On 16 July 2010 11:16, Steve Lorimer <steve.lorimer@gmail.com> wrote:

Hi folks, I have the following class:

using namespace boost::asio;

// basic tcp server

class server
{
   boost::thread thread;

   ip::tcp::acceptor acceptor;

   io_service io_svc;

   // tcp_srv_conn object which will become the local end-point of the next incoming connection

   tcp_srv_conn_p new_conn;


   void loop(unsigned short port);
   void on_accept(const boost::system::error_code &err);

public:
   server();

   virtual ~server();

   void serve(unsigned short port);

   void serve(const std::string &svc);

   void close();
};

and the constructor for server looks like this:

server::server() :
acceptor(io_svc),

new_conn(new tcp_srv_conn(io_svc))
{ }

If I create a server object on the stack:

server s;

I get a segmentation fault deep inside the asio internals (something to do with a mutex), originating from initialising acceptor with my io_service object: acceptor(io_svc)

Here is a stack trace of the core file:
Marked in red is (#6) my server constructor and (#7) the basic_socket_acceptor constructor

Core was generated by `tcp_srv.debug -p 12'.

Program terminated with signal 11, Segmentation fault.
#0 0x00007f8de6c3ed21 in pthread_mutex_lock () from /lib64/libpthread.so.0

(gdb) backtrace
#0 0x00007f8de6c3ed21 in pthread_mutex_lock () from /lib64/libpthread.so.0

#1 0x0000000000421153 in boost::asio::detail::posix_mutex::lock (this=0x8) at /usr/include/boost/asio/detail/posix_mutex.hpp:71
#2 0x0000000000422db7 in scoped_lock (this=0x7f8de58d7a70, m=...) at /usr/include/boost/asio/detail/scoped_lock.hpp:36
#3 0x0000000000426e22 in boost::asio::detail::service_registry::use_service<boost::asio::socket_acceptor_service<boost::asio::ip::tcp> > (this=0x0) at /usr/include/boost/asio/detail/service_registry.hpp:94

#4 0x000000000042573a in boost::asio::use_service<boost::asio::socket_acceptor_service<boost::asio::ip::tcp> > (ios=...) at /usr/include/boost/asio/impl/io_service.ipp:195

#5 0x000000000042427d in basic_io_object (this=0x7f8de58d7bd0, io_service=...) at /usr/include/boost/asio/basic_io_object.hpp:72
#6 0x0000000000422fd7 in basic_socket_acceptor (this=0x7f8de58d7bd0, io_service=...) at /usr/include/boost/asio/basic_socket_acceptor.hpp:77

#7 0x000000000041fe63 in server (this=0x7f8de58d7b90) at src/tcp_srv.cpp:9
#8 0x000000000040d4d2 in app::start_here (this=0x7fffaab13b2f, ac=3, av=0x7fffaab13cd8) at test/server_test.cpp:65

Am I doing something stupid? How should I be creating my io_service and acceptor objects?

TIA
Steve