|
|
"""Utilities for launching kernels
|
|
|
|
|
|
Authors:
|
|
|
|
|
|
* Min Ragan-Kelley
|
|
|
|
|
|
"""
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# 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 os
|
|
|
import sys
|
|
|
from subprocess import Popen, PIPE
|
|
|
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# 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.kernel.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
|
|
|
|
|
|
__all__ = [
|
|
|
'swallow_argv',
|
|
|
'make_ipkernel_cmd',
|
|
|
'launch_kernel',
|
|
|
]
|
