def test_extract_address():
old_style = ca.SearchResponse(port=6666, ip='1.2.3.4', cid=0, version=13)
old_style.header.parameter1 = 0xffffffff
old_style.sender_address = ('5.6.7.8', 6666)
new_style = ca.SearchResponse(port=6666, ip='1.2.3.4', cid=0, version=13)
ca.extract_address(old_style) == '1.2.3.4'
ca.extract_address(new_style) == '5.6.7.8'
async def _broadcaster_queue_loop(self):
await curio.spawn(self._broadcaster_recv_loop(), daemon=True)
command = self.broadcaster.register('127.0.0.1')
await self.send(ca.EPICS_CA2_PORT, command)
while True:
try:
commands = await self.command_bundle_queue.get()
self.broadcaster.process_commands(commands)
except curio.TaskCancelled:
break
except Exception as ex:
logger.error('Broadcaster command queue evaluation failed',
exc_info=ex)
continue
for command in commands:
if isinstance(command, ca.RepeaterConfirmResponse):
self.registered = True
if isinstance(command, ca.VersionResponse):
# Check that the server version is one we can talk to.
assert command.version > 11
if isinstance(command, ca.SearchResponse):
name = self.unanswered_searches.pop(command.cid, None)
if name is not None:
self.search_results[name] = ca.extract_address(command)
else:
# This is a redundant response, which the spec tell us
# we must ignore.
pass
async with self.broadcaster_command_condition:
await self.broadcaster_command_condition.notify_all()
async def _broadcaster_queue_loop(self):
await curio.spawn(self._broadcaster_recv_loop, daemon=True)
while True:
try:
commands = await self.command_bundle_queue.get()
self.broadcaster.process_commands(commands)
except curio.TaskCancelled:
break
except Exception as ex:
self.log.error('Broadcaster command queue evaluation failed',
exc_info=ex)
continue
for command in commands:
if isinstance(command, ca.RepeaterConfirmResponse):
self.registered = True
if isinstance(command, ca.VersionResponse):
# Check that the server version is one we can talk to.
if command.version <= 11:
self.log.debug('Old client on version %s',
command.version)
continue
if isinstance(command, ca.SearchResponse):
try:
name = self.unanswered_searches.pop(command.cid)
except KeyError:
# This is a redundant response, which the EPICS
# spec tells us to ignore. (The first responder
# to a given request wins.)
if name in self.search_results:
accepted_address = self.search_results[name]
new_address = ca.extract_address(command)
self.log.warning(
"PV found on multiple servers. "
"Accepted address is %s. "
"Also found on %s", accepted_address,
new_address)
else:
address = ca.extract_address(command)
self.log.debug('Found %s at %s', name, address)
self.search_results[name] = address
async with self.broadcaster_command_condition:
await self.broadcaster_command_condition.notify_all()
def command_loop(self):
while True:
commands = self.command_bundle_queue.get()
self.broadcaster.process_commands(commands)
with self.command_cond:
for command in commands:
if isinstance(command, ca.VersionResponse):
# Check that the server version is one we can talk to.
assert command.version > 11
if isinstance(command, ca.SearchResponse):
with self._search_lock:
name = self.unanswered_searches.get(
command.cid, None)
if name is not None:
self.search_results[name] = (
ca.extract_address(command), time.time())
self.unanswered_searches.pop(command.cid)
else:
# This is a redundant response, which the spec
# tell us we must ignore.
pass
self.command_cond.notify_all()
def test_nonet():
# Register with the repeater.
assert not cli_b._registered
bytes_to_send = cli_b.send(ca.RepeaterRegisterRequest('0.0.0.0'))
assert not cli_b._registered
# Receive response
data = bytes(ca.RepeaterConfirmResponse('127.0.0.1'))
commands = cli_b.recv(data, cli_addr)
cli_b.process_commands(commands)
