def get_ready_event(self):
"""
By default, it is always ready.
Override this in your specific process.
"""
ev = Event()
ev.set()
return ev
def ensure_ready(self, proc, errmsg=None, timeout=20):
"""
Waits until either the thread dies or reports it is ready, whichever comes first.
If the thread dies or times out while waiting for it to be ready, a ContainerError is raised.
You must be sure the thread implements get_ready_event properly, otherwise this method
returns immediately as the base class behavior simply passes.
@param proc The thread to wait on.
@param errmsg A custom error message to put in the ContainerError's message. May be blank.
@param timeout Amount of time (in seconds) to wait for the ready, default 20 seconds.
@throws ContainerError If the thread dies or if we get a timeout before the process signals ready.
"""
if not errmsg:
errmsg = "ensure_ready failed"
ev = Event()
def cb(*args, **kwargs):
ev.set()
# link either a greenlet failure due to exception OR a success via ready event
proc.proc.link_exception(cb)
ready_evt = proc.get_ready_event()
ready_evt.rawlink(cb)
retval = ev.wait(timeout=timeout)
# unlink the events: ready event is probably harmless but the exception one, we want to install our own later
ready_evt.unlink(cb)
# if the thread is stopped while we are waiting, proc.proc is set to None
if proc.proc is not None:
proc.proc.unlink(cb)
# raise an exception if:
# - we timed out
# - we caught an exception
if not retval:
raise ContainerError("%s (timed out)" % errmsg)
elif proc.proc is not None and proc.proc.dead and not proc.proc.successful(
):
raise ContainerError("%s (failed): %s" %
(errmsg, proc.proc.exception))
def __init__(self, target=None, *args, **kwargs):
"""
@param target The Callable to start as independent thread
@param args Provided as spawn args to thread
@param kwargs Provided as spawn kwargs to thread
"""
super(PyonThread, self).__init__()
if target is not None or not hasattr(
self, 'target'): # Allow setting target at class level
self.target = target
self.spawn_args = args
self.spawn_kwargs = kwargs
# The instance of Greenlet or subprocess or similar
self.proc = None
self.supervisor = None
self.ev_exit = Event() # Event that is set when greenlet exits
