ceph/src/boost/libs/fiber/examples/future.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 <exception>
   9 #include <functional>
  10 #include <iostream>
  11 #include <string>
  12
  13 #include <boost/fiber/all.hpp>
  14
  15 inline
  16 int fn( std::string const& str, int n)
  17 {
  18         for ( int i = 0; i < n; ++i)
  19         {
  20                 std::cout << i << ": " << str << std::endl;
  21                 boost::this_fiber::yield();
  22         }
  23
  24     return n;
  25 }
  26
  27 void start()
  28 {
  29     boost::fibers::future< int > fi(
  30         boost::fibers::async(
  31             std::bind( fn, "abc", 5) ) );
  32     fi.wait();
  33     std::cout << "fn() returned " << fi.get() << std::endl;
  34 }
  35
  36 int main()
  37 {
  38         try
  39         {
  40         boost::fibers::fiber( start).join();
  41                 std::cout << "done." << std::endl;
  42
  43                 return EXIT_SUCCESS;
  44         }
  45         catch ( std::exception const& e)
  46         { std::cerr << "exception: " << e.what() << std::endl; }
  47         catch (...)
  48         { std::cerr << "unhandled exception" << std::endl; }
  49         return EXIT_FAILURE;
  50 }