def occupied(host, port, timeout=float('Inf')):
"""
Wait for the specified port to become occupied (accepting requests).
Return when the port is occupied or raise a Timeout if timeout has
elapsed.
Timeout may be specified in seconds or as a timedelta.
If timeout is None or ∞, the routine will run indefinitely.
>>> occupied('localhost', find_available_local_port(), .1)
Traceback (most recent call last):
...
Timeout: Port ... not bound on localhost.
>>> occupied(None, None)
Traceback (most recent call last):
...
ValueError: Host values of '' or None are not allowed.
"""
if not host:
raise ValueError("Host values of '' or None are not allowed.")
timer = timing.Timer(timeout)
while True:
try:
Checker(timeout=0.5).assert_free(host, port)
if timer.expired():
raise Timeout("Port {port} not bound on {host}.".format(**locals()))
# Politely wait
time.sleep(0.1)
except PortNotFree:
# port is occupied
return
def free(host, port, timeout=float('Inf')):
"""
Wait for the specified port to become free (dropping or rejecting
requests). Return when the port is free or raise a Timeout if timeout has
elapsed.
Timeout may be specified in seconds or as a timedelta.
If timeout is None or ∞, the routine will run indefinitely.
>>> free('localhost', find_available_local_port())
>>> free(None, None)
Traceback (most recent call last):
...
ValueError: Host values of '' or None are not allowed.
"""
if not host:
raise ValueError("Host values of '' or None are not allowed.")
timer = timing.Timer(timeout)
while True:
try:
# Expect a free port, so use a small timeout
Checker(timeout=0.1).assert_free(host, port)
return
except PortNotFree:
if timer.expired():
raise Timeout("Port {port} not free on {host}.".format(**locals()))
# Politely wait.
time.sleep(0.1)
