Start threads for %%script as daemon thread

IPython/core/magics/script.py

@@ -1,276 +1,276 b''
 """Magic functions for running cells in various scripts."""
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2012 The IPython Development Team.
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Stdlib
 import os
 import re
 import sys
 import signal
 import time
 from subprocess import Popen, PIPE
 
 # Our own packages
 from IPython.config.configurable import Configurable
 from IPython.core import magic_arguments
 from IPython.core.error import UsageError
 from IPython.core.magic import  (
     Magics, magics_class, line_magic, cell_magic
 )
 from IPython.lib.backgroundjobs import BackgroundJobManager
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils import py3compat
 from IPython.utils.process import find_cmd, FindCmdError, arg_split
 from IPython.utils.traitlets import List, Dict
 
 #-----------------------------------------------------------------------------
 # 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, Configurable):
     """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(config=True,
         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
         """,
     )
     def _script_magics_default(self):
         """default to a common list of programs if we find them"""
         
         defaults = []
         to_try = []
         if os.name == 'nt':
             defaults.append('cmd')
             to_try.append('powershell')
         to_try.extend([
             'sh',
             'bash',
             'perl',
             'ruby',
             'python3',
             'pypy',
         ])
         
         for cmd in to_try:
             if cmd in self.script_paths:
                 defaults.append(cmd)
             else:
                 try:
                     find_cmd(cmd)
                 except FindCmdError:
                     # command not found, ignore it
                     pass
                 except ImportError:
                     # Windows without pywin32, find_cmd doesn't work
                     pass
                 else:
                     defaults.append(cmd)
         return defaults
     
     script_paths = Dict(config=True,
         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.
         """
     )
     
     def __init__(self, shell=None):
         Configurable.__init__(self, config=shell.config)
         self._generate_script_magics()
         Magics.__init__(self, shell=shell)
         self.job_manager = BackgroundJobManager()
         self.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)
 
         p = Popen(cmd, stdout=PIPE, stderr=PIPE, stdin=PIPE)
         
         cell = cell.encode('utf8', 'replace')
         if args.bg:
             self.bg_processes.append(p)
             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)
+            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 kill_bg_processes(self, dummy=None):
         """Kill all BG processes which are still running."""
         for p in self.bg_processes:
             if p.poll() is None:
                 try:
                     p.send_signal(signal.SIGINT)
                 except:
                     pass
         time.sleep(0.1)
         for p in self.bg_processes:
             if p.poll() is None:
                 try:
                     p.terminate()
                 except:
                     pass
         time.sleep(0.1)
         for p in self.bg_processes:
             if p.poll() is None:
                 try:
                     p.kill()
                 except:
                     pass

IPython/lib/backgroundjobs.py

@@ -1,480 +1,484 b''
 # -*- coding: utf-8 -*-
 """Manage background (threaded) jobs conveniently from an interactive shell.
 
 This module provides a BackgroundJobManager class.  This is the main class
 meant for public usage, it implements an object which can create and manage
 new background jobs.
 
 It also provides the actual job classes managed by these BackgroundJobManager
 objects, see their docstrings below.
 
 
 This system was inspired by discussions with B. Granger and the
 BackgroundCommand class described in the book Python Scripting for
 Computational Science, by H. P. Langtangen:
 
 http://folk.uio.no/hpl/scripting
 
 (although ultimately no code from this text was used, as IPython's system is a
 separate implementation).
 
 An example notebook is provided in our documentation illustrating interactive
 use of the system.
 """
 
 #*****************************************************************************
 #       Copyright (C) 2005-2006 Fernando Perez <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #*****************************************************************************
 
 # Code begins
 import sys
 import threading
 
 from IPython.core.ultratb import AutoFormattedTB
 from IPython.utils.warn import warn, error
 
 
 class BackgroundJobManager(object):
     """Class to manage a pool of backgrounded threaded jobs.
 
     Below, we assume that 'jobs' is a BackgroundJobManager instance.
     
