Merge pull request #3787 from minrk/raw_input_sigint

re-raise KeyboardInterrupt in raw_input

closes  #3786

IPython/core/debugger.py

@@ -1,571 +1,577 b''
 # -*- coding: utf-8 -*-
 """
 Pdb debugger class.
 
 Modified from the standard pdb.Pdb class to avoid including readline, so that
 the command line completion of other programs which include this isn't
 damaged.
 
 In the future, this class will be expanded with improvements over the standard
 pdb.
 
 The code in this file is mainly lifted out of cmd.py in Python 2.2, with minor
 changes. Licensing should therefore be under the standard Python terms.  For
 details on the PSF (Python Software Foundation) standard license, see:
 
 http://www.python.org/2.2.3/license.html"""
 
 #*****************************************************************************
 #
 #       This file is licensed under the PSF license.
 #
 #       Copyright (C) 2001 Python Software Foundation, www.python.org
 #       Copyright (C) 2005-2006 Fernando Perez. <[e-mail]>
 #
 #
 #*****************************************************************************
 from __future__ import print_function
 
 import bdb
 import functools
 import linecache
 import sys
 
 from IPython import get_ipython
 from IPython.utils import PyColorize, ulinecache
 from IPython.utils import coloransi, io, py3compat
 from IPython.core.excolors import exception_colors
 
 # See if we can use pydb.
 has_pydb = False
 prompt = 'ipdb> '
 #We have to check this directly from sys.argv, config struct not yet available
 if '--pydb' in sys.argv:
     try:
         import pydb
         if hasattr(pydb.pydb, "runl") and pydb.version>'1.17':
             # Version 1.17 is broken, and that's what ships with Ubuntu Edgy, so we
             # better protect against it.
             has_pydb = True
     except ImportError:
         print("Pydb (http://bashdb.sourceforge.net/pydb/) does not seem to be available")
 
 if has_pydb:
     from pydb import Pdb as OldPdb
     #print "Using pydb for %run -d and post-mortem" #dbg
     prompt = 'ipydb> '
 else:
     from pdb import Pdb as OldPdb
 
 # Allow the set_trace code to operate outside of an ipython instance, even if
 # it does so with some limitations.  The rest of this support is implemented in
 # the Tracer constructor.
 def BdbQuit_excepthook(et, ev, tb, excepthook=None):
     """Exception hook which handles `BdbQuit` exceptions.
 
     All other exceptions are processed using the `excepthook`
     parameter.
     """
     if et==bdb.BdbQuit:
         print('Exiting Debugger.')
     elif excepthook is not None:
         excepthook(et, ev, tb)
     else:
         # Backwards compatibility. Raise deprecation warning?
         BdbQuit_excepthook.excepthook_ori(et,ev,tb)
 
 def BdbQuit_IPython_excepthook(self,et,ev,tb,tb_offset=None):
     print('Exiting Debugger.')
 
 
 class Tracer(object):
     """Class for local debugging, similar to pdb.set_trace.
 
     Instances of this class, when called, behave like pdb.set_trace, but
     providing IPython's enhanced capabilities.
 
     This is implemented as a class which must be initialized in your own code
     and not as a standalone function because we need to detect at runtime
     whether IPython is already active or not.  That detection is done in the
     constructor, ensuring that this code plays nicely with a running IPython,
     while functioning acceptably (though with limitations) if outside of it.
     """
 
     def __init__(self,colors=None):
         """Create a local debugger instance.
 
         :Parameters:
 
           - `colors` (None): a string containing the name of the color scheme to
         use, it must be one of IPython's valid color schemes.  If not given, the
         function will default to the current IPython scheme when running inside
         IPython, and to 'NoColor' otherwise.
 
         Usage example:
 
         from IPython.core.debugger import Tracer; debug_here = Tracer()
 
         ... later in your code
         debug_here()  # -> will open up the debugger at that point.
 
         Once the debugger activates, you can use all of its regular commands to
         step through code, set breakpoints, etc.  See the pdb documentation
         from the Python standard library for usage details.
         """
 
         ip = get_ipython()
         if ip is None:
             # Outside of ipython, we set our own exception hook manually
             sys.excepthook = functools.partial(BdbQuit_excepthook,
                                                excepthook=sys.excepthook)
             def_colors = 'NoColor'
             try:
                 # Limited tab completion support
                 import readline
                 readline.parse_and_bind('tab: complete')
             except ImportError:
                 pass
         else:
             # In ipython, we use its custom exception handler mechanism
             def_colors = ip.colors
             ip.set_custom_exc((bdb.BdbQuit,), BdbQuit_IPython_excepthook)
 
         if colors is None:
             colors = def_colors
 
         # The stdlib debugger internally uses a modified repr from the `repr`
         # module, that limits the length of printed strings to a hardcoded
         # limit of 30 characters.  That much trimming is too aggressive, let's
         # at least raise that limit to 80 chars, which should be enough for
         # most interactive uses.
         try:
             from repr import aRepr
             aRepr.maxstring = 80
         except:
             # This is only a user-facing convenience, so any error we encounter
             # here can be warned about but can be otherwise ignored.  These
             # printouts will tell us about problems if this API changes
             import traceback
             traceback.print_exc()
 
         self.debugger = Pdb(colors)
 
     def __call__(self):
         """Starts an interactive debugger at the point where called.
 
