Utility class post-processing the file generated by TMemStat (default memstat.root)

TMemStat records all the calls to malloc and free and write a TTree with the position where the memory is allocated/freed , as well as the number of bytes.

To use the class TMemStat, add the following statement at the beginning of your script or program

TMemStat mm("gnubuiltin");

or in an interactive session do something like:

root > TMemStat mm("gnubuiltin");
root > .x somescript.C
root > .q

another (may be more practical way) is to modify $ROOTSYS/etc/system.rootrc and activate the variable

Root.TMemStat: 1

The file collected by TMemStat is named memstat_ProcessID and can be analyzed and results shown by executing the static function Show. When TMemStat is active it recors every call to malloc/free in a ROOT Tree. You must be careful when running jobs with many millions (or more) of calls to malloc/free because the generated Tree may become very large. The TMemStat constructor TMemStat(const char* system, Int_t buffersize, Int_t maxcalls) has its 3 arguments optional:

system refers to the internal algorithm to compute the back traces. the recommended value is "gnubuiltin"
buffersize is the number of calls to malloc or free that can be stored in one memory buffer. when the buffer is full, the calls to malloc/free pointing to the same location are eliminated and not written to the final Tree. The default value 100000 is such that between 50 and 90% of the calls are eliminated depending on the application. You can set buffersize <=1 to keep every single call to malloc/free.
maxcalls can set a limit for the maximum number of calls to be registered in the Tree. The default value is 5000000. The 3 arguments can be set in $ROOTSYS/etc/system.rootrc
Root.TMemStat.system gnubuiltin
Root.TMemStat.buffersize 100000
Root.TMemStat.maxcalls 5000000
TMemStat::Show creates 3 canvases.
In canvas1 it displays a dynamic histogram showing for pages (10 kbytes by default) the percentage of the page used. A summary pave shows the total memory still in use when the TMemStat object goes out of scope and the average occupancy of the pages. The average occupancy gives a good indication of the memory fragmentation. When moving the mouse on this canvas, a tooltip shows the backtrace for the allocations at the address at the mouse position.
In canvas2 it displays the histogram of memory leaks in decreasing order. when moving the mouse on this canvas, a tooltip shows the backtrace for the leak in the bin below the mouse.
In canvas3 it displays the histogram of the nbigleaks largest leaks (default is 20) for each leak, the number of allocs and average alloc size is shown.

Simply do:

root > TMemStat::Show()

or specifying arguments

root > TMemStat::Show(0.1,20,"mydir/mymemstat.root");

The first argument to Show is the percentage of the time of the original job that produced the file after which the display is updated. By default update=0.1, ie 10 time intervals will be shown. The second argument is nbigleaks. if <=0 canvas2 and canvas3 are not shown The third argument is the imput file name (result of TMemStat). If this argument is omitted, Show will take the most recent file generated by TMemStat.

You can restrict the address range to be analyzed via TMemStatShow::SetAddressRange You can restrict the entry range to be analyzed via TMemStatShow::SetEntryRange

Definition at line 34 of file TMemStatShow.h.

Public Member Functions
	TMemStatShow ()

virtual	~TMemStatShow ()

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

	TObject (const TObject &object)
	TObject copy ctor. More...

virtual	~TObject ()
	TObject destructor. More...

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

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

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

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

virtual void	Clear (Option_t *="")

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

virtual Int_t	Compare (const TObject *obj) const
	Compare abstract method. More...

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

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

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

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

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

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

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

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

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. More...

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

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

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

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

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

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

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

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

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

virtual Option_t *	GetOption () const

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

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

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

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

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

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

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

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

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). More...

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

Bool_t	IsOnHeap () const

virtual Bool_t	IsSortable () const

Bool_t	IsZombie () const

virtual void	ls (Option_t *option="") const
	The ls function lists the contents of a class on stdout. More...

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). More...

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

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

void	operator delete (void *ptr)
	Operator delete. More...

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

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. More...

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

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

virtual void	Print (Option_t *option="") const
	This method must be overridden when a class wants to print itself. More...

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

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

void	ResetBit (UInt_t f)

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

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

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

void	SetBit (UInt_t f)

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

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

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

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. More...

