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Reference Guide
TMemStatShow Class Reference

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:

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 32 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...
 
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. More...
 
virtual const char * ClassName () const
 Returns name of class to which the object belongs. More...
 
virtual void Clear (Option_t *="")
 
virtual TObjectClone (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 TObjectDrawClone (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 TObjectFindObject (const char *name) const
 Must be redefined in derived classes. More...
 
virtual TObjectFindObject (const TObject *obj) const
 Must be redefined in derived classes. More...
 
virtual Option_tGetDrawOption () 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_tGetOption () 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...
 
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. 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...
 
R__ALWAYS_INLINE Bool_t IsOnHeap () const
 
virtual Bool_t IsSortable () const
 
R__ALWAYS_INLINE 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...
 
voidoperator new (size_t sz)
 
voidoperator new (size_t sz, void *vp)
 
voidoperator new[] (size_t sz)
 
voidoperator new[] (size_t sz, void *vp)
 
TObjectoperator= (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)
 
void SetBit (UInt_t f, Bool_t set)
 Set or unset the user status bits as specified in f. More...
 
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...
 
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. 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 TObjArrayfgBtidlist = 0
 
static TCanvasfgC1 = 0
 
static TCanvasfgC2 = 0
 
static TCanvasfgC3 = 0
 
static Long64_t fgEntryFirst = 0
 
static Long64_t fgEntryN = 0
 
static TH1DfgH = 0
 
static TH1DfgHalloc = 0
 
static TH1IfgHdiff = 0
 
static TH1IfgHentry = 0
 
static TH1DfgHfree = 0
 
static TH1IfgHleaks = 0
 
static TTreefgT = 0
 
static TGToolTipfgTip1 = 0
 
static TGToolTipfgTip2 = 0
 
static Double_tfgV1 = 0
 
static Double_tfgV2 = 0
 
static Double_tfgV3 = 0
 
static Double_tfgV4 = 0
 

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 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 60 of file TMemStatShow.h.

◆ ~TMemStatShow()

virtual TMemStatShow::~TMemStatShow ( )
inlinevirtual

Definition at line 61 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 54 of file TMemStatShow.h.

◆ fgAddressN

Long64_t TMemStatShow::fgAddressN = 0
staticprotected

Definition at line 55 of file TMemStatShow.h.

◆ fgBtidlist

TObjArray * TMemStatShow::fgBtidlist = 0
staticprotected

Definition at line 45 of file TMemStatShow.h.

◆ fgC1

TCanvas * TMemStatShow::fgC1 = 0
staticprotected

Definition at line 50 of file TMemStatShow.h.

◆ fgC2

TCanvas * TMemStatShow::fgC2 = 0
staticprotected

Definition at line 51 of file TMemStatShow.h.

◆ fgC3

TCanvas * TMemStatShow::fgC3 = 0
staticprotected

Definition at line 52 of file TMemStatShow.h.

◆ fgEntryFirst

Long64_t TMemStatShow::fgEntryFirst = 0
staticprotected

Definition at line 56 of file TMemStatShow.h.

◆ fgEntryN

Long64_t TMemStatShow::fgEntryN = 0
staticprotected

Definition at line 57 of file TMemStatShow.h.

◆ fgH

TH1D * TMemStatShow::fgH = 0
staticprotected

Definition at line 38 of file TMemStatShow.h.

◆ fgHalloc

TH1D * TMemStatShow::fgHalloc = 0
staticprotected

Definition at line 36 of file TMemStatShow.h.

◆ fgHdiff

TH1I * TMemStatShow::fgHdiff = 0
staticprotected

Definition at line 41 of file TMemStatShow.h.

◆ fgHentry

TH1I * TMemStatShow::fgHentry = 0
staticprotected

Definition at line 40 of file TMemStatShow.h.

◆ fgHfree

TH1D * TMemStatShow::fgHfree = 0
staticprotected

Definition at line 37 of file TMemStatShow.h.

◆ fgHleaks

TH1I * TMemStatShow::fgHleaks = 0
staticprotected

Definition at line 39 of file TMemStatShow.h.

◆ fgT

TTree * TMemStatShow::fgT = 0
staticprotected

Definition at line 35 of file TMemStatShow.h.

◆ fgTip1

TGToolTip * TMemStatShow::fgTip1 = 0
staticprotected

Definition at line 43 of file TMemStatShow.h.

◆ fgTip2

TGToolTip * TMemStatShow::fgTip2 = 0
staticprotected

Definition at line 44 of file TMemStatShow.h.

◆ fgV1

Double_t * TMemStatShow::fgV1 = 0
staticprotected

Definition at line 46 of file TMemStatShow.h.

◆ fgV2

Double_t * TMemStatShow::fgV2 = 0
staticprotected

Definition at line 47 of file TMemStatShow.h.

◆ fgV3

Double_t * TMemStatShow::fgV3 = 0
staticprotected

Definition at line 48 of file TMemStatShow.h.

◆ fgV4

Double_t * TMemStatShow::fgV4 = 0
staticprotected

Definition at line 49 of file TMemStatShow.h.

Libraries for TMemStatShow:
[legend]

The documentation for this class was generated from the following files:
xmlio::Root
const char * Root
Definition: TXMLSetup.cxx:53
TMemStat::Show
static void Show(Double_t update=0.1, Int_t nbigleaks=20, const char *fname="*")
Show results.
Definition: TMemStat.cxx:175
TGeant4Unit::mm
static constexpr double mm
Definition: TGeant4SystemOfUnits.h:114
TMemStat
Definition: TMemStat.h:16