         This is similar to the pdb.set_trace() function from the std lib, but
         using IPython's enhanced debugger."""
 
         self.debugger.set_trace(sys._getframe().f_back)
 
 
 def decorate_fn_with_doc(new_fn, old_fn, additional_text=""):
     """Make new_fn have old_fn's doc string. This is particularly useful
     for the ``do_...`` commands that hook into the help system.
     Adapted from from a comp.lang.python posting
     by Duncan Booth."""
     def wrapper(*args, **kw):
         return new_fn(*args, **kw)
     if old_fn.__doc__:
         wrapper.__doc__ = old_fn.__doc__ + additional_text
     return wrapper
 
 
 def _file_lines(fname):
     """Return the contents of a named file as a list of lines.
 
     This function never raises an IOError exception: if the file can't be
     read, it simply returns an empty list."""
 
     try:
         outfile = open(fname)
     except IOError:
         return []
     else:
         out = outfile.readlines()
         outfile.close()
         return out
 
 
 class Pdb(OldPdb):
     """Modified Pdb class, does not load readline."""
 
     def __init__(self,color_scheme='NoColor',completekey=None,
                  stdin=None, stdout=None):
 
         # Parent constructor:
         if has_pydb and completekey is None:
             OldPdb.__init__(self,stdin=stdin,stdout=io.stdout)
         else:
             OldPdb.__init__(self,completekey,stdin,stdout)
 
         self.prompt = prompt # The default prompt is '(Pdb)'
 
         # IPython changes...
         self.is_pydb = has_pydb
 
         self.shell = get_ipython()
 
         if self.shell is None:
             # No IPython instance running, we must create one
             from IPython.terminal.interactiveshell import \
                 TerminalInteractiveShell
             self.shell = TerminalInteractiveShell.instance()
 
         if self.is_pydb:
 
             # interactiveshell.py's ipalias seems to want pdb's checkline
             # which located in pydb.fn
             import pydb.fns
             self.checkline = lambda filename, lineno: \
                              pydb.fns.checkline(self, filename, lineno)
 
             self.curframe = None
             self.do_restart = self.new_do_restart
 
             self.old_all_completions = self.shell.Completer.all_completions
             self.shell.Completer.all_completions=self.all_completions
 
             self.do_list = decorate_fn_with_doc(self.list_command_pydb,
                                                 OldPdb.do_list)
             self.do_l     = self.do_list
             self.do_frame = decorate_fn_with_doc(self.new_do_frame,
                                                  OldPdb.do_frame)
 
         self.aliases = {}
 
         # Create color table: we copy the default one from the traceback
         # module and add a few attributes needed for debugging
         self.color_scheme_table = exception_colors()
 
         # shorthands
         C = coloransi.TermColors
         cst = self.color_scheme_table
 
         cst['NoColor'].colors.breakpoint_enabled = C.NoColor
         cst['NoColor'].colors.breakpoint_disabled = C.NoColor
 
         cst['Linux'].colors.breakpoint_enabled = C.LightRed
         cst['Linux'].colors.breakpoint_disabled = C.Red
 
         cst['LightBG'].colors.breakpoint_enabled = C.LightRed
         cst['LightBG'].colors.breakpoint_disabled = C.Red
 
         self.set_colors(color_scheme)
 
         # Add a python parser so we can syntax highlight source while
         # debugging.
         self.parser = PyColorize.Parser()
 
     def set_colors(self, scheme):
         """Shorthand access to the color table scheme selector method."""
         self.color_scheme_table.set_active_scheme(scheme)
 
     def interaction(self, frame, traceback):
         self.shell.set_completer_frame(frame)
-        OldPdb.interaction(self, frame, traceback)
+        while True:
+            try:
+                OldPdb.interaction(self, frame, traceback)
+            except KeyboardInterrupt:
+                self.shell.write("\nKeyboardInterrupt\n")
+            else:
+                break
 
     def new_do_up(self, arg):
         OldPdb.do_up(self, arg)
         self.shell.set_completer_frame(self.curframe)
     do_u = do_up = decorate_fn_with_doc(new_do_up, OldPdb.do_up)
 
     def new_do_down(self, arg):
         OldPdb.do_down(self, arg)
         self.shell.set_completer_frame(self.curframe)
 
     do_d = do_down = decorate_fn_with_doc(new_do_down, OldPdb.do_down)
 
     def new_do_frame(self, arg):
         OldPdb.do_frame(self, arg)
         self.shell.set_completer_frame(self.curframe)
 
