image-match/python/py/Lib/site-packages/joblib/externals/loky/backend/process.py

###############################################################################
# LokyProcess implementation
#
# authors: Thomas Moreau and Olivier Grisel
#
# based on multiprocessing/process.py  (17/02/2017)
#
import sys
from multiprocessing.context import assert_spawning
from multiprocessing.process import BaseProcess


class LokyProcess(BaseProcess):
    _start_method = "loky"

    def __init__(
        self,
        group=None,
        target=None,
        name=None,
        args=(),
        kwargs={},
        daemon=None,
        init_main_module=False,
        env=None,
    ):
        super().__init__(
            group=group,
            target=target,
            name=name,
            args=args,
            kwargs=kwargs,
            daemon=daemon,
        )
        self.env = {} if env is None else env
        self.authkey = self.authkey
        self.init_main_module = init_main_module

    @staticmethod
    def _Popen(process_obj):
        if sys.platform == "win32":
            from .popen_loky_win32 import Popen
        else:
            from .popen_loky_posix import Popen
        return Popen(process_obj)


class LokyInitMainProcess(LokyProcess):
    _start_method = "loky_init_main"

    def __init__(
        self,
        group=None,
        target=None,
        name=None,
        args=(),
        kwargs={},
        daemon=None,
    ):
        super().__init__(
            group=group,
            target=target,
            name=name,
            args=args,
            kwargs=kwargs,
            daemon=daemon,
            init_main_module=True,
        )


#
# We subclass bytes to avoid accidental transmission of auth keys over network
#


class AuthenticationKey(bytes):
    def __reduce__(self):
        try:
            assert_spawning(self)
        except RuntimeError:
            raise TypeError(
                "Pickling an AuthenticationKey object is "
                "disallowed for security reasons"
            )
        return AuthenticationKey, (bytes(self),)