Add set_signal_map to utils.

import os

import sys

import errno

import signal

import resource

import subprocess

from collections import deque

        assert sys.stdin.fileno() == 0

        assert sys.stdout.fileno() == 1

        assert sys.stderr.fileno() == 2

def set_signal_map(map_):

    """Set signal map in fork children.

    :param mapping map_: (signal code, handler)...

    :returns: old handlers as dict

    """

    previous_handlers = dict()

    for sig, handler in map_.iteritems():

        previous_handlers[sig] = signal.signal(sig, handler)

    return previous_handlers