     def new_do_quit(self, arg):
 
         if hasattr(self, 'old_all_completions'):
             self.shell.Completer.all_completions=self.old_all_completions
 
 
         return OldPdb.do_quit(self, arg)
 
     do_q = do_quit = decorate_fn_with_doc(new_do_quit, OldPdb.do_quit)
 
     def new_do_restart(self, arg):
         """Restart command. In the context of ipython this is exactly the same
         thing as 'quit'."""
         self.msg("Restart doesn't make sense here. Using 'quit' instead.")
         return self.do_quit(arg)
 
     def postloop(self):
         self.shell.set_completer_frame(None)
 
     def print_stack_trace(self):
         try:
             for frame_lineno in self.stack:
                 self.print_stack_entry(frame_lineno, context = 5)
         except KeyboardInterrupt:
             pass
 
     def print_stack_entry(self,frame_lineno,prompt_prefix='\n-> ',
                           context = 3):
         #frame, lineno = frame_lineno
         print(self.format_stack_entry(frame_lineno, '', context), file=io.stdout)
 
         # vds: >>
         frame, lineno = frame_lineno
         filename = frame.f_code.co_filename
         self.shell.hooks.synchronize_with_editor(filename, lineno, 0)
         # vds: <<
 
     def format_stack_entry(self, frame_lineno, lprefix=': ', context = 3):
         import repr
 
         ret = []
 
         Colors = self.color_scheme_table.active_colors
         ColorsNormal = Colors.Normal
         tpl_link = u'%s%%s%s' % (Colors.filenameEm, ColorsNormal)
         tpl_call = u'%s%%s%s%%s%s' % (Colors.vName, Colors.valEm, ColorsNormal)
         tpl_line = u'%%s%s%%s %s%%s' % (Colors.lineno, ColorsNormal)
         tpl_line_em = u'%%s%s%%s %s%%s%s' % (Colors.linenoEm, Colors.line,
                                             ColorsNormal)
 
         frame, lineno = frame_lineno
 
         return_value = ''
         if '__return__' in frame.f_locals:
             rv = frame.f_locals['__return__']
             #return_value += '->'
             return_value += repr.repr(rv) + '\n'
         ret.append(return_value)
 
         #s = filename + '(' + `lineno` + ')'
         filename = self.canonic(frame.f_code.co_filename)
         link = tpl_link % py3compat.cast_unicode(filename)
 
         if frame.f_code.co_name:
             func = frame.f_code.co_name
         else:
             func = "<lambda>"
 
         call = ''
         if func != '?':
             if '__args__' in frame.f_locals:
                 args = repr.repr(frame.f_locals['__args__'])
             else:
                 args = '()'
             call = tpl_call % (func, args)
 
         # The level info should be generated in the same format pdb uses, to
         # avoid breaking the pdbtrack functionality of python-mode in *emacs.
         if frame is self.curframe:
             ret.append('> ')
         else:
             ret.append('  ')
         ret.append(u'%s(%s)%s\n' % (link,lineno,call))
 
         start = lineno - 1 - context//2
         lines = ulinecache.getlines(filename)
         start = min(start, len(lines) - context)
         start = max(start, 0)
         lines = lines[start : start + context]
 
         for i,line in enumerate(lines):
             show_arrow = (start + 1 + i == lineno)
             linetpl = (frame is self.curframe or show_arrow) \
                       and tpl_line_em \
                       or tpl_line
             ret.append(self.__format_line(linetpl, filename,
                                           start + 1 + i, line,
                                           arrow = show_arrow) )
         return ''.join(ret)
 
     def __format_line(self, tpl_line, filename, lineno, line, arrow = False):
         bp_mark = ""
         bp_mark_color = ""
 
         scheme = self.color_scheme_table.active_scheme_name
         new_line, err = self.parser.format2(line, 'str', scheme)
         if not err: line = new_line
 
         bp = None
         if lineno in self.get_file_breaks(filename):
             bps = self.get_breaks(filename, lineno)
             bp = bps[-1]
 
         if bp:
             Colors = self.color_scheme_table.active_colors
             bp_mark = str(bp.number)
             bp_mark_color = Colors.breakpoint_enabled
             if not bp.enabled:
                 bp_mark_color = Colors.breakpoint_disabled
 
         numbers_width = 7
         if arrow:
             # This is the line with the error
             pad = numbers_width - len(str(lineno)) - len(bp_mark)
             if pad >= 3:
                 marker = '-'*(pad-3) + '-> '
             elif pad == 2:
                  marker = '> '
             elif pad == 1:
                  marker = '>'
             else:
                  marker = ''
             num = '%s%s' % (marker, str(lineno))
             line = tpl_line % (bp_mark_color + bp_mark, num, line)
         else:
             num = '%*s' % (numbers_width - len(bp_mark), str(lineno))
             line = tpl_line % (bp_mark_color + bp_mark, num, line)
 
