ceph/src/boost/libs/smart_ptr/include/boost/smart_ptr/detail/sp_counted_base_pt.hpp

   1 #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_PT_HPP_INCLUDED
   2 #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_PT_HPP_INCLUDED
   3
   4 // MS compatible compilers support #pragma once
   5
   6 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
   7 # pragma once
   8 #endif
   9
  10 //
  11 //  detail/sp_counted_base_pt.hpp
  12 //
  13 //  Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
  14 //  Copyright 2004-2005 Peter Dimov
  15 //
  16 // Distributed under the Boost Software License, Version 1.0. (See
  17 // accompanying file LICENSE_1_0.txt or copy at
  18 // http://www.boost.org/LICENSE_1_0.txt)
  19 //
  20
  21 #include <boost/detail/sp_typeinfo.hpp>
  22 #include <boost/assert.hpp>
  23 #include <pthread.h>
  24
  25 namespace boost
  26 {
  27
  28 namespace detail
  29 {
  30
  31 class sp_counted_base
  32 {
  33 private:
  34
  35     sp_counted_base( sp_counted_base const & );
  36     sp_counted_base & operator= ( sp_counted_base const & );
  37
  38     long use_count_;        // #shared
  39     long weak_count_;       // #weak + (#shared != 0)
  40
  41     mutable pthread_mutex_t m_;
  42
  43 public:
  44
  45     sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
  46     {
  47 // HPUX 10.20 / DCE has a nonstandard pthread_mutex_init
  48
  49 #if defined(__hpux) && defined(_DECTHREADS_)
  50         BOOST_VERIFY( pthread_mutex_init( &m_, pthread_mutexattr_default ) == 0 );
  51 #else
  52         BOOST_VERIFY( pthread_mutex_init( &m_, 0 ) == 0 );
  53 #endif
  54     }
  55
  56     virtual ~sp_counted_base() // nothrow
  57     {
  58         BOOST_VERIFY( pthread_mutex_destroy( &m_ ) == 0 );
  59     }
  60
  61     // dispose() is called when use_count_ drops to zero, to release
  62     // the resources managed by *this.
  63
  64     virtual void dispose() = 0; // nothrow
  65
  66     // destroy() is called when weak_count_ drops to zero.
  67
  68     virtual void destroy() // nothrow
  69     {
  70         delete this;
  71     }
  72
  73     virtual void * get_deleter( sp_typeinfo const & ti ) = 0;
  74     virtual void * get_untyped_deleter() = 0;
  75
  76     void add_ref_copy()
  77     {
  78         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
  79         ++use_count_;
  80         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
  81     }
  82
  83     bool add_ref_lock() // true on success
  84     {
  85         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
  86         bool r = use_count_ == 0? false: ( ++use_count_, true );
  87         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
  88         return r;
  89     }
  90
  91     void release() // nothrow
  92     {
  93         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
  94         long new_use_count = --use_count_;
  95         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
  96
  97         if( new_use_count == 0 )
  98         {
  99             dispose();
 100             weak_release();
 101         }
 102     }
 103
 104     void weak_add_ref() // nothrow
 105     {
 106         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
 107         ++weak_count_;
 108         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
 109     }
 110
 111     void weak_release() // nothrow
 112     {
 113         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
 114         long new_weak_count = --weak_count_;
 115         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
 116
 117         if( new_weak_count == 0 )
 118         {
 119             destroy();
 120         }
 121     }
 122
 123     long use_count() const // nothrow
 124     {
 125         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
 126         long r = use_count_;
 127         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
 128
 129         return r;
 130     }
 131 };
 132
 133 } // namespace detail
 134
 135 } // namespace boost
 136
 137 #endif  // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_PT_HPP_INCLUDED