refcounted.h

Go to the documentation of this file.

//
// Copyright (c) 2000-2004 California Institute of Technology
// Copyright (c) 2004-2007 University of Southern California
// Rob Peters <rjpeters at usc dot edu>
//
// created: Sun Oct 22 14:40:19 2000
// commit: $Id: refcounted.h 10065 2007-04-12 05:54:56Z rjpeters $
// $HeadURL: file:///lab/rjpeters/svnrepo/code/trunk/groovx/src/nub/refcounted.h $
//
// --------------------------------------------------------------------
//
// This file is part of GroovX.
//   [http://ilab.usc.edu/rjpeters/groovx/]
//
// GroovX is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// GroovX is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with GroovX; if not, write to the Free Software Foundation,
// Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
//

#ifndef GROOVX_NUB_REFCOUNTED_H_UTC20050626084018_DEFINED
#define GROOVX_NUB_REFCOUNTED_H_UTC20050626084018_DEFINED

#include "rutz/atomic.h"

#include <cstdlib>

namespace nub
{
  class ref_counts;
  class ref_counted;
}


// If we want to enforce that destructors of objects derived form
// nub::ref_counted (and nub::object) should have an empty throw-spec
// (i.e. "throw()"), then need "#define GVX_DTOR_NOTHROW throw()",
// otherwise we just define GVX_DTOR_NOTHROW to be empty
#ifndef GVX_DTOR_NOTHROW
#  define GVX_DTOR_NOTHROW
#endif




struct nub::ref_counts
{
public:
  friend class nub::ref_counted;

  void* operator new(size_t bytes);
  void operator delete(void* space, size_t bytes);

  ref_counts() throw();

private:
  ~ref_counts() throw();

public:

  bool is_owner_alive() const throw() { return m_owner_alive; }

  void acquire_weak() throw();
  int release_weak() throw();

  void debug_dump() const throw();

private:
  ref_counts(const ref_counts&) throw();
  ref_counts& operator=(const ref_counts&) throw();

  void acquire_strong() throw();
  int release_strong() throw();
  void release_strong_no_delete() throw();

  rutz::atomic_int_t m_strong;
  rutz::atomic_int_t m_weak;
  bool m_owner_alive;
  bool m_volatile;
};






class nub::ref_counted
{
private:
  ref_counts* const m_ref_counts;

  // These are disallowed since ref_counted's should always be in
  // one-to-one correspondence with their pointee's.
  ref_counted(const ref_counted& other);
  ref_counted& operator=(const ref_counted& other);

  // If GVX_ENFORCE_FACTORY_FUNCTIONS, then we make operator new() and
  // delete() protected, as well as the default constructor and
  // destructor. This means that only derived classes can use operator
  // new() and delete(), and that thus derived classes are required to
  // define functions of the form "static nub::ref<derived_class>
  // make() { return nub::ref<derived_class>(new derived_class)."
  // While this is a bit of extra typing, it helps ensure that
  // ref_counted objects are not constructed on the stack, and are not
  // handled by the wrong type of smart pointer (such as a
  // shared_ptr).
#ifdef GVX_ENFORCE_FACTORY_FUNCTIONS
protected:
#else
public:
#endif

  void* operator new(size_t bytes);

  void operator delete(void* space, size_t bytes);

  ref_counted();

  virtual ~ref_counted() GVX_DTOR_NOTHROW;

  void mark_as_volatile() throw();

public:

  void incr_ref_count() const throw();


  void decr_ref_count() const throw();


  void decr_ref_count_no_delete() const throw();


  bool is_shared() const throw();


  bool is_unshared() const throw();

  bool is_not_shareable() const throw();

  ref_counts* get_counts() const throw();


  int dbg_ref_count() const throw();

  int dbg_weak_ref_count() const throw();
};

static const char __attribute__((used)) vcid_groovx_nub_refcounted_h_utc20050626084018[] = "$Id: refcounted.h 10065 2007-04-12 05:54:56Z rjpeters $ $HeadURL: file:
#endif // !GROOVX_NUB_REFCOUNTED_H_UTC20050626084018_DEFINED

---

The software described here is Copyright (c) 1998-2005, Rob Peters.
This page was generated Wed Dec 3 06:49:40 2008 by Doxygen version 1.5.5.