dep/include/zthread/ThreadLocalImpl.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 __ZTTHREADLOCALIMPL_H__
  24 #define __ZTTHREADLOCALIMPL_H__
  25
  26 #include "zthread/CountedPtr.h"
  27
  28 namespace ZThread {
  29
  30   /**
  31    * @class ThreadLocalImpl
  32    * @author Eric Crahen <http://www.code-foo.com>
  33    * @date <2003-07-27T10:23:19-0400>
  34    * @version 2.3.0
  35    *
  36    * @see ThreadLocal
  37    */
  38   class ZTHREAD_API ThreadLocalImpl : private NonCopyable {
  39   public:
  40
  41     class Value;
  42     typedef CountedPtr<Value, size_t> ValuePtr;
  43
  44     //!
  45     class Value {
  46       Value& operator=(const Value&);
  47     public:
  48       virtual ~Value() {}
  49       virtual bool isInheritable() const = 0;
  50       virtual ValuePtr clone() const = 0;
  51     };
  52
  53     //! Create a ThreadLocalImpl
  54     ThreadLocalImpl();
  55
  56     //! Destroy a ThreadLocalImpl
  57     ~ThreadLocalImpl();
  58
  59     /**
  60      * @class InitialValueFn
  61      */
  62     template <typename T>
  63     struct InitialValueFn {
  64       T operator()() { return T(); }
  65     };
  66
  67     /**
  68      * @class ChildValueFn
  69      */
  70     struct ChildValueFn {
  71       template <typename T>
  72       T operator()(const T& value) { return T(value); }
  73     };
  74
  75     /**
  76      * @class UniqueChildValueFn
  77      */
  78     struct UniqueChildValueFn : public ChildValueFn { };
  79
  80     /**
  81      * @class InheritableValueFn
  82      */
  83     struct InheritableValueFn {
  84
  85       template <typename T>
  86       bool operator()(const T&) { return true; }
  87
  88       bool operator()(const UniqueChildValueFn&) { return false; }
  89
  90     };
  91
  92   protected:
  93
  94     //! Get the Value for the current thread
  95     ValuePtr value( ValuePtr (*pfn)() ) const;
  96
  97     //! Clear any value set for this thread
  98     void clear() const;
  99
 100     //! Clear any value set with any ThreadLocal for this thread
 101     static void clearAll();
 102
 103   };
 104
 105 } // __ZTTHREADLOCALIMPL_H__
 106
 107 #endif
 108