SG::Arena Class Reference

Collection of memory allocators with a common lifetime,. More...

#include <Arena.h>

Inheritance diagram for SG::Arena:

Collaboration diagram for SG::Arena:

Classes
class	Push
	Helper class for making Arena instances current in a stack-like manner. More...

Public Member Functions
	Arena (const std::string &name, ArenaHeader *header=0)
	Constructor.
	~Arena ()
	Destructor.
ArenaHeader *	header ()
	Return the ArenaHeader with which this Arena is associated.
ArenaBase *	makeCurrent ()
	Make this Arena the current one for its ArenaHeader.
LockedAllocator	allocator (size_t i)
	Translate an integer index to an Allocator pointer.
void	reset ()
	Reset all contained allocators.
void	erase ()
	Erase all contained allocators.
void	report (std::ostream &os) const
	Generate a report of the memory in use by this Arena.
ArenaAllocatorBase::Stats	stats () const
	Return statistics summed over all allocators in this Arena.
const std::string &	name () const
	Return this Arena's name.

Private Types
typedef std::lock_guard< std::mutex >	lock_t

Private Member Functions
ArenaAllocatorBase *	makeAllocator (size_t i)
	Make a new Allocator for index i.

Private Attributes
ArenaHeader *	m_header
	The ArenaHeader with which we're associated.
std::vector< AllocEntry >	m_allocs
std::string	m_name
	Our name.
std::mutex	m_mutex
	To guard access to m_allocs.

Detailed Description

Collection of memory allocators with a common lifetime,.

See the file-level comments for a full description.

Definition at line 236 of file Arena.h.

Member Typedef Documentation

lock_t

typedef std::lock_guard<std::mutex> SG::ArenaBase::lock_t

privateinherited

Definition at line 102 of file ArenaBase.h.

Constructor & Destructor Documentation

Arena()

SG::Arena::Arena	(	const std::string &	name,
		ArenaHeader *	header = 0 )

Constructor.

Parameters

name	The name of this Arena; to use in reports.
header	The header with which this Arena is associated. If defaulted, the global default ArenaHeader will be used.

Definition at line 26 of file Arena.cxx.

  : ArenaBase (name),
    m_header (header)
{
  if (!m_header) {
    m_header = SG::ArenaHeader::defaultHeader();
  }
  m_header->addArena (this);
}

~Arena()

SG::Arena::~Arena

(

)

Destructor.

Definition at line 40 of file Arena.cxx.

{
  m_header->delArena (this);
}

Member Function Documentation

allocator()

LockedAllocator SG::ArenaBase::allocator ( size_t i )

inherited

Translate an integer index to an Allocator pointer.

Parameters

i	The index to look up.

If the index isn't valid, an assertion will be tripped.

erase()

void SG::ArenaBase::erase ( )

inherited

Erase all contained allocators.

All elements will be freed, and the memory returned to the system.

Definition at line 60 of file ArenaBase.cxx.

{
  lock_t l (m_mutex);
  for (AllocEntry& alloc : m_allocs) {
    if (alloc.m_alloc) {
      lock_t alloc_lock (*alloc.m_mutex);
      alloc.m_alloc->erase();
    }
  }
}

header()

ArenaHeader * SG::Arena::header

(

)

Return the ArenaHeader with which this Arena is associated.

Definition at line 49 of file Arena.cxx.

{
  return m_header;
}

makeAllocator()

ArenaAllocatorBase * SG::ArenaBase::makeAllocator ( size_t i )

privateinherited

Make a new Allocator for index i.

Parameters

i	The index of the Allocator.

The Allocator vector was empty for index i. Make an appropriate new Allocator, store it in the vector, and return it. Will trip an assertion if the index is not valid.

This should be called with m_mutex held.

Definition at line 130 of file ArenaBase.cxx.

{
  // We have to create a new Allocator.
  // Make sure there's room in the vector.
  if (m_allocs.size() <= i) {
    m_allocs.resize (i+1);
  }
 
  // Create the Allocator, using the Registry.
  std::unique_ptr<ArenaAllocatorBase> alloc =
    ArenaAllocatorRegistry::instance()->create (i);
 
  // Install it in the vector.
  m_allocs[i].m_alloc = std::move (alloc);
  m_allocs[i].m_mutex = std::make_unique<std::mutex>();
 
  return m_allocs[i].m_alloc.get();
}

makeCurrent()

ArenaBase * SG::Arena::makeCurrent

(

)

Make this Arena the current one for its ArenaHeader.

Returns

The previously current Arena.

Definition at line 59 of file Arena.cxx.

{
  return m_header->setArena (this);
}

name()

const std::string & SG::ArenaBase::name ( ) const

inherited

Return this Arena's name.

Definition at line 114 of file ArenaBase.cxx.

{
  return m_name;
}

report()

void SG::ArenaBase::report ( std::ostream & os ) const

inherited

Generate a report of the memory in use by this Arena.

Parameters

os	The stream to which to write the report.

Definition at line 76 of file ArenaBase.cxx.

{
  lock_t l (m_mutex);
  bool first = true;
  for (const AllocEntry& alloc : m_allocs) {
    if (alloc.m_alloc) {
      if (first) {
        ArenaAllocatorBase::Stats::header (os);
        os << std::endl;
        first = false;
      }
      lock_t alloc_lock (*alloc.m_mutex);
      alloc.m_alloc->report (os);
    }
  }
}

reset()

void SG::ArenaBase::reset ( )

inherited

Reset all contained allocators.

All elements will be freed.

Definition at line 44 of file ArenaBase.cxx.

{
  lock_t l (m_mutex);
  for (AllocEntry& alloc : m_allocs) {
    if (alloc.m_alloc) {
      lock_t alloc_lock (*alloc.m_mutex);
      alloc.m_alloc->reset();
    }
  }
}

stats()

ArenaAllocatorBase::Stats SG::ArenaBase::stats ( ) const

inherited

Return statistics summed over all allocators in this Arena.

Definition at line 97 of file ArenaBase.cxx.

{
  ArenaAllocatorBase::Stats stats;
  lock_t l (m_mutex);
  for (const AllocEntry& alloc : m_allocs) {
    if (alloc.m_alloc) {
      lock_t alloc_lock (*alloc.m_mutex);
      stats += alloc.m_alloc->stats();
    }
  }
  return stats;
}

Member Data Documentation

m_allocs

std::vector<AllocEntry> SG::ArenaBase::m_allocs

privateinherited

Definition at line 124 of file ArenaBase.h.

m_header

ArenaHeader* SG::Arena::m_header

private

The ArenaHeader with which we're associated.

Definition at line 300 of file Arena.h.

m_mutex

std::mutex SG::ArenaBase::m_mutex

mutableprivateinherited

To guard access to m_allocs.

Definition at line 130 of file ArenaBase.h.

m_name

std::string SG::ArenaBase::m_name

privateinherited

Our name.

Definition at line 127 of file ArenaBase.h.

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

• Arena.h
• Arena.cxx