move IPython.zmq.entry_point to IPython.utils.kernel

IPython/utils/kernel.py

@@ -1,315 +1,569 b''
-"""Utilities for connecting to kernels
+"""Utilities for working with kernels and their connection files
 
 Authors:
 
 * Min Ragan-Kelley
 
 """
 
 #-----------------------------------------------------------------------------
-#  Copyright (C) 2011  The IPython Development Team
+#  Copyright (C) 2013  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import glob
 import json
 import os
+import socket
 import sys
 from getpass import getpass
 from subprocess import Popen, PIPE
+import tempfile
 
 # external imports
 from IPython.external.ssh import tunnel
 
 # IPython imports
 from IPython.core.profiledir import ProfileDir
+from IPython.utils.localinterfaces import LOCALHOST
 from IPython.utils.path import filefind, get_ipython_dir
-from IPython.utils.py3compat import str_to_bytes
+from IPython.utils.py3compat import str_to_bytes, bytes_to_str
 
 
 #-----------------------------------------------------------------------------
-# Functions
+# Working with Connection Files
 #-----------------------------------------------------------------------------
 
+def write_connection_file(fname=None, shell_port=0, iopub_port=0, stdin_port=0, hb_port=0,
+                         ip=LOCALHOST, key=b'', transport='tcp'):
+    """Generates a JSON config file, including the selection of random ports.
+    
+    Parameters
+    ----------
+
+    fname : unicode
+        The path to the file to write
+
+    shell_port : int, optional
+        The port to use for ROUTER channel.
+
+    iopub_port : int, optional
+        The port to use for the SUB channel.
+
+    stdin_port : int, optional
+        The port to use for the REQ (raw input) channel.
+
+    hb_port : int, optional
+        The port to use for the hearbeat REP channel.
+
+    ip  : str, optional
+        The ip address the kernel will bind to.
+
+    key : str, optional
+        The Session key used for HMAC authentication.
+
+    """
+    # default to temporary connector file
+    if not fname:
+        fname = tempfile.mktemp('.json')
+    
+    # Find open ports as necessary.
+    
+    ports = []
+    ports_needed = int(shell_port <= 0) + int(iopub_port <= 0) + \
+                   int(stdin_port <= 0) + int(hb_port <= 0)
+    if transport == 'tcp':
+        for i in range(ports_needed):
+            sock = socket.socket()
+            sock.bind(('', 0))
+            ports.append(sock)
+        for i, sock in enumerate(ports):
+            port = sock.getsockname()[1]
+            sock.close()
+            ports[i] = port
+    else:
+        N = 1
+        for i in range(ports_needed):
+            while os.path.exists("%s-%s" % (ip, str(N))):
+                N += 1
+            ports.append(N)
+            N += 1
+    if shell_port <= 0:
+        shell_port = ports.pop(0)
+    if iopub_port <= 0:
+        iopub_port = ports.pop(0)
+    if stdin_port <= 0:
+        stdin_port = ports.pop(0)
+    if hb_port <= 0:
+        hb_port = ports.pop(0)
+    
+    cfg = dict( shell_port=shell_port,
+                iopub_port=iopub_port,
+                stdin_port=stdin_port,
+                hb_port=hb_port,
+              )
+    cfg['ip'] = ip
+    cfg['key'] = bytes_to_str(key)
+    cfg['transport'] = transport
+    
+    with open(fname, 'w') as f:
+        f.write(json.dumps(cfg, indent=2))
+    
+    return fname, cfg
+
+
 def get_connection_file(app=None):
     """Return the path to the connection file of an app
     
     Parameters
     ----------
     app : KernelApp instance [optional]
         If unspecified, the currently running app will be used
     """
     if app is None:
         from IPython.zmq.ipkernel import IPKernelApp
         if not IPKernelApp.initialized():
             raise RuntimeError("app not specified, and not in a running Kernel")
 
         app = IPKernelApp.instance()
     return filefind(app.connection_file, ['.', app.profile_dir.security_dir])
 
+
 def find_connection_file(filename, profile=None):
     """find a connection file, and return its absolute path.
     
     The current working directory and the profile's security
     directory will be searched for the file if it is not given by
     absolute path.
     
     If profile is unspecified, then the current running application's
     profile will be used, or 'default', if not run from IPython.
     
     If the argument does not match an existing file, it will be interpreted as a
     fileglob, and the matching file in the profile's security dir with
     the latest access time will be used.
     
     Parameters
     ----------
     filename : str
         The connection file or fileglob to search for.
     profile : str [optional]
         The name of the profile to use when searching for the connection file,
         if different from the current IPython session or 'default'.
     
     Returns
     -------
     str : The absolute path of the connection file.
     """
     from IPython.core.application import BaseIPythonApplication as IPApp
     try:
         # quick check for absolute path, before going through logic
         return filefind(filename)
     except IOError:
         pass
     
     if profile is None:
         # profile unspecified, check if running from an IPython app
         if IPApp.initialized():
             app = IPApp.instance()
             profile_dir = app.profile_dir
         else:
             # not running in IPython, use default profile
             profile_dir = ProfileDir.find_profile_dir_by_name(get_ipython_dir(), 'default')
     else:
         # find profiledir by profile name:
         profile_dir = ProfileDir.find_profile_dir_by_name(get_ipython_dir(), profile)
     security_dir = profile_dir.security_dir
     
     try:
         # first, try explicit name
         return filefind(filename, ['.', security_dir])
     except IOError:
         pass
     
     # not found by full name
     
     if '*' in filename:
         # given as a glob already
         pat = filename
     else:
         # accept any substring match
         pat = '*%s*' % filename
     matches = glob.glob( os.path.join(security_dir, pat) )
     if not matches:
         raise IOError("Could not find %r in %r" % (filename, security_dir))
     elif len(matches) == 1:
         return matches[0]
     else:
         # get most recent match, by access time:
         return sorted(matches, key=lambda f: os.stat(f).st_atime)[-1]
 
+
 def get_connection_info(connection_file=None, unpack=False, profile=None):
     """Return the connection information for the current Kernel.
     
     Parameters
     ----------
     connection_file : str [optional]
         The connection file to be used. Can be given by absolute path, or
         IPython will search in the security directory of a given profile.
         If run from IPython, 
         
         If unspecified, the connection file for the currently running
         IPython Kernel will be used, which is only allowed from inside a kernel.
     unpack : bool [default: False]
         if True, return the unpacked dict, otherwise just the string contents
         of the file.
     profile : str [optional]
         The name of the profile to use when searching for the connection file,
         if different from the current IPython session or 'default'.
         
     
     Returns
     -------
     The connection dictionary of the current kernel, as string or dict,
     depending on `unpack`.
     """
     if connection_file is None:
         # get connection file from current kernel
         cf = get_connection_file()
     else:
         # connection file specified, allow shortnames:
         cf = find_connection_file(connection_file, profile=profile)
     
     with open(cf) as f:
         info = f.read()
     
     if unpack:
         info = json.loads(info)
         # ensure key is bytes:
         info['key'] = str_to_bytes(info.get('key', ''))
     return info
 
+
 def connect_qtconsole(connection_file=None, argv=None, profile=None):
     """Connect a qtconsole to the current kernel.
     
     This is useful for connecting a second qtconsole to a kernel, or to a
     local notebook.
     
     Parameters
     ----------
     connection_file : str [optional]
         The connection file to be used. Can be given by absolute path, or
         IPython will search in the security directory of a given profile.
         If run from IPython, 
         
         If unspecified, the connection file for the currently running
         IPython Kernel will be used, which is only allowed from inside a kernel.
     argv : list [optional]
         Any extra args to be passed to the console.
     profile : str [optional]
         The name of the profile to use when searching for the connection file,
         if different from the current IPython session or 'default'.
     
