Re: [Boost-users] [asio]Why std::ofstream AND boost::asio::async_read() fails?

Subject: Re: [Boost-users] [asio]Why std::ofstream AND boost::asio::async_read() fails?
From: Yasuhiko Yoshimura \(informax.co.jp\) (yoshimura_at_[hidden])
Date: 2010-09-23 08:51:59

> I'm not able to see why downloading is sometimes fails in asio asyncread().

I found out my bug resolution that is moving the std::ofstream as a class member
to stack of function calling itself.

Thanks,
Yasuhiko Yoshimura
 
class ftp_client_dtp
{
 // Start socket and etc.
 void start()
 {
  work_resolver_.reset(new boost::asio::ip::tcp::resolver(work_io_service_));
  work_socket_.reset(new boost::asio::ip::tcp::socket(work_io_service_));
  work_.reset(new boost::asio::io_service::work(work_io_service_));
  work_thread_.reset(new boost::thread(
   boost::bind(&boost::asio::io_service::run, &work_io_service_)));
  ...
  // Start an asynchronous resolve to translate the server and service names
  // into a list of endpoints.
  ...
 }
 ...
private:
 ...
 void handle_read_content(const boost::system::error_code& err)
 {
  if (!err || err == boost::asio::error::eof) {
   std::string spath = scurrentpath_ + "\\" + sfilename_;
// insert the next line that the ofstream to stack.
   std::ofstream f(spath.c_str(), std::ios::binary | std::ios_base::out | std::ios_base::app | std::ios_base::ate);
   if (response_.size() > 0) {
    f << &response_;
   }
   f.close();
   if (!err) {
    // Continue reading remaining data until EOF.
    boost::asio::async_read(*work_socket_, response_,
      boost::asio::transfer_at_least(1),
      boost::bind(&ftp_client_dtp::handle_read_content, shared_from_this(),
      boost::asio::placeholders::error));
   } else {
    // eof
    std::cout << err;
    do_close();
   }
  } else {
   std::cout << err;
   do_close();
  }
 }
 void do_close()
 {
  work_socket_->close();
 }
// comment out the next line.
// std::ofstream f;
 
 std::string sip_, sport_, scurrentpath_, sfilename_;
 boost::asio::streambuf request_;
 boost::asio::streambuf response_;
 boost::scoped_ptr<boost::asio::ip::tcp::resolver> work_resolver_;
 boost::scoped_ptr<boost::asio::ip::tcp::socket> work_socket_;
 boost::asio::io_service work_io_service_;
 boost::scoped_ptr<boost::asio::io_service::work> work_;
 boost::scoped_ptr<boost::thread> work_thread_;
};