pc_rpc: multiple target support

This commit is contained in:
Sebastien Bourdeauducq 2014-12-31 20:13:10 +08:00
parent 9cd89a0c50
commit d2a5dfa1ec
10 changed files with 114 additions and 93 deletions

View File

@ -30,7 +30,7 @@ class RemoteError(Exception):
class IncompatibleServer(Exception):
"""Raised by the client when attempting to connect to a server that does
not have the expected type.
not have the expected target.
"""
pass
@ -62,22 +62,38 @@ class Client:
hostname or a IPv4 or IPv6 address (see
``socket.create_connection`` in the Python standard library).
:param port: TCP port to use.
:param expected_id_type: Server type to expect. ``IncompatibleServer`` is
raised when the types do not match. Use ``None`` to accept any server
type.
:param target_name: Target name to select. ``IncompatibleServer`` is
raised if the target does not exist.
Use ``None`` to skip selecting a target. The list of targets can then
be retrieved using ``get_rpc_id`` and then one can be selected later
using ``select_rpc_target``.
"""
def __init__(self, host, port, expected_id_type):
self.socket = socket.create_connection((host, port))
self.socket.sendall(_init_string)
self._identify(expected_id_type)
def __init__(self, host, port, target_name):
self._socket = socket.create_connection((host, port))
self._socket.sendall(_init_string)
server_identification = self._recv()
self._target_names = server_identification["targets"]
self._id_parameters = server_identification["parameters"]
if target_name is not None:
self.select_rpc_target(target_name)
def select_rpc_target(self, target_name):
"""Selects a RPC target by name. This function should be called
exactly once if the object was created with ``target_name=None``.
"""
if target_name not in self._target_names:
raise IncompatibleServer
self._socket.sendall((target_name + "\n").encode())
def get_rpc_id(self):
"""Returns a dictionary containing the identification information of
the server.
"""Returns a tuple (target_names, id_parameters) containing the
identification information of the server.
"""
return self._server_identification
return (self._target_names, self._id_parameters)
def close_rpc(self):
"""Closes the connection to the RPC server.
@ -85,15 +101,16 @@ class Client:
No further method calls should be done after this method is called.
"""
self.socket.close()
self._socket.close()
def _send_recv(self, obj):
def _send(self, obj):
line = pyon.encode(obj) + "\n"
self.socket.sendall(line.encode())
self._socket.sendall(line.encode())
buf = self.socket.recv(4096).decode()
def _recv(self):
buf = self._socket.recv(4096).decode()
while "\n" not in buf:
more = self.socket.recv(4096)
more = self._socket.recv(4096)
if not more:
break
buf += more.decode()
@ -101,20 +118,15 @@ class Client:
return obj
def _identify(self, expected_id_type):
obj = {"action": "identify"}
self._server_identification = self._send_recv(obj)
if (expected_id_type is not None
and self._server_identification["type"] != expected_id_type):
raise IncompatibleServer
def _do_rpc(self, name, args, kwargs):
obj = {"action": "call", "name": name, "args": args, "kwargs": kwargs}
obj = self._send_recv(obj)
if obj["result"] == "ok":
self._send(obj)
obj = self._recv()
if obj["status"] == "ok":
return obj["ret"]
elif obj["result"] == "error":
raise RemoteError(obj["message"] + "\n" + obj["traceback"])
elif obj["status"] == "failed":
raise RemoteError(obj["message"])
else:
raise ValueError
@ -134,18 +146,16 @@ class Server(AsyncioServer):
simple cases: it allows new connections to be be accepted even when the
previous client failed to properly shut down its connection.
:param target: Object providing the RPC methods to be exposed to the
client.
:param id_type: A string identifying the server type. Clients use it to
verify that they are connected to the proper server.
:param targets: A dictionary of objects providing the RPC methods to be
exposed to the client. Keys are names identifying each object.
Clients select one of these objects using its name upon connection.
:param id_parameters: An optional human-readable string giving more
information about the parameters of the server.
"""
def __init__(self, target, id_type, id_parameters=None):
def __init__(self, targets, id_parameters=None):
AsyncioServer.__init__(self)
self.target = target
self.id_type = id_type
self.targets = targets
self.id_parameters = id_parameters
@asyncio.coroutine
@ -154,34 +164,41 @@ class Server(AsyncioServer):
line = yield from reader.readline()
if line != _init_string:
return
obj = {
"targets": sorted(self.targets.keys()),
"parameters": self.id_parameters
}
line = pyon.encode(obj) + "\n"
writer.write(line.encode())
line = yield from reader.readline()
if not line:
return
target_name = line.decode()[:-1]
try:
target = self.targets[target_name]
except KeyError:
return
while True:
line = yield from reader.readline()
if not line:
break
obj = pyon.decode(line.decode())
action = obj["action"]
if action == "call":
try:
method = getattr(self.target, obj["name"])
method = getattr(target, obj["name"])
ret = method(*obj["args"], **obj["kwargs"])
obj = {"result": "ok", "ret": ret}
except Exception as e:
obj = {"result": "error",
"message": type(e).__name__ + ": " + str(e),
"traceback": traceback.format_exc()}
line = pyon.encode(obj) + "\n"
writer.write(line.encode())
elif action == "identify":
obj = {"type": self.id_type}
if self.id_parameters is not None:
obj["parameters"] = self.id_parameters
obj = {"status": "ok", "ret": ret}
except Exception:
obj = {"status": "failed",
"message": traceback.format_exc()}
line = pyon.encode(obj) + "\n"
writer.write(line.encode())
finally:
writer.close()
def simple_server_loop(target, id_type, host, port, id_parameters=None):
def simple_server_loop(targets, host, port, id_parameters=None):
"""Runs a server until an exception is raised (e.g. the user hits Ctrl-C).
See ``Server`` for a description of the parameters.
@ -189,7 +206,7 @@ def simple_server_loop(target, id_type, host, port, id_parameters=None):
"""
loop = asyncio.get_event_loop()
try:
server = Server(target, id_type, id_parameters)
server = Server(targets, id_parameters)
loop.run_until_complete(server.start(host, port))
try:
loop.run_forever()