     
     Returns
     -------
     subprocess.Popen instance running the qtconsole frontend
     """
     argv = [] if argv is None else argv
     
     if connection_file is None:
         # get connection file from current kernel
         cf = get_connection_file()
     else:
         cf = find_connection_file(connection_file, profile=profile)
     
     cmd = ';'.join([
         "from IPython.frontend.qt.console import qtconsoleapp",
         "qtconsoleapp.main()"
     ])
     
     return Popen([sys.executable, '-c', cmd, '--existing', cf] + argv, stdout=PIPE, stderr=PIPE)
 
+
 def tunnel_to_kernel(connection_info, sshserver, sshkey=None):
     """tunnel connections to a kernel via ssh
     
     This will open four SSH tunnels from localhost on this machine to the
     ports associated with the kernel.  They can be either direct
     localhost-localhost tunnels, or if an intermediate server is necessary,
     the kernel must be listening on a public IP.
     
     Parameters
     ----------
     connection_info : dict or str (path)
         Either a connection dict, or the path to a JSON connection file
     sshserver : str
         The ssh sever to use to tunnel to the kernel. Can be a full
         `user@server:port` string. ssh config aliases are respected.
     sshkey : str [optional]
         Path to file containing ssh key to use for authentication.
         Only necessary if your ssh config does not already associate
         a keyfile with the host.
     
     Returns
     -------
     
     (shell, iopub, stdin, hb) : ints
         The four ports on localhost that have been forwarded to the kernel.
     """
     if isinstance(connection_info, basestring):
         # it's a path, unpack it
         with open(connection_info) as f:
             connection_info = json.loads(f.read())
     
     cf = connection_info
     
     lports = tunnel.select_random_ports(4)
     rports = cf['shell_port'], cf['iopub_port'], cf['stdin_port'], cf['hb_port']
     
     remote_ip = cf['ip']
     
     if tunnel.try_passwordless_ssh(sshserver, sshkey):
         password=False
     else:
         password = getpass("SSH Password for %s: "%sshserver)
     
     for lp,rp in zip(lports, rports):
         tunnel.ssh_tunnel(lp, rp, sshserver, remote_ip, sshkey, password)
     
     return tuple(lports)
-    
+
+
+#-----------------------------------------------------------------------------
+# Launching Kernels
+#-----------------------------------------------------------------------------
 
 def swallow_argv(argv, aliases=None, flags=None):
     """strip frontend-specific aliases and flags from an argument list
     
     For use primarily in frontend apps that want to pass a subset of command-line
     arguments through to a subprocess, where frontend-specific flags and aliases
     should be removed from the list.
     
     Parameters
     ----------
     
     argv : list(str)
         The starting argv, to be filtered
     aliases : container of aliases (dict, list, set, etc.)
         The frontend-specific aliases to be removed
     flags : container of flags (dict, list, set, etc.)
         The frontend-specific flags to be removed
     
     Returns
     -------
     
     argv : list(str)
         The argv list, excluding flags and aliases that have been stripped
     """
     
     if aliases is None:
         aliases = set()
     if flags is None:
         flags = set()
     
     stripped = list(argv) # copy
     
     swallow_next = False
     was_flag = False
     for a in argv:
         if swallow_next:
             swallow_next = False
             # last arg was an alias, remove the next one
             # *unless* the last alias has a no-arg flag version, in which
             # case, don't swallow the next arg if it's also a flag:
             if not (was_flag and a.startswith('-')):
                 stripped.remove(a)
                 continue
         if a.startswith('-'):
             split = a.lstrip('-').split('=')
             alias = split[0]
             if alias in aliases:
                 stripped.remove(a)
                 if len(split) == 1:
                     # alias passed with arg via space
                     swallow_next = True
                     # could have been a flag that matches an alias, e.g. `existing`
                     # in which case, we might not swallow the next arg
                     was_flag = alias in flags
             elif alias in flags and len(split) == 1:
                 # strip flag, but don't swallow next, as flags don't take args
                 stripped.remove(a)
     
     # return shortened list
     return stripped
 
+
+def make_ipkernel_cmd(code, executable=None, extra_arguments=[], **kw):
+    """Build Popen command list for launching an IPython kernel.
+
+    Parameters
+    ----------
+    code : str,
+        A string of Python code that imports and executes a kernel entry point.
+
+    executable : str, optional (default sys.executable)
+        The Python executable to use for the kernel process.
+
+    extra_arguments : list, optional
+        A list of extra arguments to pass when executing the launch code.
+    
+    Returns
+    -------
+    
+    A Popen command list
+    """
+    
+    # Build the kernel launch command.
+    if executable is None:
+        executable = sys.executable
+    arguments = [ executable, '-c', code, '-f', '{connection_file}' ]
+    arguments.extend(extra_arguments)
+
+    # Spawn a kernel.
+    if sys.platform == 'win32':
+
+        # If the kernel is running on pythonw and stdout/stderr are not been
+        # re-directed, it will crash when more than 4KB of data is written to
+        # stdout or stderr. This is a bug that has been with Python for a very
+        # long time; see http://bugs.python.org/issue706263.
+        # A cleaner solution to this problem would be to pass os.devnull to
+        # Popen directly. Unfortunately, that does not work.
+        if executable.endswith('pythonw.exe'):
+            arguments.append('--no-stdout')
+            arguments.append('--no-stderr')
+
+    return arguments
+
+
+def launch_kernel(cmd, stdin=None, stdout=None, stderr=None,
+                        independent=False,
+                        cwd=None, ipython_kernel=True,
+                        **kw
+                        ):
+    """ Launches a localhost kernel, binding to the specified ports.
+
+    Parameters
+    ----------
+    cmd : Popen list,
+        A string of Python code that imports and executes a kernel entry point.
+
+    stdin, stdout, stderr : optional (default None)
+        Standards streams, as defined in subprocess.Popen.
+
+    independent : bool, optional (default False)
+        If set, the kernel process is guaranteed to survive if this process
+        dies. If not set, an effort is made to ensure that the kernel is killed
+        when this process dies. Note that in this case it is still good practice
+        to kill kernels manually before exiting.
+
+    cwd : path, optional
+        The working dir of the kernel process (default: cwd of this process).
+
+    ipython_kernel : bool, optional
+        Whether the kernel is an official IPython one,
+        and should get a bit of special treatment.
+
+    Returns
+    -------
+    
+    Popen instance for the kernel subprocess
+    """
+
+    # Popen will fail (sometimes with a deadlock) if stdin, stdout, and stderr
+    # are invalid. Unfortunately, there is in general no way to detect whether
+    # they are valid.  The following two blocks redirect them to (temporary)
+    # pipes in certain important cases.
+
+    # If this process has been backgrounded, our stdin is invalid. Since there
+    # is no compelling reason for the kernel to inherit our stdin anyway, we'll
+    # place this one safe and always redirect.
+    redirect_in = True
+    _stdin = PIPE if stdin is None else stdin
+
+    # If this process in running on pythonw, we know that stdin, stdout, and
+    # stderr are all invalid.
+    redirect_out = sys.executable.endswith('pythonw.exe')
+    if redirect_out:
+        _stdout = PIPE if stdout is None else stdout
+        _stderr = PIPE if stderr is None else stderr
+    else:
+        _stdout, _stderr = stdout, stderr
+
+    # Spawn a kernel.
+    if sys.platform == 'win32':
+        from IPython.zmq.parentpoller import ParentPollerWindows
+        # Create a Win32 event for interrupting the kernel.
+        interrupt_event = ParentPollerWindows.create_interrupt_event()
+        if ipython_kernel:
+            cmd += [ '--interrupt=%i' % interrupt_event ]
+
+            # If the kernel is running on pythonw and stdout/stderr are not been
+            # re-directed, it will crash when more than 4KB of data is written to
+            # stdout or stderr. This is a bug that has been with Python for a very
+            # long time; see http://bugs.python.org/issue706263.
+            # A cleaner solution to this problem would be to pass os.devnull to
+            # Popen directly. Unfortunately, that does not work.
+            if cmd[0].endswith('pythonw.exe'):
+                if stdout is None:
+                    cmd.append('--no-stdout')
+                if stderr is None:
+                    cmd.append('--no-stderr')
+
+        # Launch the kernel process.
+        if independent:
+            proc = Popen(cmd,
+                         creationflags=512, # CREATE_NEW_PROCESS_GROUP
+                         stdin=_stdin, stdout=_stdout, stderr=_stderr)
+        else:
+            if ipython_kernel:
+                try:
+                    from _winapi import DuplicateHandle, GetCurrentProcess, \
+                        DUPLICATE_SAME_ACCESS
+                except:
+                    from _subprocess import DuplicateHandle, GetCurrentProcess, \
+                        DUPLICATE_SAME_ACCESS
+                pid = GetCurrentProcess()
+                handle = DuplicateHandle(pid, pid, pid, 0,
+                                         True, # Inheritable by new processes.
+                                         DUPLICATE_SAME_ACCESS)
+                cmd +=[ '--parent=%i' % handle ]
+            
+            
+            proc = Popen(cmd,
+                         stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd)
+
+        # Attach the interrupt event to the Popen objet so it can be used later.
+        proc.win32_interrupt_event = interrupt_event
+
+    else:
+        if independent:
+            proc = Popen(cmd, preexec_fn=lambda: os.setsid(),
+                         stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd)
+        else:
+            if ipython_kernel:
+                cmd += ['--parent=1']
+            proc = Popen(cmd,
+                         stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd)
+
+    # Clean up pipes created to work around Popen bug.
+    if redirect_in:
+        if stdin is None:
+            proc.stdin.close()
+    if redirect_out:
+        if stdout is None:
+            proc.stdout.close()
+        if stderr is None:
+            proc.stderr.close()
+
+    return proc
+

