static void
setup_reload_pipe (DBusLoop *loop)
{
DBusError error;
DBusWatch *watch;
dbus_error_init (&error);
if (!_dbus_socketpair (&reload_pipe[0], &reload_pipe[1],
TRUE, &error))
{
_dbus_warn ("Unable to create reload pipe: %s\n",
error.message);
dbus_error_free (&error);
exit (1);
}
watch = _dbus_watch_new (_dbus_socket_get_pollable (reload_pipe[RELOAD_READ_END]),
DBUS_WATCH_READABLE, TRUE,
handle_reload_watch, NULL, NULL);
if (watch == NULL)
{
_dbus_warn ("Unable to create reload watch: %s\n",
error.message);
dbus_error_free (&error);
exit (1);
}
if (!_dbus_loop_add_watch (loop, watch))
{
_dbus_warn ("Unable to add reload watch to main loop: %s\n",
error.message);
dbus_error_free (&error);
exit (1);
}
}
/**
* Creates a new transport for the given socket file descriptor. The file
* descriptor must be nonblocking (use _dbus_set_fd_nonblocking() to
* make it so). This function is shared by various transports that
* boil down to a full duplex file descriptor.
*
* @param fd the file descriptor.
* @param server_guid non-#NULL if this transport is on the server side of a connection
* @param address the transport's address
* @returns the new transport, or #NULL if no memory.
*/
DBusTransport*
_dbus_transport_new_for_socket (DBusSocket fd,
const DBusString *server_guid,
const DBusString *address)
{
DBusTransportSocket *socket_transport;
socket_transport = dbus_new0 (DBusTransportSocket, 1);
if (socket_transport == NULL)
return NULL;
if (!_dbus_string_init (&socket_transport->encoded_outgoing))
goto failed_0;
if (!_dbus_string_init (&socket_transport->encoded_incoming))
goto failed_1;
socket_transport->write_watch = _dbus_watch_new (_dbus_socket_get_pollable (fd),
DBUS_WATCH_WRITABLE,
FALSE,
NULL, NULL, NULL);
if (socket_transport->write_watch == NULL)
goto failed_2;
socket_transport->read_watch = _dbus_watch_new (_dbus_socket_get_pollable (fd),
DBUS_WATCH_READABLE,
FALSE,
NULL, NULL, NULL);
if (socket_transport->read_watch == NULL)
goto failed_3;
if (!_dbus_transport_init_base (&socket_transport->base,
&socket_vtable,
server_guid, address))
goto failed_4;
#ifdef HAVE_UNIX_FD_PASSING
_dbus_auth_set_unix_fd_possible(socket_transport->base.auth, _dbus_socket_can_pass_unix_fd(fd));
#endif
socket_transport->fd = fd;
socket_transport->message_bytes_written = 0;
/* These values should probably be tunable or something. */
socket_transport->max_bytes_read_per_iteration = 2048;
socket_transport->max_bytes_written_per_iteration = 2048;
return (DBusTransport*) socket_transport;
failed_4:
_dbus_watch_invalidate (socket_transport->read_watch);
_dbus_watch_unref (socket_transport->read_watch);
failed_3:
_dbus_watch_invalidate (socket_transport->write_watch);
_dbus_watch_unref (socket_transport->write_watch);
failed_2:
_dbus_string_free (&socket_transport->encoded_incoming);
failed_1:
_dbus_string_free (&socket_transport->encoded_outgoing);
failed_0:
dbus_free (socket_transport);
return NULL;
}
/**
* @todo We need to have a way to wake up the select sleep if
* a new iteration request comes in with a flag (read/write) that
* we're not currently serving. Otherwise a call that just reads
* could block a write call forever (if there are no incoming
* messages).
*/
static void
socket_do_iteration (DBusTransport *transport,
unsigned int flags,
int timeout_milliseconds)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
DBusPollFD poll_fd;
int poll_res;
int poll_timeout;
_dbus_verbose (" iteration flags = %s%s timeout = %d read_watch = %p write_watch = %p fd = %" DBUS_SOCKET_FORMAT "\n",
flags & DBUS_ITERATION_DO_READING ? "read" : "",
flags & DBUS_ITERATION_DO_WRITING ? "write" : "",
timeout_milliseconds,
socket_transport->read_watch,
socket_transport->write_watch,
_dbus_socket_printable (socket_transport->fd));
/* the passed in DO_READING/DO_WRITING flags indicate whether to
* read/write messages, but regardless of those we may need to block
* for reading/writing to do auth. But if we do reading for auth,
* we don't want to read any messages yet if not given DO_READING.