View File

@ -66,7 +66,7 @@ def run_server():
loop = asyncio.get_event_loop()
try:
echo = Echo()
server = pc_rpc.Server(echo, "test")
server = pc_rpc.Server({"test": echo})
loop.run_until_complete(server.start(test_address, test_port))
try:
loop.run_until_complete(echo.wait_quit())

View File

@ -30,12 +30,14 @@ Default TCP port list
When writing a new driver, choose a free TCP port and add it to this list.
+-----------+--------------+
+--------------------------+--------------+
| Component | Default port |
+===========+==============+
| Master | 8888 |
+-----------+--------------+
+==========================+==============+
| Master (notifications) | 8887 |
+--------------------------+--------------+
| Master (control) | 8888 |
+--------------------------+--------------+
| PDQ2 | 8889 |
+-----------+--------------+
+--------------------------+--------------+
| LDA | 8890 |
+-----------+--------------+
+--------------------------+--------------+

View File

@ -23,7 +23,7 @@ To turn it into a server, we use :class:`artiq.management.pc_rpc`. Import the fu
and add a ``main`` function that is run when the program is executed: ::
def main():
simple_server_loop(Hello(), "hello", "::1", 7777)
simple_server_loop({"hello": Hello()}, "::1", 7777)
if __name__ == "__main__":
main()
@ -49,10 +49,10 @@ and verify that you can connect to the TCP port: ::
:tip: Use the key combination Ctrl-AltGr-9 to get the ``telnet>`` prompt, and enter ``close`` to quit Telnet. Quit the controller with Ctrl-C.
Also verify that you can get the type of the server (the "hello" string passed to ``simple_server_loop``) using the ``artiq_ctlid.py`` program from the ARTIQ front-end tools: ::
Also verify that a target (service) named "hello" (as passed in the first argument to ``simple_server_loop``) exists using the ``artiq_ctlid.py`` program from the ARTIQ front-end tools: ::
$ artiq_ctlid.py ::1 7777
Type: hello
Target(s): hello
The client
----------

