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Diffstat (limited to 'src/console/zmq/devices/basedevice.py')
-rwxr-xr-x | src/console/zmq/devices/basedevice.py | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/src/console/zmq/devices/basedevice.py b/src/console/zmq/devices/basedevice.py new file mode 100755 index 00000000..7ba1b7ac --- /dev/null +++ b/src/console/zmq/devices/basedevice.py @@ -0,0 +1,229 @@ +"""Classes for running 0MQ Devices in the background.""" + +# Copyright (C) PyZMQ Developers +# Distributed under the terms of the Modified BSD License. + + +import time +from threading import Thread +from multiprocessing import Process + +from zmq import device, QUEUE, Context, ETERM, ZMQError + + +class Device: + """A 0MQ Device to be run in the background. + + You do not pass Socket instances to this, but rather Socket types:: + + Device(device_type, in_socket_type, out_socket_type) + + For instance:: + + dev = Device(zmq.QUEUE, zmq.DEALER, zmq.ROUTER) + + Similar to zmq.device, but socket types instead of sockets themselves are + passed, and the sockets are created in the work thread, to avoid issues + with thread safety. As a result, additional bind_{in|out} and + connect_{in|out} methods and setsockopt_{in|out} allow users to specify + connections for the sockets. + + Parameters + ---------- + device_type : int + The 0MQ Device type + {in|out}_type : int + zmq socket types, to be passed later to context.socket(). e.g. + zmq.PUB, zmq.SUB, zmq.REQ. If out_type is < 0, then in_socket is used + for both in_socket and out_socket. + + Methods + ------- + bind_{in_out}(iface) + passthrough for ``{in|out}_socket.bind(iface)``, to be called in the thread + connect_{in_out}(iface) + passthrough for ``{in|out}_socket.connect(iface)``, to be called in the + thread + setsockopt_{in_out}(opt,value) + passthrough for ``{in|out}_socket.setsockopt(opt, value)``, to be called in + the thread + + Attributes + ---------- + daemon : int + sets whether the thread should be run as a daemon + Default is true, because if it is false, the thread will not + exit unless it is killed + context_factory : callable (class attribute) + Function for creating the Context. This will be Context.instance + in ThreadDevices, and Context in ProcessDevices. The only reason + it is not instance() in ProcessDevices is that there may be a stale + Context instance already initialized, and the forked environment + should *never* try to use it. + """ + + context_factory = Context.instance + """Callable that returns a context. Typically either Context.instance or Context, + depending on whether the device should share the global instance or not. + """ + + def __init__(self, device_type=QUEUE, in_type=None, out_type=None): + self.device_type = device_type + if in_type is None: + raise TypeError("in_type must be specified") + if out_type is None: + raise TypeError("out_type must be specified") + self.in_type = in_type + self.out_type = out_type + self._in_binds = [] + self._in_connects = [] + self._in_sockopts = [] + self._out_binds = [] + self._out_connects = [] + self._out_sockopts = [] + self.daemon = True + self.done = False + + def bind_in(self, addr): + """Enqueue ZMQ address for binding on in_socket. + + See zmq.Socket.bind for details. + """ + self._in_binds.append(addr) + + def connect_in(self, addr): + """Enqueue ZMQ address for connecting on in_socket. + + See zmq.Socket.connect for details. + """ + self._in_connects.append(addr) + + def setsockopt_in(self, opt, value): + """Enqueue setsockopt(opt, value) for in_socket + + See zmq.Socket.setsockopt for details. + """ + self._in_sockopts.append((opt, value)) + + def bind_out(self, addr): + """Enqueue ZMQ address for binding on out_socket. + + See zmq.Socket.bind for details. + """ + self._out_binds.append(addr) + + def connect_out(self, addr): + """Enqueue ZMQ address for connecting on out_socket. + + See zmq.Socket.connect for details. + """ + self._out_connects.append(addr) + + def setsockopt_out(self, opt, value): + """Enqueue setsockopt(opt, value) for out_socket + + See zmq.Socket.setsockopt for details. + """ + self._out_sockopts.append((opt, value)) + + def _setup_sockets(self): + ctx = self.context_factory() + + self._context = ctx + + # create the sockets + ins = ctx.socket(self.in_type) + if self.out_type < 0: + outs = ins + else: + outs = ctx.socket(self.out_type) + + # set sockopts (must be done first, in case of zmq.IDENTITY) + for opt,value in self._in_sockopts: + ins.setsockopt(opt, value) + for opt,value in self._out_sockopts: + outs.setsockopt(opt, value) + + for iface in self._in_binds: + ins.bind(iface) + for iface in self._out_binds: + outs.bind(iface) + + for iface in self._in_connects: + ins.connect(iface) + for iface in self._out_connects: + outs.connect(iface) + + return ins,outs + + def run_device(self): + """The runner method. + + Do not call me directly, instead call ``self.start()``, just like a Thread. + """ + ins,outs = self._setup_sockets() + device(self.device_type, ins, outs) + + def run(self): + """wrap run_device in try/catch ETERM""" + try: + self.run_device() + except ZMQError as e: + if e.errno == ETERM: + # silence TERM errors, because this should be a clean shutdown + pass + else: + raise + finally: + self.done = True + + def start(self): + """Start the device. Override me in subclass for other launchers.""" + return self.run() + + def join(self,timeout=None): + """wait for me to finish, like Thread.join. + + Reimplemented appropriately by subclasses.""" + tic = time.time() + toc = tic + while not self.done and not (timeout is not None and toc-tic > timeout): + time.sleep(.001) + toc = time.time() + + +class BackgroundDevice(Device): + """Base class for launching Devices in background processes and threads.""" + + launcher=None + _launch_class=None + + def start(self): + self.launcher = self._launch_class(target=self.run) + self.launcher.daemon = self.daemon + return self.launcher.start() + + def join(self, timeout=None): + return self.launcher.join(timeout=timeout) + + +class ThreadDevice(BackgroundDevice): + """A Device that will be run in a background Thread. + + See Device for details. + """ + _launch_class=Thread + +class ProcessDevice(BackgroundDevice): + """A Device that will be run in a background Process. + + See Device for details. + """ + _launch_class=Process + context_factory = Context + """Callable that returns a context. Typically either Context.instance or Context, + depending on whether the device should share the global instance or not. + """ + + +__all__ = ['Device', 'ThreadDevice', 'ProcessDevice'] |