IPython/zmq/kernelapp.py

@@ -1,372 +1,372 b''
 """An Application for launching a kernel
 
 Authors
 -------
 * MinRK
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2011  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
 #-----------------------------------------------------------------------------
 
 # Standard library imports
 import atexit
 import json
 import os
 import sys
 import signal
 
 # System library imports
 import zmq
 from zmq.eventloop import ioloop
 
 # IPython imports
 from IPython.core.ultratb import FormattedTB
 from IPython.core.application import (
     BaseIPythonApplication, base_flags, base_aliases, catch_config_error
 )
 from IPython.utils import io
 from IPython.utils.localinterfaces import LOCALHOST
 from IPython.utils.path import filefind
 from IPython.utils.py3compat import str_to_bytes
 from IPython.utils.traitlets import (
     Any, Instance, Dict, Unicode, Integer, Bool, CaselessStrEnum,
     DottedObjectName,
 )
 from IPython.utils.importstring import import_item
+from IPython.utils.kernel import write_connection_file
 # local imports
-from IPython.zmq.entry_point import write_connection_file
 from IPython.zmq.heartbeat import Heartbeat
 from IPython.zmq.parentpoller import ParentPollerUnix, ParentPollerWindows
 from IPython.zmq.session import (
     Session, session_flags, session_aliases, default_secure,
 )
 
 
 #-----------------------------------------------------------------------------
 # Flags and Aliases
 #-----------------------------------------------------------------------------
 
 kernel_aliases = dict(base_aliases)
 kernel_aliases.update({
     'ip' : 'KernelApp.ip',
     'hb' : 'KernelApp.hb_port',
     'shell' : 'KernelApp.shell_port',
     'iopub' : 'KernelApp.iopub_port',
     'stdin' : 'KernelApp.stdin_port',
     'f' : 'KernelApp.connection_file',
     'parent': 'KernelApp.parent',
     'transport': 'KernelApp.transport',
 })
 if sys.platform.startswith('win'):
     kernel_aliases['interrupt'] = 'KernelApp.interrupt'
 
 kernel_flags = dict(base_flags)
 kernel_flags.update({
     'no-stdout' : (
             {'KernelApp' : {'no_stdout' : True}},
             "redirect stdout to the null device"),
     'no-stderr' : (
             {'KernelApp' : {'no_stderr' : True}},
             "redirect stderr to the null device"),
 })
 
 # inherit flags&aliases for Sessions
 kernel_aliases.update(session_aliases)
 kernel_flags.update(session_flags)
 
 
 
 #-----------------------------------------------------------------------------
 # Application class for starting a Kernel
 #-----------------------------------------------------------------------------
 
 class KernelApp(BaseIPythonApplication):
     name='ipkernel'
     aliases = Dict(kernel_aliases)
     flags = Dict(kernel_flags)
     classes = [Session]
     # the kernel class, as an importstring
     kernel_class = DottedObjectName('IPython.zmq.ipkernel.Kernel')
     kernel = Any()
     poller = Any() # don't restrict this even though current pollers are all Threads
     heartbeat = Instance(Heartbeat)
     session = Instance('IPython.zmq.session.Session')
     ports = Dict()
     
     # inherit config file name from parent:
     parent_appname = Unicode(config=True)
     def _parent_appname_changed(self, name, old, new):
         if self.config_file_specified:
             # it was manually specified, ignore
             return
         self.config_file_name = new.replace('-','_') + u'_config.py'
         # don't let this count as specifying the config file
         self.config_file_specified = False
         
     # connection info:
     transport = CaselessStrEnum(['tcp', 'ipc'], default_value='tcp', config=True)
     ip = Unicode(config=True,
         help="Set the IP or interface on which the kernel will listen.")
     def _ip_default(self):
         if self.transport == 'ipc':
             if self.connection_file:
                 return os.path.splitext(self.abs_connection_file)[0] + '-ipc'
             else:
                 return 'kernel-ipc'
         else:
             return LOCALHOST
     hb_port = Integer(0, config=True, help="set the heartbeat port [default: random]")
     shell_port = Integer(0, config=True, help="set the shell (ROUTER) port [default: random]")
     iopub_port = Integer(0, config=True, help="set the iopub (PUB) port [default: random]")
     stdin_port = Integer(0, config=True, help="set the stdin (DEALER) port [default: random]")
     connection_file = Unicode('', config=True, 
     help="""JSON file in which to store connection info [default: kernel-<pid>.json]
     
     This file will contain the IP, ports, and authentication key needed to connect
     clients to this kernel. By default, this file will be created in the security dir
     of the current profile, but can be specified by absolute path.
     """)
     @property
     def abs_connection_file(self):
         if os.path.basename(self.connection_file) == self.connection_file:
             return os.path.join(self.profile_dir.security_dir, self.connection_file)
         else:
             return self.connection_file
         
 
     # streams, etc.
     no_stdout = Bool(False, config=True, help="redirect stdout to the null device")
     no_stderr = Bool(False, config=True, help="redirect stderr to the null device")
     outstream_class = DottedObjectName('IPython.zmq.iostream.OutStream',
         config=True, help="The importstring for the OutStream factory")
     displayhook_class = DottedObjectName('IPython.zmq.displayhook.ZMQDisplayHook',
         config=True, help="The importstring for the DisplayHook factory")
 
     # polling
     parent = Integer(0, config=True,
         help="""kill this process if its parent dies.  On Windows, the argument
         specifies the HANDLE of the parent process, otherwise it is simply boolean.
         """)
     interrupt = Integer(0, config=True,
         help="""ONLY USED ON WINDOWS
         Interrupt this process when the parent is signaled.
         """)
 
     def init_crash_handler(self):
         # Install minimal exception handling
         sys.excepthook = FormattedTB(mode='Verbose', color_scheme='NoColor',
                                      ostream=sys.__stdout__)
 
     def init_poller(self):
         if sys.platform == 'win32':
             if self.interrupt or self.parent:
                 self.poller = ParentPollerWindows(self.interrupt, self.parent)
         elif self.parent:
             self.poller = ParentPollerUnix()
 
     def _bind_socket(self, s, port):
         iface = '%s://%s' % (self.transport, self.ip)
         if self.transport == 'tcp':
             if port <= 0:
                 port = s.bind_to_random_port(iface)
             else:
                 s.bind("tcp://%s:%i" % (self.ip, port))
         elif self.transport == 'ipc':
             if port <= 0:
                 port = 1
                 path = "%s-%i" % (self.ip, port)
                 while os.path.exists(path):
                     port = port + 1
                     path = "%s-%i" % (self.ip, port)
             else:
                 path = "%s-%i" % (self.ip, port)
             s.bind("ipc://%s" % path)
         return port
 
