ceph/src/boost/boost/interprocess/sync/spin/interprocess_barrier.hpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2006. 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 #include<boost/interprocess/exceptions.hpp>
  12 #include <boost/interprocess/detail/posix_time_types_wrk.hpp>
  13 #include <boost/interprocess/sync/scoped_lock.hpp>
  14
  15 #ifndef BOOST_CONFIG_HPP
  16 #  include <boost/config.hpp>
  17 #endif
  18 #
  19 #if defined(BOOST_HAS_PRAGMA_ONCE)
  20 #  pragma once
  21 #endif
  22
  23 namespace boost {
  24 namespace interprocess {
  25
  26 inline barrier::barrier(unsigned int count)
  27    : m_threshold(count), m_count(count), m_generation(0)
  28 {
  29    if (count == 0)
  30       throw std::invalid_argument("count cannot be zero.");
  31 }
  32
  33 inline barrier::~barrier(){}
  34
  35 inline bool barrier::wait()
  36 {
  37    scoped_lock<interprocess_mutex> lock(m_mutex);
  38    unsigned int gen = m_generation;
  39
  40    if (--m_count == 0){
  41       m_generation++;
  42       m_count = m_threshold;
  43       m_cond.notify_all();
  44       return true;
  45    }
  46
  47    while (gen == m_generation){
  48       m_cond.wait(lock);
  49    }
  50    return false;
  51 }
  52
  53 }  //namespace interprocess {
  54 }  //namespace boost {