/home/mhx/git/github/libmoost/include/moost/io/detail/async_stream_forwarder_posix.hpp

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/* vim:set ts=3 sw=3 sts=3 et: */
#ifndef MOOST_IO_DETAIL_ASYNC_STREAM_FORWARDER_POSIX_HPP__
#define MOOST_IO_DETAIL_ASYNC_STREAM_FORWARDER_POSIX_HPP__

#include <unistd.h>
#include <poll.h>

namespace moost { namespace io { namespace detail {

class forwarding_loop
{
public:
   forwarding_loop()
     : m_signal_in(-1)
   {
   }

   void stop() const
   {
      if (m_signal_in != -1)
      {
         char input = 'S';
         if (::write(m_signal_in, &input, 1) != 1)
         {
            // there's just nothing we can do...
         }
      }
   }

   void run(int from, int to) const
   {
      int signal_out;
      moost::io::helper::create_pipe(signal_out, m_signal_in);

      char input;
      struct pollfd pfd[2];
      pfd[0].fd = from;
      pfd[0].events = POLLIN;
      pfd[1].fd = signal_out;
      pfd[1].events = POLLIN;

      for (;;)
      {
         pfd[0].revents = 0;
         pfd[1].revents = 0;

         int rv = ::poll(&pfd[0], 2, -1);

         if (rv <= 0)
         {
            break;
         }

         if (pfd[1].revents & POLLIN)
         {
            break;
         }
         else if (pfd[0].revents & POLLIN)
         {
            if (::read(from, &input, 1) != 1 ||
                ::write(to, &input, 1) != 1)
            {
               break;
            }
         }
      }
   }

private:
   mutable int m_signal_in;
};

} } }

#endif