add the multiprocessing package to fulfill PEP 371
diff --git a/Lib/multiprocessing/forking.py b/Lib/multiprocessing/forking.py
new file mode 100644
index 0000000..2c1d3cf
--- /dev/null
+++ b/Lib/multiprocessing/forking.py
@@ -0,0 +1,429 @@
+#
+# Module for starting a process object using os.fork() or CreateProcess()
+#
+# multiprocessing/forking.py
+#
+# Copyright (c) 2006-2008, R Oudkerk --- see COPYING.txt
+#
+
+import os
+import sys
+import signal
+
+from multiprocessing import util, process
+
+__all__ = ['Popen', 'assert_spawning', 'exit', 'duplicate', 'close']
+
+#
+# Check that the current thread is spawning a child process
+#
+
+def assert_spawning(self):
+ if not Popen.thread_is_spawning():
+ raise RuntimeError(
+ '%s objects should only be shared between processes'
+ ' through inheritance' % type(self).__name__
+ )
+
+#
+# Unix
+#
+
+if sys.platform != 'win32':
+ import time
+
+ exit = os._exit
+ duplicate = os.dup
+ close = os.close
+
+ #
+ # We define a Popen class similar to the one from subprocess, but
+ # whose constructor takes a process object as its argument.
+ #
+
+ class Popen(object):
+
+ def __init__(self, process_obj):
+ sys.stdout.flush()
+ sys.stderr.flush()
+ self.returncode = None
+
+ self.pid = os.fork()
+ if self.pid == 0:
+ if 'random' in sys.modules:
+ import random
+ random.seed()
+ code = process_obj._bootstrap()
+ sys.stdout.flush()
+ sys.stderr.flush()
+ os._exit(code)
+
+ def poll(self, flag=os.WNOHANG):
+ if self.returncode is None:
+ pid, sts = os.waitpid(self.pid, flag)
+ if pid == self.pid:
+ if os.WIFSIGNALED(sts):
+ self.returncode = -os.WTERMSIG(sts)
+ else:
+ assert os.WIFEXITED(sts)
+ self.returncode = os.WEXITSTATUS(sts)
+ return self.returncode
+
+ def wait(self, timeout=None):
+ if timeout is None:
+ return self.poll(0)
+ deadline = time.time() + timeout
+ delay = 0.0005
+ while 1:
+ res = self.poll()
+ if res is not None:
+ break
+ remaining = deadline - time.time()
+ if remaining <= 0:
+ break
+ delay = min(delay * 2, remaining, 0.05)
+ time.sleep(delay)
+ return res
+
+ def terminate(self):
+ if self.returncode is None:
+ try:
+ os.kill(self.pid, signal.SIGTERM)
+ except OSError, e:
+ if self.wait(timeout=0.1) is None:
+ raise
+
+ @staticmethod
+ def thread_is_spawning():
+ return False
+
+#
+# Windows
+#
+
+else:
+ import thread
+ import msvcrt
+ import _subprocess
+ import copy_reg
+ import time
+
+ from ._multiprocessing import win32, Connection, PipeConnection
+ from .util import Finalize
+
+ try:
+ from cPickle import dump, load, HIGHEST_PROTOCOL
+ except ImportError:
+ from pickle import dump, load, HIGHEST_PROTOCOL
+
+ #
+ #
+ #
+
+ TERMINATE = 0x10000
+ WINEXE = (sys.platform == 'win32' and getattr(sys, 'frozen', False))
+
+ exit = win32.ExitProcess
+ close = win32.CloseHandle
+
+ #
+ # _python_exe is the assumed path to the python executable.
+ # People embedding Python want to modify it.
+ #
+
+ if sys.executable.lower().endswith('pythonservice.exe'):
+ _python_exe = os.path.join(sys.exec_prefix, 'python.exe')
+ else:
+ _python_exe = sys.executable
+
+ def set_executable(exe):
+ global _python_exe
+ _python_exe = exe
+
+ #
+ #
+ #
+
+ def duplicate(handle, target_process=None, inheritable=False):
+ if target_process is None:
+ target_process = _subprocess.GetCurrentProcess()
+ return _subprocess.DuplicateHandle(
+ _subprocess.GetCurrentProcess(), handle, target_process,
+ 0, inheritable, _subprocess.DUPLICATE_SAME_ACCESS
+ ).Detach()
+
+ #
+ # We define a Popen class similar to the one from subprocess, but
+ # whose constructor takes a process object as its argument.
