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Merge pull request #937 from minrk/readline...
Merge pull request #937 from minrk/readline Add dirty trick for readline import on OSX to more aggressively detect the presence of libedit masquerading as true GNU readline. Also made the libedit warning extremely loud, so people don't miss it. See the original PR page for the gory details; short version: 1. remove lib-dynload from sys.path before trying to import readline the first time 2. after import, restore lib-dynload to its place in sys.path 3. if import failed without lib-dynload, try it one more time, to get the default module

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ipkernel.py
789 lines | 28.6 KiB | text/x-python | PythonLexer
#!/usr/bin/env python
"""A simple interactive kernel that talks to a frontend over 0MQ.
Things to do:
* Implement `set_parent` logic. Right before doing exec, the Kernel should
call set_parent on all the PUB objects with the message about to be executed.
* Implement random port and security key logic.
* Implement control messages.
* Implement event loop and poll version.
"""
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
from __future__ import print_function
# Standard library imports.
import __builtin__
import atexit
import sys
import time
import traceback
import logging
# System library imports.
import zmq
# Local imports.
from IPython.config.configurable import Configurable
from IPython.config.application import boolean_flag
from IPython.core.application import ProfileDir
from IPython.core.error import StdinNotImplementedError
from IPython.core.shellapp import (
InteractiveShellApp, shell_flags, shell_aliases
)
from IPython.utils import io
from IPython.utils import py3compat
from IPython.utils.jsonutil import json_clean
from IPython.lib import pylabtools
from IPython.utils.traitlets import (
Any, List, Instance, Float, Dict, Bool, Int, Unicode, CaselessStrEnum
)
from entry_point import base_launch_kernel
from kernelapp import KernelApp, kernel_flags, kernel_aliases
from iostream import OutStream
from session import Session, Message
from zmqshell import ZMQInteractiveShell
#-----------------------------------------------------------------------------
# Main kernel class
#-----------------------------------------------------------------------------
class Kernel(Configurable):
#---------------------------------------------------------------------------
# Kernel interface
#---------------------------------------------------------------------------
# attribute to override with a GUI
eventloop = Any(None)
shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
session = Instance(Session)
shell_socket = Instance('zmq.Socket')
iopub_socket = Instance('zmq.Socket')
stdin_socket = Instance('zmq.Socket')
log = Instance(logging.Logger)
# Private interface
# Time to sleep after flushing the stdout/err buffers in each execute
# cycle. While this introduces a hard limit on the minimal latency of the
# execute cycle, it helps prevent output synchronization problems for
# clients.
# Units are in seconds. The minimum zmq latency on local host is probably
# ~150 microseconds, set this to 500us for now. We may need to increase it
# a little if it's not enough after more interactive testing.
_execute_sleep = Float(0.0005, config=True)
# Frequency of the kernel's event loop.
# Units are in seconds, kernel subclasses for GUI toolkits may need to
# adapt to milliseconds.
_poll_interval = Float(0.05, config=True)
# If the shutdown was requested over the network, we leave here the
# necessary reply message so it can be sent by our registered atexit
# handler. This ensures that the reply is only sent to clients truly at
# the end of our shutdown process (which happens after the underlying
# IPython shell's own shutdown).
_shutdown_message = None
# This is a dict of port number that the kernel is listening on. It is set
# by record_ports and used by connect_request.
_recorded_ports = Dict()
def __init__(self, **kwargs):
super(Kernel, self).__init__(**kwargs)
# Before we even start up the shell, register *first* our exit handlers
# so they come before the shell's
atexit.register(self._at_shutdown)
# Initialize the InteractiveShell subclass
self.shell = ZMQInteractiveShell.instance(config=self.config)
self.shell.displayhook.session = self.session
self.shell.displayhook.pub_socket = self.iopub_socket
self.shell.display_pub.session = self.session
self.shell.display_pub.pub_socket = self.iopub_socket
# TMP - hack while developing
self.shell._reply_content = None
# Build dict of handlers for message types
msg_types = [ 'execute_request', 'complete_request',
'object_info_request', 'history_request',
'connect_request', 'shutdown_request']
self.handlers = {}
for msg_type in msg_types:
self.handlers[msg_type] = getattr(self, msg_type)
def do_one_iteration(self):
"""Do one iteration of the kernel's evaluation loop.