View File

@ -144,7 +144,7 @@ def main():
_run_subscriber(args.server, args.port, subscriber)
else:
port = 8888 if args.port is None else args.port
remote = Client(args.server, port, "schedule_control")
remote = Client(args.server, port, "master_schedule")
try:
globals()["_action_" + args.action](remote, args)
finally:

View File

@ -19,12 +19,12 @@ def main():
args = _get_args()
remote = Client(args.server, args.port, None)
try:
ident = remote.get_rpc_id()
target_names, id_parameters = remote.get_rpc_id()
finally:
remote.close_rpc()
print("Type: " + ident["type"])
if "parameters" in ident:
print("Parameters: " + ident["parameters"])
print("Target(s): " + ", ".join(target_names))
if id_parameters is not None:
print("Parameters: " + id_parameters)
if __name__ == "__main__":
main()

View File

@ -16,11 +16,11 @@ def _get_args():
"-s", "--server", default="::1",
help="hostname or IP of the master to connect to")
parser.add_argument(
"--port-schedule-control", default=8888, type=int,
help="TCP port to connect to for schedule control")
"--port-notify", default=8887, type=int,
help="TCP port to connect to for notifications")
parser.add_argument(
"--port-schedule-notify", default=8887, type=int,
help="TCP port to connect to for schedule notifications")
"--port-control", default=8888, type=int,
help="TCP port to connect to for control")
return parser.parse_args()
@ -39,7 +39,7 @@ def main():
parameters_win.show_all()
loop.run_until_complete(scheduler_win.sub_connect(
args.server, args.port_schedule_notify))
args.server, args.port_notify))
try:
loop.run_forever()
finally:

View File

@ -16,11 +16,11 @@ def _get_args():
"--bind", default="::1",
help="hostname or IP address to bind to")
parser.add_argument(
"--port-schedule-control", default=8888, type=int,
help="TCP port to listen to for schedule control")
"--port-notify", default=8887, type=int,
help="TCP port to listen to for notifications")
parser.add_argument(
"--port-schedule-notify", default=8887, type=int,
help="TCP port to listen to for schedule notifications")
"--port-control", default=8888, type=int,
help="TCP port to listen to for control")
return parser.parse_args()
@ -38,18 +38,20 @@ def main():
loop.run_until_complete(scheduler.start())
atexit.register(lambda: loop.run_until_complete(scheduler.stop()))
schedule_control = Server(scheduler, "schedule_control")
loop.run_until_complete(schedule_control.start(
args.bind, args.port_schedule_control))
atexit.register(lambda: loop.run_until_complete(schedule_control.stop()))
server_control = Server({
"master_schedule": scheduler
})
loop.run_until_complete(server_control.start(
args.bind, args.port_control))
atexit.register(lambda: loop.run_until_complete(server_control.stop()))
schedule_notify = Publisher({
server_notify = Publisher({
"queue": scheduler.queue,
"periodic": scheduler.periodic
})
loop.run_until_complete(schedule_notify.start(
args.bind, args.port_schedule_notify))
atexit.register(lambda: loop.run_until_complete(schedule_notify.stop()))
loop.run_until_complete(server_notify.start(
args.bind, args.port_notify))
atexit.register(lambda: loop.run_until_complete(server_notify.stop()))
loop.run_forever()

View File

@ -23,7 +23,7 @@ def main():
else:
lda = Lda(args.serial, args.device)
simple_server_loop(lda, "lda",
simple_server_loop({"lda": lda},
args.bind, args.port)
if __name__ == "__main__":

View File

@ -32,7 +32,7 @@ def main():
dev = Pdq2(serial=args.serial)
try:
simple_server_loop(dev, "pdq2", args.bind, args.port,
simple_server_loop({"pdq2": dev}, args.bind, args.port,
id_parameters="serial=" + str(args.serial))
finally:
dev.close()