assert cli_b._registered
# Search for pv1.
# CA requires us to send a VersionRequest and a SearchRequest bundled into
# one datagram.
bytes_to_send = cli_b.send(ca.VersionRequest(0, ca.DEFAULT_PROTOCOL_VERSION),
ca.SearchRequest(pv1, 0,
ca.DEFAULT_PROTOCOL_VERSION))
commands = srv_b.recv(bytes_to_send, cli_addr)
srv_b.process_commands(commands)
ver_req, search_req = commands
bytes_to_send = srv_b.send(
ca.VersionResponse(ca.DEFAULT_PROTOCOL_VERSION),
ca.SearchResponse(5064, None, search_req.cid, ca.DEFAULT_PROTOCOL_VERSION))
# Receive a VersionResponse and SearchResponse.
commands = iter(cli_b.recv(bytes_to_send, cli_addr))
command = next(commands)
assert type(command) is ca.VersionResponse
command = next(commands)
assert type(command) is ca.SearchResponse
address = ca.extract_address(command)
circuit = ca.VirtualCircuit(our_role=ca.CLIENT,
address=address,
priority=0)
circuit.log.setLevel('DEBUG')
chan1 = ca.ClientChannel(pv1, circuit)
assert chan1.states[ca.CLIENT] is ca.SEND_CREATE_CHAN_REQUEST
assert chan1.states[ca.SERVER] is ca.IDLE
srv_circuit = ca.VirtualCircuit(our_role=ca.SERVER,
address=address, priority=None)
cli_send(chan1.circuit, ca.VersionRequest(priority=0,
version=ca.DEFAULT_PROTOCOL_VERSION))
srv_recv(srv_circuit)
srv_send(srv_circuit, ca.VersionResponse(version=ca.DEFAULT_PROTOCOL_VERSION))
cli_recv(chan1.circuit)
cli_send(chan1.circuit, ca.HostNameRequest('localhost'))
cli_send(chan1.circuit, ca.ClientNameRequest('username'))
cli_send(chan1.circuit, ca.CreateChanRequest(name=pv1, cid=chan1.cid,
version=ca.DEFAULT_PROTOCOL_VERSION))
assert chan1.states[ca.CLIENT] is ca.AWAIT_CREATE_CHAN_RESPONSE
assert chan1.states[ca.SERVER] is ca.SEND_CREATE_CHAN_RESPONSE
srv_recv(srv_circuit)
assert chan1.states[ca.CLIENT] is ca.AWAIT_CREATE_CHAN_RESPONSE
assert chan1.states[ca.SERVER] is ca.SEND_CREATE_CHAN_RESPONSE
srv_chan1, = srv_circuit.channels.values()
assert srv_chan1.states[ca.CLIENT] is ca.AWAIT_CREATE_CHAN_RESPONSE
assert srv_chan1.states[ca.SERVER] is ca.SEND_CREATE_CHAN_RESPONSE
srv_send(srv_circuit, ca.CreateChanResponse(cid=chan1.cid, sid=1,
data_type=5, data_count=1))
assert srv_chan1.states[ca.CLIENT] is ca.CONNECTED
assert srv_chan1.states[ca.SERVER] is ca.CONNECTED
# At this point the CLIENT is not aware that we are CONNECTED because it
# has not yet received the CreateChanResponse. It should not be allowed to
# read or write.
assert chan1.states[ca.CLIENT] is ca.AWAIT_CREATE_CHAN_RESPONSE
assert chan1.states[ca.SERVER] is ca.SEND_CREATE_CHAN_RESPONSE
# Try sending a premature read request.
read_req = ca.ReadNotifyRequest(sid=srv_chan1.sid,
data_type=srv_chan1.native_data_type,
data_count=srv_chan1.native_data_count,
ioid=0)
with pytest.raises(ca.LocalProtocolError):
cli_send(chan1.circuit, read_req)