     def load_connection_file(self):
         """load ip/port/hmac config from JSON connection file"""
         try:
             fname = filefind(self.connection_file, ['.', self.profile_dir.security_dir])
         except IOError:
             self.log.debug("Connection file not found: %s", self.connection_file)
             # This means I own it, so I will clean it up:
             atexit.register(self.cleanup_connection_file)
             return
         self.log.debug(u"Loading connection file %s", fname)
         with open(fname) as f:
             s = f.read()
         cfg = json.loads(s)
         self.transport = cfg.get('transport', self.transport)
         if self.ip == self._ip_default() and 'ip' in cfg:
             # not overridden by config or cl_args
             self.ip = cfg['ip']
         for channel in ('hb', 'shell', 'iopub', 'stdin'):
             name = channel + '_port'
             if getattr(self, name) == 0 and name in cfg:
                 # not overridden by config or cl_args
                 setattr(self, name, cfg[name])
         if 'key' in cfg:
             self.config.Session.key = str_to_bytes(cfg['key'])
     
     def write_connection_file(self):
         """write connection info to JSON file"""
         cf = self.abs_connection_file
         self.log.debug("Writing connection file: %s", cf)
         write_connection_file(cf, ip=self.ip, key=self.session.key, transport=self.transport,
         shell_port=self.shell_port, stdin_port=self.stdin_port, hb_port=self.hb_port,
         iopub_port=self.iopub_port)
     
     def cleanup_connection_file(self):
         cf = self.abs_connection_file
         self.log.debug("Cleaning up connection file: %s", cf)
         try:
             os.remove(cf)
         except (IOError, OSError):
             pass
         
         self.cleanup_ipc_files()
     
     def cleanup_ipc_files(self):
         """cleanup ipc files if we wrote them"""
         if self.transport != 'ipc':
             return
         for port in (self.shell_port, self.iopub_port, self.stdin_port, self.hb_port):
             ipcfile = "%s-%i" % (self.ip, port)
             try:
                 os.remove(ipcfile)
             except (IOError, OSError):
                 pass
     
     def init_connection_file(self):
         if not self.connection_file:
             self.connection_file = "kernel-%s.json"%os.getpid()
         try:
             self.load_connection_file()
         except Exception:
             self.log.error("Failed to load connection file: %r", self.connection_file, exc_info=True)
             self.exit(1)
     
     def init_sockets(self):
         # Create a context, a session, and the kernel sockets.
         self.log.info("Starting the kernel at pid: %i", os.getpid())
         context = zmq.Context.instance()
         # Uncomment this to try closing the context.
         # atexit.register(context.term)
 
         self.shell_socket = context.socket(zmq.ROUTER)
         self.shell_port = self._bind_socket(self.shell_socket, self.shell_port)
         self.log.debug("shell ROUTER Channel on port: %i"%self.shell_port)
 
         self.iopub_socket = context.socket(zmq.PUB)
         self.iopub_port = self._bind_socket(self.iopub_socket, self.iopub_port)
         self.log.debug("iopub PUB Channel on port: %i"%self.iopub_port)
 
         self.stdin_socket = context.socket(zmq.ROUTER)
         self.stdin_port = self._bind_socket(self.stdin_socket, self.stdin_port)
         self.log.debug("stdin ROUTER Channel on port: %i"%self.stdin_port)
     
     def init_heartbeat(self):
         """start the heart beating"""
         # heartbeat doesn't share context, because it mustn't be blocked
         # by the GIL, which is accessed by libzmq when freeing zero-copy messages
         hb_ctx = zmq.Context()
         self.heartbeat = Heartbeat(hb_ctx, (self.transport, self.ip, self.hb_port))
         self.hb_port = self.heartbeat.port
         self.log.debug("Heartbeat REP Channel on port: %i"%self.hb_port)
         self.heartbeat.start()
 
         # Helper to make it easier to connect to an existing kernel.
         # set log-level to critical, to make sure it is output
         self.log.critical("To connect another client to this kernel, use:")
     
     def log_connection_info(self):
         """display connection info, and store ports"""
         basename = os.path.basename(self.connection_file)
         if basename == self.connection_file or \
             os.path.dirname(self.connection_file) == self.profile_dir.security_dir:
             # use shortname
             tail = basename
             if self.profile != 'default':
                 tail += " --profile %s" % self.profile
         else:
             tail = self.connection_file
         self.log.critical("--existing %s", tail)
 
 
         self.ports = dict(shell=self.shell_port, iopub=self.iopub_port,
                                 stdin=self.stdin_port, hb=self.hb_port)
 
     def init_session(self):
         """create our session object"""
         default_secure(self.config)
         self.session = Session(config=self.config, username=u'kernel')
 
     def init_blackhole(self):
         """redirects stdout/stderr to devnull if necessary"""
         if self.no_stdout or self.no_stderr:
             blackhole = open(os.devnull, 'w')
             if self.no_stdout:
                 sys.stdout = sys.__stdout__ = blackhole
             if self.no_stderr:
                 sys.stderr = sys.__stderr__ = blackhole
     
     def init_io(self):
         """Redirect input streams and set a display hook."""
         if self.outstream_class:
             outstream_factory = import_item(str(self.outstream_class))
             sys.stdout = outstream_factory(self.session, self.iopub_socket, u'stdout')
             sys.stderr = outstream_factory(self.session, self.iopub_socket, u'stderr')
         if self.displayhook_class:
             displayhook_factory = import_item(str(self.displayhook_class))
             sys.displayhook = displayhook_factory(self.session, self.iopub_socket)
 
     def init_signal(self):
         signal.signal(signal.SIGINT, signal.SIG_IGN)
 
     def init_kernel(self):
         """Create the Kernel object itself"""
         kernel_factory = import_item(str(self.kernel_class))
         self.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.record_ports(self.ports)
 
     @catch_config_error
     def initialize(self, argv=None):
         super(KernelApp, self).initialize(argv)
         self.init_blackhole()
         self.init_connection_file()
         self.init_session()
         self.init_poller()
         self.init_sockets()
         self.init_heartbeat()
         # writing/displaying connection info must be *after* init_sockets/heartbeat
         self.log_connection_info()
         self.write_connection_file()
         self.init_io()
         self.init_signal()
         self.init_kernel()
         # flush stdout/stderr, so that anything written to these streams during
         # initialization do not get associated with the first execution request
         sys.stdout.flush()
         sys.stderr.flush()
 
     def start(self):
         if self.poller is not None:
             self.poller.start()
         self.kernel.start()
         try:
             ioloop.IOLoop.instance().start()
         except KeyboardInterrupt:
             pass
 

IPython/zmq/kernelmanager.py

@@ -1,1134 +1,1129 b''
 """Base classes to manage the interaction with a running kernel.
 
 TODO
 * Create logger to handle debugging and console messages.
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Standard library imports.
 import atexit
 import errno
 import json
 from subprocess import Popen
 import os
 import signal
 import sys
 from threading import Thread
 import time
 
 # System library imports.
 import zmq
 # import ZMQError in top-level namespace, to avoid ugly attribute-error messages
 # during garbage collection of threads at exit:
 from zmq import ZMQError
 from zmq.eventloop import ioloop, zmqstream
 
 # Local imports.
 from IPython.config.configurable import Configurable
 from IPython.utils.localinterfaces import LOCALHOST, LOCAL_IPS
 from IPython.utils.traitlets import (
     Any, Instance, Type, Unicode, List, Integer, Bool, CaselessStrEnum
 )
 from IPython.utils.py3compat import str_to_bytes
-from IPython.zmq.entry_point import (
+from IPython.utils.kernel import (
     write_connection_file,
     make_ipkernel_cmd,
     launch_kernel,
 )
 from session import Session
 from IPython.zmq.kernelmanagerabc import (
     ShellChannelABC, IOPubChannelABC,
     HBChannelABC, StdInChannelABC,
     KernelManagerABC
 )
 
 
 #-----------------------------------------------------------------------------
 # Constants and exceptions
 #-----------------------------------------------------------------------------
 
 class InvalidPortNumber(Exception):
     pass
 
 #-----------------------------------------------------------------------------
 # Utility functions
 #-----------------------------------------------------------------------------
 
 # some utilities to validate message structure, these might get moved elsewhere
 # if they prove to have more generic utility
 
 def validate_string_list(lst):
     """Validate that the input is a list of strings.
 
