Current Path : /lib64/python2.7/multiprocessing/ |
Current File : //lib64/python2.7/multiprocessing/__init__.py |
# # Package analogous to 'threading.py' but using processes # # multiprocessing/__init__.py # # This package is intended to duplicate the functionality (and much of # the API) of threading.py but uses processes instead of threads. A # subpackage 'multiprocessing.dummy' has the same API but is a simple # wrapper for 'threading'. # # Try calling `multiprocessing.doc.main()` to read the html # documentation in a webbrowser. # # # Copyright (c) 2006-2008, R Oudkerk # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions # are met: # # 1. Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # 2. Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in the # documentation and/or other materials provided with the distribution. # 3. Neither the name of author nor the names of any contributors may be # used to endorse or promote products derived from this software # without specific prior written permission. # # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF # SUCH DAMAGE. # __version__ = '0.70a1' __all__ = [ 'Process', 'current_process', 'active_children', 'freeze_support', 'Manager', 'Pipe', 'cpu_count', 'log_to_stderr', 'get_logger', 'allow_connection_pickling', 'BufferTooShort', 'TimeoutError', 'Lock', 'RLock', 'Semaphore', 'BoundedSemaphore', 'Condition', 'Event', 'Queue', 'JoinableQueue', 'Pool', 'Value', 'Array', 'RawValue', 'RawArray', 'SUBDEBUG', 'SUBWARNING', ] __author__ = 'R. Oudkerk (r.m.oudkerk@gmail.com)' # # Imports # import os import sys from multiprocessing.process import Process, current_process, active_children from multiprocessing.util import SUBDEBUG, SUBWARNING # # Exceptions # class ProcessError(Exception): pass class BufferTooShort(ProcessError): pass class TimeoutError(ProcessError): pass class AuthenticationError(ProcessError): pass # This is down here because _multiprocessing uses BufferTooShort import _multiprocessing # # Definitions not depending on native semaphores # def Manager(): ''' Returns a manager associated with a running server process The managers methods such as `Lock()`, `Condition()` and `Queue()` can be used to create shared objects. ''' from multiprocessing.managers import SyncManager m = SyncManager() m.start() return m def Pipe(duplex=True): ''' Returns two connection object connected by a pipe ''' from multiprocessing.connection import Pipe return Pipe(duplex) def cpu_count(): ''' Returns the number of CPUs in the system ''' if sys.platform == 'win32': try: num = int(os.environ['NUMBER_OF_PROCESSORS']) except (ValueError, KeyError): num = 0 elif 'bsd' in sys.platform or sys.platform == 'darwin': comm = '/sbin/sysctl -n hw.ncpu' if sys.platform == 'darwin': comm = '/usr' + comm try: with os.popen(comm) as p: num = int(p.read()) except ValueError: num = 0 else: try: num = os.sysconf('SC_NPROCESSORS_ONLN') except (ValueError, OSError, AttributeError): num = 0 if num >= 1: return num else: raise NotImplementedError('cannot determine number of cpus') def freeze_support(): ''' Check whether this is a fake forked process in a frozen executable. If so then run code specified by commandline and exit. ''' if sys.platform == 'win32' and getattr(sys, 'frozen', False): from multiprocessing.forking import freeze_support freeze_support() def get_logger(): ''' Return package logger -- if it does not already exist then it is created ''' from multiprocessing.util import get_logger return get_logger() def log_to_stderr(level=None): ''' Turn on logging and add a handler which prints to stderr ''' from multiprocessing.util import log_to_stderr return log_to_stderr(level) def allow_connection_pickling(): ''' Install support for sending connections and sockets between processes ''' from multiprocessing import reduction # # Definitions depending on native semaphores # def Lock(): ''' Returns a non-recursive lock object ''' from multiprocessing.synchronize import Lock return Lock() def RLock(): ''' Returns a recursive lock object ''' from multiprocessing.synchronize import RLock return RLock() def Condition(lock=None): ''' Returns a condition object ''' from multiprocessing.synchronize import Condition return Condition(lock) def Semaphore(value=1): ''' Returns a semaphore object ''' from multiprocessing.synchronize import Semaphore return Semaphore(value) def BoundedSemaphore(value=1): ''' Returns a bounded semaphore object ''' from multiprocessing.synchronize import BoundedSemaphore return BoundedSemaphore(value) def Event(): ''' Returns an event object ''' from multiprocessing.synchronize import Event return Event() def Queue(maxsize=0): ''' Returns a queue object ''' from multiprocessing.queues import Queue return Queue(maxsize) def JoinableQueue(maxsize=0): ''' Returns a queue object ''' from multiprocessing.queues import JoinableQueue return JoinableQueue(maxsize) def Pool(processes=None, initializer=None, initargs=(), maxtasksperchild=None): ''' Returns a process pool object ''' from multiprocessing.pool import Pool return Pool(processes, initializer, initargs, maxtasksperchild) def RawValue(typecode_or_type, *args): ''' Returns a shared object ''' from multiprocessing.sharedctypes import RawValue return RawValue(typecode_or_type, *args) def RawArray(typecode_or_type, size_or_initializer): ''' Returns a shared array ''' from multiprocessing.sharedctypes import RawArray return RawArray(typecode_or_type, size_or_initializer) def Value(typecode_or_type, *args, **kwds): ''' Returns a synchronized shared object ''' from multiprocessing.sharedctypes import Value return Value(typecode_or_type, *args, **kwds) def Array(typecode_or_type, size_or_initializer, **kwds): ''' Returns a synchronized shared array ''' from multiprocessing.sharedctypes import Array return Array(typecode_or_type, size_or_initializer, **kwds) # # # if sys.platform == 'win32': def set_executable(executable): ''' Sets the path to a python.exe or pythonw.exe binary used to run child processes on Windows instead of sys.executable. Useful for people embedding Python. ''' from multiprocessing.forking import set_executable set_executable(executable) __all__ += ['set_executable']