"""
try:
ident,msg = self.session.recv(self.shell_socket, zmq.NOBLOCK)
except Exception:
self.log.warn("Invalid Message:", exc_info=True)
return
if msg is None:
return
msg_type = msg['header']['msg_type']
# This assert will raise in versions of zeromq 2.0.7 and lesser.
# We now require 2.0.8 or above, so we can uncomment for safety.
# print(ident,msg, file=sys.__stdout__)
assert ident is not None, "Missing message part."
# Print some info about this message and leave a '--->' marker, so it's
# easier to trace visually the message chain when debugging. Each
# handler prints its message at the end.
self.log.debug('\n*** MESSAGE TYPE:'+str(msg_type)+'***')
self.log.debug(' Content: '+str(msg['content'])+'\n --->\n ')
# Find and call actual handler for message
handler = self.handlers.get(msg_type, None)
if handler is None:
self.log.error("UNKNOWN MESSAGE TYPE:" +str(msg))
else:
handler(ident, msg)
# Check whether we should exit, in case the incoming message set the
# exit flag on
if self.shell.exit_now:
self.log.debug('\nExiting IPython kernel...')
# We do a normal, clean exit, which allows any actions registered
# via atexit (such as history saving) to take place.
sys.exit(0)
def start(self):
""" Start the kernel main loop.
"""
poller = zmq.Poller()
poller.register(self.shell_socket, zmq.POLLIN)
# loop while self.eventloop has not been overridden
while self.eventloop is None:
try:
# scale by extra factor of 10, because there is no
# reason for this to be anything less than ~ 0.1s
# since it is a real poller and will respond
# to events immediately
# double nested try/except, to properly catch KeyboardInterrupt
# due to pyzmq Issue #130
try:
poller.poll(10*1000*self._poll_interval)
self.do_one_iteration()
except:
raise
except KeyboardInterrupt:
# Ctrl-C shouldn't crash the kernel
io.raw_print("KeyboardInterrupt caught in kernel")
if self.eventloop is not None:
try:
self.eventloop(self)
except KeyboardInterrupt:
# Ctrl-C shouldn't crash the kernel
io.raw_print("KeyboardInterrupt caught in kernel")
def record_ports(self, ports):
"""Record the ports that this kernel is using.
The creator of the Kernel instance must call this methods if they
want the :meth:`connect_request` method to return the port numbers.
"""
self._recorded_ports = ports
#---------------------------------------------------------------------------
# Kernel request handlers
#---------------------------------------------------------------------------
def _publish_pyin(self, code, parent):
"""Publish the code request on the pyin stream."""
pyin_msg = self.session.send(self.iopub_socket, u'pyin',{u'code':code}, parent=parent)
def execute_request(self, ident, parent):
status_msg = self.session.send(self.iopub_socket,
u'status',
{u'execution_state':u'busy'},
parent=parent
)
try:
content = parent[u'content']
code = content[u'code']
silent = content[u'silent']
except:
self.log.error("Got bad msg: ")
self.log.error(str(Message(parent)))
return
shell = self.shell # we'll need this a lot here
# Replace raw_input. Note that is not sufficient to replace
# raw_input in the user namespace.
if content.get('allow_stdin', False):
raw_input = lambda prompt='': self._raw_input(prompt, ident, parent)
else:
raw_input = lambda prompt='' : self._no_raw_input()
if py3compat.PY3:
__builtin__.input = raw_input
else:
__builtin__.raw_input = raw_input
# Set the parent message of the display hook and out streams.
shell.displayhook.set_parent(parent)
shell.display_pub.set_parent(parent)
sys.stdout.set_parent(parent)
sys.stderr.set_parent(parent)
# Re-broadcast our input for the benefit of listening clients, and
# start computing output
if not silent:
self._publish_pyin(code, parent)
reply_content = {}
try:
if silent:
