_daemonize_windows.py 文件源码

def _fork_worker(namespace_path, child_env, pid_file, invocation, chdir,
                 stdin_goto, stdout_goto, stderr_goto, _exit_caller, args):
    ''' Opens a fork worker, shielding the parent from cancellation via
    signal sending. Basically, thanks Windows for being a dick about
    signals.
    '''
    # Find out our PID so the daughter can tell us to exit
    my_pid = os.getpid()
    # Pack up all of the args that the child will need to use.
    # Prepend it to *args
    payload = (my_pid, pid_file, chdir, stdin_goto, stdout_goto,
               stderr_goto, _exit_caller) + args

    # Pack it up. We're shielded from pickling errors already because pickle is
    # needed to start the worker.
    # Write the payload to the namespace passer using the highest available
    # protocol
    with open(namespace_path, 'wb') as f:
        pickle.dump(payload, f, protocol=-1)

    # Invoke the invocation!
    daemon = subprocess.Popen(
        invocation,
        # This is important, because the parent _forkish is telling the child
        # to run as a daemon via env. Also note that we need to calculate this
        # in the root _daemonize1, or else we'll have a polluted environment
        # due to the '__CREATE_DAEMON__' key.
        env = child_env,
        # This is vital; without it, our process will be reaped at parent
        # exit.
        creationflags = subprocess.CREATE_NEW_CONSOLE,
    )
    # Busy wait until either the daemon exits, or it sends a signal to kill us.
    daemon.wait()