boost/interprocess/sync/interprocess_condition.hpp

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