     Usage summary (see the method docstrings for details):
 
       jobs.new(...) -> start a new job
       
       jobs() or jobs.status() -> print status summary of all jobs
 
       jobs[N] -> returns job number N.
 
       foo = jobs[N].result -> assign to variable foo the result of job N
 
       jobs[N].traceback() -> print the traceback of dead job N
 
       jobs.remove(N) -> remove (finished) job N
 
       jobs.flush() -> remove all finished jobs
       
     As a convenience feature, BackgroundJobManager instances provide the
     utility result and traceback methods which retrieve the corresponding
     information from the jobs list:
 
       jobs.result(N) <--> jobs[N].result
       jobs.traceback(N) <--> jobs[N].traceback()
 
     While this appears minor, it allows you to use tab completion
     interactively on the job manager instance.
     """
 
     def __init__(self):
         # Lists for job management, accessed via a property to ensure they're
         # up to date.x
         self._running  = []
         self._completed = []
         self._dead = []
         # A dict of all jobs, so users can easily access any of them
         self.all = {}
         # For reporting
         self._comp_report = []
         self._dead_report = []
         # Store status codes locally for fast lookups
         self._s_created   = BackgroundJobBase.stat_created_c
         self._s_running   = BackgroundJobBase.stat_running_c
         self._s_completed = BackgroundJobBase.stat_completed_c
         self._s_dead      = BackgroundJobBase.stat_dead_c
 
     @property
     def running(self):
         self._update_status()
         return self._running
 
     @property
     def dead(self):
         self._update_status()
         return self._dead
 
     @property
     def completed(self):
         self._update_status()
         return self._completed
 
     def new(self, func_or_exp, *args, **kwargs):
         """Add a new background job and start it in a separate thread.
 
         There are two types of jobs which can be created:
 
         1. Jobs based on expressions which can be passed to an eval() call.
         The expression must be given as a string.  For example:
 
           job_manager.new('myfunc(x,y,z=1)'[,glob[,loc]])
 
         The given expression is passed to eval(), along with the optional
         global/local dicts provided.  If no dicts are given, they are
         extracted automatically from the caller's frame.
         
         A Python statement is NOT a valid eval() expression.  Basically, you
         can only use as an eval() argument something which can go on the right
         of an '=' sign and be assigned to a variable.
 
         For example,"print 'hello'" is not valid, but '2+3' is.
 
         2. Jobs given a function object, optionally passing additional
         positional arguments:
 
           job_manager.new(myfunc, x, y)
 
         The function is called with the given arguments.
 
         If you need to pass keyword arguments to your function, you must
         supply them as a dict named kw:
 
           job_manager.new(myfunc, x, y, kw=dict(z=1))
 
         The reason for this assymmetry is that the new() method needs to
         maintain access to its own keywords, and this prevents name collisions
         between arguments to new() and arguments to your own functions.
 
         In both cases, the result is stored in the job.result field of the
         background job object.
 
+        You can set `daemon` attribute of the thread by giving the keyword
+        argument `daemon`.
 
         Notes and caveats:
 
         1. All threads running share the same standard output.  Thus, if your
         background jobs generate output, it will come out on top of whatever
         you are currently writing.  For this reason, background jobs are best
         used with silent functions which simply return their output.
 
         2. Threads also all work within the same global namespace, and this
         system does not lock interactive variables.  So if you send job to the
         background which operates on a mutable object for a long time, and
         start modifying that same mutable object interactively (or in another
         backgrounded job), all sorts of bizarre behaviour will occur.
 
         3. If a background job is spending a lot of time inside a C extension
         module which does not release the Python Global Interpreter Lock
         (GIL), this will block the IPython prompt.  This is simply because the
         Python interpreter can only switch between threads at Python
         bytecodes.  While the execution is inside C code, the interpreter must
         simply wait unless the extension module releases the GIL.
 
         4. There is no way, due to limitations in the Python threads library,
         to kill a thread once it has started."""
         
         if callable(func_or_exp):
             kw  = kwargs.get('kw',{})
             job = BackgroundJobFunc(func_or_exp,*args,**kw)
         elif isinstance(func_or_exp, basestring):
             if not args:
                 frame = sys._getframe(1)
                 glob, loc = frame.f_globals, frame.f_locals
             elif len(args)==1:
                 glob = loc = args[0]
             elif len(args)==2:
                 glob,loc = args
             else:
                 raise ValueError(
                       'Expression jobs take at most 2 args (globals,locals)')
             job = BackgroundJobExpr(func_or_exp, glob, loc)
         else:
             raise TypeError('invalid args for new job')
-        
+
+        if kwargs.get('daemon', False):
+            job.daemon = True
         job.num = len(self.all)+1 if self.all else 0
         self.running.append(job)
         self.all[job.num] = job
         print 'Starting job # %s in a separate thread.' % job.num
         job.start()
         return job
 
     def __getitem__(self, job_key):
         num = job_key if isinstance(job_key, int) else job_key.num
         return self.all[num]
 
     def __call__(self):
         """An alias to self.status(),
 
         This allows you to simply call a job manager instance much like the
         Unix `jobs` shell command."""
 
         return self.status()
 
     def _update_status(self):
         """Update the status of the job lists.
 
