libMesh::ReferenceCounter Class Reference

This is the base class for enabling reference counting. More...

#include <reference_counter.h>

Inheritance diagram for libMesh::ReferenceCounter:

Public Member Functions
	~ReferenceCounter ()
	Destructor.

Static Public Member Functions
static std::string	get_info ()
	Gets a string containing the reference information.
static void	print_info (std::ostream &out_stream=libMesh::out)
	Prints the reference information, by default to libMesh::out.
static unsigned int	n_objects ()
	Prints the number of outstanding (created, but not yet destroyed) objects.
static void	enable_print_counter_info ()
	Methods to enable/disable the reference counter output from print_info().
static void	disable_print_counter_info ()

Protected Types
typedef std::map< std::string, std::pair< unsigned int, unsigned int > >	Counts
	Data structure to log the information.

Protected Member Functions
	ReferenceCounter ()
	Constructors.
	ReferenceCounter (const ReferenceCounter &)
	ReferenceCounter (ReferenceCounter &&other) noexcept
	Move constructor, must be declared noexcept.
void	increment_constructor_count (const std::string &name) noexcept
	Increments the construction counter.
void	increment_destructor_count (const std::string &name) noexcept
	Increments the destruction counter.

Static Protected Attributes
static Counts	_counts
	Actually holds the data.
static Threads::atomic< unsigned int >	_n_objects
	The number of objects.
static Threads::spin_mutex	_mutex
	Mutual exclusion object to enable thread-safe reference counting.
static bool	_enable_print_counter = true
	Flag to control whether reference count information is printed when print_info is called.

Detailed Description

This is the base class for enabling reference counting.

It should not be used by the user, thus it has a private constructor.

Author

Benjamin S. Kirk

Date

2002-2007

Common base for all objects whose creations/destructions are counted.

Definition at line 46 of file reference_counter.h.

Member Typedef Documentation

Counts

typedef std::map<std::string, std::pair<unsigned int, unsigned int> > libMesh::ReferenceCounter::Counts

protected

Data structure to log the information.

The log is identified by the class name.

Definition at line 119 of file reference_counter.h.

Constructor & Destructor Documentation

ReferenceCounter() [1/3]

libMesh::ReferenceCounter::ReferenceCounter ( )

inlineprotected

Constructors.

Protected so that you cannot instantiate a ReferenceCounter, only derive from it.

Definition at line 150 of file reference_counter.h.

{
  ++_n_objects;
}

References _n_objects.

ReferenceCounter() [2/3]

libMesh::ReferenceCounter::ReferenceCounter ( const ReferenceCounter &  )

inlineprotected

Definition at line 157 of file reference_counter.h.

{
  ++_n_objects;
}

References _n_objects.

ReferenceCounter() [3/3]

libMesh::ReferenceCounter::ReferenceCounter ( ReferenceCounter &&  other )

inlineprotectednoexcept

Move constructor, must be declared noexcept.

Definition at line 164 of file reference_counter.h.

{
  ++_n_objects;
}

References _n_objects.

~ReferenceCounter()

libMesh::ReferenceCounter::~ReferenceCounter ( )

inline

Destructor.

Definition at line 171 of file reference_counter.h.

{
  --_n_objects;
}

References _n_objects.

Member Function Documentation

disable_print_counter_info()

void libMesh::ReferenceCounter::disable_print_counter_info ( )

static

Definition at line 100 of file reference_counter.C.

{
  _enable_print_counter = false;
  return;
}

References _enable_print_counter.

enable_print_counter_info()

void libMesh::ReferenceCounter::enable_print_counter_info ( )

static

Methods to enable/disable the reference counter output from print_info().

Enabled by default.

Definition at line 94 of file reference_counter.C.

{
  _enable_print_counter = true;
  return;
}

References _enable_print_counter.

Referenced by libMesh::LibMeshInit::~LibMeshInit().

get_info()

std::string libMesh::ReferenceCounter::get_info ( )

static

Gets a string containing the reference information.

Definition at line 47 of file reference_counter.C.

{
#if defined(LIBMESH_ENABLE_REFERENCE_COUNTING) && defined(DEBUG)
 
  std::ostringstream oss;
 
  oss << '\n'
      << " ---------------------------------------------------------------------------- \n"
      << "| Reference count information                                                |\n"
      << " ---------------------------------------------------------------------------- \n";
 
  for (const auto & [name, cd] : _counts)
    oss << "| " << name << " reference count information:\n"
        << "|  Creations:    " << cd.first    << '\n'
        << "|  Destructions: " << cd.second << '\n';
 
  oss << " ---------------------------------------------------------------------------- \n";
 
  return oss.str();
 
#else
 
  return "";
 
#endif
}

References _counts.

