375 lines
10 KiB
Python
375 lines
10 KiB
Python
#
|
|
# Module providing various facilities to other parts of the package
|
|
#
|
|
# multiprocessing/util.py
|
|
#
|
|
# Copyright (c) 2006-2008, R Oudkerk
|
|
# Licensed to PSF under a Contributor Agreement.
|
|
#
|
|
|
|
import os
|
|
import itertools
|
|
import weakref
|
|
import atexit
|
|
import threading # we want threading to install it's
|
|
# cleanup function before multiprocessing does
|
|
from subprocess import _args_from_interpreter_flags
|
|
|
|
from . import process
|
|
|
|
__all__ = [
|
|
'sub_debug', 'debug', 'info', 'sub_warning', 'get_logger',
|
|
'log_to_stderr', 'get_temp_dir', 'register_after_fork',
|
|
'is_exiting', 'Finalize', 'ForkAwareThreadLock', 'ForkAwareLocal',
|
|
'close_all_fds_except', 'SUBDEBUG', 'SUBWARNING',
|
|
]
|
|
|
|
#
|
|
# Logging
|
|
#
|
|
|
|
NOTSET = 0
|
|
SUBDEBUG = 5
|
|
DEBUG = 10
|
|
INFO = 20
|
|
SUBWARNING = 25
|
|
|
|
LOGGER_NAME = 'multiprocessing'
|
|
DEFAULT_LOGGING_FORMAT = '[%(levelname)s/%(processName)s] %(message)s'
|
|
|
|
_logger = None
|
|
_log_to_stderr = False
|
|
|
|
def sub_debug(msg, *args):
|
|
if _logger:
|
|
_logger.log(SUBDEBUG, msg, *args)
|
|
|
|
def debug(msg, *args):
|
|
if _logger:
|
|
_logger.log(DEBUG, msg, *args)
|
|
|
|
def info(msg, *args):
|
|
if _logger:
|
|
_logger.log(INFO, msg, *args)
|
|
|
|
def sub_warning(msg, *args):
|
|
if _logger:
|
|
_logger.log(SUBWARNING, msg, *args)
|
|
|
|
def get_logger():
|
|
'''
|
|
Returns logger used by multiprocessing
|
|
'''
|
|
global _logger
|
|
import logging
|
|
|
|
logging._acquireLock()
|
|
try:
|
|
if not _logger:
|
|
|
|
_logger = logging.getLogger(LOGGER_NAME)
|
|
_logger.propagate = 0
|
|
|
|
# XXX multiprocessing should cleanup before logging
|
|
if hasattr(atexit, 'unregister'):
|
|
atexit.unregister(_exit_function)
|
|
atexit.register(_exit_function)
|
|
else:
|
|
atexit._exithandlers.remove((_exit_function, (), {}))
|
|
atexit._exithandlers.append((_exit_function, (), {}))
|
|
|
|
finally:
|
|
logging._releaseLock()
|
|
|
|
return _logger
|
|
|
|
def log_to_stderr(level=None):
|
|
'''
|
|
Turn on logging and add a handler which prints to stderr
|
|
'''
|
|
global _log_to_stderr
|
|
import logging
|
|
|
|
logger = get_logger()
|
|
formatter = logging.Formatter(DEFAULT_LOGGING_FORMAT)
|
|
handler = logging.StreamHandler()
|
|
handler.setFormatter(formatter)
|
|
logger.addHandler(handler)
|
|
|
|
if level:
|
|
logger.setLevel(level)
|
|
_log_to_stderr = True
|
|
return _logger
|
|
|
|
#
|
|
# Function returning a temp directory which will be removed on exit
|
|
#
|
|
|
|
def get_temp_dir():
|
|
# get name of a temp directory which will be automatically cleaned up
|
|
tempdir = process.current_process()._config.get('tempdir')
|
|
if tempdir is None:
|
|
import shutil, tempfile
|
|
tempdir = tempfile.mkdtemp(prefix='pymp-')
|
|
info('created temp directory %s', tempdir)
|
|
Finalize(None, shutil.rmtree, args=[tempdir], exitpriority=-100)
|
|
process.current_process()._config['tempdir'] = tempdir
|
|
return tempdir
|
|
|
|
#
|
|
# Support for reinitialization of objects when bootstrapping a child process
|
|
#
|
|
|
|
