def _register(watch_states, notifier, cb):
registered = []
try:
for s in watch_states:
if not notifier.is_registered(s, cb):
notifier.register(s, cb)
registered.append((s, cb))
except ValueError:
with excutils.save_and_reraise_exception():
for (s, cb) in registered:
notifier.deregister(s, cb)
def _bulk_deregister(notifier, registered, details_filter=None):
"""Bulk deregisters callbacks associated with many states."""
while registered:
state, cb = registered.pop()
notifier.deregister(state, cb,
details_filter=details_filter)
def _bulk_deregister(notifier, registered, details_filter=None):
"""Bulk deregisters callbacks associated with many states."""
while registered:
state, cb = registered.pop()
notifier.deregister(state, cb,
details_filter=details_filter)
def _deregister(watch_states, notifier, cb):
for s in watch_states:
notifier.deregister(s, cb)