*/
poll_fd.fd = _dbus_socket_get_pollable (socket_transport->fd);
poll_fd.events = 0;
if (_dbus_transport_try_to_authenticate (transport))
{
/* This is kind of a hack; if we have stuff to write, then try
* to avoid the poll. This is probably about a 5% speedup on an
* echo client/server.
*
* If both reading and writing were requested, we want to avoid this
* since it could have funky effects:
* - both ends spinning waiting for the other one to read
* data so they can finish writing
* - prioritizing all writing ahead of reading
*/
if ((flags & DBUS_ITERATION_DO_WRITING) &&
!(flags & (DBUS_ITERATION_DO_READING | DBUS_ITERATION_BLOCK)) &&
!transport->disconnected &&
_dbus_connection_has_messages_to_send_unlocked (transport->connection))
{
do_writing (transport);
if (transport->disconnected ||
!_dbus_connection_has_messages_to_send_unlocked (transport->connection))
goto out;
}
/* If we get here, we decided to do the poll() after all */
_dbus_assert (socket_transport->read_watch);
if (flags & DBUS_ITERATION_DO_READING)
poll_fd.events |= _DBUS_POLLIN;
_dbus_assert (socket_transport->write_watch);
if (flags & DBUS_ITERATION_DO_WRITING)
poll_fd.events |= _DBUS_POLLOUT;
}
else
{
DBusAuthState auth_state;
auth_state = _dbus_auth_do_work (transport->auth);
if (transport->receive_credentials_pending ||
auth_state == DBUS_AUTH_STATE_WAITING_FOR_INPUT)
poll_fd.events |= _DBUS_POLLIN;
if (transport->send_credentials_pending ||
auth_state == DBUS_AUTH_STATE_HAVE_BYTES_TO_SEND)
poll_fd.events |= _DBUS_POLLOUT;
}
if (poll_fd.events)
{
int saved_errno;
if (flags & DBUS_ITERATION_BLOCK)
poll_timeout = timeout_milliseconds;
else
poll_timeout = 0;
/* For blocking selects we drop the connection lock here
* to avoid blocking out connection access during a potentially
* indefinite blocking call. The io path is still protected
* by the io_path_cond condvar, so we won't reenter this.
*/
if (flags & DBUS_ITERATION_BLOCK)
{
_dbus_verbose ("unlock pre poll\n");
_dbus_connection_unlock (transport->connection);
}
again:
poll_res = _dbus_poll (&poll_fd, 1, poll_timeout);
saved_errno = _dbus_save_socket_errno ();
if (poll_res < 0 && _dbus_get_is_errno_eintr (saved_errno))
goto again;
if (flags & DBUS_ITERATION_BLOCK)
{
_dbus_verbose ("lock post poll\n");
_dbus_connection_lock (transport->connection);
}
if (poll_res >= 0)
{
if (poll_res == 0)
poll_fd.revents = 0; /* some concern that posix does not guarantee this;
* valgrind flags it as an error. though it probably
* is guaranteed on linux at least.
*/
if (poll_fd.revents & _DBUS_POLLERR)
do_io_error (transport);
else
{
dbus_bool_t need_read = (poll_fd.revents & _DBUS_POLLIN) > 0;
dbus_bool_t need_write = (poll_fd.revents & _DBUS_POLLOUT) > 0;
dbus_bool_t authentication_completed;
_dbus_verbose ("in iteration, need_read=%d need_write=%d\n",
need_read, need_write);
do_authentication (transport, need_read, need_write,
&authentication_completed);
/* See comment in socket_handle_watch. */
if (authentication_completed)
goto out;
if (need_read && (flags & DBUS_ITERATION_DO_READING))
do_reading (transport);
if (need_write && (flags & DBUS_ITERATION_DO_WRITING))
do_writing (transport);
}
}
else
{
_dbus_verbose ("Error from _dbus_poll(): %s\n",
_dbus_strerror (saved_errno));
}
}
out:
/* We need to install the write watch only if we did not
* successfully write everything. Note we need to be careful that we
* don't call check_write_watch *before* do_writing, since it's
* inefficient to add the write watch, and we can avoid it most of
* the time since we can write immediately.
*
* However, we MUST always call check_write_watch(); DBusConnection code
* relies on the fact that running an iteration will notice that
* messages are pending.
*/
check_write_watch (transport);
_dbus_verbose (" ... leaving do_iteration()\n");
}
