class EventLoopPolicy(events.AbstractEventLoopPolicy):
"""Rubicon event loop policy
In this policy, each thread has its own event loop. However, we only
automatically create an event loop by default for the main thread; other
threads by default have no event loop.
"""
def __init__(self):
self._lifecycle = None
self._default_loop = None
self._watcher_lock = threading.Lock()
self._watcher = None
self._policy = DefaultEventLoopPolicy()
self._policy.new_event_loop = self.new_event_loop
self.get_event_loop = self._policy.get_event_loop
self.set_event_loop = self._policy.set_event_loop
def new_event_loop(self):
"""Create a new event loop and return it."""
if not self._default_loop and threading.current_thread() == threading.main_thread():
loop = self.get_default_loop()
else:
loop = CFEventLoop(self._lifecycle)
loop._policy = self
return loop
def get_default_loop(self):
"""Get the default event loop."""
if not self._default_loop:
self._default_loop = self._new_default_loop()
return self._default_loop
def _new_default_loop(self):
loop = CFEventLoop(self._lifecycle)
loop._policy = self
return loop
def _init_watcher(self):
with events._lock:
if self._watcher is None: # pragma: no branch
self._watcher = SafeChildWatcher()
if threading.current_thread() == threading.main_thread():
self._watcher.attach_loop(self._default_loop)
def get_child_watcher(self):
"""Get the watcher for child processes.
If not yet set, a SafeChildWatcher object is automatically created.
"""
if self._watcher is None:
self._init_watcher()
return self._watcher
def set_child_watcher(self, watcher):
"""Set the watcher for child processes."""
if self._watcher is not None:
self._watcher.close()
self._watcher = watcher
def _init_watcher(self):
with events._lock:
if self._watcher is None: # pragma: no branch
self._watcher = SafeChildWatcher()
if threading.current_thread() == threading.main_thread():
self._watcher.attach_loop(self._default_loop)
