def test_udp_server_disconnect_timeout(stack):
"""UDP server detects disconnections when clients are silent."""
server = stack.enter_context(udpsocket())
clients = [
stack.enter_context(udpsocket())
for i in range(2)
]
def echo_pairs(push, pull, peer):
"""Echo, but flush only on every other packet."""
assert peer in [
str(socket.getsockname())
for socket in clients
]
while True:
d1 = pull()
d2 = pull()
push(d1)
push(d2)
# Spawn the server and wait for it to finish booting.
stack.enter_context(
concurrently(
udp_server,
server, echo_pairs,
disconnect_timeout=0.0,
)
)
gevent.idle()
def block(socket):
"""Block until the server replies."""
socket.settimeout(0.01)
peer = server.getsockname()
data = os.urandom(3)
socket.sendto(data, peer)
try:
assert recvfrom(socket, peer) == data
except RecvTimeout:
pass
# Spawn a bunch of clients.
tasks = [
stack.enter_context(concurrently(
block, socket,
))
for socket in clients
]
# Wait until all clients are blocked.
gevent.idle()
# Client will time out and return.
assert gevent.wait(tasks, timeout=0.05) == tasks
def test_udp_server_never_block(stack):
"""UDP server does not block when one handler is blocked."""
server = stack.enter_context(udpsocket())
clients = [
stack.enter_context(udpsocket())
for i in range(2)
]
bad_peer = str(clients[0].getsockname())
def echo(push, pull, peer):
"""Echo, but block for one specific peer."""
if peer == bad_peer:
print('S:', 'bad peer', peer)
while True:
gevent.sleep(1.0)
else:
print('S:', 'good peer', peer)
while True:
push(pull())
# Spawn the server and wait for it to finish booting.
stack.enter_context(
concurrently(
udp_server,
server, echo,
max_pending_packets=1,
)
)
gevent.idle()
def pound(socket):
host = socket.getsockname()
peer = server.getsockname()
socket.settimeout(0.01)
try:
packets = [os.urandom(3) for i in range(3)]
for data in packets:
print('C:', host, 'send')
socket.sendto(data, peer)
for data in packets:
print('C:', host, 'recv')
assert recvfrom(socket, peer) == data
except RecvTimeout:
pass
# Spawn a bunch of clients.
tasks = [
stack.enter_context(concurrently(
pound, socket,
))
for socket in clients
]
gevent.wait(tasks, timeout=1.0)
def test_udp_server(stack):
"""UDP server can exchange packets with multiple clients."""
server = stack.enter_context(udpsocket())
clients = [
stack.enter_context(udpsocket())
for i in range(2)
]
def echo(push, pull, peer):
assert peer in [
str(socket.getsockname())
for socket in clients
]
while True:
push(pull())
stack.enter_context(
concurrently(
udp_server,
server, echo,
)
)
def pound(socket):
peer = server.getsockname()
for i in range(3):
data = os.urandom(3)
socket.sendto(data, peer)
assert recvfrom(socket, peer) == data
tasks = [
stack.enter_context(concurrently(
pound, socket,
))
for socket in clients
]
gevent.wait(tasks, timeout=1.0)
def test_concurrently(stack):
"""Tests can run a UDP client-server pair in parallel."""
def echo(socket):
"""UDP echo service."""
while True:
data, peer = socket.recvfrom(1024)
socket.sendto(data, peer)
server = stack.enter_context(udpsocket())
client = stack.enter_context(udpsocket())
with concurrently(echo, server):
peer = server.getsockname()
for i in range(100):
data = os.urandom(3)
client.sendto(data, peer)
d, p = client.recvfrom(1024)
assert p == peer
assert d == data
def test_udp_client(stack):
"""UDP client can exchange packets with a server."""
client = stack.enter_context(udpsocket())
server = stack.enter_context(udpsocket())
def echo(push, pull, peer):
assert peer == str(server.getsockname())
while True:
push(pull())
stack.enter_context(
concurrently(
udp_client,
client, echo,
server.getsockname(),
)
)
peer = client.getsockname()
for i in range(3):
data = os.urandom(3)
server.sendto(data, peer)
assert recvfrom(server, peer) == data