Referenced by print_info().

increment_constructor_count()

void libMesh::ReferenceCounter::increment_constructor_count ( const std::string &  name )

inlineprotectednoexcept

Increments the construction counter.

Should be called in the constructor of any derived class that will be reference counted.

Definition at line 183 of file reference_counter.h.

{
  libmesh_try
  {
    Threads::spin_mutex::scoped_lock lock(Threads::spin_mtx);
    std::pair<unsigned int, unsigned int> & p = _counts[name];
    p.first++;
  }
  libmesh_catch (...)
  {
    auto stream = libMesh::err.get();
    stream->exceptions(stream->goodbit); // stream must not throw
    libMesh::err << "Encountered unrecoverable error while calling "
                 << "ReferenceCounter::increment_constructor_count() "
                 << "for a(n) " << name << " object." << std::endl;
    std::terminate();
  }
}

References libMesh::err, libMesh::BasicOStreamProxy< charT, traits >::get(), and libMesh::Threads::spin_mtx.

Referenced by libMesh::ReferenceCountedObject< T >::ReferenceCountedObject(), libMesh::ReferenceCountedObject< T >::ReferenceCountedObject(), and libMesh::ReferenceCountedObject< T >::ReferenceCountedObject().

increment_destructor_count()

void libMesh::ReferenceCounter::increment_destructor_count ( const std::string &  name )

inlineprotectednoexcept

Increments the destruction counter.

Should be called in the destructor of any derived class that will be reference counted.

Definition at line 207 of file reference_counter.h.

{
  libmesh_try
  {
    Threads::spin_mutex::scoped_lock lock(Threads::spin_mtx);
    std::pair<unsigned int, unsigned int> & p = _counts[name];
    p.second++;
  }
  libmesh_catch (...)
  {
    auto stream = libMesh::err.get();
    stream->exceptions(stream->goodbit); // stream must not throw
    libMesh::err << "Encountered unrecoverable error while calling "
                 << "ReferenceCounter::increment_destructor_count() "
                 << "for a(n) " << name << " object." << std::endl;
    std::terminate();
  }
}

References libMesh::err, libMesh::BasicOStreamProxy< charT, traits >::get(), and libMesh::Threads::spin_mtx.

Referenced by libMesh::ReferenceCountedObject< T >::~ReferenceCountedObject().

n_objects()

static unsigned int libMesh::ReferenceCounter::n_objects ( )

inlinestatic

Prints the number of outstanding (created, but not yet destroyed) objects.

Definition at line 85 of file reference_counter.h.

  { return _n_objects; }

References _n_objects.

Referenced by libMesh::LibMeshInit::~LibMeshInit().

print_info()

void libMesh::ReferenceCounter::print_info ( std::ostream &  out_stream = libMesh::out )

static

Prints the reference information, by default to libMesh::out.

Definition at line 81 of file reference_counter.C.

{
  if (_enable_print_counter)
    out_stream << ReferenceCounter::get_info();
}

References _enable_print_counter, and get_info().

Referenced by libMesh::LibMeshInit::~LibMeshInit().

Member Data Documentation

_counts

ReferenceCounter::Counts libMesh::ReferenceCounter::_counts

staticprotected

Actually holds the data.

Definition at line 124 of file reference_counter.h.

Referenced by get_info().

_enable_print_counter

bool libMesh::ReferenceCounter::_enable_print_counter = true

staticprotected

Flag to control whether reference count information is printed when print_info is called.

Definition at line 143 of file reference_counter.h.

Referenced by disable_print_counter_info(), enable_print_counter_info(), and print_info().

_mutex

Threads::spin_mutex libMesh::ReferenceCounter::_mutex

staticprotected

Mutual exclusion object to enable thread-safe reference counting.

Definition at line 137 of file reference_counter.h.

_n_objects

Threads::atomic< unsigned int > libMesh::ReferenceCounter::_n_objects

staticprotected

The number of objects.

Print the reference count information when the number returns to 0.

Definition at line 132 of file reference_counter.h.

Referenced by n_objects(), ReferenceCounter(), ReferenceCounter(), ReferenceCounter(), and ~ReferenceCounter().

---

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

• include/base/reference_counter.h
• src/base/reference_counter.C