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 
sp_counted_base()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 
~sp_counted_base()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 
destroy()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_local_deleter( sp_typeinfo const & ti ) = 0;
75     virtual void * get_untyped_deleter() = 0;
76 
add_ref_copy()77     void add_ref_copy()
78     {
79         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
80         ++use_count_;
81         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
82     }
83 
add_ref_lock()84     bool add_ref_lock() // true on success
85     {
86         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
87         bool r = use_count_ == 0? false: ( ++use_count_, true );
88         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
89         return r;
90     }
91 
release()92     void release() // nothrow
93     {
94         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
95         long new_use_count = --use_count_;
96         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
97 
98         if( new_use_count == 0 )
99         {
100             dispose();
101             weak_release();
102         }
103     }
104 
weak_add_ref()105     void weak_add_ref() // nothrow
106     {
107         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
108         ++weak_count_;
109         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
110     }
111 
weak_release()112     void weak_release() // nothrow
113     {
114         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
115         long new_weak_count = --weak_count_;
116         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
117 
118         if( new_weak_count == 0 )
119         {
120             destroy();
121         }
122     }
123 
use_count() const124     long use_count() const // nothrow
125     {
126         BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
127         long r = use_count_;
128         BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
129 
130         return r;
131     }
132 };
133 
134 } // namespace detail
135 
136 } // namespace boost
137 
138 #endif  // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_PT_HPP_INCLUDED
139