1 //////////////////////////////////////////////////////////////////////////////
2 //
3 // (C) Copyright Ion Gaztanaga 2005-2012. Distributed under the Boost
4 // Software License, Version 1.0. (See accompanying file
5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 //
7 // See http://www.boost.org/libs/interprocess for documentation.
8 //
9 //////////////////////////////////////////////////////////////////////////////
10 
11 #ifndef BOOST_INTERPROCESS_CONDITION_HPP
12 #define BOOST_INTERPROCESS_CONDITION_HPP
13 
14 #ifndef BOOST_CONFIG_HPP
15 #  include <boost/config.hpp>
16 #endif
17 #
18 #if defined(BOOST_HAS_PRAGMA_ONCE)
19 #  pragma once
20 #endif
21 
22 #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
23 
24 #include <boost/interprocess/detail/config_begin.hpp>
25 #include <boost/interprocess/detail/workaround.hpp>
26 
27 #include <boost/interprocess/detail/posix_time_types_wrk.hpp>
28 #include <boost/interprocess/sync/interprocess_mutex.hpp>
29 #include <boost/interprocess/sync/detail/locks.hpp>
30 #include <boost/interprocess/exceptions.hpp>
31 #include <boost/limits.hpp>
32 #include <boost/assert.hpp>
33 
34 #if !defined(BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION) && defined(BOOST_INTERPROCESS_POSIX_PROCESS_SHARED)
35    #include <boost/interprocess/sync/posix/condition.hpp>
36    #define BOOST_INTERPROCESS_USE_POSIX
37 //Experimental...
38 #elif !defined(BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION) && defined (BOOST_INTERPROCESS_WINDOWS)
39    #include <boost/interprocess/sync/windows/condition.hpp>
40    #define BOOST_INTERPROCESS_USE_WINDOWS
41 #elif !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
42    #include <boost/interprocess/sync/spin/condition.hpp>
43    #define BOOST_INTERPROCESS_USE_GENERIC_EMULATION
44 #endif
45 
46 #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
47 
48 //!\file
49 //!Describes process-shared variables interprocess_condition class
50 
51 namespace boost {
52 
53 #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
54 
55 namespace posix_time
56 {  class ptime;   }
57 
58 #endif   //#if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
59 
60 namespace interprocess {
61 
62 class named_condition;
63 
64 //!This class is a condition variable that can be placed in shared memory or
65 //!memory mapped files.
66 //!Destroys the object of type std::condition_variable_any
67 //!
68 //!Unlike std::condition_variable in C++11, it is NOT safe to invoke the destructor if all
69 //!threads have been only notified. It is required that they have exited their respective wait
70 //!functions.
71 class interprocess_condition
72 {
73    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
74    //Non-copyable
75    interprocess_condition(const interprocess_condition &);
76    interprocess_condition &operator=(const interprocess_condition &);
77    friend class named_condition;
78    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
79 
80    public:
81    //!Constructs a interprocess_condition. On error throws interprocess_exception.
interprocess_condition()82    interprocess_condition()
83    {}
84 
85    //!Destroys *this
86    //!liberating system resources.
~interprocess_condition()87    ~interprocess_condition()
88    {}
89 
90    //!If there is a thread waiting on *this, change that
91    //!thread's state to ready. Otherwise there is no effect.
notify_one()92    void notify_one()
93    {  m_condition.notify_one();  }
94 
95    //!Change the state of all threads waiting on *this to ready.
96    //!If there are no waiting threads, notify_all() has no effect.
notify_all()97    void notify_all()
98    {  m_condition.notify_all();  }
99 
100    //!Releases the lock on the interprocess_mutex object associated with lock, blocks
101    //!the current thread of execution until readied by a call to
102    //!this->notify_one() or this->notify_all(), and then reacquires the lock.
103    template <typename L>
wait(L & lock)104    void wait(L& lock)
105    {
106       ipcdetail::internal_mutex_lock<L> internal_lock(lock);
107       m_condition.wait(internal_lock);
108    }
109 
110    //!The same as:
111    //!while (!pred()) wait(lock)
112    template <typename L, typename Pr>
wait(L & lock,Pr pred)113    void wait(L& lock, Pr pred)
114    {
115       ipcdetail::internal_mutex_lock<L> internal_lock(lock);
116       m_condition.wait(internal_lock, pred);
117    }
118 
119    //!Releases the lock on the interprocess_mutex object associated with lock, blocks
120    //!the current thread of execution until readied by a call to
121    //!this->notify_one() or this->notify_all(), or until time abs_time is reached,
122    //!and then reacquires the lock.
123    //!Returns: false if time abs_time is reached, otherwise true.
124    template <typename L>
timed_wait(L & lock,const boost::posix_time::ptime & abs_time)125    bool timed_wait(L& lock, const boost::posix_time::ptime &abs_time)
126    {
127       ipcdetail::internal_mutex_lock<L> internal_lock(lock);
128       return m_condition.timed_wait(internal_lock, abs_time);
129    }
130 
131    //!The same as:   while (!pred()) {
132    //!                  if (!timed_wait(lock, abs_time)) return pred();
133    //!               } return true;
134    template <typename L, typename Pr>
timed_wait(L & lock,const boost::posix_time::ptime & abs_time,Pr pred)135    bool timed_wait(L& lock, const boost::posix_time::ptime &abs_time, Pr pred)
136    {
137       ipcdetail::internal_mutex_lock<L> internal_lock(lock);
138       return m_condition.timed_wait(internal_lock, abs_time, pred);
139    }
140 
141    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
142 
143    private:
144    #if defined (BOOST_INTERPROCESS_USE_GENERIC_EMULATION)
145       #undef BOOST_INTERPROCESS_USE_GENERIC_EMULATION
146       ipcdetail::spin_condition m_condition;
147    #elif defined(BOOST_INTERPROCESS_USE_POSIX)
148       #undef BOOST_INTERPROCESS_USE_POSIX
149       ipcdetail::posix_condition m_condition;
150    #elif defined(BOOST_INTERPROCESS_USE_WINDOWS)
151       #undef BOOST_INTERPROCESS_USE_WINDOWS
152       ipcdetail::windows_condition m_condition;
153    #else
154       #error "Unknown platform for interprocess_mutex"
155    #endif
156    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
157 };
158 
159 }  //namespace interprocess
160 }  // namespace boost
161 
162 #include <boost/interprocess/detail/config_end.hpp>
163 
164 #endif // BOOST_INTERPROCESS_CONDITION_HPP
165