_afterfork_registry = weakref.WeakValueDictionary()
|
|
_afterfork_counter = itertools.count()
|
|
|
|
def _run_after_forkers():
|
|
items = list(_afterfork_registry.items())
|
|
items.sort()
|
|
for (index, ident, func), obj in items:
|
|
try:
|
|
func(obj)
|
|
except Exception as e:
|
|
info('after forker raised exception %s', e)
|
|
|
|
def register_after_fork(obj, func):
|
|
_afterfork_registry[(next(_afterfork_counter), id(obj), func)] = obj
|
|
|
|
#
|
|
# Finalization using weakrefs
|
|
#
|
|
|
|
_finalizer_registry = {}
|
|
_finalizer_counter = itertools.count()
|
|
|
|
|
|
class Finalize(object):
|
|
'''
|
|
Class which supports object finalization using weakrefs
|
|
'''
|
|
def __init__(self, obj, callback, args=(), kwargs=None, exitpriority=None):
|
|
assert exitpriority is None or type(exitpriority) is int
|
|
|
|
if obj is not None:
|
|
self._weakref = weakref.ref(obj, self)
|
|
else:
|
|
assert exitpriority is not None
|
|
|
|
self._callback = callback
|
|
self._args = args
|
|
self._kwargs = kwargs or {}
|
|
self._key = (exitpriority, next(_finalizer_counter))
|
|
self._pid = os.getpid()
|
|
|
|
_finalizer_registry[self._key] = self
|
|
|
|
def __call__(self, wr=None,
|
|
# Need to bind these locally because the globals can have
|
|
# been cleared at shutdown
|
|
_finalizer_registry=_finalizer_registry,
|
|
sub_debug=sub_debug, getpid=os.getpid):
|
|
'''
|
|
Run the callback unless it has already been called or cancelled
|
|
'''
|
|
try:
|
|
del _finalizer_registry[self._key]
|
|
except KeyError:
|
|
sub_debug('finalizer no longer registered')
|
|
else:
|
|
if self._pid != getpid():
|
|
sub_debug('finalizer ignored because different process')
|
|
res = None
|
|
else:
|
|
sub_debug('finalizer calling %s with args %s and kwargs %s',
|
|
self._callback, self._args, self._kwargs)
|
|
res = self._callback(*self._args, **self._kwargs)
|
|
self._weakref = self._callback = self._args = \
|
|
self._kwargs = self._key = None
|
|
return res
|
|
|
|
def cancel(self):
|
|
'''
|
|
Cancel finalization of the object
|
|
'''
|
|
try:
|
|
del _finalizer_registry[self._key]
|
|
except KeyError:
|
|
pass
|
|
else:
|
|
self._weakref = self._callback = self._args = \
|
|
self._kwargs = self._key = None
|
|
|
|
def still_active(self):
|
|
'''
|
|
Return whether this finalizer is still waiting to invoke callback
|
|
'''
|
|
return self._key in _finalizer_registry
|
|
|
|
def __repr__(self):
|
|
try:
|
|
obj = self._weakref()
|
|
except (AttributeError, TypeError):
|
|
obj = None
|
|
|
|
if obj is None:
|
|
return '<Finalize object, dead>'
|
|
|
|
x = '<Finalize object, callback=%s' % \
|
|
getattr(self._callback, '__name__', self._callback)
|
|
if self._args:
|
|
x += ', args=' + str(self._args)
|
|
if self._kwargs:
|
|
x += ', kwargs=' + str(self._kwargs)
|
|
if self._key[0] is not None:
|
|
x += ', exitprority=' + str(self._key[0])
|
|
return x + '>'
|
|
|
|
|
|
def _run_finalizers(minpriority=None):
|
|
'''
|
|
Run all finalizers whose exit priority is not None and at least minpriority
|
|
|
|
Finalizers with highest priority are called first; finalizers with
|
|
the same priority will be called in reverse order of creation.