# run_code uses 'exec' mode, so no displayhook will fire, and it
# doesn't call logging or history manipulations. Print
# statements in that code will obviously still execute.
shell.run_code(code)
else:
# FIXME: the shell calls the exception handler itself.
shell.run_cell(code, store_history=True)
except:
status = u'error'
# FIXME: this code right now isn't being used yet by default,
# because the run_cell() call above directly fires off exception
# reporting. This code, therefore, is only active in the scenario
# where runlines itself has an unhandled exception. We need to
# uniformize this, for all exception construction to come from a
# single location in the codbase.
etype, evalue, tb = sys.exc_info()
tb_list = traceback.format_exception(etype, evalue, tb)
reply_content.update(shell._showtraceback(etype, evalue, tb_list))
else:
status = u'ok'
reply_content[u'status'] = status
# Return the execution counter so clients can display prompts
reply_content['execution_count'] = shell.execution_count -1
# FIXME - fish exception info out of shell, possibly left there by
# runlines. We'll need to clean up this logic later.
if shell._reply_content is not None:
reply_content.update(shell._reply_content)
# reset after use
shell._reply_content = None
# At this point, we can tell whether the main code execution succeeded
# or not. If it did, we proceed to evaluate user_variables/expressions
if reply_content['status'] == 'ok':
reply_content[u'user_variables'] = \
shell.user_variables(content[u'user_variables'])
reply_content[u'user_expressions'] = \
shell.user_expressions(content[u'user_expressions'])
else:
# If there was an error, don't even try to compute variables or
# expressions
reply_content[u'user_variables'] = {}
reply_content[u'user_expressions'] = {}
# Payloads should be retrieved regardless of outcome, so we can both
# recover partial output (that could have been generated early in a
# block, before an error) and clear the payload system always.
reply_content[u'payload'] = shell.payload_manager.read_payload()
# Be agressive about clearing the payload because we don't want
# it to sit in memory until the next execute_request comes in.
shell.payload_manager.clear_payload()
# Flush output before sending the reply.
sys.stdout.flush()
sys.stderr.flush()
# FIXME: on rare occasions, the flush doesn't seem to make it to the
# clients... This seems to mitigate the problem, but we definitely need
# to better understand what's going on.
if self._execute_sleep:
time.sleep(self._execute_sleep)
# Send the reply.
reply_content = json_clean(reply_content)
reply_msg = self.session.send(self.shell_socket, u'execute_reply',
reply_content, parent, ident=ident)
self.log.debug(str(reply_msg))
if reply_msg['content']['status'] == u'error':
self._abort_queue()
status_msg = self.session.send(self.iopub_socket,
u'status',
{u'execution_state':u'idle'},
parent=parent
)
def complete_request(self, ident, parent):
txt, matches = self._complete(parent)
matches = {'matches' : matches,
'matched_text' : txt,
'status' : 'ok'}
matches = json_clean(matches)
completion_msg = self.session.send(self.shell_socket, 'complete_reply',
matches, parent, ident)
self.log.debug(str(completion_msg))
def object_info_request(self, ident, parent):
object_info = self.shell.object_inspect(parent['content']['oname'])
# Before we send this object over, we scrub it for JSON usage
oinfo = json_clean(object_info)
msg = self.session.send(self.shell_socket, 'object_info_reply',
oinfo, parent, ident)
self.log.debug(msg)
def history_request(self, ident, parent):