         return line
 
     def list_command_pydb(self, arg):
         """List command to use if we have a newer pydb installed"""
         filename, first, last = OldPdb.parse_list_cmd(self, arg)
         if filename is not None:
             self.print_list_lines(filename, first, last)
 
     def print_list_lines(self, filename, first, last):
         """The printing (as opposed to the parsing part of a 'list'
         command."""
         try:
             Colors = self.color_scheme_table.active_colors
             ColorsNormal = Colors.Normal
             tpl_line = '%%s%s%%s %s%%s' % (Colors.lineno, ColorsNormal)
             tpl_line_em = '%%s%s%%s %s%%s%s' % (Colors.linenoEm, Colors.line, ColorsNormal)
             src = []
             if filename == "<string>" and hasattr(self, "_exec_filename"):
                 filename = self._exec_filename
 
             for lineno in range(first, last+1):
                 line = ulinecache.getline(filename, lineno)
                 if not line:
                     break
 
                 if lineno == self.curframe.f_lineno:
                     line = self.__format_line(tpl_line_em, filename, lineno, line, arrow = True)
                 else:
                     line = self.__format_line(tpl_line, filename, lineno, line, arrow = False)
 
                 src.append(line)
                 self.lineno = lineno
 
             print(''.join(src), file=io.stdout)
 
         except KeyboardInterrupt:
             pass
 
     def do_list(self, arg):
         self.lastcmd = 'list'
         last = None
         if arg:
             try:
                 x = eval(arg, {}, {})
                 if type(x) == type(()):
                     first, last = x
                     first = int(first)
                     last = int(last)
                     if last < first:
                         # Assume it's a count
                         last = first + last
                 else:
                     first = max(1, int(x) - 5)
             except:
                 print('*** Error in argument:', repr(arg))
                 return
         elif self.lineno is None:
             first = max(1, self.curframe.f_lineno - 5)
         else:
             first = self.lineno + 1
         if last is None:
             last = first + 10
         self.print_list_lines(self.curframe.f_code.co_filename, first, last)
 
         # vds: >>
         lineno = first
         filename = self.curframe.f_code.co_filename
         self.shell.hooks.synchronize_with_editor(filename, lineno, 0)
         # vds: <<
 
     do_l = do_list
 
     def do_pdef(self, arg):
         """Print the call signature for any callable object.
 
         The debugger interface to %pdef"""
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('pdef')(arg, namespaces=namespaces)
 
     def do_pdoc(self, arg):
         """Print the docstring for an object.
 
         The debugger interface to %pdoc."""
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('pdoc')(arg, namespaces=namespaces)
 
     def do_pfile(self, arg):
         """Print (or run through pager) the file where an object is defined.
 
         The debugger interface to %pfile.
         """
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('pfile')(arg, namespaces=namespaces)
 
     def do_pinfo(self, arg):
         """Provide detailed information about an object.
 
         The debugger interface to %pinfo, i.e., obj?."""
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('pinfo')(arg, namespaces=namespaces)
 
     def do_pinfo2(self, arg):
         """Provide extra detailed information about an object.
 
         The debugger interface to %pinfo2, i.e., obj??."""
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('pinfo2')(arg, namespaces=namespaces)
 
     def do_psource(self, arg):
         """Print (or run through pager) the source code for an object."""
         namespaces = [('Locals', self.curframe.f_locals),
                       ('Globals', self.curframe.f_globals)]
         self.shell.find_line_magic('psource')(arg, namespaces=namespaces)
 
     def checkline(self, filename, lineno):
         """Check whether specified line seems to be executable.
 
         Return `lineno` if it is, 0 if not (e.g. a docstring, comment, blank
         line or EOF). Warning: testing is not comprehensive.
         """
         #######################################################################
         # XXX Hack!  Use python-2.5 compatible code for this call, because with
         # all of our changes, we've drifted from the pdb api in 2.6.  For now,
         # changing:
         #
         #line = linecache.getline(filename, lineno, self.curframe.f_globals)
         # to:
         #
         line = linecache.getline(filename, lineno)
         #
         # does the trick.  But in reality, we need to fix this by reconciling
         # our updates with the new Pdb APIs in Python 2.6.
         #
         # End hack.  The rest of this method is copied verbatim from 2.6 pdb.py
         #######################################################################
 
         if not line:
             print('End of file', file=self.stdout)
             return 0
         line = line.strip()
         # Don't allow setting breakpoint at a blank line
         if (not line or (line[0] == '#') or
              (line[:3] == '"""') or line[:3] == "'''"):
             print('*** Blank or comment', file=self.stdout)
             return 0
         return lineno

IPython/kernel/zmq/ipkernel.py

@@ -1,803 +1,806 b''
 #!/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 sys
 import time
 import traceback
 import logging
 import uuid
 
 from datetime import datetime
 from signal import (
         signal, default_int_handler, SIGINT
 )
 