# The above failed because the sid is not recognized. Remove that failure
# by editing the sid cache, and check that it *still* fails, this time
# because of the state machine prohibiting this command before the channel
# is in a CONNECTED state.
chan1.circuit.channels_sid[1] = chan1
with pytest.raises(ca.LocalProtocolError):
cli_send(chan1.circuit, read_req)
cli_recv(chan1.circuit)
assert chan1.states[ca.CLIENT] is ca.CONNECTED
assert chan1.states[ca.SERVER] is ca.CONNECTED
# Test subscriptions.
assert chan1.native_data_type and chan1.native_data_count
add_req = ca.EventAddRequest(data_type=chan1.native_data_type,
data_count=chan1.native_data_count,
sid=chan1.sid,
subscriptionid=0,
low=0, high=0, to=0, mask=1)
cli_send(chan1.circuit, add_req)
srv_recv(srv_circuit)
add_res = ca.EventAddResponse(data=(3,),
data_type=chan1.native_data_type,
data_count=chan1.native_data_count,
subscriptionid=0,
status=1)
srv_send(srv_circuit, add_res)
cli_recv(chan1.circuit)
cancel_req = ca.EventCancelRequest(data_type=add_req.data_type,
sid=add_req.sid,
subscriptionid=add_req.subscriptionid)
cli_send(chan1.circuit, cancel_req)
srv_recv(srv_circuit)
# Test reading.
cli_send(chan1.circuit, ca.ReadNotifyRequest(data_type=5, data_count=1,
sid=chan1.sid,
ioid=12))
srv_recv(srv_circuit)
srv_send(srv_circuit, ca.ReadNotifyResponse(data=(3,),
data_type=5, data_count=1,
ioid=12, status=1))
cli_recv(chan1.circuit)
# Test writing.
request = ca.WriteNotifyRequest(data_type=2, data_count=1,
sid=chan1.sid,
ioid=13, data=(4,))
cli_send(chan1.circuit, request)
srv_recv(srv_circuit)
srv_send(srv_circuit, ca.WriteNotifyResponse(data_type=5, data_count=1,
ioid=13, status=1))
cli_recv(chan1.circuit)
# Test "clearing" (closing) the channel.
cli_send(chan1.circuit, ca.ClearChannelRequest(sid=chan1.sid, cid=chan1.cid))
assert chan1.states[ca.CLIENT] is ca.MUST_CLOSE
assert chan1.states[ca.SERVER] is ca.MUST_CLOSE
srv_recv(srv_circuit)
assert srv_chan1.states[ca.CLIENT] is ca.MUST_CLOSE
assert srv_chan1.states[ca.SERVER] is ca.MUST_CLOSE
srv_send(srv_circuit, ca.ClearChannelResponse(sid=chan1.sid, cid=chan1.cid))
assert srv_chan1.states[ca.CLIENT] is ca.CLOSED
assert srv_chan1.states[ca.SERVER] is ca.CLOSED
def search(pv_name, udp_sock, timeout, *, max_retries=2):
# Set Broadcaster log level to match our logger.
b = ca.Broadcaster(our_role=ca.CLIENT)
b.client_address = safe_getsockname(udp_sock)
# Send registration request to the repeater
logger.debug('Registering with the Channel Access repeater.')
bytes_to_send = b.send(ca.RepeaterRegisterRequest())
env = get_environment_variables()
repeater_port = env['EPICS_CA_REPEATER_PORT']
client_address_list = ca.get_client_address_list()
local_address = ca.get_local_address()
try:
udp_sock.sendto(bytes_to_send, (local_address, repeater_port))
except OSError as exc:
raise ca.CaprotoNetworkError(
f"Failed to send to {local_address}:{repeater_port}") from exc
logger.debug("Searching for %r....", pv_name)
commands = (ca.VersionRequest(0, ca.DEFAULT_PROTOCOL_VERSION),
ca.SearchRequest(pv_name, 0, ca.DEFAULT_PROTOCOL_VERSION))
bytes_to_send = b.send(*commands)
tags = {
'role': 'CLIENT',
'our_address': b.client_address,
'direction': '--->>>'
}
def send_search():
for dest in client_address_list:
tags['their_address'] = dest
b.log.debug('%d commands %dB',
len(commands),
len(bytes_to_send),
extra=tags)
try:
udp_sock.sendto(bytes_to_send, dest)
except OSError as exc:
host, port = dest
raise ca.CaprotoNetworkError(
f"Failed to send to {host}:{port}") from exc
def check_timeout():
nonlocal retry_at
if time.monotonic() >= retry_at:
send_search()
retry_at = time.monotonic() + retry_timeout
if time.monotonic() - t > timeout:
raise CaprotoTimeoutError(
f"Timed out while awaiting a response "
f"from the search for {pv_name!r}. Search "
f"requests were sent to this address list: "
f"{ca.get_address_list()}.")
