helpers.py 文件源码

def kill_process_tree(logger, pid, timeout=DEFAULT_TIME_TO_WAIT_AFTER_SIGTERM):
    """
    TODO(saguziel): also kill the root process after killing descendants

    Kills the process's descendants. Kills using the `kill`
    shell command so that it can change users. Note: killing via PIDs
    has the potential to the wrong process if the process dies and the
    PID gets recycled in a narrow time window.

    :param logger: logger
    :type logger: logging.Logger
    """
    try:
        root_process = psutil.Process(pid)
    except psutil.NoSuchProcess:
        logger.warning("PID: {} does not exist".format(pid))
        return

    # Check child processes to reduce cases where a child process died but
    # the PID got reused.
    descendant_processes = [x for x in root_process.children(recursive=True)
                            if x.is_running()]

    if len(descendant_processes) != 0:
        logger.info("Terminating descendant processes of {} PID: {}"
                    .format(root_process.cmdline(),
                            root_process.pid))
        temp_processes = descendant_processes[:]
        for descendant in temp_processes:
            logger.info("Terminating descendant process {} PID: {}"
                        .format(descendant.cmdline(), descendant.pid))
            if not kill_using_shell(logger, descendant.pid, signal.SIGTERM):
                descendant_processes.remove(descendant)

        logger.info("Waiting up to {}s for processes to exit..."
                    .format(timeout))
        try:
            psutil.wait_procs(descendant_processes, timeout)
            logger.info("Done waiting")
        except psutil.TimeoutExpired:
            logger.warning("Ran out of time while waiting for "
                           "processes to exit")
        # Then SIGKILL
        descendant_processes = [x for x in root_process.children(recursive=True)
                                if x.is_running()]

        if len(descendant_processes) > 0:
            temp_processes = descendant_processes[:]
            for descendant in temp_processes:
                logger.info("Killing descendant process {} PID: {}"
                            .format(descendant.cmdline(), descendant.pid))
                if not kill_using_shell(logger, descendant.pid, signal.SIGKILL):
                    descendant_processes.remove(descendant)
                else:
                    descendant.wait()
            logger.info("Killed all descendant processes of {} PID: {}"
                        .format(root_process.cmdline(),
                                root_process.pid))
    else:
        logger.debug("There are no descendant processes to kill")