Does boost::asio makes excessive small heap allocations or am I wrong?
- by Poni
#include <cstdlib>
#include <iostream>
#include <boost/bind.hpp>
#include <boost/asio.hpp>
using boost::asio::ip::tcp;
class session
{
public:
session(boost::asio::io_service& io_service)
: socket_(io_service)
{
}
tcp::socket& socket()
{
return socket_;
}
void start()
{
socket_.async_read_some(boost::asio::buffer(data_, max_length - 1),
boost::bind(&session::handle_read, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
void handle_read(const boost::system::error_code& error,
size_t bytes_transferred)
{
if (!error)
{
data_[bytes_transferred] = '\0';
if(NULL != strstr(data_, "quit"))
{
this->socket().shutdown(boost::asio::ip::tcp::socket::shutdown_both);
this->socket().close(); // how to make this dispatch "handle_read()" with a "disconnected" flag?
}
else
{
boost::asio::async_write(socket_,
boost::asio::buffer(data_, bytes_transferred),
boost::bind(&session::handle_write, this,
boost::asio::placeholders::error));
socket_.async_read_some(boost::asio::buffer(data_, max_length - 1),
boost::bind(&session::handle_read, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
}
}
else
{
delete this;
}
}
void handle_write(const boost::system::error_code& error)
{
if (!error)
{
//
}
else
{
delete this;
}
}
private:
tcp::socket socket_;
enum { max_length = 1024 };
char data_[max_length];
};
class server
{
public:
server(boost::asio::io_service& io_service, short port)
: io_service_(io_service),
acceptor_(io_service, tcp::endpoint(tcp::v4(), port))
{
session* new_session = new session(io_service_);
acceptor_.async_accept(new_session->socket(),
boost::bind(&server::handle_accept, this, new_session,
boost::asio::placeholders::error));
}
void handle_accept(session* new_session,
const boost::system::error_code& error)
{
if (!error)
{
new_session->start();
new_session = new session(io_service_);
acceptor_.async_accept(new_session->socket(),
boost::bind(&server::handle_accept, this, new_session,
boost::asio::placeholders::error));
}
else
{
delete new_session;
}
}
private:
boost::asio::io_service& io_service_;
tcp::acceptor acceptor_;
};
int main(int argc, char* argv[])
{
try
{
if (argc != 2)
{
std::cerr << "Usage: async_tcp_echo_server <port>\n";
return 1;
}
boost::asio::io_service io_service;
using namespace std; // For atoi.
server s(io_service, atoi(argv[1]));
io_service.run();
}
catch (std::exception& e)
{
std::cerr << "Exception: " << e.what() << "\n";
}
return 0;
}
While experimenting with boost::asio I've noticed that within the calls to async_write()/async_read_some() there is a usage of the C++ "new" keyword.
Also, when stressing this echo server with a client (1 connection) that sends for example 100,000 times some data, the memory usage of this program is getting higher and higher.
What's going on? Will it allocate memory for every call? Or am I wrong? Asking because it doesn't seem right that a server app will allocate, anything. Can I handle it, say with a memory pool?
Another side-question:
See the "this-socket().close();" ?
I want it, as the comment right to it says, to dispatch that same function one last time, with a disconnection error. Need that to do some clean-up. How do I do that?
Thank you all gurus (:
