extl/synch/lock_base.h

   1 /* ///////////////////////////////////////////////////////////////////////
   2  * File:                lock_base.h
   3  *
   4  * Created:             08.03.20
   5  * Updated:             08.12.13
   6  *
   7  * Brief:               The lock_base class
   8  *
   9  * [<Home>]
  10  * Copyright (c) 2008-2020, Waruqi All rights reserved.
  11  * //////////////////////////////////////////////////////////////////// */
  12 #ifndef EXTL_SYNCH_LOCK_BASE_H
  13 #define EXTL_SYNCH_LOCK_BASE_H
  14
  15 /*!\file lock_base.h
  16  * \brief The lock_base class
  17  */
  18 #ifndef __cplusplus
  19 #       error lock_base.h need be supported by c++.
  20 #endif
  21
  22 /* ///////////////////////////////////////////////////////////////////////
  23  * Includes
  24  */
  25 #include "prefix.h"
  26 #include "../utility/uncopyable.h"
  27 #include "../error/error.h"
  28
  29 /* ///////////////////////////////////////////////////////////////////////
  30  * ::extl namespace
  31  */
  32 EXTL_BEGIN_NAMESPACE
  33
  34 /*!\brief lock_base class
  35  *
  36  * \param Dev The derived type
  37  *
  38  * \ingroup extl_group_synch
  39  */
  40 template<typename_param_k Dev>
  41 class lock_base
  42         : private uncopyable<lock_base<Dev> >
  43 {
  44         /// \name Types
  45         /// @{
  46         public:
  47                 typedef lock_base                       class_type;
  48                 typedef Dev                                     derived_type;
  49                 typedef e_bool_t                        bool_type;
  50                 typedef e_size_t                        size_type;
  51         /// @}
  52
  53         /// \name Members
  54         /// @{
  55         private:
  56                 size_type                                       m_lock_n;
  57         /// @}
  58
  59         /// \name Constructors
  60         /// @{
  61         public:
  62                 lock_base()
  63                         : m_lock_n(0)
  64                 {}
  65         /// @}
  66
  67         /// \name Methods
  68         /// @{
  69         public:
  70                 void                            lock();         //!< Lock
  71                 bool_type                       trylock();      //!< Try lock
  72                 void                            unlock();       //!< Unlock
  73         /// @}
  74
  75         /// \name Attributes
  76         /// @{
  77         public:
  78                 /// Returns the lock count
  79                 size_type                       count() const           { return m_lock_n;                      }
  80                 /// Indicates whether is locked
  81                 bool_type                       is_locked() const       { return (count() != 0);        }
  82         /// @}
  83
  84         /// \name Helpers
  85         /// @{
  86         protected:
  87                 derived_type&           derive()                        { return static_cast<derived_type&>(*this);                     }
  88                 derived_type const&     derive() const          { return static_cast<derived_type const&>(*this);       }
  89         /// @}
  90 };
  91 /* ///////////////////////////////////////////////////////////////////////
  92  * Implemention
  93  */
  94 template<typename_param_k Dev>
  95 inline void lock_base<Dev>::lock()
  96 {
  97         EXTL_MESSAGE_ASSERT(0 == count(), "lock repeatly");
  98         EXTL_ASSERT_THROW(0 == count(), lock_error("lock_error: repeat lock"));
  99
 100         derive().do_lock();
 101         ++m_lock_n;
 102 }
 103 template<typename_param_k Dev>
 104 inline typename_type_ret_k lock_base<Dev>::bool_type
 105 lock_base<Dev>::trylock()
 106 {
 107         EXTL_MESSAGE_ASSERT(0 == count(), "lock repeatly");
 108         EXTL_ASSERT_THROW(0 == count(), lock_error("lock_error: repeat trylock"));
 109
 110         bool_type ret = derive().do_trylock();
 111         // lock successfully
 112         if (ret) ++m_lock_n;
 113         return ret;
 114
 115 }
 116 template<typename_param_k Dev>
 117 inline void lock_base<Dev>::unlock()
 118 {
 119         EXTL_MESSAGE_ASSERT(0 != count(), "unlock repeatly");
 120         EXTL_ASSERT_THROW(0 != count(), lock_error("lock_error: repeat unlock"));
 121
 122         derive().do_unlock();
 123         --m_lock_n;
 124 }
 125
 126 /* ///////////////////////////////////////////////////////////////////////
 127  * ::extl namespace
 128  */
 129 EXTL_END_NAMESPACE
 130
 131 /* //////////////////////////////////////////////////////////////////// */
 132 #endif /* EXTL_SYNCH_LOCK_BASE_H */
 133 /* //////////////////////////////////////////////////////////////////// */