def _handle_establish_bond(self, req):
rospy.loginfo("Request to establish a bond")
bond_id = str(uuid.uuid1())
def on_formed():
rospy.loginfo("Bond formed with bond_id of '{0}'"
.format(bond_id))
def on_broken():
# if bond_id in self.__bonds:
rospy.loginfo("Bond with bond id '{0}' was broken, freeing associated capabilities"
.format(bond_id))
self.__free_capabilities_by_bond_id(bond_id)
del self.__bonds[bond_id]
self.__bonds[bond_id] = Bond(self.__bond_topic, bond_id, on_broken=on_broken, on_formed=on_formed)
self.__bonds[bond_id].start()
return EstablishBondResponse(bond_id)
def establish_bond(self, timeout=None):
"""Establishes a bond using the ``~establish_bond`` service call
The bond id which is returned by the service call is stored internally
and used implicitly by the use/free capabilities functions.
If :py:meth:`establish_bond` had previously been called, then the old bond will be
broken, which will result in any capability uses under that bond to be
implicitly freed.
This function is called implicitly by :py:meth:`use_capability` if
no bond exists.
This function will block waiting for the service call to become
available and to wait for the bond to be established. In both cases
the timeout parameter is used.
None is returned if the timeout occurs while waiting on the service
to become available or while waiting for the bond to form.
:param timeout: time in seconds to wait for the service to be available
:type timeout: float
:returns: the bond_id received from the server or :py:obj:`None` on failure
:rtype: :py:obj:`str`
"""
if self.__wait_for_service(self.__establish_bond, timeout) is False:
return None
resp = self.__establish_bond()
if not resp.bond_id: # pragma: no cover
return None
self._bond_id = resp.bond_id
self._bond = Bond('{0}/bonds'.format(self._name), self._bond_id)
self._bond.start()
timeout_dur = None if timeout is None else rospy.Duration.from_sec(
timeout)
if self._bond.wait_until_formed(
timeout_dur) is False: # pragma: no cover
return None
return self._bond_id