[Boost-users] [asio] async_read and 100% CPU

Subject: [Boost-users] [asio] async_read and 100% CPU
From: Etienne Philip Pretorius (icewolfhunter_at_[hidden])
Date: 2009-06-30 14:07:19

Hello list,

Could someone please shed some light on this subject. It seems that me 
read handler keeps on being called even when there has been no data 
transferred...

Here is the accept handler that starts off the read handler (All methods 
are part of the same class, namely 'client'):

         /* Accept Handler */
         void handle_accept(
             const boost::system::error_code& error
         ) {

             client* c;
             switch(error.value()) {
                 case boost::system::posix_error::success: {
                     c = new client();

                     socket.async_receive(
                         boost::asio::buffer(
                             buffer
                         ),boost::bind(
                             &client::handle_read,
                             this,
                             boost::asio::placeholders::error,
                             boost::asio::placeholders::bytes_transferred
                         )
                     );
                     break;
                 }
                 case boost::system::posix_error::interrupted:
                 case boost::system::posix_error::connection_aborted: {
                     c = this;
                     break;
                 }
                 default: {
                     throw error;
                 }
             }
             acceptor.async_accept(
                 c->socket,
                 boost::bind(
                     &client::handle_accept,
                     c,
                     boost::asio::placeholders::error
                 )
             );

         };

And here is the read handler....

         /* Read Handler */
         void handle_read(
             const boost::system::error_code& error,
             std::size_t bytes_transferred
         ) {

             switch(error.value()) {
                 case boost::system::posix_error::success: {
                     if(bytes_transferred > 0) {
                         std::copy(
                             buffer.begin(),
                             buffer.end(),
                             std::back_insert_iterator<std::string>(data)
                         );
                         break;
                     }
                 }
                 case boost::system::posix_error::interrupted: {
                     socket.async_receive(
                         boost::asio::buffer(
                             buffer
                         ),boost::bind(
                             &client::handle_read,
                             this,
                             boost::asio::placeholders::error,
                             boost::asio::placeholders::bytes_transferred
                         )
                     );
                     return;
                 }
                 default: {
                     throw error;
                 }
             }
             //TODO: parse contents..
         };

Using epoll interface, as I am running Ubuntu Jaunty.

Calling io_service.run() from the main thread.

Thank you,
Etienne Pretorius.