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

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

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

Static Public Member Functions
static void	EventInfo1 (Int_t event, Int_t px, Int_t py, TObject *selected)
	Static: draw the tooltip showing the backtrace for the allocatios histogram. More...

static void	EventInfo2 (Int_t event, Int_t px, Int_t py, TObject *selected)
	Static: draw the tooltip showing the backtrace for the histogram of leaks. More...

static void	FillBTString (Int_t bin, Int_t mode, TString &btstring)
	Static: fill btstring with the traceback corresponding to entry in T btstring must be initialized in calling function. More...

static void	SetAddressRange (Long64_t nbytes=0, Long64_t first=0)
	Specify a memory address range to process (static function). More...

static void	SetEntryRange (Long64_t nentries=0, Long64_t first=0)
	Specify a range of entries to process (static function) More...

static void	Show (Double_t update=0.1, Int_t nbigleaks=20, const char fname="")
	Function called by TMemStat::Show Open the memstat data file, then call TTree::Draw to precompute the arrays of positions and nbytes per entry. More...

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

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

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

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

Static Protected Attributes
static Long64_t	fgAddressFirst = 0

static Long64_t	fgAddressN = 0

static TObjArray *	fgBtidlist = 0

static TCanvas *	fgC1 = 0

static TCanvas *	fgC2 = 0

static TCanvas *	fgC3 = 0

static Long64_t	fgEntryFirst = 0

static Long64_t	fgEntryN = 0

static TH1D *	fgH = 0

static TH1D *	fgHalloc = 0

static TH1I *	fgHdiff = 0

static TH1I *	fgHentry = 0

static TH1D *	fgHfree = 0

static TH1I *	fgHleaks = 0

static TTree *	fgT = 0

static TGToolTip *	fgTip1 = 0

static TGToolTip *	fgTip2 = 0

static Double_t *	fgV1 = 0

static Double_t *	fgV2 = 0

static Double_t *	fgV3 = 0

static Double_t *	fgV4 = 0

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

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

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

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). More...

void	MakeZombie ()

#include <TMemStatShow.h>

Inheritance diagram for TMemStatShow:

[legend]

Constructor & Destructor Documentation

◆ TMemStatShow()

TMemStatShow::TMemStatShow ( )

inline

Definition at line 62 of file TMemStatShow.h.

◆ ~TMemStatShow()

virtual TMemStatShow::~TMemStatShow ( )

inlinevirtual

Definition at line 63 of file TMemStatShow.h.

Member Function Documentation

◆ EventInfo1()

void TMemStatShow::EventInfo1	(	Int_t	event,
		Int_t	px,
		Int_t	py,
		TObject *	selected
	)

static

Static: draw the tooltip showing the backtrace for the allocatios histogram.

Definition at line 539 of file TMemStatShow.cxx.

◆ EventInfo2()

void TMemStatShow::EventInfo2	(	Int_t	event,
		Int_t	px,
		Int_t	py,
		TObject *	selected
	)

static

Static: draw the tooltip showing the backtrace for the histogram of leaks.

Definition at line 588 of file TMemStatShow.cxx.

◆ FillBTString()

void TMemStatShow::FillBTString	(	Int_t	bin,
		Int_t	mode,
		TString &	btstring
	)

static

Static: fill btstring with the traceback corresponding to entry in T btstring must be initialized in calling function.

Definition at line 615 of file TMemStatShow.cxx.

◆ SetAddressRange()

void TMemStatShow::SetAddressRange	(	Long64_t	nbytes = `0`,
		Long64_t	first = `0`
	)

static

Specify a memory address range to process (static function).

This function can be used to restrict the range of memory addresses to be analyzed. For example whem TmemStat is run on a 64 bits machine and the results visualized on a 32 bits machine, it might be necessary to restrict the analysis range to the addresses below 2 Gigabytes, eg TMemStatShow::SetMemoryRange(500000000,0); //analyse only the first 500 MBytes

first : first address to process (default is 0)
nbytes : number of addresses in bytes to process starting at first if 0 (default), then all addresses are processed

Definition at line 141 of file TMemStatShow.cxx.

◆ SetEntryRange()

void TMemStatShow::SetEntryRange	(	Long64_t	nentries = `0`,
		Long64_t	first = `0`
	)

static

Specify a range of entries to process (static function)

first : first entry to process (default is 0)
nentries : number of entries to process starting at first if 0 (default), then all entries are processed call this function when the amount of data collected in the Tree is large and therefore making the analysis slow.

Definition at line 155 of file TMemStatShow.cxx.