 # System library imports
 import zmq
 from zmq.eventloop import ioloop
 from zmq.eventloop.zmqstream import ZMQStream
 
 # Local imports
 from IPython.config.configurable import Configurable
 from IPython.core.error import StdinNotImplementedError
 from IPython.core import release
 from IPython.utils import py3compat
 from IPython.utils.jsonutil import json_clean
 from IPython.utils.traitlets import (
     Any, Instance, Float, Dict, List, Set, Integer, Unicode,
     Type
 )
 
 from serialize import serialize_object, unpack_apply_message
 from session import Session
 from zmqshell import ZMQInteractiveShell
 
 
 #-----------------------------------------------------------------------------
 # Main kernel class
 #-----------------------------------------------------------------------------
 
 protocol_version = list(release.kernel_protocol_version_info)
 ipython_version = list(release.version_info)
 language_version = list(sys.version_info[:3])
 
 
 class Kernel(Configurable):
 
     #---------------------------------------------------------------------------
     # Kernel interface
     #---------------------------------------------------------------------------
 
     # attribute to override with a GUI
     eventloop = Any(None)
     def _eventloop_changed(self, name, old, new):
         """schedule call to eventloop from IOLoop"""
         loop = ioloop.IOLoop.instance()
         loop.add_timeout(time.time()+0.1, self.enter_eventloop)
 
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
     shell_class = Type(ZMQInteractiveShell)
 
     session = Instance(Session)
     profile_dir = Instance('IPython.core.profiledir.ProfileDir')
     shell_streams = List()
     control_stream = Instance(ZMQStream)
     iopub_socket = Instance(zmq.Socket)
     stdin_socket = Instance(zmq.Socket)
     log = Instance(logging.Logger)
     
     user_module = Any()
     def _user_module_changed(self, name, old, new):
         if self.shell is not None:
             self.shell.user_module = new
     
     user_ns = Dict(default_value=None)
     def _user_ns_changed(self, name, old, new):
         if self.shell is not None:
             self.shell.user_ns = new
             self.shell.init_user_ns()
 
     # identities:
     int_id = Integer(-1)
     ident = Unicode()
 
     def _ident_default(self):
         return unicode(uuid.uuid4())
 
 
     # 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()
 
     # A reference to the Python builtin 'raw_input' function.
     # (i.e., __builtin__.raw_input for Python 2.7, builtins.input for Python 3)
     _sys_raw_input = Any()
 
     # set of aborted msg_ids
     aborted = Set()
 
 
     def __init__(self, **kwargs):
         super(Kernel, self).__init__(**kwargs)
 
         # Initialize the InteractiveShell subclass
         self.shell = self.shell_class.instance(parent=self,
             profile_dir = self.profile_dir,
             user_module = self.user_module,
             user_ns     = self.user_ns,
         )
         self.shell.displayhook.session = self.session
         self.shell.displayhook.pub_socket = self.iopub_socket
         self.shell.displayhook.topic = self._topic('pyout')
         self.shell.display_pub.session = self.session
         self.shell.display_pub.pub_socket = self.iopub_socket
         self.shell.data_pub.session = self.session
         self.shell.data_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',
                       'kernel_info_request',
                       'connect_request', 'shutdown_request',
                       'apply_request',
                     ]
         self.shell_handlers = {}
         for msg_type in msg_types:
             self.shell_handlers[msg_type] = getattr(self, msg_type)
         
         control_msg_types = msg_types + [ 'clear_request', 'abort_request' ]
         self.control_handlers = {}
         for msg_type in control_msg_types:
             self.control_handlers[msg_type] = getattr(self, msg_type)
 
     def dispatch_control(self, msg):
         """dispatch control requests"""
         idents,msg = self.session.feed_identities(msg, copy=False)
         try:
             msg = self.session.unserialize(msg, content=True, copy=False)
         except:
             self.log.error("Invalid Control Message", exc_info=True)
             return
 
         self.log.debug("Control received: %s", msg)
 
         header = msg['header']
         msg_id = header['msg_id']
         msg_type = header['msg_type']
 
         handler = self.control_handlers.get(msg_type, None)
         if handler is None:
             self.log.error("UNKNOWN CONTROL MESSAGE TYPE: %r", msg_type)
         else:
             try:
                 handler(self.control_stream, idents, msg)
             except Exception:
                 self.log.error("Exception in control handler:", exc_info=True)
     
     def dispatch_shell(self, stream, msg):
         """dispatch shell requests"""
         # flush control requests first
         if self.control_stream:
             self.control_stream.flush()
         
         idents,msg = self.session.feed_identities(msg, copy=False)
         try:
             msg = self.session.unserialize(msg, content=True, copy=False)
         except:
             self.log.error("Invalid Message", exc_info=True)
             return
 
         header = msg['header']
         msg_id = header['msg_id']
         msg_type = msg['header']['msg_type']
         