# Initial search attempt
send_search()
# Await a search response, and keep track of registration status
retry_timeout = timeout / max((max_retries, 1))
t = time.monotonic()
retry_at = t + retry_timeout
try:
orig_timeout = udp_sock.gettimeout()
udp_sock.settimeout(retry_timeout)
while True:
try:
bytes_received, address = udp_sock.recvfrom(ca.MAX_UDP_RECV)
except socket.timeout:
check_timeout()
continue
check_timeout()
commands = b.recv(bytes_received, address)
b.process_commands(commands)
for command in commands:
if isinstance(command, ca.SearchResponse) and command.cid == 0:
address = ca.extract_address(command)
logger.debug('Found %r at %s:%d', pv_name, *address)
return address
else:
# None of the commands we have seen are a reply to our request.
# Receive more data.
continue
finally:
udp_sock.settimeout(orig_timeout)
def search(pv_name, udp_sock, timeout, *, max_retries=2):
# Set Broadcaster log level to match our logger.
b = ca.Broadcaster(our_role=ca.CLIENT)
# Send registration request to the repeater
logger.debug('Registering with the Channel Access repeater.')
bytes_to_send = b.send(ca.RepeaterRegisterRequest())
repeater_port = os.environ.get('EPICS_CA_REPEATER_PORT', 5065)
for host in ca.get_address_list():
udp_sock.sendto(bytes_to_send, (host, repeater_port))
logger.debug("Searching for '%s'....", pv_name)
bytes_to_send = b.send(
ca.VersionRequest(0, ca.DEFAULT_PROTOCOL_VERSION),
ca.SearchRequest(pv_name, 0, ca.DEFAULT_PROTOCOL_VERSION))
def send_search():
for host in ca.get_address_list():
if ':' in host:
host, _, specified_port = host.partition(':')
dest = (host, int(specified_port))
else:
dest = (host, CA_SERVER_PORT)
udp_sock.sendto(bytes_to_send, dest)
logger.debug('Search request sent to %r.', dest)
def check_timeout():
nonlocal retry_at
if time.monotonic() >= retry_at:
send_search()
retry_at = time.monotonic() + retry_timeout
if time.monotonic() - t > timeout:
raise TimeoutError(f"Timed out while awaiting a response "
f"from the search for {pv_name!r}. Search "
f"requests were sent to this address list: "
f"{ca.get_address_list()}.")
# Initial search attempt
send_search()
# Await a search response, and keep track of registration status
retry_timeout = timeout / max((max_retries, 1))
t = time.monotonic()
retry_at = t + retry_timeout
try:
orig_timeout = udp_sock.gettimeout()
udp_sock.settimeout(retry_timeout)
while True:
try:
bytes_received, address = udp_sock.recvfrom(ca.MAX_UDP_RECV)
except socket.timeout:
check_timeout()
continue
check_timeout()
commands = b.recv(bytes_received, address)
b.process_commands(commands)
for command in commands:
if isinstance(command, ca.SearchResponse) and command.cid == 0:
address = ca.extract_address(command)
logger.debug('Found %s at %s', pv_name, address)
return address
else:
