##// END OF EJS Templates
inputhook: disable CTRL+C when a hook is active....
inputhook: disable CTRL+C when a hook is active. On systems with 'readline', it's very likely to intercept a signal during a select() call. The default SIGINT handler will schedule a KeyboardInterrupt exception to be raised as soon as possible. If ctypes is used to install a Python callback for PyOS_InputHook, this will happen as soon as the bytecode execution starts, so even if the first instruction of the callback is a `try: ... except KeyboardInterrupt` clause, it's actually too late. As ctypes doesn't allow a Python callback to raise an exception, this ends up with IPython detecting an internal error... not pretty. We must therefore ignore the SIGINT signals until we are sure the exception handler is active, in the Python callback.

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blockingkernelmanager.py
129 lines | 4.1 KiB | text/x-python | PythonLexer
/ IPython / zmq / blockingkernelmanager.py
"""Implement a fully blocking kernel manager.
Useful for test suites and blocking terminal interfaces.
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2010 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING.txt, distributed as part of this software.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
from __future__ import print_function
# Stdlib
from Queue import Queue, Empty
# Our own
from IPython.utils import io
from IPython.utils.traitlets import Type
from .kernelmanager import (KernelManager, SubSocketChannel, HBSocketChannel,
ShellSocketChannel, StdInSocketChannel)
#-----------------------------------------------------------------------------
# Functions and classes
#-----------------------------------------------------------------------------
class BlockingSubSocketChannel(SubSocketChannel):
def __init__(self, context, session, address=None):
super(BlockingSubSocketChannel, self).__init__(context, session,
address)
self._in_queue = Queue()
def call_handlers(self, msg):
#io.rprint('[[Sub]]', msg) # dbg
self._in_queue.put(msg)
def msg_ready(self):
"""Is there a message that has been received?"""
if self._in_queue.qsize() == 0:
return False
else:
return True
def get_msg(self, block=True, timeout=None):
"""Get a message if there is one that is ready."""
if block and timeout is None:
# never use timeout=None, because get
# becomes uninterruptible
timeout = 1e6
return self._in_queue.get(block, timeout)
def get_msgs(self):
"""Get all messages that are currently ready."""
msgs = []
while True:
try:
msgs.append(self.get_msg(block=False))
except Empty:
break
return msgs
class BlockingShellSocketChannel(ShellSocketChannel):
def __init__(self, context, session, address=None):
super(BlockingShellSocketChannel, self).__init__(context, session,
address)
self._in_queue = Queue()
def call_handlers(self, msg):
#io.rprint('[[Shell]]', msg) # dbg
self._in_queue.put(msg)
def msg_ready(self):
"""Is there a message that has been received?"""
if self._in_queue.qsize() == 0:
return False
else:
return True
def get_msg(self, block=True, timeout=None):
"""Get a message if there is one that is ready."""
if block and timeout is None:
# never use timeout=None, because get
# becomes uninterruptible
timeout = 1e6
return self._in_queue.get(block, timeout)
def get_msgs(self):
"""Get all messages that are currently ready."""
msgs = []
while True:
try:
msgs.append(self.get_msg(block=False))
except Empty:
break
return msgs
class BlockingStdInSocketChannel(StdInSocketChannel):
def call_handlers(self, msg):
#io.rprint('[[Rep]]', msg) # dbg
pass
class BlockingHBSocketChannel(HBSocketChannel):
# This kernel needs rapid monitoring capabilities
time_to_dead = 0.2
def call_handlers(self, since_last_heartbeat):
#io.rprint('[[Heart]]', since_last_heartbeat) # dbg
pass
class BlockingKernelManager(KernelManager):
# The classes to use for the various channels.
shell_channel_class = Type(BlockingShellSocketChannel)
sub_channel_class = Type(BlockingSubSocketChannel)
stdin_channel_class = Type(BlockingStdInSocketChannel)
hb_channel_class = Type(BlockingHBSocketChannel)