◆ Show()

void TMemStatShow::Show	(	Double_t	update = `0.1`,
		Int_t	nbigleaks = `20`,
		const char *	fname = `"*"`
	)

static

Function called by TMemStat::Show Open the memstat data file, then call TTree::Draw to precompute the arrays of positions and nbytes per entry.

update is the time interval in the data file in seconds after which the display is updated. For example is the job producing the memstat.root file took 100s to execute, an update of 0.1s will generate 1000 time views of the memory use. the histogram hbigleaks will contain the nbigleaks largest leaks if fname=="*" (default), the most recent file memstat*.root will be taken.

Definition at line 172 of file TMemStatShow.cxx.

Member Data Documentation

◆ fgAddressFirst

Long64_t TMemStatShow::fgAddressFirst = 0

staticprotected

Definition at line 56 of file TMemStatShow.h.

◆ fgAddressN

Long64_t TMemStatShow::fgAddressN = 0

staticprotected

Definition at line 57 of file TMemStatShow.h.

◆ fgBtidlist

TObjArray * TMemStatShow::fgBtidlist = 0

staticprotected

Definition at line 47 of file TMemStatShow.h.

◆ fgC1

TCanvas * TMemStatShow::fgC1 = 0

staticprotected

Definition at line 52 of file TMemStatShow.h.

◆ fgC2

TCanvas * TMemStatShow::fgC2 = 0

staticprotected

Definition at line 53 of file TMemStatShow.h.

◆ fgC3

TCanvas * TMemStatShow::fgC3 = 0

staticprotected

Definition at line 54 of file TMemStatShow.h.

◆ fgEntryFirst

Long64_t TMemStatShow::fgEntryFirst = 0

staticprotected

Definition at line 58 of file TMemStatShow.h.

◆ fgEntryN

Long64_t TMemStatShow::fgEntryN = 0

staticprotected

Definition at line 59 of file TMemStatShow.h.

◆ fgH

TH1D * TMemStatShow::fgH = 0

staticprotected

Definition at line 40 of file TMemStatShow.h.

◆ fgHalloc

TH1D * TMemStatShow::fgHalloc = 0

staticprotected

Definition at line 38 of file TMemStatShow.h.

◆ fgHdiff

TH1I * TMemStatShow::fgHdiff = 0

staticprotected

Definition at line 43 of file TMemStatShow.h.

◆ fgHentry

TH1I * TMemStatShow::fgHentry = 0

staticprotected

Definition at line 42 of file TMemStatShow.h.

◆ fgHfree

TH1D * TMemStatShow::fgHfree = 0

staticprotected

Definition at line 39 of file TMemStatShow.h.

◆ fgHleaks

TH1I * TMemStatShow::fgHleaks = 0

staticprotected

Definition at line 41 of file TMemStatShow.h.

◆ fgT

TTree * TMemStatShow::fgT = 0

staticprotected

Definition at line 37 of file TMemStatShow.h.

◆ fgTip1

TGToolTip * TMemStatShow::fgTip1 = 0

staticprotected

Definition at line 45 of file TMemStatShow.h.

◆ fgTip2

TGToolTip * TMemStatShow::fgTip2 = 0

staticprotected

Definition at line 46 of file TMemStatShow.h.

◆ fgV1

Double_t * TMemStatShow::fgV1 = 0

staticprotected

Definition at line 48 of file TMemStatShow.h.

◆ fgV2

Double_t * TMemStatShow::fgV2 = 0

staticprotected

Definition at line 49 of file TMemStatShow.h.

◆ fgV3

Double_t * TMemStatShow::fgV3 = 0

staticprotected

Definition at line 50 of file TMemStatShow.h.

◆ fgV4

Double_t * TMemStatShow::fgV4 = 0

staticprotected

Definition at line 51 of file TMemStatShow.h.

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

tree/treeviewer/inc/TMemStatShow.h
tree/treeviewer/src/TMemStatShow.cxx

Public Member Functions

Static Public Member Functions

Static Protected Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ TMemStatShow()

◆ ~TMemStatShow()

Member Function Documentation

◆ EventInfo1()

◆ EventInfo2()

◆ FillBTString()

◆ SetAddressRange()

◆ SetEntryRange()

◆ Show()

Member Data Documentation

◆ fgAddressFirst

◆ fgAddressN

◆ fgBtidlist

◆ fgC1

◆ fgC2

◆ fgC3

◆ fgEntryFirst

◆ fgEntryN

◆ fgH

◆ fgHalloc

◆ fgHdiff

◆ fgHentry

◆ fgHfree

◆ fgHleaks

◆ fgT

◆ fgTip1

◆ fgTip2

◆ fgV1

◆ fgV2

◆ fgV3

◆ fgV4