ns-3-dev: src/core/simple-ref-count.h@c0ac392289c3

     1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

     2 /*

     3  * Copyright (c) 2007 Georgia Tech Research Corporation, INRIA

     4  *

     5  * This program is free software; you can redistribute it and/or modify

     6  * it under the terms of the GNU General Public License version 2 as

     7  * published by the Free Software Foundation;

     8  *

     9  * This program is distributed in the hope that it will be useful,

    10  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    12  * GNU General Public License for more details.

    13  *

    14  * You should have received a copy of the GNU General Public License

    15  * along with this program; if not, write to the Free Software

    16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    17  *

    18  * Authors: George Riley <riley@ece.gatech.edu>

    19  *          Gustavo Carneiro <gjcarneiro@gmail.com>,

    20  *          Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

    21  */

    22 #ifndef SIMPLE_REF_COUNT_H

    23 #define SIMPLE_REF_COUNT_H

    25 #include "empty.h"

    26 #include <stdint.h>

    28 namespace ns3 {

    30 /**

    31  * \brief A template-based reference counting class

    32  *

    33  * This template can be used to give reference-counting powers

    34  * to a class. This template does not require this class to

    35  * have a virtual destructor or no parent class.

    36  *

    37  * Note: if you are moving to this template from the RefCountBase class,

    38  * you need to be careful to mark appropriately your destructor virtual

    39  * if needed. i.e., if your class has subclasses, _do_ mark your destructor

    40  * virtual.

    41  *

    42  * \internal

    43  * Note: we rely on the fairly common EBCO (empty base class optimization)

    44  * to get rid of the empty parent when the user does not provide

    45  * a non-trivial parent.

    46  */

    47 template <typename T, typename PARENT = empty>

    48 class SimpleRefCount : public PARENT

    49 {

    50 public:

    51   SimpleRefCount ()

    52     : m_count (1)

    53   {}

    54   SimpleRefCount (const SimpleRefCount &o)

    55     : m_count (1)

    56   {}

    57   SimpleRefCount &operator = (const SimpleRefCount &o)

    58   {

    59     return *this;

    60   }

    61   /**

    62    * Increment the reference count. This method should not be called

    63    * by user code. SimpleRefCount instances are expected to be used in

    64    * conjunction with the Ptr template which would make calling Ref

    65    * unecessary and dangerous.

    66    */

    67   inline void Ref (void) const

    68   {

    69     m_count++;

    70   }

    71   /**

    72    * Decrement the reference count. This method should not be called

    73    * by user code. SimpleRefCount instances are expected to be used in

    74    * conjunction with the Ptr template which would make calling Ref

    75    * unecessary and dangerous.

    76    */

    77   inline void Unref (void) const

    78   {

    79     m_count--;

    80     if (m_count == 0)

    81       {

    82 	delete static_cast<T*> (const_cast<SimpleRefCount *> (this));

    83       }

    84   }

    86   /**

    87    * Get the reference count of the object.

    88    * Normally not needed; for language bindings.

    89    */

    90   uint32_t GetReferenceCount (void) const

    91   {

    92     return m_count;

    93   }

    95 private:

    96   // Note we make this mutable so that the const methods can still

    97   // change it.

    98   mutable uint32_t m_count;

    99 };

   101 } // namespace ns3

   103 #endif /* SIMPLE_REF_COUNT_H */

author	Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
	Thu Nov 12 13:01:01 2009 +0100 (2009-11-12)
changeset 5505	c0ac392289c3
child 5840	c2b3762932e8
permissions	-rw-r--r--