ceph/src/boost/libs/fiber/examples/barrier.cpp

   1
   2 //          Copyright Oliver Kowalke 2013.
   3 // Distributed under the Boost Software License, Version 1.0.
   4 //    (See accompanying file LICENSE_1_0.txt or copy at
   5 //          http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #include <cstdlib>
   8 #include <functional>
   9 #include <iostream>
  10 #include <stdexcept>
  11
  12 #include <boost/assert.hpp>
  13
  14 #include <boost/fiber/all.hpp>
  15
  16 int value1 = 0;
  17 int value2 = 0;
  18
  19 inline
  20 void fn1( boost::fibers::barrier & b)
  21 {
  22     boost::fibers::fiber::id id = boost::this_fiber::get_id();
  23         std::cout << "fiber " << id << ": fn1 entered" << std::endl;
  24
  25         ++value1;
  26         std::cout << "fiber " << id << ": incremented value1: " << value1 << std::endl;
  27         boost::this_fiber::yield();
  28
  29         std::cout << "fiber " << id << ": waits for barrier" << std::endl;
  30         b.wait();
  31         std::cout << "fiber " << id << ": passed barrier" << std::endl;
  32
  33         ++value1;
  34         std::cout << "fiber " << id << ": incremented value1: " << value1 << std::endl;
  35         boost::this_fiber::yield();
  36
  37         ++value1;
  38         std::cout << "fiber " << id << ": incremented value1: " << value1 << std::endl;
  39         boost::this_fiber::yield();
  40
  41         ++value1;
  42         std::cout << "fiber " << id << ": incremented value1: " << value1 << std::endl;
  43         boost::this_fiber::yield();
  44
  45         std::cout << "fiber " << id << ": fn1 returns" << std::endl;
  46 }
  47
  48 inline
  49 void fn2( boost::fibers::barrier & b)
  50 {
  51     boost::fibers::fiber::id id = boost::this_fiber::get_id();
  52         std::cout << "fiber " << id << ": fn2 entered" << std::endl;
  53
  54         ++value2;
  55         std::cout << "fiber " << id << ": incremented value2: " << value2 << std::endl;
  56         boost::this_fiber::yield();
  57
  58         ++value2;
  59         std::cout << "fiber " << id << ": incremented value2: " << value2 << std::endl;
  60         boost::this_fiber::yield();
  61
  62         ++value2;
  63         std::cout << "fiber " << id << ": incremented value2: " << value2 << std::endl;
  64         boost::this_fiber::yield();
  65
  66         std::cout << "fiber " << id << ": waits for barrier" << std::endl;
  67         b.wait();
  68         std::cout << "fiber " << id << ": passed barrier" << std::endl;
  69
  70         ++value2;
  71         std::cout << "fiber " << id << ": incremented value2: " << value2 << std::endl;
  72         boost::this_fiber::yield();
  73
  74         std::cout << "fiber " << id << ": fn2 returns" << std::endl;
  75 }
  76
  77 int main()
  78 {
  79         try
  80         {
  81                 boost::fibers::barrier fb( 2);
  82
  83                 boost::fibers::fiber f1( & fn1, std::ref( fb) );
  84                 boost::fibers::fiber f2( & fn2, std::ref( fb) );
  85
  86         f1.join();
  87         f2.join();
  88
  89                 std::cout << "done." << std::endl;
  90
  91                 return EXIT_SUCCESS;
  92         }
  93         catch ( std::exception const& e)
  94         { std::cerr << "exception: " << e.what() << std::endl; }
  95         catch (...)
  96         { std::cerr << "unhandled exception" << std::endl; }
  97         return EXIT_FAILURE;
  98 }