         # 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:%s***', msg_type)
         self.log.debug('   Content: %s\n   --->\n   ', msg['content'])
 
         if msg_id in self.aborted:
             self.aborted.remove(msg_id)
             # is it safe to assume a msg_id will not be resubmitted?
             reply_type = msg_type.split('_')[0] + '_reply'
             status = {'status' : 'aborted'}
             md = {'engine' : self.ident}
             md.update(status)
             reply_msg = self.session.send(stream, reply_type, metadata=md,
                         content=status, parent=msg, ident=idents)
             return
         
         handler = self.shell_handlers.get(msg_type, None)
         if handler is None:
             self.log.error("UNKNOWN MESSAGE TYPE: %r", msg_type)
         else:
             # ensure default_int_handler during handler call
             sig = signal(SIGINT, default_int_handler)
             try:
                 handler(stream, idents, msg)
             except Exception:
                 self.log.error("Exception in message handler:", exc_info=True)
             finally:
                 signal(SIGINT, sig)
     
     def enter_eventloop(self):
         """enter eventloop"""
         self.log.info("entering eventloop")
         # restore default_int_handler
         signal(SIGINT, default_int_handler)
         while self.eventloop is not None:
             try:
                 self.eventloop(self)
             except KeyboardInterrupt:
                 # Ctrl-C shouldn't crash the kernel
                 self.log.error("KeyboardInterrupt caught in kernel")
                 continue
             else:
                 # eventloop exited cleanly, this means we should stop (right?)
                 self.eventloop = None
                 break
         self.log.info("exiting eventloop")
 
     def start(self):
         """register dispatchers for streams"""
         self.shell.exit_now = False
         if self.control_stream:
             self.control_stream.on_recv(self.dispatch_control, copy=False)
 
         def make_dispatcher(stream):
             def dispatcher(msg):
                 return self.dispatch_shell(stream, msg)
             return dispatcher
 
         for s in self.shell_streams:
             s.on_recv(make_dispatcher(s), copy=False)
 
         # publish idle status
         self._publish_status('starting')
     
     def do_one_iteration(self):
         """step eventloop just once"""
         if self.control_stream:
             self.control_stream.flush()
         for stream in self.shell_streams:
             # handle at most one request per iteration
             stream.flush(zmq.POLLIN, 1)
             stream.flush(zmq.POLLOUT)
 
 
     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 _make_metadata(self, other=None):
         """init metadata dict, for execute/apply_reply"""
         new_md = {
             'dependencies_met' : True,
             'engine' : self.ident,
             'started': datetime.now(),
         }
         if other:
             new_md.update(other)
         return new_md
     
     def _publish_pyin(self, code, parent, execution_count):
         """Publish the code request on the pyin stream."""
 
         self.session.send(self.iopub_socket, u'pyin',
                             {u'code':code, u'execution_count': execution_count},
                             parent=parent, ident=self._topic('pyin')
         )
     
     def _publish_status(self, status, parent=None):
         """send status (busy/idle) on IOPub"""
         self.session.send(self.iopub_socket,
                           u'status',
                           {u'execution_state': status},
                           parent=parent,
                           ident=self._topic('status'),
                           )
         
 
     def execute_request(self, stream, ident, parent):
         """handle an execute_request"""
         
         self._publish_status(u'busy', parent)
         
         try:
             content = parent[u'content']
             code = content[u'code']
             silent = content[u'silent']
             store_history = content.get(u'store_history', not silent)
         except:
             self.log.error("Got bad msg: ")
             self.log.error("%s", parent)
             return
         
         md = self._make_metadata(parent['metadata'])
 
         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:
             self._sys_raw_input = __builtin__.input
             __builtin__.input = raw_input
         else:
             self._sys_raw_input = __builtin__.raw_input
             __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)
         shell.data_pub.set_parent(parent)
         try:
             sys.stdout.set_parent(parent)
         except AttributeError:
             pass
         try:
             sys.stderr.set_parent(parent)
         except AttributeError:
             pass
 
         # Re-broadcast our input for the benefit of listening clients, and
         # start computing output
         if not silent:
             self._publish_pyin(code, parent, shell.execution_count)
 
         reply_content = {}
         try:
             # FIXME: the shell calls the exception handler itself.
             shell.run_cell(code, store_history=store_history, silent=silent)
         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'
         finally:
             # Restore raw_input.
              if py3compat.PY3:
                  __builtin__.input = self._sys_raw_input
              else:
                  __builtin__.raw_input = self._sys_raw_input
 
         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)
             e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method='execute')
             reply_content['engine_info'] = e_info
             # reset after use
             shell._reply_content = None
         
         if 'traceback' in reply_content:
             self.log.info("Exception in execute request:\n%s", '\n'.join(reply_content['traceback']))
         