     Raises ValueError if not."""
     if not isinstance(lst, list):
         raise ValueError('input %r must be a list' % lst)
     for x in lst:
         if not isinstance(x, basestring):
             raise ValueError('element %r in list must be a string' % x)
 
 
 def validate_string_dict(dct):
     """Validate that the input is a dict with string keys and values.
 
     Raises ValueError if not."""
     for k,v in dct.iteritems():
         if not isinstance(k, basestring):
             raise ValueError('key %r in dict must be a string' % k)
         if not isinstance(v, basestring):
             raise ValueError('value %r in dict must be a string' % v)
 
 
 #-----------------------------------------------------------------------------
 # ZMQ Socket Channel classes
 #-----------------------------------------------------------------------------
 
 class ZMQSocketChannel(Thread):
     """The base class for the channels that use ZMQ sockets."""
     context = None
     session = None
     socket = None
     ioloop = None
     stream = None
     _address = None
     _exiting = False
 
     def __init__(self, context, session, address):
         """Create a channel.
 
         Parameters
         ----------
         context : :class:`zmq.Context`
             The ZMQ context to use.
         session : :class:`session.Session`
             The session to use.
         address : zmq url
             Standard (ip, port) tuple that the kernel is listening on.
         """
         super(ZMQSocketChannel, self).__init__()
         self.daemon = True
 
         self.context = context
         self.session = session
         if isinstance(address, tuple):
             if address[1] == 0:
                 message = 'The port number for a channel cannot be 0.'
                 raise InvalidPortNumber(message)
             address = "tcp://%s:%i" % address
         self._address = address
         atexit.register(self._notice_exit)
     
     def _notice_exit(self):
         self._exiting = True
 
     def _run_loop(self):
         """Run my loop, ignoring EINTR events in the poller"""
         while True:
             try:
                 self.ioloop.start()
             except ZMQError as e:
                 if e.errno == errno.EINTR:
                     continue
                 else:
                     raise
             except Exception:
                 if self._exiting:
                     break
                 else:
                     raise
             else:
                 break
 
     def stop(self):
         """Stop the channel's event loop and join its thread.
 
         This calls :method:`Thread.join` and returns when the thread
         terminates. :class:`RuntimeError` will be raised if
         :method:`self.start` is called again.
         """
         self.join()
 
     @property
     def address(self):
         """Get the channel's address as a zmq url string.
 
         These URLS have the form: 'tcp://127.0.0.1:5555'.
         """
         return self._address
 
     def _queue_send(self, msg):
         """Queue a message to be sent from the IOLoop's thread.
         
         Parameters
         ----------
         msg : message to send
         
         This is threadsafe, as it uses IOLoop.add_callback to give the loop's
         thread control of the action.
         """
         def thread_send():
             self.session.send(self.stream, msg)
         self.ioloop.add_callback(thread_send)
 
     def _handle_recv(self, msg):
         """Callback for stream.on_recv.
 
         Unpacks message, and calls handlers with it.
         """
         ident,smsg = self.session.feed_identities(msg)
         self.call_handlers(self.session.unserialize(smsg))
     
 
 
 class ShellChannel(ZMQSocketChannel):
     """The shell channel for issuing request/replies to the kernel."""
 
     command_queue = None
     # flag for whether execute requests should be allowed to call raw_input:
     allow_stdin = True
 
     def __init__(self, context, session, address):
         super(ShellChannel, self).__init__(context, session, address)
         self.ioloop = ioloop.IOLoop()
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self.socket = self.context.socket(zmq.DEALER)
         self.socket.setsockopt(zmq.IDENTITY, self.session.bsession)
         self.socket.connect(self.address)
         self.stream = zmqstream.ZMQStream(self.socket, self.ioloop)
         self.stream.on_recv(self._handle_recv)
         self._run_loop()
         try:
             self.socket.close()
         except:
             pass
 
     def stop(self):
         """Stop the channel's event loop and join its thread."""
         self.ioloop.stop()
         super(ShellChannel, self).stop()
 
     def call_handlers(self, msg):
         """This method is called in the ioloop thread when a message arrives.
 
         Subclasses should override this method to handle incoming messages.
         It is important to remember that this method is called in the thread
         so that some logic must be done to ensure that the application leve
         handlers are called in the application thread.
         """
         raise NotImplementedError('call_handlers must be defined in a subclass.')
 
     def execute(self, code, silent=False, store_history=True,
                 user_variables=None, user_expressions=None, allow_stdin=None):
         """Execute code in the kernel.
 
         Parameters
         ----------
         code : str
             A string of Python code.
 
         silent : bool, optional (default False)
             If set, the kernel will execute the code as quietly possible, and
             will force store_history to be False.
 
         store_history : bool, optional (default True)
             If set, the kernel will store command history.  This is forced
             to be False if silent is True.
 
         user_variables : list, optional
             A list of variable names to pull from the user's namespace.  They
             will come back as a dict with these names as keys and their
             :func:`repr` as values.
 
         user_expressions : dict, optional
             A dict mapping names to expressions to be evaluated in the user's
             dict. The expression values are returned as strings formatted using
             :func:`repr`.
 
         allow_stdin : bool, optional (default self.allow_stdin)
             Flag for whether the kernel can send stdin requests to frontends.
 
             Some frontends (e.g. the Notebook) do not support stdin requests. 
             If raw_input is called from code executed from such a frontend, a
             StdinNotImplementedError will be raised.
 
         Returns
         -------
         The msg_id of the message sent.
         """
         if user_variables is None:
             user_variables = []
         if user_expressions is None:
             user_expressions = {}
         if allow_stdin is None:
             allow_stdin = self.allow_stdin
         
         
         # Don't waste network traffic if inputs are invalid
         if not isinstance(code, basestring):
             raise ValueError('code %r must be a string' % code)
         validate_string_list(user_variables)
         validate_string_dict(user_expressions)
 
         # Create class for content/msg creation. Related to, but possibly
         # not in Session.
         content = dict(code=code, silent=silent, store_history=store_history,
                        user_variables=user_variables,
                        user_expressions=user_expressions,
                        allow_stdin=allow_stdin,
                        )
         msg = self.session.msg('execute_request', content)
         self._queue_send(msg)
         return msg['header']['msg_id']
 
     def complete(self, text, line, cursor_pos, block=None):
         """Tab complete text in the kernel's namespace.
 
         Parameters
         ----------
         text : str
             The text to complete.
         line : str
             The full line of text that is the surrounding context for the
             text to complete.
         cursor_pos : int
             The position of the cursor in the line where the completion was
             requested.
         block : str, optional
             The full block of code in which the completion is being requested.
 
         Returns
         -------
         The msg_id of the message sent.
         """
         content = dict(text=text, line=line, block=block, cursor_pos=cursor_pos)
         msg = self.session.msg('complete_request', content)
         self._queue_send(msg)
         return msg['header']['msg_id']
 
     def object_info(self, oname, detail_level=0):
         """Get metadata information about an object in the kernel's namespace.
 
         Parameters
         ----------
         oname : str
             A string specifying the object name.
         detail_level : int, optional
             The level of detail for the introspection (0-2)
 
         Returns
         -------
         The msg_id of the message sent.
         """
         content = dict(oname=oname, detail_level=detail_level)
         msg = self.session.msg('object_info_request', content)
         self._queue_send(msg)
         return msg['header']['msg_id']
 
     def history(self, raw=True, output=False, hist_access_type='range', **kwargs):
         """Get entries from the kernel's history list.
 
