boost/libs/thread/example/future_then.cpp

// Copyright (C) 2012-2013 Vicente Botet
//
//  Distributed under the Boost Software License, Version 1.0. (See accompanying
//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#include <boost/config.hpp>
#if ! defined  BOOST_NO_CXX11_DECLTYPE
#define BOOST_RESULT_OF_USE_DECLTYPE
#endif


#define BOOST_THREAD_VERSION 4
//#define BOOST_THREAD_USES_LOG
#define BOOST_THREAD_USES_LOG_THREAD_ID

#include <boost/thread/detail/log.hpp>
#include <boost/thread/future.hpp>
#include <boost/assert.hpp>
#include <string>
#if defined BOOST_THREAD_PROVIDES_FUTURE_CONTINUATION

int p1()
{
  BOOST_THREAD_LOG << "P1" << BOOST_THREAD_END_LOG;
  return 123;
}

int p2(boost::future<int> f)
{
  BOOST_THREAD_LOG << "P2<" << BOOST_THREAD_END_LOG;
  try
  {
    return 2 * f.get();
  }
  catch (std::exception& ex)
  {
    std::cout << "ERRORRRRR "<<ex.what() << "" << std::endl;
    BOOST_THREAD_LOG << "ERRORRRRR "<<ex.what() << "" << BOOST_THREAD_END_LOG;
    BOOST_ASSERT(false);
  }
  catch (...)
  {
    BOOST_THREAD_LOG << " ERRORRRRR exception thrown" << BOOST_THREAD_END_LOG;
    BOOST_ASSERT(false);
  }
  BOOST_THREAD_LOG << "P2>" << BOOST_THREAD_END_LOG;
  return 0;
}
int p2s(boost::shared_future<int> f)
{
  BOOST_THREAD_LOG << "<P2S" << BOOST_THREAD_END_LOG;
  try
  {
    return 2 * f.get();
  }
  catch (std::exception& ex)
  {
    std::cout << "ERRORRRRR "<<ex.what() << "" << std::endl;
    BOOST_THREAD_LOG << "ERRORRRRR "<<ex.what() << "" << BOOST_THREAD_END_LOG;
    BOOST_ASSERT(false);
  }
  catch (...)
  {
    BOOST_THREAD_LOG << " ERRORRRRR exception thrown" << BOOST_THREAD_END_LOG;
    BOOST_ASSERT(false);
  }
  BOOST_THREAD_LOG << "P2S>" << BOOST_THREAD_END_LOG;
  return 0;
}

int main()
{
  const int number_of_tests = 100;
  BOOST_THREAD_LOG << "<MAIN" << BOOST_THREAD_END_LOG;
  {
    for (int i=0; i< number_of_tests; i++)
    try
    {
      BOOST_THREAD_LOG << "" << BOOST_THREAD_END_LOG;
      boost::future<int> f1 = boost::async(&p1);
      BOOST_THREAD_LOG << "" << BOOST_THREAD_END_LOG;
      boost::future<int> f2 = f1.then(&p2);
      BOOST_THREAD_LOG << "" << BOOST_THREAD_END_LOG;
      (void)f2.get();
      BOOST_THREAD_LOG << "" << BOOST_THREAD_END_LOG;
    }
    catch (std::exception& ex)
    {
      std::cout << "ERRORRRRR "<<ex.what() << "" << std::endl;
      BOOST_THREAD_LOG << "ERRORRRRR "<<ex.what() << "" << BOOST_THREAD_END_LOG;
      return 1;
    }
    catch (...)
    {
      BOOST_THREAD_LOG << " ERRORRRRR exception thrown" << BOOST_THREAD_END_LOG;
      return 2;
    }
  }
  {
    for (int i=0; i< number_of_tests; i++)
    try
    {
      BOOST_THREAD_LOG << "" << BOOST_THREAD_END_LOG;
      boost::shared_future<int> f1 = boost::async(&p1).share();
      BOOST_THREAD_LOG << "" << BOOST_THREAD_END_LOG;
      boost::future<int> f2 = f1.then(&p2s);
      BOOST_THREAD_LOG << "" << BOOST_THREAD_END_LOG;
      (void)f2.get();
      BOOST_THREAD_LOG << "" << BOOST_THREAD_END_LOG;
    }
    catch (std::exception& ex)
    {
      std::cout << "ERRORRRRR "<<ex.what() << "" << std::endl;
      BOOST_THREAD_LOG << "ERRORRRRR "<<ex.what() << "" << BOOST_THREAD_END_LOG;
      return 1;
    }
    catch (...)
    {
      BOOST_THREAD_LOG << " ERRORRRRR exception thrown" << BOOST_THREAD_END_LOG;
      return 2;
    }
  }
  BOOST_THREAD_LOG << "MAIN>" << BOOST_THREAD_END_LOG;
  return 0;
}
#else

int main()
{
  return 0;
}
#endif