         This method moves finished jobs to one of two lists:
           - self.completed: jobs which completed successfully
           - self.dead: jobs which finished but died.
 
         It also copies those jobs to corresponding _report lists.  These lists
         are used to report jobs completed/dead since the last update, and are
         then cleared by the reporting function after each call."""
 
         # Status codes
         srun, scomp, sdead = self._s_running, self._s_completed, self._s_dead
         # State lists, use the actual lists b/c the public names are properties
         # that call this very function on access
         running, completed, dead = self._running, self._completed, self._dead
 
         # Now, update all state lists
         for num, job in enumerate(running):
             stat = job.stat_code
             if stat == srun:
                 continue
             elif stat == scomp:
                 completed.append(job)
                 self._comp_report.append(job)
                 running[num] = False
             elif stat == sdead:
                 dead.append(job)
                 self._dead_report.append(job)
                 running[num] = False
         # Remove dead/completed jobs from running list
         running[:] = filter(None, running)
 
     def _group_report(self,group,name):
         """Report summary for a given job group.
 
         Return True if the group had any elements."""
 
         if group:
             print '%s jobs:' % name
             for job in group:
                 print '%s : %s' % (job.num,job)
             print
             return True
 
     def _group_flush(self,group,name):
         """Flush a given job group
 
         Return True if the group had any elements."""
 
         njobs = len(group)
         if njobs:
             plural = {1:''}.setdefault(njobs,'s')
             print 'Flushing %s %s job%s.' % (njobs,name,plural)
             group[:] = []
             return True
         
     def _status_new(self):
         """Print the status of newly finished jobs.
 
         Return True if any new jobs are reported.
 
         This call resets its own state every time, so it only reports jobs
         which have finished since the last time it was called."""
 
         self._update_status()
         new_comp = self._group_report(self._comp_report, 'Completed')
         new_dead = self._group_report(self._dead_report,
                                       'Dead, call jobs.traceback() for details')
         self._comp_report[:] = []
         self._dead_report[:] = []
         return new_comp or new_dead
                 
     def status(self,verbose=0):
         """Print a status of all jobs currently being managed."""
 
         self._update_status()
         self._group_report(self.running,'Running')
         self._group_report(self.completed,'Completed')
         self._group_report(self.dead,'Dead')
         # Also flush the report queues
         self._comp_report[:] = []
         self._dead_report[:] = []
 
     def remove(self,num):
         """Remove a finished (completed or dead) job."""
 
         try:
             job = self.all[num]
         except KeyError:
             error('Job #%s not found' % num)
         else:
             stat_code = job.stat_code
             if stat_code == self._s_running:
                 error('Job #%s is still running, it can not be removed.' % num)
                 return
             elif stat_code == self._s_completed:
                 self.completed.remove(job)
             elif stat_code == self._s_dead:
                 self.dead.remove(job)
 
     def flush(self):
         """Flush all finished jobs (completed and dead) from lists.
 
         Running jobs are never flushed.
 
         It first calls _status_new(), to update info. If any jobs have
         completed since the last _status_new() call, the flush operation
         aborts."""
 
         # Remove the finished jobs from the master dict
         alljobs = self.all
         for job in self.completed+self.dead:
             del(alljobs[job.num])
 
         # Now flush these lists completely
         fl_comp = self._group_flush(self.completed, 'Completed')
         fl_dead = self._group_flush(self.dead, 'Dead')
         if not (fl_comp or fl_dead):
             print 'No jobs to flush.'
 
     def result(self,num):
         """result(N) -> return the result of job N."""
         try:
             return self.all[num].result
         except KeyError:
             error('Job #%s not found' % num)
 
     def _traceback(self, job):
         num = job if isinstance(job, int) else job.num
         try:
             self.all[num].traceback()
         except KeyError:
             error('Job #%s not found' % num)
 
     def traceback(self, job=None):
         if job is None:
             self._update_status()
             for deadjob in self.dead:
                 print "Traceback for: %r" % deadjob
                 self._traceback(deadjob)
                 print
         else:
             self._traceback(job)
 
 
 class BackgroundJobBase(threading.Thread):
     """Base class to build BackgroundJob classes.
 