         Parameters
         ----------
         raw : bool
             If True, return the raw input.
         output : bool
             If True, then return the output as well.
         hist_access_type : str
             'range' (fill in session, start and stop params), 'tail' (fill in n)
              or 'search' (fill in pattern param).
 
         session : int
             For a range request, the session from which to get lines. Session
             numbers are positive integers; negative ones count back from the
             current session.
         start : int
             The first line number of a history range.
         stop : int
             The final (excluded) line number of a history range.
 
         n : int
             The number of lines of history to get for a tail request.
 
         pattern : str
             The glob-syntax pattern for a search request.
 
         Returns
         -------
         The msg_id of the message sent.
         """
         content = dict(raw=raw, output=output, hist_access_type=hist_access_type,
                                                                     **kwargs)
         msg = self.session.msg('history_request', content)
         self._queue_send(msg)
         return msg['header']['msg_id']
 
     def kernel_info(self):
         """Request kernel info."""
         msg = self.session.msg('kernel_info_request')
         self._queue_send(msg)
         return msg['header']['msg_id']
 
     def shutdown(self, restart=False):
         """Request an immediate kernel shutdown.
 
         Upon receipt of the (empty) reply, client code can safely assume that
         the kernel has shut down and it's safe to forcefully terminate it if
         it's still alive.
 
         The kernel will send the reply via a function registered with Python's
         atexit module, ensuring it's truly done as the kernel is done with all
         normal operation.
         """
         # Send quit message to kernel. Once we implement kernel-side setattr,
         # this should probably be done that way, but for now this will do.
         msg = self.session.msg('shutdown_request', {'restart':restart})
         self._queue_send(msg)
         return msg['header']['msg_id']
 
 
 
 class IOPubChannel(ZMQSocketChannel):
     """The iopub channel which listens for messages that the kernel publishes.
 
     This channel is where all output is published to frontends.
     """
 
     def __init__(self, context, session, address):
         super(IOPubChannel, self).__init__(context, session, address)
         self.ioloop = ioloop.IOLoop()
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self.socket = self.context.socket(zmq.SUB)
         self.socket.setsockopt(zmq.SUBSCRIBE,b'')
         self.socket.setsockopt(zmq.IDENTITY, self.session.bsession)
         self.socket.connect(self.address)
         self.stream = zmqstream.ZMQStream(self.socket, self.ioloop)
         self.stream.on_recv(self._handle_recv)
         self._run_loop()
         try:
             self.socket.close()
         except:
             pass
 
     def stop(self):
         """Stop the channel's event loop and join its thread."""
         self.ioloop.stop()
         super(IOPubChannel, self).stop()
 
     def call_handlers(self, msg):
         """This method is called in the ioloop thread when a message arrives.
 
         Subclasses should override this method to handle incoming messages.
         It is important to remember that this method is called in the thread
         so that some logic must be done to ensure that the application leve
         handlers are called in the application thread.
         """
         raise NotImplementedError('call_handlers must be defined in a subclass.')
 
     def flush(self, timeout=1.0):
         """Immediately processes all pending messages on the iopub channel.
 
         Callers should use this method to ensure that :method:`call_handlers`
         has been called for all messages that have been received on the
         0MQ SUB socket of this channel.
 
         This method is thread safe.
 
         Parameters
         ----------
         timeout : float, optional
             The maximum amount of time to spend flushing, in seconds. The
             default is one second.
         """
         # We do the IOLoop callback process twice to ensure that the IOLoop
         # gets to perform at least one full poll.
         stop_time = time.time() + timeout
         for i in xrange(2):
             self._flushed = False
             self.ioloop.add_callback(self._flush)
             while not self._flushed and time.time() < stop_time:
                 time.sleep(0.01)
 
     def _flush(self):
         """Callback for :method:`self.flush`."""
         self.stream.flush()
         self._flushed = True
 
 
 class StdInChannel(ZMQSocketChannel):
     """The stdin channel to handle raw_input requests that the kernel makes."""
 
     msg_queue = None
 
     def __init__(self, context, session, address):
         super(StdInChannel, self).__init__(context, session, address)
         self.ioloop = ioloop.IOLoop()
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self.socket = self.context.socket(zmq.DEALER)
         self.socket.setsockopt(zmq.IDENTITY, self.session.bsession)
         self.socket.connect(self.address)
         self.stream = zmqstream.ZMQStream(self.socket, self.ioloop)
         self.stream.on_recv(self._handle_recv)
         self._run_loop()
         try:
             self.socket.close()
         except:
             pass
 
     def stop(self):
         """Stop the channel's event loop and join its thread."""
         self.ioloop.stop()
         super(StdInChannel, self).stop()
 
     def call_handlers(self, msg):
         """This method is called in the ioloop thread when a message arrives.
 
         Subclasses should override this method to handle incoming messages.
         It is important to remember that this method is called in the thread
         so that some logic must be done to ensure that the application leve
         handlers are called in the application thread.
         """
         raise NotImplementedError('call_handlers must be defined in a subclass.')
 
     def input(self, string):
         """Send a string of raw input to the kernel."""
         content = dict(value=string)
         msg = self.session.msg('input_reply', content)
         self._queue_send(msg)
 
 
 class HBChannel(ZMQSocketChannel):
     """The heartbeat channel which monitors the kernel heartbeat.
 
     Note that the heartbeat channel is paused by default. As long as you start
     this channel, the kernel manager will ensure that it is paused and un-paused
     as appropriate.
     """
 
     time_to_dead = 3.0
     socket = None
     poller = None
     _running = None
     _pause = None
     _beating = None
 
     def __init__(self, context, session, address):
         super(HBChannel, self).__init__(context, session, address)
         self._running = False
         self._pause =True
         self.poller = zmq.Poller()
 
     def _create_socket(self):
         if self.socket is not None:
             # close previous socket, before opening a new one
             self.poller.unregister(self.socket)
             self.socket.close()
         self.socket = self.context.socket(zmq.REQ)
         self.socket.setsockopt(zmq.LINGER, 0)
         self.socket.connect(self.address)
         
         self.poller.register(self.socket, zmq.POLLIN)
     
     def _poll(self, start_time):
         """poll for heartbeat replies until we reach self.time_to_dead.
         
         Ignores interrupts, and returns the result of poll(), which
         will be an empty list if no messages arrived before the timeout,
         or the event tuple if there is a message to receive.
         """
         
         until_dead = self.time_to_dead - (time.time() - start_time)
         # ensure poll at least once
         until_dead = max(until_dead, 1e-3)
         events = []
         while True:
             try:
                 events = self.poller.poll(1000 * until_dead)
             except ZMQError as e:
                 if e.errno == errno.EINTR:
                     # ignore interrupts during heartbeat
                     # this may never actually happen
                     until_dead = self.time_to_dead - (time.time() - start_time)
                     until_dead = max(until_dead, 1e-3)
                     pass
                 else:
                     raise
             except Exception:
                 if self._exiting:
                     break
                 else:
                     raise
             else:
                 break
         return events
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self._create_socket()
         self._running = True
         self._beating = True
         
         while self._running:
             if self._pause:
                 # just sleep, and skip the rest of the loop
                 time.sleep(self.time_to_dead)
                 continue
             
             since_last_heartbeat = 0.0
             # io.rprint('Ping from HB channel') # dbg
             # no need to catch EFSM here, because the previous event was
             # either a recv or connect, which cannot be followed by EFSM
             self.socket.send(b'ping')
             request_time = time.time()
             ready = self._poll(request_time)
             if ready:
                 self._beating = True
                 # the poll above guarantees we have something to recv
                 self.socket.recv()
                 # sleep the remainder of the cycle
                 remainder = self.time_to_dead - (time.time() - request_time)
                 if remainder > 0:
                     time.sleep(remainder)
                 continue
             else:
                 # nothing was received within the time limit, signal heart failure
                 self._beating = False
                 since_last_heartbeat = time.time() - request_time
                 self.call_handlers(since_last_heartbeat)
                 # and close/reopen the socket, because the REQ/REP cycle has been broken
                 self._create_socket()
                 continue
         try:
             self.socket.close()
         except:
             pass
 
     def pause(self):
         """Pause the heartbeat."""
         self._pause = True
 
     def unpause(self):
         """Unpause the heartbeat."""
         self._pause = False
 
     def is_beating(self):
         """Is the heartbeat running and responsive (and not paused)."""
         if self.is_alive() and not self._pause and self._beating:
             return True
         else:
             return False
 
     def stop(self):
         """Stop the channel's event loop and join its thread."""
         self._running = False
         super(HBChannel, self).stop()
 
     def call_handlers(self, since_last_heartbeat):
         """This method is called in the ioloop thread when a message arrives.
 