 
         # 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.get(u'user_variables', []))
             reply_content[u'user_expressions'] = \
                          shell.user_expressions(content.get(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)
         
         md['status'] = reply_content['status']
         if reply_content['status'] == 'error' and \
                         reply_content['ename'] == 'UnmetDependency':
                 md['dependencies_met'] = False
 
         reply_msg = self.session.send(stream, u'execute_reply',
                                       reply_content, parent, metadata=md,
                                       ident=ident)
         
         self.log.debug("%s", reply_msg)
 
         if not silent and reply_msg['content']['status'] == u'error':
             self._abort_queues()
 
         self._publish_status(u'idle', parent)
 
     def complete_request(self, stream, ident, parent):
         txt, matches = self._complete(parent)
         matches = {'matches' : matches,
                    'matched_text' : txt,
                    'status' : 'ok'}
         matches = json_clean(matches)
         completion_msg = self.session.send(stream, 'complete_reply',
                                            matches, parent, ident)
         self.log.debug("%s", completion_msg)
 
     def object_info_request(self, stream, ident, parent):
         content = parent['content']
         object_info = self.shell.object_inspect(content['oname'],
                         detail_level = content.get('detail_level', 0)
         )
         # Before we send this object over, we scrub it for JSON usage
         oinfo = json_clean(object_info)
         msg = self.session.send(stream, 'object_info_reply',
                                 oinfo, parent, ident)
         self.log.debug("%s", msg)
 
     def history_request(self, stream, 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':
             n = parent['content'].get('n')
             unique = parent['content'].get('unique', False)
             pattern = parent['content']['pattern']
             hist = self.shell.history_manager.search(
                 pattern, raw=raw, output=output, n=n, unique=unique)
 
         else:
             hist = []
         hist = list(hist)
         content = {'history' : hist}
         content = json_clean(content)
         msg = self.session.send(stream, 'history_reply',
                                 content, parent, ident)
         self.log.debug("Sending history reply with %i entries", len(hist))
 
     def connect_request(self, stream, ident, parent):
         if self._recorded_ports is not None:
             content = self._recorded_ports.copy()
         else:
             content = {}
         msg = self.session.send(stream, 'connect_reply',
                                 content, parent, ident)
         self.log.debug("%s", msg)
 
     def kernel_info_request(self, stream, ident, parent):
         vinfo = {
             'protocol_version': protocol_version,
             'ipython_version': ipython_version,
             'language_version': language_version,
             'language': 'python',
         }
         msg = self.session.send(stream, 'kernel_info_reply',
                                 vinfo, parent, ident)
         self.log.debug("%s", msg)
 
     def shutdown_request(self, stream, ident, parent):
         self.shell.exit_now = True
         content = dict(status='ok')
         content.update(parent['content'])
         self.session.send(stream, u'shutdown_reply', content, parent, ident=ident)
         # same content, but different msg_id for broadcasting on IOPub
         self._shutdown_message = self.session.msg(u'shutdown_reply',
                                                   content, parent
         )
 
         self._at_shutdown()
         # call sys.exit after a short delay
         loop = ioloop.IOLoop.instance()
         loop.add_timeout(time.time()+0.1, loop.stop)
 
     #---------------------------------------------------------------------------
     # Engine methods
     #---------------------------------------------------------------------------
 
     def apply_request(self, stream, ident, parent):
         try:
             content = parent[u'content']
             bufs = parent[u'buffers']
             msg_id = parent['header']['msg_id']
         except:
             self.log.error("Got bad msg: %s", parent, exc_info=True)
             return
 
         self._publish_status(u'busy', parent)
 
         # Set the parent message of the display hook and out streams.
         shell = self.shell
         shell.displayhook.set_parent(parent)
         shell.display_pub.set_parent(parent)
         shell.data_pub.set_parent(parent)
         try:
             sys.stdout.set_parent(parent)
         except AttributeError:
             pass
         try:
             sys.stderr.set_parent(parent)
         except AttributeError:
             pass
 
         # pyin_msg = self.session.msg(u'pyin',{u'code':code}, parent=parent)
         # self.iopub_socket.send(pyin_msg)
         # self.session.send(self.iopub_socket, u'pyin', {u'code':code},parent=parent)
         md = self._make_metadata(parent['metadata'])
         try:
             working = shell.user_ns
 
             prefix = "_"+str(msg_id).replace("-","")+"_"
 
             f,args,kwargs = unpack_apply_message(bufs, working, copy=False)
 
             fname = getattr(f, '__name__', 'f')
 
             fname = prefix+"f"
             argname = prefix+"args"
             kwargname = prefix+"kwargs"
             resultname = prefix+"result"
 
             ns = { fname : f, argname : args, kwargname : kwargs , resultname : None }
             # print ns
             working.update(ns)
             code = "%s = %s(*%s,**%s)" % (resultname, fname, argname, kwargname)
             try:
                 exec code in shell.user_global_ns, shell.user_ns
                 result = working.get(resultname)
             finally:
                 for key in ns.iterkeys():
                     working.pop(key)
 
