue ( )

virtual

Resume execution at the current break point.

Definition at line 247 of file TTask.cxx.

◆ DeclFileName()

static const char * TTask::DeclFileName ( )

inlinestatic

Returns: Name of the file containing the class declaration

Definition at line 76 of file TTask.h.

◆ Exec()

void TTask::Exec ( Option_t * option )

virtual

Dummy Execute.

This function must be redefined in the derived classes.

Definition at line 267 of file TTask.cxx.

◆ ExecuteTask()

void TTask::ExecuteTask ( Option_t * option = "0" )

virtual

Execute main task and its subtasks.

When calling this function, the Exec function of the corresponding class is invoked, then the list of its subtasks is executed calling recursively all the subtasks, etc.

The option parameter may be used to select different execution steps within a task. This parameter is passed also to all the subtasks.

Definition at line 280 of file TTask.cxx.

◆ ExecuteTasks()

void TTask::ExecuteTasks ( Option_t * option )

virtual

Execute all the subtasks of a task.

Definition at line 315 of file TTask.cxx.

◆ GetBreakin()

Int_t TTask::GetBreakin ( ) const

inline

Definition at line 66 of file TTask.h.

◆ GetBreakout()

Int_t TTask::GetBreakout ( ) const

inline

Definition at line 67 of file TTask.h.

◆ GetListOfTasks()

TList * TTask::GetListOfTasks ( ) const

inline

Definition at line 74 of file TTask.h.

◆ IsA()

TClass * TTask::IsA ( ) const

inlineoverridevirtual

Returns: TClass describing current object

Reimplemented from TNamed.

Definition at line 76 of file TTask.h.

◆ IsActive()

Bool_t TTask::IsActive ( ) const

inline

Definition at line 68 of file TTask.h.

◆ IsFolder()

Bool_t TTask::IsFolder ( ) const

inlineoverridevirtual

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

Reimplemented from TObject.

Definition at line 69 of file TTask.h.

◆ ls()

void TTask::ls ( Option_t * option = "*" ) const

overridevirtual

List the tree of tasks.

Indentation is used to identify the task tree.

Reimplemented from TNamed.

Definition at line 359 of file TTask.cxx.

◆ operator=()

TTask & TTask::operator= ( const TTask & tt )

Assignment operator.

Definition at line 124 of file TTask.cxx.

◆ SetActive()

void TTask::SetActive ( Bool_t active = kTRUE )

inline

Definition at line 71 of file TTask.h.

◆ SetBreakin()

void TTask::SetBreakin ( Int_t breakin = 1 )

inline

Definition at line 72 of file TTask.h.

◆ SetBreakout()

void TTask::SetBreakout ( Int_t breakout = 1 )

inline

Definition at line 73 of file TTask.h.

◆ Streamer()

void TTask::Streamer ( TBuffer & R__b )

overridevirtual

Stream an object of class TObject.

Reimplemented from TNamed.

◆ StreamerNVirtual()

void TTask::StreamerNVirtual ( TBuffer & ClassDef_StreamerNVirtual_b )

inline

Definition at line 76 of file TTask.h.

Member Data Documentation

◆ fActive

Bool_t TTask::fActive

protected

Definition at line 43 of file TTask.h.

◆ fBreakin

Int_t TTask::fBreakin

protected

Definition at line 40 of file TTask.h.

◆ fBreakout

Int_t TTask::fBreakout

protected

Definition at line 41 of file TTask.h.

◆ fgBeginTask

TTask * TTask::fgBeginTask = nullptr

staticprotected

Definition at line 45 of file TTask.h.

◆ fgBreakPoint

TTask * TTask::fgBreakPoint = nullptr

staticprotected

Definition at line 46 of file TTask.h.

◆ fHasExecuted

Bool_t TTask::fHasExecuted

protected

Definition at line 42 of file TTask.h.

◆ fOption

TString TTask::fOption

protected

Definition at line 39 of file TTask.h.

◆ fTasks

TList* TTask::fTasks

protected

Definition at line 38 of file TTask.h.

Libraries for TTask:

[legend]

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

core/base/inc/TTask.h
core/base/src/TTask.cxx

Legacy Code

Public Member Functions

Static Public Member Functions

Protected Attributes

Static Protected Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ TTask() [1/3]

◆ TTask() [2/3]

◆ ~TTask()

◆ TTask() [3/3]

Member Function Documentation

◆ Abort()

◆ Add()

◆ Browse()

◆ Class()

◆ Class_Name()

◆ Class_Version()

◆ CleanTasks()

◆ Clear()

◆ Continue()

◆ DeclFileName()

◆ Exec()

◆ ExecuteTask()

◆ ExecuteTasks()

◆ GetBreakin()

◆ GetBreakout()

◆ GetListOfTasks()

◆ IsA()

◆ IsActive()

◆ IsFolder()

◆ ls()

◆ operator=()

◆ SetActive()

◆ SetBreakin()

◆ SetBreakout()

◆ Streamer()

◆ StreamerNVirtual()

Member Data Documentation

◆ fActive

◆ fBreakin

◆ fBreakout

◆ fgBeginTask

◆ fgBreakPoint

◆ fHasExecuted

◆ fOption

◆ fTasks