         Subclasses should override this method to handle incoming messages.
         It is important to remember that this method is called in the thread
         so that some logic must be done to ensure that the application level
         handlers are called in the application thread.
         """
         raise NotImplementedError('call_handlers must be defined in a subclass.')
 
 
 #-----------------------------------------------------------------------------
 # Main kernel manager class
 #-----------------------------------------------------------------------------
 
 class KernelManager(Configurable):
     """Manages a single kernel on this host along with its channels.
 
     There are four channels associated with each kernel:
 
     * shell: for request/reply calls to the kernel.
     * iopub: for the kernel to publish results to frontends.
     * hb: for monitoring the kernel's heartbeat.
     * stdin: for frontends to reply to raw_input calls in the kernel.
 
     The usage of the channels that this class manages is optional. It is
     entirely possible to connect to the kernels directly using ZeroMQ
     sockets. These channels are useful primarily for talking to a kernel
     whose :class:`KernelManager` is in the same process.
 
     This version manages kernels started using Popen.
     """
     # The PyZMQ Context to use for communication with the kernel.
     context = Instance(zmq.Context)
     def _context_default(self):
         return zmq.Context.instance()
 
     # The Session to use for communication with the kernel.
     session = Instance(Session)
     def _session_default(self):
         return Session(config=self.config)
 
     # The kernel process with which the KernelManager is communicating.
     # generally a Popen instance
     kernel = Any() 
     
     kernel_cmd = List(Unicode, config=True,
         help="""The Popen Command to launch the kernel.
         Override this if you have a custom 
         """
     )
     def _kernel_cmd_changed(self, name, old, new):
         print 'kernel cmd changed', new
         self.ipython_kernel = False
 
     ipython_kernel = Bool(True)
     
 
     # The addresses for the communication channels.
     connection_file = Unicode('')
     
     transport = CaselessStrEnum(['tcp', 'ipc'], default_value='tcp', config=True)
 
     ip = Unicode(LOCALHOST, config=True,
         help="""Set the kernel\'s IP address [default localhost].
         If the IP address is something other than localhost, then
         Consoles on other machines will be able to connect
         to the Kernel, so be careful!"""
     )
     def _ip_default(self):
         if self.transport == 'ipc':
             if self.connection_file:
                 return os.path.splitext(self.connection_file)[0] + '-ipc'
             else:
                 return 'kernel-ipc'
         else:
             return LOCALHOST
     def _ip_changed(self, name, old, new):
         if new == '*':
             self.ip = '0.0.0.0'
     shell_port = Integer(0)
     iopub_port = Integer(0)
     stdin_port = Integer(0)
     hb_port = Integer(0)
 
     # The classes to use for the various channels.
     shell_channel_class = Type(ShellChannel)
     iopub_channel_class = Type(IOPubChannel)
     stdin_channel_class = Type(StdInChannel)
     hb_channel_class = Type(HBChannel)
 
     # Protected traits.
     _launch_args = Any
     _shell_channel = Any
     _iopub_channel = Any
     _stdin_channel = Any
     _hb_channel = Any
     _connection_file_written=Bool(False)
 
     def __del__(self):
         self.cleanup_connection_file()
 
     #--------------------------------------------------------------------------
     # Channel management methods:
     #--------------------------------------------------------------------------
 
     def start_channels(self, shell=True, iopub=True, stdin=True, hb=True):
         """Starts the channels for this kernel.
 
         This will create the channels if they do not exist and then start
         them (their activity runs in a thread). If port numbers of 0 are
         being used (random ports) then you must first call 
         :method:`start_kernel`. If the channels have been stopped and you
         call this, :class:`RuntimeError` will be raised.
         """
         if shell:
             self.shell_channel.start()
         if iopub:
             self.iopub_channel.start()
         if stdin:
             self.stdin_channel.start()
             self.shell_channel.allow_stdin = True
         else:
             self.shell_channel.allow_stdin = False
         if hb:
             self.hb_channel.start()
 
     def stop_channels(self):
         """Stops all the running channels for this kernel.
 
         This stops their event loops and joins their threads.
         """
         if self.shell_channel.is_alive():
             self.shell_channel.stop()
         if self.iopub_channel.is_alive():
             self.iopub_channel.stop()
         if self.stdin_channel.is_alive():
             self.stdin_channel.stop()
         if self.hb_channel.is_alive():
             self.hb_channel.stop()
 
     @property
     def channels_running(self):
         """Are any of the channels created and running?"""
         return (self.shell_channel.is_alive() or self.iopub_channel.is_alive() or
                 self.stdin_channel.is_alive() or self.hb_channel.is_alive())
 
     def _make_url(self, port):
         """Make a zmq url with a port.
 
         There are two cases that this handles:
 
         * tcp: tcp://ip:port
         * ipc: ipc://ip-port
         """
         if self.transport == 'tcp':
             return "tcp://%s:%i" % (self.ip, port)
         else:
             return "%s://%s-%s" % (self.transport, self.ip, port)
 
     @property
     def shell_channel(self):
         """Get the shell channel object for this kernel."""
         if self._shell_channel is None:
             self._shell_channel = self.shell_channel_class(
                 self.context, self.session, self._make_url(self.shell_port)
             )
         return self._shell_channel
 
     @property
     def iopub_channel(self):
         """Get the iopub channel object for this kernel."""
         if self._iopub_channel is None:
             self._iopub_channel = self.iopub_channel_class(
                 self.context, self.session, self._make_url(self.iopub_port)
             )
         return self._iopub_channel
 
     @property
     def stdin_channel(self):
         """Get the stdin channel object for this kernel."""
         if self._stdin_channel is None:
             self._stdin_channel = self.stdin_channel_class(
                 self.context, self.session, self._make_url(self.stdin_port)
             )
         return self._stdin_channel
 
     @property
     def hb_channel(self):
         """Get the hb channel object for this kernel."""
         if self._hb_channel is None:
             self._hb_channel = self.hb_channel_class(
                 self.context, self.session, self._make_url(self.hb_port)
             )
         return self._hb_channel
 
     #--------------------------------------------------------------------------
     # Connection and ipc file management
     #--------------------------------------------------------------------------
     
     def cleanup_connection_file(self):
         """Cleanup connection file *if we wrote it*
         
         Will not raise if the connection file was already removed somehow.
         """
         if self._connection_file_written:
             # cleanup connection files on full shutdown of kernel we started
             self._connection_file_written = False
             try:
                 os.remove(self.connection_file)
             except (IOError, OSError):
                 pass
     
     def cleanup_ipc_files(self):
         """Cleanup ipc files if we wrote them."""
         if self.transport != 'ipc':
             return
         for port in (self.shell_port, self.iopub_port, self.stdin_port, self.hb_port):
             ipcfile = "%s-%i" % (self.ip, port)
             try:
                 os.remove(ipcfile)
             except (IOError, OSError):
                 pass
 
     def load_connection_file(self):
         """Load connection info from JSON dict in self.connection_file."""
         with open(self.connection_file) as f:
             cfg = json.loads(f.read())
 
         from pprint import pprint
         pprint(cfg)
         self.transport = cfg.get('transport', 'tcp')
         self.ip = cfg['ip']
         self.shell_port = cfg['shell_port']
         self.stdin_port = cfg['stdin_port']
         self.iopub_port = cfg['iopub_port']
         self.hb_port = cfg['hb_port']
         self.session.key = str_to_bytes(cfg['key'])
     
