~singpolyma/biboumi

11a1c0cc99af9629302184fac2b7adf3ac48516b — louiz’ 6 years ago de0eff6
Always remove all the DNS sockets on an c-ares event

Because c-ares may close one of its socket, even if it’s not the one that
has the event. Otherwise we may not know when a socket has been removed from
our poller (automatically, when close()ed) and this leads to bugs.
M louloulibs/network/dns_handler.cpp => louloulibs/network/dns_handler.cpp +10 -1
@@ 37,6 37,7 @@ ares_channel& DNSHandler::get_channel()

void DNSHandler::destroy()
{
  this->remove_all_sockets_from_poller();
  this->socket_handlers.clear();
  ::ares_destroy(this->channel);
  ::ares_library_cleanup();


@@ 95,7 96,7 @@ void DNSHandler::watch_dns_sockets(std::shared_ptr<Poller>& poller)
          if (it == this->socket_handlers.end())
            {
              this->socket_handlers.emplace(this->socket_handlers.begin(),
                                            std::make_unique<DNSSocketHandler>(poller, i));
                                            std::make_unique<DNSSocketHandler>(poller, *this, i));
              it = this->socket_handlers.begin();
            }
          poller->add_socket_handler(it->get());


@@ 122,4 123,12 @@ void DNSHandler::watch_dns_sockets(std::shared_ptr<Poller>& poller)
    }
}

void DNSHandler::remove_all_sockets_from_poller()
{
  for (const auto& socket_handler: this->socket_handlers)
  {
    socket_handler->remove_from_poller();
  }
}

#endif /* CARES_FOUND */

M louloulibs/network/dns_handler.hpp => louloulibs/network/dns_handler.hpp +1 -0
@@ 40,6 40,7 @@ public:
   * and library.
   */
  void destroy();
  void remove_all_sockets_from_poller();
  ares_channel& get_channel();

  static DNSHandler instance;

M louloulibs/network/dns_socket_handler.cpp => louloulibs/network/dns_socket_handler.cpp +10 -3
@@ 8,8 8,10 @@
#include <ares.h>

DNSSocketHandler::DNSSocketHandler(std::shared_ptr<Poller> poller,
                                   DNSHandler& handler,
                                   const socket_t socket):
  SocketHandler(poller, socket)
  SocketHandler(poller, socket),
  handler(handler)
{
}



@@ 21,7 23,7 @@ void DNSSocketHandler::on_recv()
{
  // always stop watching send and read events. We will re-watch them if the
  // next call to ares_fds tell us to
  this->poller->remove_socket_handler(this->socket);
  this->handler.remove_all_sockets_from_poller();
  ::ares_process_fd(DNSHandler::instance.get_channel(), this->socket, ARES_SOCKET_BAD);
}



@@ 29,7 31,7 @@ void DNSSocketHandler::on_send()
{
  // always stop watching send and read events. We will re-watch them if the
  // next call to ares_fds tell us to
  this->poller->remove_socket_handler(this->socket);
  this->handler.remove_all_sockets_from_poller();
  ::ares_process_fd(DNSHandler::instance.get_channel(), ARES_SOCKET_BAD, this->socket);
}



@@ 38,4 40,9 @@ bool DNSSocketHandler::is_connected() const
  return true;
}

void DNSSocketHandler::remove_from_poller()
{
  this->poller->remove_socket_handler(this->socket);
}

#endif /* CARES_FOUND */

M louloulibs/network/dns_socket_handler.hpp => louloulibs/network/dns_socket_handler.hpp +5 -1
@@ 13,10 13,12 @@
 * (Poller reported it to be writable or readeable)
 */

class DNSHandler;

class DNSSocketHandler: public SocketHandler
{
public:
  explicit DNSSocketHandler(std::shared_ptr<Poller> poller, const socket_t socket);
  explicit DNSSocketHandler(std::shared_ptr<Poller> poller, DNSHandler& handler, const socket_t socket);
  ~DNSSocketHandler() = default;
  DNSSocketHandler(const DNSSocketHandler&) = delete;
  DNSSocketHandler(DNSSocketHandler&&) = delete;


@@ 38,8 40,10 @@ public:
   * Always true, see the comment for connect()
   */
  bool is_connected() const override final;
  void remove_from_poller();

private:
  DNSHandler& handler;
};

#endif // CARES_FOUND