dep/include/zthread/GuardedClass.h

   1 /*
   2  * Copyright (c) 2005, Eric Crahen
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is furnished
   9  * to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in all
  12  * copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  18  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  19  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  20  *
  21  */
  22
  23 #ifndef __GUARDEDCLASS_H__
  24 #define __GUARDEDCLASS_H__
  25
  26 #include "zthread/Guard.h"
  27 #include "zthread/Mutex.h"
  28
  29 namespace ZThread {
  30
  31   /**
  32    * @class GuardedClass
  33    * @author Eric Crahen <http://www.code-foo.com>
  34    * @date <2003-07-20T20:17:34-0400>
  35    * @version 2.3.0
  36    *
  37    * A simple wrapper template that uses Guard's to provide
  38    * serialized access to an objects member functions.
  39    */
  40   template <class T, class LockType = Mutex>
  41     class GuardedClass {
  42
  43       LockType _lock;
  44       T* _ptr;
  45
  46       class TransferedScope {
  47       public:
  48
  49         template <class LockType1, class LockType2>
  50           static void shareScope(LockHolder<LockType1>& l1,
  51                                  LockHolder<LockType2>& l2) {
  52           l1.disable();
  53           l2.getLock().acquire();
  54         }
  55
  56         template <class LockType1>
  57           static void createScope(LockHolder<LockType1>& l) {
  58           // Don't acquire the lock when scope the Guard is created
  59         }
  60
  61         template <class LockType1>
  62           static void destroyScope(LockHolder<LockType1>& l) {
  63           l.getLock().release();
  64         }
  65
  66       };
  67
  68       class Proxy : Guard<LockType, TransferedScope> {
  69
  70         T* _object;
  71
  72       public:
  73
  74         Proxy(LockType& lock, T* object) :
  75           Guard<LockType, TransferedScope>(lock), _object(object) { }
  76
  77         T* operator->() {
  78           return _object;
  79         }
  80
  81       };
  82
  83       GuardedClass();
  84       GuardedClass& operator=(const GuardedClass&);
  85
  86       public:
  87
  88       GuardedClass(T* ptr) : _ptr(ptr) {}
  89       ~GuardedClass() {
  90         if(_ptr)
  91           delete _ptr;
  92       }
  93
  94       Proxy operator->() {
  95         Proxy p(_lock, _ptr);
  96         return p;
  97       }
  98
  99     };
 100
 101 } // namespace ZThread
 102
 103 #endif // __ZTGUARDEDCLASS_H__