# We need to pull these out, as passing **kwargs doesn't work with
# unicode keys before Python 2.6.5.
hist_access_type = parent['content']['hist_access_type']
raw = parent['content']['raw']
output = parent['content']['output']
if hist_access_type == 'tail':
n = parent['content']['n']
hist = self.shell.history_manager.get_tail(n, raw=raw, output=output,
include_latest=True)
elif hist_access_type == 'range':
session = parent['content']['session']
start = parent['content']['start']
stop = parent['content']['stop']
hist = self.shell.history_manager.get_range(session, start, stop,
raw=raw, output=output)
elif hist_access_type == 'search':
pattern = parent['content']['pattern']
hist = self.shell.history_manager.search(pattern, raw=raw, output=output)
else:
hist = []
content = {'history' : list(hist)}
content = json_clean(content)
msg = self.session.send(self.shell_socket, 'history_reply',
content, parent, ident)
self.log.debug(str(msg))
def connect_request(self, ident, parent):
if self._recorded_ports is not None:
content = self._recorded_ports.copy()
else:
content = {}
msg = self.session.send(self.shell_socket, 'connect_reply',
content, parent, ident)
self.log.debug(msg)
def shutdown_request(self, ident, parent):
self.shell.exit_now = True
self._shutdown_message = self.session.msg(u'shutdown_reply', parent['content'], parent)
sys.exit(0)
#---------------------------------------------------------------------------
# Protected interface
#---------------------------------------------------------------------------
def _abort_queue(self):
while True:
try:
ident,msg = self.session.recv(self.shell_socket, zmq.NOBLOCK)
except Exception:
self.log.warn("Invalid Message:", exc_info=True)
continue
if msg is None:
break
else:
assert ident is not None, \
"Unexpected missing message part."
self.log.debug("Aborting:\n"+str(Message(msg)))
msg_type = msg['header']['msg_type']
reply_type = msg_type.split('_')[0] + '_reply'
reply_msg = self.session.send(self.shell_socket, reply_type,
{'status' : 'aborted'}, msg, ident=ident)
self.log.debug(reply_msg)
# We need to wait a bit for requests to come in. This can probably
# be set shorter for true asynchronous clients.
time.sleep(0.1)
def _no_raw_input(self):
"""Raise StdinNotImplentedError if active frontend doesn't support stdin."""
raise StdinNotImplementedError("raw_input was called, but this frontend does not support stdin.")
def _raw_input(self, prompt, ident, parent):
# Flush output before making the request.
sys.stderr.flush()
sys.stdout.flush()
# Send the input request.
content = json_clean(dict(prompt=prompt))
msg = self.session.send(self.stdin_socket, u'input_request', content, parent, ident=ident)
# Await a response.
while True:
try:
ident, reply = self.session.recv(self.stdin_socket, 0)
except Exception:
self.log.warn("Invalid Message:", exc_info=True)
else:
break
try:
value = reply['content']['value']
except:
self.log.error("Got bad raw_input reply: ")
self.log.error(str(Message(parent)))
value = ''
return value
def _complete(self, msg):
c = msg['content']
try:
cpos = int(c['cursor_pos'])
except:
# If we don't get something that we can convert to an integer, at
# least attempt the completion guessing the cursor is at the end of
# the text, if there's any, and otherwise of the line
cpos = len(c['text'])
if cpos==0:
cpos = len(c['line'])
return self.shell.complete(c['text'], c['line'], cpos)
def _object_info(self, context):
symbol, leftover = self._symbol_from_context(context)
if symbol is not None and not leftover:
doc = getattr(symbol, '__doc__', '')
else:
doc = ''
object_info = dict(docstring = doc)
return object_info
def _symbol_from_context(self, context):
if not context:
return None, context
base_symbol_string = context[0]
symbol = self.shell.user_ns.get(base_symbol_string, None)
if symbol is None:
symbol = __builtin__.__dict__.get(base_symbol_string, None)
if symbol is None:
return None, context
context = context[1:]
for i, name in enumerate(context):
new_symbol = getattr(symbol, name, None)
if new_symbol is None:
return symbol, context[i:]
else:
symbol = new_symbol
return symbol, []
def _at_shutdown(self):
"""Actions taken at shutdown by the kernel, called by python's atexit.