             result_buf = serialize_object(result,
                 buffer_threshold=self.session.buffer_threshold,
                 item_threshold=self.session.item_threshold,
             )
         
         except:
             # invoke IPython traceback formatting
             shell.showtraceback()
             # FIXME - fish exception info out of shell, possibly left there by
             # run_code.  We'll need to clean up this logic later.
             reply_content = {}
             if shell._reply_content is not None:
                 reply_content.update(shell._reply_content)
                 e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method='apply')
                 reply_content['engine_info'] = e_info
                 # reset after use
                 shell._reply_content = None
             
             self.session.send(self.iopub_socket, u'pyerr', reply_content, parent=parent,
                                 ident=self._topic('pyerr'))
             self.log.info("Exception in apply request:\n%s", '\n'.join(reply_content['traceback']))
             result_buf = []
 
             if reply_content['ename'] == 'UnmetDependency':
                 md['dependencies_met'] = False
         else:
             reply_content = {'status' : 'ok'}
 
         # put 'ok'/'error' status in header, for scheduler introspection:
         md['status'] = reply_content['status']
 
         # flush i/o
         sys.stdout.flush()
         sys.stderr.flush()
         
         reply_msg = self.session.send(stream, u'apply_reply', reply_content,
                     parent=parent, ident=ident,buffers=result_buf, metadata=md)
 
         self._publish_status(u'idle', parent)
 
     #---------------------------------------------------------------------------
     # Control messages
     #---------------------------------------------------------------------------
 
     def abort_request(self, stream, ident, parent):
         """abort a specifig msg by id"""
         msg_ids = parent['content'].get('msg_ids', None)
         if isinstance(msg_ids, basestring):
             msg_ids = [msg_ids]
         if not msg_ids:
             self.abort_queues()
         for mid in msg_ids:
             self.aborted.add(str(mid))
 
         content = dict(status='ok')
         reply_msg = self.session.send(stream, 'abort_reply', content=content,
                 parent=parent, ident=ident)
         self.log.debug("%s", reply_msg)
 
     def clear_request(self, stream, idents, parent):
         """Clear our namespace."""
         self.shell.reset(False)
         msg = self.session.send(stream, 'clear_reply', ident=idents, parent=parent,
                 content = dict(status='ok'))
 
 
     #---------------------------------------------------------------------------
     # Protected interface
     #---------------------------------------------------------------------------
 
     def _wrap_exception(self, method=None):
         # import here, because _wrap_exception is only used in parallel,
         # and parallel has higher min pyzmq version
         from IPython.parallel.error import wrap_exception
         e_info = dict(engine_uuid=self.ident, engine_id=self.int_id, method=method)
         content = wrap_exception(e_info)
         return content
 
     def _topic(self, topic):
         """prefixed topic for IOPub messages"""
         if self.int_id >= 0:
             base = "engine.%i" % self.int_id
         else:
             base = "kernel.%s" % self.ident
         
         return py3compat.cast_bytes("%s.%s" % (base, topic))
     
     def _abort_queues(self):
         for stream in self.shell_streams:
             if stream:
                 self._abort_queue(stream)
 
     def _abort_queue(self, stream):
         poller = zmq.Poller()
         poller.register(stream.socket, zmq.POLLIN)
         while True:
             idents,msg = self.session.recv(stream, zmq.NOBLOCK, content=True)
             if msg is None:
                 return
 
             self.log.info("Aborting:")
             self.log.info("%s", msg)
             msg_type = msg['header']['msg_type']
             reply_type = msg_type.split('_')[0] + '_reply'
 
             status = {'status' : 'aborted'}
             md = {'engine' : self.ident}
             md.update(status)
             reply_msg = self.session.send(stream, reply_type, metadata=md,
                         content=status, parent=msg, ident=idents)
             self.log.debug("%s", reply_msg)
             # We need to wait a bit for requests to come in. This can probably
             # be set shorter for true asynchronous clients.
             poller.poll(50)
 
 
     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()
         # flush the stdin socket, to purge stale replies
         while True:
             try:
                 self.stdin_socket.recv_multipart(zmq.NOBLOCK)
             except zmq.ZMQError as e:
                 if e.errno == zmq.EAGAIN:
                     break
                 else:
                     raise
         
         # Send the input request.
         content = json_clean(dict(prompt=prompt))
         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)
+            except KeyboardInterrupt:
+                # re-raise KeyboardInterrupt, to truncate traceback
+                raise KeyboardInterrupt
             else:
                 break
         try:
             value = py3compat.unicode_to_str(reply['content']['value'])
         except:
             self.log.error("Got bad raw_input reply: ")
             self.log.error("%s", parent)
             value = ''
         if value == '\x04':
             # EOF
             raise EOFError
         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 _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.iopub_socket, self._shutdown_message, ident=self._topic('shutdown'))
             self.log.debug("%s", self._shutdown_message)
         [ s.flush(zmq.POLLOUT) for s in self.shell_streams ]