##// END OF EJS Templates
Speed up shutdown by eliminating unnecessary sleeping...
Speed up shutdown by eliminating unnecessary sleeping Eliminate an annoying split-second pause when closing a shell session by reducing unnecessary sleeps while killing background scripts. If there are no bacgkround scripts running, or if they shut down on the first or second attempt, then we can eliminate some pauses.

File last commit:

r23508:a75cb90d
r23508:a75cb90d
Show More
script.py
279 lines | 8.6 KiB | text/x-python | PythonLexer
"""Magic functions for running cells in various scripts."""
# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
import errno
import os
import sys
import signal
import time
from subprocess import Popen, PIPE
import atexit
from IPython.core import magic_arguments
from IPython.core.magic import (
Magics, magics_class, line_magic, cell_magic
)
from IPython.lib.backgroundjobs import BackgroundJobManager
from IPython.utils import py3compat
from IPython.utils.process import arg_split
from traitlets import List, Dict, default
#-----------------------------------------------------------------------------
# Magic implementation classes
#-----------------------------------------------------------------------------
def script_args(f):
"""single decorator for adding script args"""
args = [
magic_arguments.argument(
'--out', type=str,
help="""The variable in which to store stdout from the script.
If the script is backgrounded, this will be the stdout *pipe*,
instead of the stderr text itself.
"""
),
magic_arguments.argument(
'--err', type=str,
help="""The variable in which to store stderr from the script.
If the script is backgrounded, this will be the stderr *pipe*,
instead of the stderr text itself.
"""
),
magic_arguments.argument(
'--bg', action="store_true",
help="""Whether to run the script in the background.
If given, the only way to see the output of the command is
with --out/err.
"""
),
magic_arguments.argument(
'--proc', type=str,
help="""The variable in which to store Popen instance.
This is used only when --bg option is given.
"""
),
]
for arg in args:
f = arg(f)
return f
@magics_class
class ScriptMagics(Magics):
"""Magics for talking to scripts
This defines a base `%%script` cell magic for running a cell
with a program in a subprocess, and registers a few top-level
magics that call %%script with common interpreters.
"""
script_magics = List(
help="""Extra script cell magics to define
This generates simple wrappers of `%%script foo` as `%%foo`.
If you want to add script magics that aren't on your path,
specify them in script_paths
""",
).tag(config=True)
@default('script_magics')
def _script_magics_default(self):
"""default to a common list of programs"""
defaults = [
'sh',
'bash',
'perl',
'ruby',
'python',
'python2',
'python3',
'pypy',
]
if os.name == 'nt':
defaults.extend([
'cmd',
])
return defaults
script_paths = Dict(
help="""Dict mapping short 'ruby' names to full paths, such as '/opt/secret/bin/ruby'
Only necessary for items in script_magics where the default path will not
find the right interpreter.
"""
).tag(config=True)
def __init__(self, shell=None):
super(ScriptMagics, self).__init__(shell=shell)
self._generate_script_magics()
self.job_manager = BackgroundJobManager()
self.bg_processes = []
atexit.register(self.kill_bg_processes)
def __del__(self):
self.kill_bg_processes()
def _generate_script_magics(self):
cell_magics = self.magics['cell']
for name in self.script_magics:
cell_magics[name] = self._make_script_magic(name)
def _make_script_magic(self, name):
"""make a named magic, that calls %%script with a particular program"""
# expand to explicit path if necessary:
script = self.script_paths.get(name, name)
@magic_arguments.magic_arguments()
@script_args
def named_script_magic(line, cell):
# if line, add it as cl-flags
if line:
line = "%s %s" % (script, line)
else:
line = script
return self.shebang(line, cell)
# write a basic docstring:
named_script_magic.__doc__ = \
"""%%{name} script magic
Run cells with {script} in a subprocess.
This is a shortcut for `%%script {script}`
""".format(**locals())
return named_script_magic
@magic_arguments.magic_arguments()
@script_args
@cell_magic("script")
def shebang(self, line, cell):
"""Run a cell via a shell command
The `%%script` line is like the #! line of script,
specifying a program (bash, perl, ruby, etc.) with which to run.
The rest of the cell is run by that program.
Examples
--------
::
In [1]: %%script bash
...: for i in 1 2 3; do
...: echo $i
...: done
1
2
3
"""
argv = arg_split(line, posix = not sys.platform.startswith('win'))
args, cmd = self.shebang.parser.parse_known_args(argv)
try:
p = Popen(cmd, stdout=PIPE, stderr=PIPE, stdin=PIPE)
except OSError as e:
if e.errno == errno.ENOENT:
print("Couldn't find program: %r" % cmd[0])
return
else:
raise
if not cell.endswith('\n'):
cell += '\n'
cell = cell.encode('utf8', 'replace')
if args.bg:
self.bg_processes.append(p)
self._gc_bg_processes()
if args.out:
self.shell.user_ns[args.out] = p.stdout
if args.err:
self.shell.user_ns[args.err] = p.stderr
self.job_manager.new(self._run_script, p, cell, daemon=True)
if args.proc:
self.shell.user_ns[args.proc] = p
return
try:
out, err = p.communicate(cell)
except KeyboardInterrupt:
try:
p.send_signal(signal.SIGINT)
time.sleep(0.1)
if p.poll() is not None:
print("Process is interrupted.")
return
p.terminate()
time.sleep(0.1)
if p.poll() is not None:
print("Process is terminated.")
return
p.kill()
print("Process is killed.")
except OSError:
pass
except Exception as e:
print("Error while terminating subprocess (pid=%i): %s" \
% (p.pid, e))
return
out = py3compat.bytes_to_str(out)
err = py3compat.bytes_to_str(err)
if args.out:
self.shell.user_ns[args.out] = out
else:
sys.stdout.write(out)
sys.stdout.flush()
if args.err:
self.shell.user_ns[args.err] = err
else:
sys.stderr.write(err)
sys.stderr.flush()
def _run_script(self, p, cell):
"""callback for running the script in the background"""
p.stdin.write(cell)
p.stdin.close()
p.wait()
@line_magic("killbgscripts")
def killbgscripts(self, _nouse_=''):
"""Kill all BG processes started by %%script and its family."""
self.kill_bg_processes()
print("All background processes were killed.")
def kill_bg_processes(self):
"""Kill all BG processes which are still running."""
if not self.bg_processes:
return
for p in self.bg_processes:
if p.poll() is None:
try:
p.send_signal(signal.SIGINT)
except:
pass
time.sleep(0.1)
self._gc_bg_processes()
if not self.bg_processes:
return
for p in self.bg_processes:
if p.poll() is None:
try:
p.terminate()
except:
pass
time.sleep(0.1)
self._gc_bg_processes()
if not self.bg_processes:
return
for p in self.bg_processes:
if p.poll() is None:
try:
p.kill()
except:
pass
self._gc_bg_processes()
def _gc_bg_processes(self):
self.bg_processes = [p for p in self.bg_processes if p.poll() is None]