FryingPan/framework/Generic/RWSyncT.h

   1 /*
   2  * Amiga Generic Set - set of libraries and includes to ease sw development for all Amiga platforms
   3  * Copyright (C) 2001-2011 Tomasz Wiszkowski Tomasz.Wiszkowski at gmail.com.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19
  20 #ifndef RWSYNCT_H_
  21 #define RWSYNCT_H_
  22
  23 #include "RWSync.h"
  24
  25 namespace GenNS
  26 {
  27    template <typename T>
  28       class RWSyncT
  29    {
  30       T                 resource;
  31       RWSync            pSync;
  32    public:
  33
  34       RWSyncT()
  35       {
  36       }
  37
  38       virtual          ~RWSyncT()
  39       {
  40          pSync.ObtainWrite();
  41       }
  42
  43       virtual T        &AttemptRead(bool *bResult)
  44       {
  45          if ((pSync.AttemptRead()) && (0 != bResult))
  46             *bResult = true;
  47          else if (0 != bResult)
  48             *bResult = false;
  49          return resource;
  50       }
  51
  52       virtual T        &ObtainRead()
  53       {
  54          pSync.ObtainRead();
  55          return resource;
  56       }
  57
  58       virtual T        &AttemptWrite(bool *bResult)
  59       {
  60          if ((pSync.AttemptWrite()) && (0 != bResult))
  61             *bResult = true;
  62          else if (0 != bResult)
  63             *bResult = false;
  64          return resource;
  65       }
  66
  67       virtual T        &ObtainWrite()
  68       {
  69          pSync.ObtainWrite();
  70          return resource;
  71       }
  72
  73       virtual void      Release()
  74       {
  75          pSync.Release();
  76       }
  77
  78       virtual T         Assign(T newValue)
  79       {
  80          T oldValue;
  81          oldValue = ObtainWrite();
  82          resource = newValue;
  83          Release();
  84          return oldValue;
  85       }
  86
  87       virtual T         AttemptAssign(T newValue, bool *bResult)
  88       {
  89          T oldValue;
  90          bool bRes;
  91          oldValue = AttemptWrite(&bRes);
  92          if (bRes)
  93          {
  94             resource = newValue;
  95             Release();
  96             if (bResult)
  97                *bResult = true;
  98             return oldValue;
  99          }
 100          if (bResult)
 101             *bResult = false;
 102          return resource;
 103       }
 104
 105       RWSyncT<T>       &operator = (RWSyncT<T> &hOther)
 106       {
 107          pSync.ObtainWrite();             // make sure nobody accesses us atm
 108
 109          *resource = *hOther.resource;    // copy elements, dont bother how.
 110
 111          pSync.Release();                 // this is the obtained one :)
 112          return *this;
 113       }
 114
 115
 116    };
 117 };
 118
 119 #endif /*RWSYNCT_H_*/