[boost] [context review] Performance questions

Subject: [boost] [context review] Performance questions
From: Antony Polukhin (antoshkka_at_[hidden])
Date: 2012-01-09 13:35:50

I`ve read through the documentation of Boost.Context and some questions pop up:

1) What if we reimplement the ASIO example without Boost.Context
(server class will look like this):

class server : public boost::enable_shared_from_this< server >
{
private:
    boost::asio::ip::tcp::acceptor      acceptor_;
    boost::array< char, 1024 > buffer_;

    void do_()
    {
            boost::asio::ip::tcp::socket socket( acceptor_.get_io_service() );
            acceptor_.async_accept( socket, boost::bind( &
server::do_1_, this->shared_from_this(), _1) );
    }

    void do_1_(boost::system::error_code ec)
    {
            if (!ec) {
                socket.async_read_some(
                    boost::asio::buffer(buffer_),
                    boost::bind( & server::do_2_,
this->shared_from_this(), _1, _2) );
             } else {
                do_();
             }
    }

    void do_2_(boost::system::error_code ec, size_t n)
            if (!ec) {
                boost::asio::async_write(
                    socket,
                    boost::asio::buffer( buffer, n),
                    boost::bind( & server::do_1_,
this->shared_from_this(), _1) );
            } else {
                do_();
            }
       }
    }

    server( boost::asio::io_service & io_service, short port) :
        acceptor_( io_service, boost::asio::ip::tcp::endpoint(
boost::asio::ip::tcp::v4(), port) ),
    {}

public:
    typedef boost::shared_ptr< server >     ptr_t;

    static ptr_t create( boost::asio::io_service & io_service, short port)
    { return ptr_t( new server( io_service, port) ); }

    void operator()( boost::system::error_code /*ec*/, size_t /*n*/)
    {
        do_();
    }
};

Looks like this implementation will be faster (it has the same amount
of io_service posted functions, no dynamic allocations, but has no
context switches). Am I missing something?

2) Can we use contexts like condition variables? For example:

struct task{

};

std::deque

void thread_1()

void threads