src/mem/gems_common/RefCnt.hh

   1 /*
   2  * Copyright (c) 1999-2005 Mark D. Hill and David A. Wood
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef REFCNT_H
  30 #define REFCNT_H
  31
  32 template <class TYPE>
  33 class RefCnt {
  34 public:
  35   // Constructors
  36   RefCnt();
  37   RefCnt(const TYPE& data);
  38
  39   // Destructor
  40   ~RefCnt();
  41
  42   // Public Methods
  43   const TYPE* ref() const { return m_data_ptr; }
  44   TYPE* ref() { return m_data_ptr; }
  45   TYPE* mod_ref() const { return m_data_ptr; }
  46   void freeRef();
  47   void print(ostream& out) const;
  48
  49   // Public copy constructor and assignment operator
  50   RefCnt(const RefCnt& obj);
  51   RefCnt& operator=(const RefCnt& obj);
  52
  53 private:
  54   // Private Methods
  55
  56   // Data Members (m_ prefix)
  57   TYPE* m_data_ptr;
  58   //  int* m_count_ptr; // Not used yet
  59 };
  60
  61 // Output operator declaration
  62 template <class TYPE>
  63 inline
  64 ostream& operator<<(ostream& out, const RefCnt<TYPE>& obj);
  65
  66 // ******************* Definitions *******************
  67
  68 // Constructors
  69 template <class TYPE>
  70 inline
  71 RefCnt<TYPE>::RefCnt()
  72 {
  73   m_data_ptr = NULL;
  74 }
  75
  76 template <class TYPE>
  77 inline
  78 RefCnt<TYPE>::RefCnt(const TYPE& data)
  79 {
  80   m_data_ptr = data.clone();
  81   m_data_ptr->setRefCnt(1);
  82 }
  83
  84 template <class TYPE>
  85 inline
  86 RefCnt<TYPE>::~RefCnt()
  87 {
  88   freeRef();
  89 }
  90
  91 template <class TYPE>
  92 inline
  93 void RefCnt<TYPE>::freeRef()
  94 {
  95   if (m_data_ptr != NULL) {
  96     m_data_ptr->decRefCnt();
  97     if (m_data_ptr->getRefCnt() == 0) {
  98       m_data_ptr->destroy();
  99     }
 100     m_data_ptr = NULL;
 101   }
 102 }
 103
 104 template <class TYPE>
 105 inline
 106 void RefCnt<TYPE>::print(ostream& out) const
 107 {
 108   if (m_data_ptr == NULL) {
 109     out << "[RefCnt: Null]";
 110   } else {
 111     out << "[RefCnt: ";
 112     m_data_ptr->print(out);
 113     out << "]";
 114   }
 115 }
 116
 117 // Copy constructor
 118 template <class TYPE>
 119 inline
 120 RefCnt<TYPE>::RefCnt(const RefCnt<TYPE>& obj)
 121 {
 122   //  m_data_ptr = obj.m_data_ptr->clone();
 123   m_data_ptr = obj.m_data_ptr;
 124
 125   // Increment the reference count
 126   if (m_data_ptr != NULL) {
 127     m_data_ptr->incRefCnt();
 128   }
 129 }
 130
 131 // Assignment operator
 132 template <class TYPE>
 133 inline
 134 RefCnt<TYPE>& RefCnt<TYPE>::operator=(const RefCnt<TYPE>& obj)
 135 {
 136   if (this == &obj) {
 137     // If this is the case, do nothing
 138     //    assert(false);
 139   } else {
 140     freeRef();
 141     m_data_ptr = obj.m_data_ptr;
 142     if (m_data_ptr != NULL) {
 143       m_data_ptr->incRefCnt();
 144     }
 145   }
 146   return *this;
 147 }
 148
 149
 150 // Output operator definition
 151 template <class TYPE>
 152 inline
 153 ostream& operator<<(ostream& out, const RefCnt<TYPE>& obj)
 154 {
 155   obj.print(out);
 156   out << flush;
 157   return out;
 158 }
 159
 160
 161
 162 #endif //REFCNT_H