     def write_connection_file(self):
         """Write connection info to JSON dict in self.connection_file."""
         if self._connection_file_written:
             return
         self.connection_file,cfg = write_connection_file(self.connection_file,
             transport=self.transport, ip=self.ip, key=self.session.key,
             stdin_port=self.stdin_port, iopub_port=self.iopub_port,
             shell_port=self.shell_port, hb_port=self.hb_port)
         # write_connection_file also sets default ports:
         self.shell_port = cfg['shell_port']
         self.stdin_port = cfg['stdin_port']
         self.iopub_port = cfg['iopub_port']
         self.hb_port = cfg['hb_port']
         
         self._connection_file_written = True
 
     #--------------------------------------------------------------------------
     # Kernel management
     #--------------------------------------------------------------------------
     
     def format_kernel_cmd(self, **kw):
         """format templated args (e.g. {connection_file})"""
         if self.kernel_cmd:
             cmd = self.kernel_cmd
         else:
             cmd = make_ipkernel_cmd(
                 'from IPython.zmq.ipkernel import main; main()',
                 **kw
             )
         ns = dict(connection_file=self.connection_file)
         ns.update(self._launch_args)
         return [ c.format(**ns) for c in cmd ]
     
     def _launch_kernel(self, kernel_cmd, **kw):
         """actually launch the kernel
         
         override in a subclass to launch kernel subprocesses differently
         """
         return launch_kernel(kernel_cmd, **kw)
     
     def start_kernel(self, **kw):
         """Starts a kernel on this host in a separate process.
 
         If random ports (port=0) are being used, this method must be called
         before the channels are created.
 
         Parameters:
         -----------
-        launcher : callable, optional (default None)
-             A custom function for launching the kernel process (generally a
-             wrapper around ``entry_point.base_launch_kernel``). In most cases,
-             it should not be necessary to use this parameter.
-
         **kw : optional
-             keyword arguments that are passed down into the launcher
-             callable.
+             keyword arguments that are passed down to build the kernel_cmd
+             and launching the kernel (e.g. Popen kwargs).
         """
         if self.transport == 'tcp' and self.ip not in LOCAL_IPS:
             raise RuntimeError("Can only launch a kernel on a local interface. "
                                "Make sure that the '*_address' attributes are "
                                "configured properly. "
                                "Currently valid addresses are: %s"%LOCAL_IPS
                                )
         
         # write connection file / get default ports
         self.write_connection_file()
 
         # save kwargs for use in restart
         self._launch_args = kw.copy()
         # build the Popen cmd
         kernel_cmd = self.format_kernel_cmd(**kw)
         # launch the kernel subprocess
         self.kernel = self._launch_kernel(kernel_cmd,
                                     ipython_kernel=self.ipython_kernel,
                                     **kw)
 
     def shutdown_kernel(self, now=False, restart=False):
         """Attempts to the stop the kernel process cleanly. 
 
         This attempts to shutdown the kernels cleanly by:
 
         1. Sending it a shutdown message over the shell channel.
         2. If that fails, the kernel is shutdown forcibly by sending it
            a signal.
 
         Parameters:
         -----------
         now : bool
             Should the kernel be forcible killed *now*. This skips the
             first, nice shutdown attempt.
         restart: bool
             Will this kernel be restarted after it is shutdown. When this
             is True, connection files will not be cleaned up.
         """
         # FIXME: Shutdown does not work on Windows due to ZMQ errors!
         if sys.platform == 'win32':
             self._kill_kernel()
             return
 
         # Pause the heart beat channel if it exists.
         if self._hb_channel is not None:
             self._hb_channel.pause()
 
         if now:
             if self.has_kernel:
                 self._kill_kernel()
         else:
             # Don't send any additional kernel kill messages immediately, to give
             # the kernel a chance to properly execute shutdown actions. Wait for at
             # most 1s, checking every 0.1s.
             self.shell_channel.shutdown(restart=restart)
             for i in range(10):
                 if self.is_alive:
                     time.sleep(0.1)
                 else:
                     break
             else:
                 # OK, we've waited long enough.
                 if self.has_kernel:
                     self._kill_kernel()
 
         if not restart:
             self.cleanup_connection_file()
             self.cleanup_ipc_files()
         else:
             self.cleanup_ipc_files()
 
     def restart_kernel(self, now=False, **kw):
         """Restarts a kernel with the arguments that were used to launch it.
 
         If the old kernel was launched with random ports, the same ports will be
         used for the new kernel. The same connection file is used again.
 
         Parameters
         ----------
         now : bool, optional
             If True, the kernel is forcefully restarted *immediately*, without
             having a chance to do any cleanup action.  Otherwise the kernel is
             given 1s to clean up before a forceful restart is issued.
 
             In all cases the kernel is restarted, the only difference is whether
             it is given a chance to perform a clean shutdown or not.
 
         **kw : optional
             Any options specified here will overwrite those used to launch the
             kernel.
         """
         if self._launch_args is None:
             raise RuntimeError("Cannot restart the kernel. "
                                "No previous call to 'start_kernel'.")
         else:
             # Stop currently running kernel.
             self.shutdown_kernel(now=now, restart=True)
 
             # Start new kernel.
             self._launch_args.update(kw)
             self.start_kernel(**self._launch_args)
 
             # FIXME: Messages get dropped in Windows due to probable ZMQ bug
             # unless there is some delay here.
             if sys.platform == 'win32':
                 time.sleep(0.2)
 
     @property
     def has_kernel(self):
         """Has a kernel been started that we are managing."""
         return self.kernel is not None
 
     def _kill_kernel(self):
         """Kill the running kernel.
 
         This is a private method, callers should use shutdown_kernel(now=True).
         """
         if self.has_kernel:
             # Pause the heart beat channel if it exists.
             if self._hb_channel is not None:
                 self._hb_channel.pause()
 
             # Signal the kernel to terminate (sends SIGKILL on Unix and calls
             # TerminateProcess() on Win32).
             try:
                 self.kernel.kill()
             except OSError as e:
                 # In Windows, we will get an Access Denied error if the process
                 # has already terminated. Ignore it.
                 if sys.platform == 'win32':
                     if e.winerror != 5:
                         raise
                 # On Unix, we may get an ESRCH error if the process has already
                 # terminated. Ignore it.
                 else:
                     from errno import ESRCH
                     if e.errno != ESRCH:
                         raise
 
             # Block until the kernel terminates.
             self.kernel.wait()
             self.kernel = None
         else:
             raise RuntimeError("Cannot kill kernel. No kernel is running!")
 
     def interrupt_kernel(self):
         """Interrupts the kernel by sending it a signal.
 
         Unlike ``signal_kernel``, this operation is well supported on all
         platforms.
         """
         if self.has_kernel:
             if sys.platform == 'win32':
                 from parentpoller import ParentPollerWindows as Poller
                 Poller.send_interrupt(self.kernel.win32_interrupt_event)
             else:
                 self.kernel.send_signal(signal.SIGINT)
         else:
             raise RuntimeError("Cannot interrupt kernel. No kernel is running!")
 
     def signal_kernel(self, signum):
         """Sends a signal to the kernel.
 
         Note that since only SIGTERM is supported on Windows, this function is
         only useful on Unix systems.
         """
         if self.has_kernel:
             self.kernel.send_signal(signum)
         else:
             raise RuntimeError("Cannot signal kernel. No kernel is running!")
 
     @property
     def is_alive(self):
         """Is the kernel process still running?"""
         if self.has_kernel:
             if self.kernel.poll() is None:
                 return True
             else:
                 return False
         elif self._hb_channel is not None:
             # We didn't start the kernel with this KernelManager so we
             # use the heartbeat.
             return self._hb_channel.is_beating()
         else:
             # no heartbeat and not local, we can't tell if it's running,
             # so naively return True
             return True
 
 
 #-----------------------------------------------------------------------------
 # ABC Registration
 #-----------------------------------------------------------------------------
 
 ShellChannelABC.register(ShellChannel)
 IOPubChannelABC.register(IOPubChannel)
 HBChannelABC.register(HBChannel)
 StdInChannelABC.register(StdInChannel)
 KernelManagerABC.register(KernelManager)