"""
# io.rprint("Kernel at_shutdown") # dbg
if self._shutdown_message is not None:
self.session.send(self.shell_socket, self._shutdown_message)
self.session.send(self.iopub_socket, self._shutdown_message)
self.log.debug(str(self._shutdown_message))
# A very short sleep to give zmq time to flush its message buffers
# before Python truly shuts down.
time.sleep(0.01)
#------------------------------------------------------------------------------
# Eventloops for integrating the Kernel into different GUIs
#------------------------------------------------------------------------------
def loop_qt4(kernel):
"""Start a kernel with PyQt4 event loop integration."""
from IPython.external.qt_for_kernel import QtCore
from IPython.lib.guisupport import get_app_qt4, start_event_loop_qt4
kernel.app = get_app_qt4([" "])
kernel.app.setQuitOnLastWindowClosed(False)
kernel.timer = QtCore.QTimer()
kernel.timer.timeout.connect(kernel.do_one_iteration)
# Units for the timer are in milliseconds
kernel.timer.start(1000*kernel._poll_interval)
start_event_loop_qt4(kernel.app)
def loop_wx(kernel):
"""Start a kernel with wx event loop support."""
import wx
from IPython.lib.guisupport import start_event_loop_wx
doi = kernel.do_one_iteration
# Wx uses milliseconds
poll_interval = int(1000*kernel._poll_interval)
# We have to put the wx.Timer in a wx.Frame for it to fire properly.
# We make the Frame hidden when we create it in the main app below.
class TimerFrame(wx.Frame):
def __init__(self, func):
wx.Frame.__init__(self, None, -1)
self.timer = wx.Timer(self)
# Units for the timer are in milliseconds
self.timer.Start(poll_interval)
self.Bind(wx.EVT_TIMER, self.on_timer)
self.func = func
def on_timer(self, event):
self.func()
# We need a custom wx.App to create our Frame subclass that has the
# wx.Timer to drive the ZMQ event loop.
class IPWxApp(wx.App):
def OnInit(self):
self.frame = TimerFrame(doi)
self.frame.Show(False)
return True
# The redirect=False here makes sure that wx doesn't replace
# sys.stdout/stderr with its own classes.
kernel.app = IPWxApp(redirect=False)
start_event_loop_wx(kernel.app)
def loop_tk(kernel):
"""Start a kernel with the Tk event loop."""
import Tkinter
doi = kernel.do_one_iteration
# Tk uses milliseconds
poll_interval = int(1000*kernel._poll_interval)
# For Tkinter, we create a Tk object and call its withdraw method.
class Timer(object):
def __init__(self, func):
self.app = Tkinter.Tk()
self.app.withdraw()
self.func = func
def on_timer(self):
self.func()
self.app.after(poll_interval, self.on_timer)
def start(self):
self.on_timer() # Call it once to get things going.
self.app.mainloop()
kernel.timer = Timer(doi)
kernel.timer.start()
def loop_gtk(kernel):
"""Start the kernel, coordinating with the GTK event loop"""
from .gui.gtkembed import GTKEmbed
gtk_kernel = GTKEmbed(kernel)
gtk_kernel.start()
def loop_cocoa(kernel):
"""Start the kernel, coordinating with the Cocoa CFRunLoop event loop
via the matplotlib MacOSX backend.
"""
import matplotlib
if matplotlib.__version__ < '1.1.0':
kernel.log.warn(
"MacOSX backend in matplotlib %s doesn't have a Timer, "
"falling back on Tk for CFRunLoop integration. Note that "
"even this won't work if Tk is linked against X11 instead of "
"Cocoa (e.g. EPD). To use the MacOSX backend in the kernel, "
"you must use matplotlib >= 1.1.0, or a native libtk."
