使用BOOST的asio库连接服务器发生内存泄露问题，附代码~~~

以下代码可在vs2008下编译通过，其中61.135.169.125为百度网站的IP地址，作为测试用。程序产生的问题在于，当用任务管理器查看程序耗占的内存时，发现耗占内存以8K，12k或者更大的数值持续增加。如果注释掉connect方法的调用，则没有内存泄露问题。因此应该Net_connector的connect方法中。但是该方法以及其调用的其它方法都没有内存分配的操作，不知道是否是asio库的使用存在什么问题。请大家提出看法，谢谢~~~~

Net_connector.h

#ifndef _NET_CONNECTOR_H

#define _NET_CONNECTOR_H



#include <boost/asio.hpp>

#include <boost/thread.hpp>

#include <memory>

#include <string>

#include <boost/date_time.hpp>



/**

 * Net_connector is a class implementing asynchronous connection to remote

 * location.

 */

class Net_connector {

public:

  /**

   * Construct Net_connector object with io_service object.

   *

   * @param[in] io_service boost::asio::io_service object for deadline_time

   */

  Net_connector(boost::asio::io_service& io_service,

    boost::asio::ip::tcp::socket& socket);



  /**

   * connect to specified remote location within a period time.

   *

   * @param[in] ip the ip address to connect

   * @param[in] port the port on remote location to connect

   * @param[in] seconds a period time in second

   *

   * @return true if successfully made connection to remote location

   */

  bool connect(const std::string& ip, const unsigned short& port, 

    const boost::posix_time::seconds& seconds);



  /** return true if the connection is established, or false. */

  operator bool() const;



private:

  /** asynchronous connection handler. */

  void handle_connect(const boost::system::error_code& error);



  /** asynchronous wait handler. */

  void handle_timeout(const boost::system::error_code& error);



  /** reference socket for asynchronous connection. */

  boost::asio::ip::tcp::socket& _socket_ref;



  /** deadline_timer object for implementing asynchronous connection. */

  boost::asio::deadline_timer _dealine_timer;



  /** time point to computing time period for specified operation. */

  //std::chrono::system_clock::time_point _last_time_point;



  /** flag indicates whether or not connection is made with a period time. */

  bool _connected;



  /** mechanism for implementing asynchronous connection. */

  boost::mutex _mutex;

  boost::condition_variable _cond_var;

};



#endif  // _NET_CONNECTOR_

Net_connector.cpp

#include "Net_connector.h"

#include <boost/lexical_cast.hpp>

#include <boost/bind.hpp>



Net_connector::Net_connector(boost::asio::io_service& io_service,

                             boost::asio::ip::tcp::socket& socket)

  : _socket_ref(socket)

  , _dealine_timer(io_service)

  , _connected(false)

{

}



bool Net_connector::connect(const std::string& ip, const unsigned short& port, 

                            const boost::posix_time::seconds& seconds)

{

  boost::mutex::scoped_lock lock(_mutex);



  boost::asio::ip::tcp::endpoint endpoint(

    boost::asio::ip::address::from_string(ip), port);



  _connected = false;



  _dealine_timer.expires_from_now(seconds);

  _dealine_timer.async_wait(boost::bind(&Net_connector::handle_timeout, 

    this, boost::asio::placeholders::error));



  _socket_ref.async_connect(endpoint,

    boost::bind(&Net_connector::handle_connect, this, 

    boost::asio::placeholders::error));

  

  _cond_var.wait(lock);



  return _connected;

}



void Net_connector::handle_connect(const boost::system::error_code& error)

{

  if (boost::asio::error::operation_aborted == error) {

    return;

  }

  

  if (!error) {

    _connected = true;

  }



  _dealine_timer.cancel();

}



void Net_connector::handle_timeout(const boost::system::error_code& error)

{

  boost::mutex::scoped_lock lock(_mutex);



  // timeout, cancel asynchronous connect operation

  if (boost::asio::error::operation_aborted != error) {

    boost::system::error_code ec;

    _socket_ref.close(ec);

  }



  _cond_var.notify_one();

}



Net_connector::operator bool() const

{

  return _connected;

}

main.cpp

#include "Net_connector.h"

#include <boost/thread.hpp>



void run_service(boost::asio::io_service& io_service)

{

  io_service.run();

}



int main(int, char**)

{

  boost::asio::io_service io_service;

  boost::asio::io_service::work work(io_service);

  boost::thread t(run_service, boost::ref(io_service));



  while (true) {

    boost::asio::ip::tcp::socket socket(io_service);

    boost::system::error_code ec;



    Net_connector connector(io_service, socket);

    if (!connector.connect("61.135.169.125", 80, boost::posix_time::seconds(5))) {

      std::cout << "failed to connect server" << std::endl;

    }



    socket.shutdown(boost::asio::ip::tcp::socket::shutdown_send, ec);

    socket.close(ec);

  }



  return 0;

}