|
|
'''
|
|
if _finalizer_registry is None:
|
|
# This function may be called after this module's globals are
|
|
# destroyed. See the _exit_function function in this module for more
|
|
# notes.
|
|
return
|
|
|
|
if minpriority is None:
|
|
f = lambda p : p[0][0] is not None
|
|
else:
|
|
f = lambda p : p[0][0] is not None and p[0][0] >= minpriority
|
|
|
|
items = [x for x in list(_finalizer_registry.items()) if f(x)]
|
|
items.sort(reverse=True)
|
|
|
|
for key, finalizer in items:
|
|
sub_debug('calling %s', finalizer)
|
|
try:
|
|
finalizer()
|
|
except Exception:
|
|
import traceback
|
|
traceback.print_exc()
|
|
|
|
if minpriority is None:
|
|
_finalizer_registry.clear()
|
|
|
|
#
|
|
# Clean up on exit
|
|
#
|
|
|
|
def is_exiting():
|
|
'''
|
|
Returns true if the process is shutting down
|
|
'''
|
|
return _exiting or _exiting is None
|
|
|
|
_exiting = False
|
|
|
|
def _exit_function(info=info, debug=debug, _run_finalizers=_run_finalizers,
|
|
active_children=process.active_children,
|
|
current_process=process.current_process):
|
|
# We hold on to references to functions in the arglist due to the
|
|
# situation described below, where this function is called after this
|
|
# module's globals are destroyed.
|
|
|
|
global _exiting
|
|
|
|
if not _exiting:
|
|
_exiting = True
|
|
|
|
info('process shutting down')
|
|
debug('running all "atexit" finalizers with priority >= 0')
|
|
_run_finalizers(0)
|
|
|
|
if current_process() is not None:
|
|
# We check if the current process is None here because if
|
|
# it's None, any call to ``active_children()`` will raise
|
|
# an AttributeError (active_children winds up trying to
|
|
# get attributes from util._current_process). One
|
|
# situation where this can happen is if someone has
|
|
# manipulated sys.modules, causing this module to be
|
|
# garbage collected. The destructor for the module type
|
|
# then replaces all values in the module dict with None.
|
|
# For instance, after setuptools runs a test it replaces
|
|
# sys.modules with a copy created earlier. See issues
|
|
# #9775 and #15881. Also related: #4106, #9205, and
|
|
# #9207.
|
|
|
|
for p in active_children():
|
|
if p.daemon:
|
|
info('calling terminate() for daemon %s', p.name)
|
|
p._popen.terminate()
|
|
|
|
for p in active_children():
|
|
info('calling join() for process %s', p.name)
|
|
p.join()
|
|
|
|
debug('running the remaining "atexit" finalizers')
|
|
_run_finalizers()
|
|
|
|
atexit.register(_exit_function)
|
|
|
|
#
|
|
# Some fork aware types
|
|
#
|
|
|
|
class ForkAwareThreadLock(object):
|
|
def __init__(self):
|
|
self._reset()
|
|
register_after_fork(self, ForkAwareThreadLock._reset)
|
|
|
|
def _reset(self):
|
|
self._lock = threading.Lock()
|
|
self.acquire = self._lock.acquire
|
|
self.release = self._lock.release
|
|
|
|
def __enter__(self):
|
|
return self._lock.__enter__()
|
|
|
|
def __exit__(self, *args):
|
|
return self._lock.__exit__(*args)
|
|
|
|
|
|
class ForkAwareLocal(threading.local):
|
|
def __init__(self):
|
|
register_after_fork(self, lambda obj : obj.__dict__.clear())
|
|
def __reduce__(self):
|
|
return type(self), ()
|
|
|
|
#
|
|
# Close fds except those specified
|
|
#
|
|
|
|
try:
|
|
MAXFD = os.sysconf("SC_OPEN_MAX")
|
|
except Exception:
|
|
MAXFD = 256
|
|
|
|
def close_all_fds_except(fds):
|
|
fds = list(fds) + [-1, MAXFD]
|
|
fds.sort()
|
|
assert fds[-1] == MAXFD, 'fd too large'
|
|
for i in range(len(fds) - 1):
|
|
os.closerange(fds[i]+1, fds[i+1])
|
|
|
|
#
|
|
# Start a program with only specified fds kept open
|
|
#
|
|
|
|
def spawnv_passfds(path, args, passfds):
|
|
import _posixsubprocess
|
|
passfds = sorted(passfds)
|
|
errpipe_read, errpipe_write = os.pipe()
|
|
try:
|
|
return _posixsubprocess.fork_exec(
|
|
args, [os.fsencode(path)], True, passfds, None, None,
|
|
-1, -1, -1, -1, -1, -1, errpipe_read, errpipe_write,
|
|
False, False, None)
|
|
finally:
|
|
os.close(errpipe_read)
|
|
os.close(errpipe_write)
|