)
return loop_tk(kernel)
from matplotlib.backends.backend_macosx import TimerMac, show
# scale interval for sec->ms
poll_interval = int(1000*kernel._poll_interval)
real_excepthook = sys.excepthook
def handle_int(etype, value, tb):
"""don't let KeyboardInterrupts look like crashes"""
if etype is KeyboardInterrupt:
io.raw_print("KeyboardInterrupt caught in CFRunLoop")
else:
real_excepthook(etype, value, tb)
# add doi() as a Timer to the CFRunLoop
def doi():
# restore excepthook during IPython code
sys.excepthook = real_excepthook
kernel.do_one_iteration()
# and back:
sys.excepthook = handle_int
t = TimerMac(poll_interval)
t.add_callback(doi)
t.start()
# but still need a Poller for when there are no active windows,
# during which time mainloop() returns immediately
poller = zmq.Poller()
poller.register(kernel.shell_socket, zmq.POLLIN)
while True:
try:
# double nested try/except, to properly catch KeyboardInterrupt
# due to pyzmq Issue #130
try:
# don't let interrupts during mainloop invoke crash_handler:
sys.excepthook = handle_int
show.mainloop()
sys.excepthook = real_excepthook
# use poller if mainloop returned (no windows)
# scale by extra factor of 10, since it's a real poll
poller.poll(10*poll_interval)
kernel.do_one_iteration()
except:
raise
except KeyboardInterrupt:
# Ctrl-C shouldn't crash the kernel
io.raw_print("KeyboardInterrupt caught in kernel")
finally:
# ensure excepthook is restored
sys.excepthook = real_excepthook
# mapping of keys to loop functions
loop_map = {
'qt' : loop_qt4,
'qt4': loop_qt4,
'inline': None,
'osx': loop_cocoa,
'wx' : loop_wx,
'tk' : loop_tk,
'gtk': loop_gtk,
}
def enable_gui(gui, kernel=None):
"""Enable integration with a give GUI"""
if kernel is None:
kernel = IPKernelApp.instance().kernel
if gui not in loop_map:
raise ValueError("GUI %r not supported" % gui)
loop = loop_map[gui]
if kernel.eventloop is not None and kernel.eventloop is not loop:
raise RuntimeError("Cannot activate multiple GUI eventloops")
kernel.eventloop = loop
#-----------------------------------------------------------------------------
# Aliases and Flags for the IPKernelApp
#-----------------------------------------------------------------------------
flags = dict(kernel_flags)
flags.update(shell_flags)
addflag = lambda *args: flags.update(boolean_flag(*args))
flags['pylab'] = (
{'IPKernelApp' : {'pylab' : 'auto'}},
"""Pre-load matplotlib and numpy for interactive use with
the default matplotlib backend."""
)
aliases = dict(kernel_aliases)
aliases.update(shell_aliases)
# it's possible we don't want short aliases for *all* of these:
aliases.update(dict(
pylab='IPKernelApp.pylab',
))
#-----------------------------------------------------------------------------
# The IPKernelApp class
#-----------------------------------------------------------------------------
class IPKernelApp(KernelApp, InteractiveShellApp):
name = 'ipkernel'
aliases = Dict(aliases)
flags = Dict(flags)
classes = [Kernel, ZMQInteractiveShell, ProfileDir, Session]
# configurables
pylab = CaselessStrEnum(['tk', 'qt', 'wx', 'gtk', 'osx', 'inline', 'auto'],
config=True,
help="""Pre-load matplotlib and numpy for interactive use,
selecting a particular matplotlib backend and loop integration.
"""
)
def initialize(self, argv=None):
super(IPKernelApp, self).initialize(argv)
self.init_shell()
self.init_extensions()
self.init_code()
def init_kernel(self):
kernel_factory = Kernel
if self.pylab:
gui, backend = pylabtools.find_gui_and_backend(self.pylab)
kernel = kernel_factory(config=self.config, session=self.session,
shell_socket=self.shell_socket,
iopub_socket=self.iopub_socket,
stdin_socket=self.stdin_socket,
log=self.log,
)
self.kernel = kernel
kernel.record_ports(self.ports)
if self.pylab:
kernel.shell.enable_pylab(gui, import_all=self.pylab_import_all)
def init_shell(self):
self.shell = self.kernel.shell
#-----------------------------------------------------------------------------
# Kernel main and launch functions
#-----------------------------------------------------------------------------
def launch_kernel(*args, **kwargs):
"""Launches a localhost IPython kernel, binding to the specified ports.
This function simply calls entry_point.base_launch_kernel with the right first
command to start an ipkernel. See base_launch_kernel for arguments.
Returns
-------
A tuple of form:
(kernel_process, shell_port, iopub_port, stdin_port, hb_port)
where kernel_process is a Popen object and the ports are integers.
"""
return base_launch_kernel('from IPython.zmq.ipkernel import main; main()',
*args, **kwargs)
def main():
"""Run an IPKernel as an application"""
app = IPKernelApp.instance()
app.initialize()
app.start()
if __name__ == '__main__':
main()