# None of the commands we have seen are a reply to our request.
# Receive more data.
continue
finally:
udp_sock.settimeout(orig_timeout)
def main(*, skip_monitor_section=False):
# A broadcast socket
udp_sock = ca.bcast_socket()
# Register with the repeater.
bytes_to_send = b.send(ca.RepeaterRegisterRequest('0.0.0.0'))
# TODO: for test environment with specific hosts listed in
# EPICS_CA_ADDR_LIST
if False:
fake_reg = (('127.0.0.1', ca.EPICS_CA1_PORT),
[ca.RepeaterConfirmResponse(repeater_address='127.0.0.1')])
b.command_queue.put(fake_reg)
else:
udp_sock.sendto(bytes_to_send, ('', CA_REPEATER_PORT))
# Receive response
data, address = udp_sock.recvfrom(1024)
commands = b.recv(data, address)
b.process_commands(commands)
# Search for pv1.
# CA requires us to send a VersionRequest and a SearchRequest bundled into
# one datagram.
bytes_to_send = b.send(ca.VersionRequest(0, 13),
ca.SearchRequest(pv1, 0, 13))
for host in ca.get_address_list():
if ':' in host:
host, _, specified_port = host.partition(':')
udp_sock.sendto(bytes_to_send, (host, int(specified_port)))
else:
udp_sock.sendto(bytes_to_send, (host, CA_SERVER_PORT))
print('searching for %s' % pv1)
# Receive a VersionResponse and SearchResponse.
bytes_received, address = udp_sock.recvfrom(1024)
commands = b.recv(bytes_received, address)
b.process_commands(commands)
c1, c2 = commands
assert type(c1) is ca.VersionResponse
assert type(c2) is ca.SearchResponse
address = ca.extract_address(c2)
circuit = ca.VirtualCircuit(our_role=ca.CLIENT,
address=address,
priority=0)
circuit.log.setLevel('DEBUG')
chan1 = ca.ClientChannel(pv1, circuit)
sockets[chan1.circuit] = socket.create_connection(chan1.circuit.address)
# Initialize our new TCP-based CA connection with a VersionRequest.
send(chan1.circuit, ca.VersionRequest(priority=0, version=13))
recv(chan1.circuit)
# Send info about us.
send(chan1.circuit, ca.HostNameRequest('localhost'))
send(chan1.circuit, ca.ClientNameRequest('username'))
send(chan1.circuit,
ca.CreateChanRequest(name=pv1, cid=chan1.cid, version=13))
commands = recv(chan1.circuit)
# Test subscriptions.
assert chan1.native_data_type and chan1.native_data_count
add_req = ca.EventAddRequest(data_type=chan1.native_data_type,
data_count=chan1.native_data_count,
sid=chan1.sid,
subscriptionid=0,
low=0,
high=0,
to=0,
mask=1)
send(chan1.circuit, add_req)
commands = recv(chan1.circuit)
if not skip_monitor_section:
try:
print('Monitoring until Ctrl-C is hit. Meanwhile, use caput to '
'change the value and watch for commands to arrive here.')
while True:
commands = recv(chan1.circuit)
if commands:
print(commands)
except KeyboardInterrupt:
pass
cancel_req = ca.EventCancelRequest(data_type=add_req.data_type,
sid=add_req.sid,
subscriptionid=add_req.subscriptionid)
send(chan1.circuit, cancel_req)
commands, = recv(chan1.circuit)
# Test reading.
send(
chan1.circuit,
ca.ReadNotifyRequest(data_type=2, data_count=1, sid=chan1.sid,
ioid=12))
commands, = recv(chan1.circuit)
# Test writing.
request = ca.WriteNotifyRequest(data_type=2,
data_count=1,
sid=chan1.sid,
ioid=13,
data=(4, ))
send(chan1.circuit, request)
recv(chan1.circuit)
time.sleep(2)
send(
chan1.circuit,
ca.ReadNotifyRequest(data_type=2, data_count=1, sid=chan1.sid,
ioid=14))
recv(chan1.circuit)
# Test "clearing" (closing) the channel.
send(chan1.circuit, ca.ClearChannelRequest(chan1.sid, chan1.cid))
recv(chan1.circuit)
sockets.pop(chan1.circuit).close()
udp_sock.close()