     The derived classes must implement:
 
     - Their own __init__, since the one here raises NotImplementedError.  The
     derived constructor must call self._init() at the end, to provide common
     initialization.
 
     - A strform attribute used in calls to __str__.
 
     - A call() method, which will make the actual execution call and must
     return a value to be held in the 'result' field of the job object."""
 
     # Class constants for status, in string and as numerical codes (when
     # updating jobs lists, we don't want to do string comparisons).  This will
     # be done at every user prompt, so it has to be as fast as possible
     stat_created   = 'Created'; stat_created_c = 0
     stat_running   = 'Running'; stat_running_c = 1
     stat_completed = 'Completed'; stat_completed_c = 2
     stat_dead      = 'Dead (Exception), call jobs.traceback() for details'
     stat_dead_c = -1
 
     def __init__(self):
         raise NotImplementedError, \
               "This class can not be instantiated directly."
 
     def _init(self):
         """Common initialization for all BackgroundJob objects"""
         
         for attr in ['call','strform']:
             assert hasattr(self,attr), "Missing attribute <%s>" % attr
         
         # The num tag can be set by an external job manager
         self.num = None
       
         self.status    = BackgroundJobBase.stat_created
         self.stat_code = BackgroundJobBase.stat_created_c
         self.finished  = False
         self.result    = '<BackgroundJob has not completed>'
         
         # reuse the ipython traceback handler if we can get to it, otherwise
         # make a new one
         try:
             make_tb = get_ipython().InteractiveTB.text
         except:
             make_tb = AutoFormattedTB(mode = 'Context',
                                       color_scheme='NoColor',
                                       tb_offset = 1).text
         # Note that the actual API for text() requires the three args to be
         # passed in, so we wrap it in a simple lambda.
         self._make_tb = lambda : make_tb(None, None, None)
 
         # Hold a formatted traceback if one is generated.
         self._tb = None
         
         threading.Thread.__init__(self)
 
     def __str__(self):
         return self.strform
 
     def __repr__(self):
         return '<BackgroundJob #%d: %s>' % (self.num, self.strform)
 
     def traceback(self):
         print self._tb
         
     def run(self):
         try:
             self.status    = BackgroundJobBase.stat_running
             self.stat_code = BackgroundJobBase.stat_running_c
             self.result    = self.call()
         except:
             self.status    = BackgroundJobBase.stat_dead
             self.stat_code = BackgroundJobBase.stat_dead_c
             self.finished  = None
             self.result    = ('<BackgroundJob died, call jobs.traceback() for details>')
             self._tb       = self._make_tb()
         else:
             self.status    = BackgroundJobBase.stat_completed
             self.stat_code = BackgroundJobBase.stat_completed_c
             self.finished  = True
 
 
 class BackgroundJobExpr(BackgroundJobBase):
     """Evaluate an expression as a background job (uses a separate thread)."""
 
     def __init__(self, expression, glob=None, loc=None):
         """Create a new job from a string which can be fed to eval().
 
         global/locals dicts can be provided, which will be passed to the eval
         call."""
 
         # fail immediately if the given expression can't be compiled
         self.code = compile(expression,'<BackgroundJob compilation>','eval')
                 
         glob = {} if glob is None else glob
         loc = {} if loc is None else loc
         self.expression = self.strform = expression
         self.glob = glob
         self.loc = loc
         self._init()
         
     def call(self):
         return eval(self.code,self.glob,self.loc)
 
 
 class BackgroundJobFunc(BackgroundJobBase):
     """Run a function call as a background job (uses a separate thread)."""
 
     def __init__(self, func, *args, **kwargs):
         """Create a new job from a callable object.
 
         Any positional arguments and keyword args given to this constructor
         after the initial callable are passed directly to it."""
 
         if not callable(func):
             raise TypeError(
                 'first argument to BackgroundJobFunc must be callable')
         
         self.func = func
         self.args = args
         self.kwargs = kwargs
         # The string form will only include the function passed, because
         # generating string representations of the arguments is a potentially
         # _very_ expensive operation (e.g. with large arrays).
         self.strform = str(func)
         self._init()
 
     def call(self):
         return self.func(*self.args, **self.kwargs)