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+# coding: utf-8
+"""tornado IOLoop API with zmq compatibility
+
+If you have tornado ≥ 3.0, this is a subclass of tornado's IOLoop,
+otherwise we ship a minimal subset of tornado in zmq.eventloop.minitornado.
+
+The minimal shipped version of tornado's IOLoop does not include
+support for concurrent futures - this will only be available if you
+have tornado ≥ 3.0.
+"""
+
+# Copyright (C) PyZMQ Developers
+# Distributed under the terms of the Modified BSD License.
+
+from __future__ import absolute_import, division, with_statement
+
+import os
+import time
+import warnings
+
+from zmq import (
+ Poller,
+ POLLIN, POLLOUT, POLLERR,
+ ZMQError, ETERM,
+)
+
+try:
+ import tornado
+ tornado_version = tornado.version_info
+except (ImportError, AttributeError):
+ tornado_version = ()
+
+try:
+ # tornado ≥ 3
+ from tornado.ioloop import PollIOLoop, PeriodicCallback
+ from tornado.log import gen_log
+except ImportError:
+ from .minitornado.ioloop import PollIOLoop, PeriodicCallback
+ from .minitornado.log import gen_log
+
+
+class DelayedCallback(PeriodicCallback):
+ """Schedules the given callback to be called once.
+
+ The callback is called once, after callback_time milliseconds.
+
+ `start` must be called after the DelayedCallback is created.
+
+ The timeout is calculated from when `start` is called.
+ """
+ def __init__(self, callback, callback_time, io_loop=None):
+ # PeriodicCallback require callback_time to be positive
+ warnings.warn("""DelayedCallback is deprecated.
+ Use loop.add_timeout instead.""", DeprecationWarning)
+ callback_time = max(callback_time, 1e-3)
+ super(DelayedCallback, self).__init__(callback, callback_time, io_loop)
+
+ def start(self):
+ """Starts the timer."""
+ self._running = True
+ self._firstrun = True
+ self._next_timeout = time.time() + self.callback_time / 1000.0
+ self.io_loop.add_timeout(self._next_timeout, self._run)
+
+ def _run(self):
+ if not self._running: return
+ self._running = False
+ try:
+ self.callback()
+ except Exception:
+ gen_log.error("Error in delayed callback", exc_info=True)
+
+
+class ZMQPoller(object):
+ """A poller that can be used in the tornado IOLoop.
+
+ This simply wraps a regular zmq.Poller, scaling the timeout
+ by 1000, so that it is in seconds rather than milliseconds.
+ """
+
+ def __init__(self):
+ self._poller = Poller()
+
+ @staticmethod
+ def _map_events(events):
+ """translate IOLoop.READ/WRITE/ERROR event masks into zmq.POLLIN/OUT/ERR"""
+ z_events = 0
+ if events & IOLoop.READ:
+ z_events |= POLLIN
+ if events & IOLoop.WRITE:
+ z_events |= POLLOUT
+ if events & IOLoop.ERROR:
+ z_events |= POLLERR
+ return z_events
+
+ @staticmethod
+ def _remap_events(z_events):
+ """translate zmq.POLLIN/OUT/ERR event masks into IOLoop.READ/WRITE/ERROR"""
+ events = 0
+ if z_events & POLLIN:
+ events |= IOLoop.READ
+ if z_events & POLLOUT:
+ events |= IOLoop.WRITE
+ if z_events & POLLERR:
+ events |= IOLoop.ERROR
+ return events
+
+ def register(self, fd, events):
+ return self._poller.register(fd, self._map_events(events))
+
+ def modify(self, fd, events):
+ return self._poller.modify(fd, self._map_events(events))
+
+ def unregister(self, fd):
+ return self._poller.unregister(fd)
+
+ def poll(self, timeout):
+ """poll in seconds rather than milliseconds.
+
+ Event masks will be IOLoop.READ/WRITE/ERROR
+ """
+ z_events = self._poller.poll(1000*timeout)
+ return [ (fd,self._remap_events(evt)) for (fd,evt) in z_events ]
+
+ def close(self):
+ pass
+
+
+class ZMQIOLoop(PollIOLoop):
+ """ZMQ subclass of tornado's IOLoop"""
+ def initialize(self, impl=None, **kwargs):
+ impl = ZMQPoller() if impl is None else impl
+ super(ZMQIOLoop, self).initialize(impl=impl, **kwargs)
+
+ @staticmethod
+ def instance():
+ """Returns a global `IOLoop` instance.
+
+ Most applications have a single, global `IOLoop` running on the
+ main thread. Use this method to get this instance from
+ another thread. To get the current thread's `IOLoop`, use `current()`.
+ """
+ # install ZMQIOLoop as the active IOLoop implementation
+ # when using tornado 3
+ if tornado_version >= (3,):
+ PollIOLoop.configure(ZMQIOLoop)
+ return PollIOLoop.instance()
+
+ def start(self):
+ try:
+ super(ZMQIOLoop, self).start()
+ except ZMQError as e:
+ if e.errno == ETERM:
+ # quietly return on ETERM
+ pass
+ else:
+ raise e
+
+
+if tornado_version >= (3,0) and tornado_version < (3,1):
+ def backport_close(self, all_fds=False):
+ """backport IOLoop.close to 3.0 from 3.1 (supports fd.close() method)"""
+ from zmq.eventloop.minitornado.ioloop import PollIOLoop as mini_loop
+ return mini_loop.close.__get__(self)(all_fds)
+ ZMQIOLoop.close = backport_close
+
+
+# public API name
+IOLoop = ZMQIOLoop
+
+
+def install():
+ """set the tornado IOLoop instance with the pyzmq IOLoop.
+
+ After calling this function, tornado's IOLoop.instance() and pyzmq's
+ IOLoop.instance() will return the same object.
+
+ An assertion error will be raised if tornado's IOLoop has been initialized
+ prior to calling this function.
+ """
+ from tornado import ioloop
+ # check if tornado's IOLoop is already initialized to something other
+ # than the pyzmq IOLoop instance:
+ assert (not ioloop.IOLoop.initialized()) or \
+ ioloop.IOLoop.instance() is IOLoop.instance(), "tornado IOLoop already initialized"
+
+ if tornado_version >= (3,):
+ # tornado 3 has an official API for registering new defaults, yay!
+ ioloop.IOLoop.configure(ZMQIOLoop)
+ else:
+ # we have to set the global instance explicitly
+ ioloop.IOLoop._instance = IOLoop.instance()
+