def initialize(self):
if self.current_state(self.INITIAL):
with self.action_lock:
# Can only start a backend iff in the INITIAL state.
Logging.log(
'Starting backend \'{0}\''.format(
self.current_backend_name), Logging.LOG_INFO)
backend_info = self.possible_backends.get(
self.current_backend_name, {})
backend_clazz = self.BACKEND_META.get(
backend_info.get('backend')
or Backend.NullHaskellBackend.backend_name())
if backend_clazz is not None:
the_backend = backend_clazz(
self, **backend_info.get('options', {}))
else:
the_backend = None
if the_backend is not None:
self.state_startup(the_backend)
self.state_connect(the_backend)
self.state_active(the_backend)
if self.current_state(self.INITIAL):
# Something failed during startup, revert to the null backend
self.set_backend(Backend.NullHaskellBackend(self))
elif not self.current_state(self.ACTIVE):
state_str = self.STATES_TO_NAME.get(
self.state, str(self.state))
Logging.log(
'BackendManager: Invalid state after starting backend: {0}'
.format(state_str), Logging.LOG_ERROR)
def shutdown_backend(self, get_action_lock=True):
'''Step through the backend shutdown process: disconnect (if active), stop backend (if disconnected). Backend
manager's state should end up in INITIAL.
'''
# If the action lock was previously acquired, don't try to re-acquire it.
got_lock = get_action_lock and self.action_lock.acquire()
try:
the_backend = BackendManager.ACTIVE_BACKEND
self.set_backend(Backend.NullHaskellBackend(self))
self.state_disconnect(the_backend)
self.state_shutdown(the_backend)
self.state_inactive()
finally:
if got_lock:
self.action_lock.release()
def __init__(self):
'''Initializes the backend manager.
.. py:attribute:: state
The :py:class:`BackendManager`'s current state.
.. py:attribute:: state_lock
Recursive lock to mediate access to :py:attr:`state`.
.. py:attribute:: action_lock
Hard lock to serialize backend life cycle actions. This lock is acquired while initializing and shutting down
the backend.
.. py:attribute:: src_inspector
The source inspector object, :py:class:`Inspector`.
.. py:attribute:: current_backend_name
The name of the current backend. This starts out as the default backend's name, but can be changed to a different
backend name.
.. py:attribute:: possible_backends
Filtered list of backend names. This is a subset of the *backends* settings, filtered on whether the backend's *type*
is avaiable. For example, if *hsdev* is not installed (not available), then none of the *hsdev* backend names are
possible (and not in this list).
.. py:attribute:: project_cache
A mapping between project names and files associated with each project.
'''
super().__init__()
BackendManager.ACTIVE_BACKEND = Backend.NullHaskellBackend(self)
self.state = self.INITIAL
self.state_lock = threading.RLock()
self.action_lock = threading.Lock()
self.src_inspector = Inspector.Inspector(BackendManager.ACTIVE_BACKEND)
self.current_backend_name = BackendManager.ACTIVE_BACKEND.backend_name(
)
self.possible_backends = {}
self.project_cache = {}
def __init__(self, view):
super().__init__(view)
self.candidates = None
self.backend = Backend.NullHaskellBackend(BackendManager.BackendManager())