+ #
+
+ class Popen(object):
+ '''
+ Start a subprocess to run the code of a process object
+ '''
+ _tls = thread._local()
+
+ def __init__(self, process_obj):
+ # create pipe for communication with child
+ rfd, wfd = os.pipe()
+
+ # get handle for read end of the pipe and make it inheritable
+ rhandle = duplicate(msvcrt.get_osfhandle(rfd), inheritable=True)
+ os.close(rfd)
+
+ # start process
+ cmd = get_command_line() + [rhandle]
+ cmd = ' '.join('"%s"' % x for x in cmd)
+ hp, ht, pid, tid = _subprocess.CreateProcess(
+ _python_exe, cmd, None, None, 1, 0, None, None, None
+ )
+ ht.Close()
+ close(rhandle)
+
+ # set attributes of self
+ self.pid = pid
+ self.returncode = None
+ self._handle = hp
+
+ # send information to child
+ prep_data = get_preparation_data(process_obj._name)
+ to_child = os.fdopen(wfd, 'wb')
+ Popen._tls.process_handle = int(hp)
+ try:
+ dump(prep_data, to_child, HIGHEST_PROTOCOL)
+ dump(process_obj, to_child, HIGHEST_PROTOCOL)
+ finally:
+ del Popen._tls.process_handle
+ to_child.close()
+
+ @staticmethod
+ def thread_is_spawning():
+ return getattr(Popen._tls, 'process_handle', None) is not None
+
+ @staticmethod
+ def duplicate_for_child(handle):
+ return duplicate(handle, Popen._tls.process_handle)
+
+ def wait(self, timeout=None):
+ if self.returncode is None:
+ if timeout is None:
+ msecs = _subprocess.INFINITE
+ else:
+ msecs = max(0, int(timeout * 1000 + 0.5))
+
+ res = _subprocess.WaitForSingleObject(int(self._handle), msecs)
+ if res == _subprocess.WAIT_OBJECT_0:
+ code = _subprocess.GetExitCodeProcess(self._handle)
+ if code == TERMINATE:
+ code = -signal.SIGTERM
+ self.returncode = code
+
+ return self.returncode
+
+ def poll(self):
+ return self.wait(timeout=0)
+
+ def terminate(self):
+ if self.returncode is None:
+ try:
+ _subprocess.TerminateProcess(int(self._handle), TERMINATE)
+ except WindowsError:
+ if self.wait(timeout=0.1) is None:
+ raise
+
+ #
+ #
+ #
+
+ def is_forking(argv):
+ '''
+ Return whether commandline indicates we are forking
+ '''
+ if len(argv) >= 2 and argv[1] == '--multiprocessing-fork':
+ assert len(argv) == 3
+ return True
+ else:
+ return False
+
+
+ def freeze_support():
+ '''
+ Run code for process object if this in not the main process
+ '''
+ if is_forking(sys.argv):
+ main()
+ sys.exit()
+
+
+ def get_command_line():
+ '''
+ Returns prefix of command line used for spawning a child process
+ '''
+ if process.current_process()._identity==() and is_forking(sys.argv):
+ raise RuntimeError('''
+ Attempt to start a new process before the current process
+ has finished its bootstrapping phase.
+
+ This probably means that you are on Windows and you have
+ forgotten to use the proper idiom in the main module:
+
+ if __name__ == '__main__':
+ freeze_support()
+ ...
+
+ The "freeze_support()" line can be omitted if the program
+ is not going to be frozen to produce a Windows executable.''')
