def start(self):
L.info("Starting %s Model Service.", self.name)
pva_server = PVAServer(providers=[{
f"SIMULACRUM:SYS0:1:{self.name}:LIVE:TWISS":
self.live_twiss_pv,
f"SIMULACRUM:SYS0:1:{self.name}:DESIGN:TWISS":
self.design_twiss_pv,
f"SIMULACRUM:SYS0:1:{self.name}:LIVE:RMAT":
self.live_rmat_pv,
f"SIMULACRUM:SYS0:1:{self.name}:DESIGN:RMAT":
self.design_rmat_pv,
}])
try:
zmq_task = self.loop.create_task(self.recv())
pva_refresh_task = self.loop.create_task(self.refresh_pva_table())
broadcast_task = self.loop.create_task(
self.broadcast_model_changes())
jitter_task = self.loop.create_task(self.add_jitter())
self.loop.run_forever()
except KeyboardInterrupt:
L.info("Shutting down Model Service.")
zmq_task.cancel()
pva_refresh_task.cancel()
broadcast_task.cancel()
pva_server.stop()
finally:
self.loop.close()
L.info("Model Service shutdown complete.")
def quickRPCServer(provider,
prefix,
target,
maxsize=20,
workers=1,
useenv=True,
conf=None):
"""Run an RPC server in the current thread
Calls are handled sequentially, and always in the current thread, if workers=1 (the default).
If workers>1 then calls are handled concurrently by a pool of worker threads.
Requires NTURI style argument encoding.
:param str provider: A provider name. Must be unique in this process.
:param str prefix: PV name prefix. Along with method names, must be globally unique.
:param target: The object which is exporting methods. (use the :func:`rpc` decorator)
:param int maxsize: Number of pending RPC calls to be queued.
:param int workers: Number of worker threads (default 1)
:param useenv: Passed to :class:`~p4p.server.Server`
:param conf: Passed to :class:`~p4p.server.Server`
"""
from p4p.server import Server, installProvider, removeProvider
queue = WorkQueue(maxsize=maxsize)
installProvider(provider,
NTURIDispatcher(queue, target=target, prefix=prefix))
try:
threads = []
server = Server(providers=provider, useenv=useenv, conf=conf)
try:
for n in range(1, workers):
T = Thread(name='%s Worker %d' % (provider, n),
target=queue.handle)
threads.append(T)
T.start()
# handle calls in the current thread until KeyboardInterrupt
queue.handle()
finally:
try:
for T in threads:
queue.interrupt()
T.join()
finally:
# we really need to do this or the process will hang on exit
server.stop()
finally:
removeProvider(provider)
def start(self):
L.info("Starting Model Service.")
pva_server = PVAServer(providers=[{
"BMAD:SYS0:1:FULL_MACHINE:LIVE:TWISS":
self.live_twiss_pv,
"BMAD:SYS0:1:FULL_MACHINE:DESIGN:TWISS":
self.design_twiss_pv
}])
zmq_task = self.loop.create_task(self.recv())
pva_refresh_task = self.loop.create_task(self.refresh_pva_table())
broadcast_task = self.loop.create_task(self.broadcast_model_changes())
try:
self.loop.run_until_complete(zmq_task)
except KeyboardInterrupt:
zmq_task.cancel()
pva_refresh_task.cancel()
broadcast_task.cancel()
pva_server.stop()
class PvaServerComms(builtin.controllers.ServerComms):
"""A class for communication between pva client and server"""
def __init__(self, mri: builtin.controllers.AMri) -> None:
super().__init__(mri)
self._pva_server = None
self._provider = None
self._published: Set[str] = set()
self._pvs: Dict[str, Dict[Optional[str], SharedPV]] = {}
# Hooks
self.register_hooked(ProcessPublishHook, self.publish)
# Need camelCase as called by p4p Server
# noinspection PyPep8Naming
def testChannel(self, channel_name: str) -> bool:
if channel_name in self._published:
# Someone is asking for a Block
return True
elif "." in channel_name:
# Someone is asking for the field of a Block
mri, field = channel_name.rsplit(".", 1)
return mri in self._published
else:
# We don't have it
return False
# Need camelCase as called by p4p Server
# noinspection PyPep8Naming
def makeChannel(self, channel_name: str, src: str) -> SharedPV:
# Need to spawn as we take a lock here and in process
return cothread.CallbackResult(self._make_channel,
channel_name,
src,
callback_timeout=1.0)
def _make_channel(self, channel_name: str, src: str) -> SharedPV:
self.log.debug(f"Making PV {channel_name} for {src}")
if channel_name in self._published:
# Someone is asking for a Block
mri = channel_name
field = None
elif "." in channel_name:
# Someone is asking for the field of a Block
mri, field = channel_name.rsplit(".", 1)
else:
raise NameError("Bad channel %s" % channel_name)
with self._lock:
pvs = self._pvs.setdefault(mri, {})
try:
pv = pvs[field]
except KeyError:
assert self.process, "No attached process"
controller = self.process.get_controller(mri)
handler = BlockHandler(controller, field)
# We want any client passing a pvRequest field() to ONLY receive
# that field. The default behaviour of p4p is to send a masked
# version of the full structure. The mapperMode option allows us
# to tell p4p to send a slice instead
# https://github.com/mdavidsaver/pvDataCPP/blob/master/src/copy/pv/createRequest.h#L76
pv = SharedPV(handler=handler, options={"mapperMode": "Slice"})
pvs[field] = pv
return pv
def do_init(self):
super().do_init()
if self._pva_server is None:
self.log.info("Starting PVA server")
self._provider = DynamicProvider("PvaServerComms", self)
self._pva_server = Server(providers=[self._provider])
self.log.info("Started PVA server")
def do_disable(self):
super().do_disable()
if self._pva_server is not None:
self.log.info("Stopping PVA server")
# Stop the server
self._pva_server.stop()
# Disconnect everyone
self.disconnect_pv_clients(list(self._pvs))
# Get rid of the server reference so we can't stop again
self._pva_server = None
self.log.info("Stopped PVA server")
@add_call_types
def publish(self, published: APublished) -> None:
self._published = set(published)
if self._pva_server:
with self._lock:
mris = [mri for mri in self._pvs if mri not in published]
# Delete blocks we no longer have
self.disconnect_pv_clients(mris)
def disconnect_pv_clients(self, mris: List[str]) -> None:
"""Disconnect anyone listening to any of the given mris"""
for mri in mris:
for pv in self._pvs.pop(mri, {}).values():
# Close pv with force destroy on, this will call
# onLastDisconnect
pv.close(destroy=True, sync=True, timeout=1.0)