+
+ if getattr(sys, 'frozen', False):
+ return [sys.executable, '--multiprocessing-fork']
+ else:
+ prog = 'from multiprocessing.forking import main; main()'
+ return [_python_exe, '-c', prog, '--multiprocessing-fork']
+
+
+ def main():
+ '''
+ Run code specifed by data received over pipe
+ '''
+ assert is_forking(sys.argv)
+
+ handle = int(sys.argv[-1])
+ fd = msvcrt.open_osfhandle(handle, os.O_RDONLY)
+ from_parent = os.fdopen(fd, 'rb')
+
+ process.current_process()._inheriting = True
+ preparation_data = load(from_parent)
+ prepare(preparation_data)
+ self = load(from_parent)
+ process.current_process()._inheriting = False
+
+ from_parent.close()
+
+ exitcode = self._bootstrap()
+ exit(exitcode)
+
+
+ def get_preparation_data(name):
+ '''
+ Return info about parent needed by child to unpickle process object
+ '''
+ from .util import _logger, _log_to_stderr
+
+ d = dict(
+ name=name,
+ sys_path=sys.path,
+ sys_argv=sys.argv,
+ log_to_stderr=_log_to_stderr,
+ orig_dir=process.ORIGINAL_DIR,
+ authkey=process.current_process().get_authkey(),
+ )
+
+ if _logger is not None:
+ d['log_level'] = _logger.getEffectiveLevel()
+
+ if not WINEXE:
+ main_path = getattr(sys.modules['__main__'], '__file__', None)
+ if not main_path and sys.argv[0] not in ('', '-c'):
+ main_path = sys.argv[0]
+ if main_path is not None:
+ if not os.path.isabs(main_path) and \
+ process.ORIGINAL_DIR is not None:
+ main_path = os.path.join(process.ORIGINAL_DIR, main_path)
+ d['main_path'] = os.path.normpath(main_path)
+
+ return d
+
+ #
+ # Make (Pipe)Connection picklable
+ #
+
+ def reduce_connection(conn):
+ if not Popen.thread_is_spawning():
+ raise RuntimeError(
+ 'By default %s objects can only be shared between processes\n'
+ 'using inheritance' % type(conn).__name__
+ )
+ return type(conn), (Popen.duplicate_for_child(conn.fileno()),
+ conn.readable, conn.writable)
+
+ copy_reg.pickle(Connection, reduce_connection)
+ copy_reg.pickle(PipeConnection, reduce_connection)
+
+
+#
+# Prepare current process
+#
+
+old_main_modules = []
+
+def prepare(data):
+ '''
+ Try to get current process ready to unpickle process object
+ '''
+ old_main_modules.append(sys.modules['__main__'])
+
+ if 'name' in data:
+ process.current_process().set_name(data['name'])
+
+ if 'authkey' in data:
+ process.current_process()._authkey = data['authkey']
+
+ if 'log_to_stderr' in data and data['log_to_stderr']:
+ util.log_to_stderr()
+
+ if 'log_level' in data:
+ util.get_logger().setLevel(data['log_level'])
+
+ if 'sys_path' in data:
+ sys.path = data['sys_path']
+
+ if 'sys_argv' in data:
+ sys.argv = data['sys_argv']
+
+ if 'dir' in data:
+ os.chdir(data['dir'])
+
+ if 'orig_dir' in data:
+ process.ORIGINAL_DIR = data['orig_dir']
+
+ if 'main_path' in data:
+ main_path = data['main_path']
+ main_name = os.path.splitext(os.path.basename(main_path))[0]
+ if main_name == '__init__':
+ main_name = os.path.basename(os.path.dirname(main_path))
+
+ if main_name != 'ipython':
+ import imp
+
+ if main_path is None:
+ dirs = None
+ elif os.path.basename(main_path).startswith('__init__.py'):
+ dirs = [os.path.dirname(os.path.dirname(main_path))]
+ else:
+ dirs = [os.path.dirname(main_path)]
+
+ assert main_name not in sys.modules, main_name
+ file, path_name, etc = imp.find_module(main_name, dirs)
+ try:
+ # We would like to do "imp.load_module('__main__', ...)"
+ # here. However, that would cause 'if __name__ ==
+ # "__main__"' clauses to be executed.
+ main_module = imp.load_module(
+ '__parents_main__', file, path_name, etc
+ )
+ finally:
+ if file:
+ file.close()
+
+ sys.modules['__main__'] = main_module
+ main_module.__name__ = '__main__'
+
+ # Try to make the potentially picklable objects in
+ # sys.modules['__main__'] realize they are in the main
+ # module -- somewhat ugly.
+ for obj in main_module.__dict__.values():
+ try:
+ if obj.__module__ == '__parents_main__':
+ obj.__module__ = '__main__'
+ except Exception:
+ pass